X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Fggc-zone.c;h=cae23e128deb4d184a13d049a37a9021d138f87d;hb=c1630d65d745a592779683d793933220559986d9;hp=ced786bd23576234165cc247b24b14990dd99112;hpb=e324a77367020e13802b462ac82d74e403cb720d;p=pf3gnuchains%2Fgcc-fork.git diff --git a/gcc/ggc-zone.c b/gcc/ggc-zone.c index ced786bd235..cae23e128de 100644 --- a/gcc/ggc-zone.c +++ b/gcc/ggc-zone.c @@ -1,13 +1,16 @@ /* "Bag-of-pages" zone garbage collector for the GNU compiler. - Copyright (C) 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc. - Contributed by Richard Henderson (rth@redhat.com) and Daniel Berlin (dberlin@dberlin.org) + Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008 + Free Software Foundation, Inc. + Contributed by Richard Henderson (rth@redhat.com) and Daniel Berlin + (dberlin@dberlin.org). Rewritten by Daniel Jacobowitz + . This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free -Software Foundation; either version 2, or (at your option) any later +Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY @@ -16,9 +19,8 @@ FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License -along with GCC; see the file COPYING. If not, write to the Free -Software Foundation, 59 Temple Place - Suite 330, Boston, MA -02111-1307, USA. */ +along with GCC; see the file COPYING3. If not see +. */ #include "config.h" #include "system.h" @@ -34,21 +36,8 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA #include "timevar.h" #include "params.h" #include "bitmap.h" +#include "plugin.h" -#ifdef ENABLE_VALGRIND_CHECKING -# ifdef HAVE_VALGRIND_MEMCHECK_H -# include -# elif defined HAVE_MEMCHECK_H -# include -# else -# include -# endif -#else -/* Avoid #ifdef:s when we can help it. */ -#define VALGRIND_DISCARD(x) -#define VALGRIND_MALLOCLIKE_BLOCK(w,x,y,z) -#define VALGRIND_FREELIKE_BLOCK(x,y) -#endif /* Prefer MAP_ANON(YMOUS) to /dev/zero, since we don't need to keep a file open. Prefer either to valloc. */ #ifdef HAVE_MMAP_ANON @@ -62,56 +51,58 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA # define MAP_ANONYMOUS MAP_ANON # endif # define USING_MMAP - #endif #ifdef HAVE_MMAP_DEV_ZERO - # include # ifndef MAP_FAILED # define MAP_FAILED -1 # endif # define USING_MMAP - #endif #ifndef USING_MMAP -#define USING_MALLOC_PAGE_GROUPS +#error Zone collector requires mmap #endif #if (GCC_VERSION < 3001) #define prefetch(X) ((void) X) +#define prefetchw(X) ((void) X) #else #define prefetch(X) __builtin_prefetch (X) +#define prefetchw(X) __builtin_prefetch (X, 1, 3) #endif -/* NOTES: +/* FUTURE NOTES: + If we track inter-zone pointers, we can mark single zones at a time. + If we have a zone where we guarantee no inter-zone pointers, we - could mark that zone seperately. + could mark that zone separately. + The garbage zone should not be marked, and we should return 1 in ggc_set_mark for any object in the garbage zone, which cuts off marking quickly. */ -/* Stategy: + +/* Strategy: This garbage-collecting allocator segregates objects into zones. It also segregates objects into "large" and "small" bins. Large - objects are greater or equal to page size. + objects are greater than page size. - Pages for small objects are broken up into chunks, each of which - are described by a struct alloc_chunk. One can walk over all - chunks on the page by adding the chunk size to the chunk's data - address. The free space for a page exists in the free chunk bins. - - Each page-entry also has a context depth, which is used to track - pushing and popping of allocation contexts. Only objects allocated - in the current (highest-numbered) context may be collected. + Pages for small objects are broken up into chunks. The page has + a bitmap which marks the start position of each chunk (whether + allocated or free). Free chunks are on one of the zone's free + lists and contain a pointer to the next free chunk. Chunks in + most of the free lists have a fixed size determined by the + free list. Chunks in the "other" sized free list have their size + stored right after their chain pointer. Empty pages (of all sizes) are kept on a single page cache list, and are considered first when new pages are required; they are deallocated at the start of the next collection if they haven't - been recycled by then. */ + been recycled by then. The free page list is currently per-zone. */ /* Define GGC_DEBUG_LEVEL to print debugging information. 0: No debugging output. @@ -124,77 +115,89 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA #ifndef HOST_BITS_PER_PTR #define HOST_BITS_PER_PTR HOST_BITS_PER_LONG #endif -#ifdef COOKIE_CHECKING -#define CHUNK_MAGIC 0x95321123 -#define DEADCHUNK_MAGIC 0x12817317 -#endif -/* This structure manages small chunks. When the chunk is free, it's - linked with other chunks via free_next. When the chunk is allocated, - the data starts at u. Large chunks are allocated one at a time to - their own page, and so don't come in here. - - The "type" field is a placeholder for a future change to do - generational collection. At present it is 0 when free and - and 1 when allocated. */ +/* This structure manages small free chunks. The SIZE field is only + initialized if the chunk is in the "other" sized free list. Large + chunks are allocated one at a time to their own page, and so don't + come in here. */ struct alloc_chunk { -#ifdef COOKIE_CHECKING - unsigned int magic; -#endif - unsigned int type:1; - unsigned int typecode:15; - unsigned int size:15; - unsigned int mark:1; - union { - struct alloc_chunk *next_free; - char data[1]; + struct alloc_chunk *next_free; + unsigned int size; +}; - /* Make sure the data is sufficiently aligned. */ - HOST_WIDEST_INT align_i; -#ifdef HAVE_LONG_DOUBLE - long double align_d; -#else - double align_d; +/* The size of the fixed-size portion of a small page descriptor. */ +#define PAGE_OVERHEAD (offsetof (struct small_page_entry, alloc_bits)) + +/* The collector's idea of the page size. This must be a power of two + no larger than the system page size, because pages must be aligned + to this amount and are tracked at this granularity in the page + table. We choose a size at compile time for efficiency. + + We could make a better guess at compile time if PAGE_SIZE is a + constant in system headers, and PAGE_SHIFT is defined... */ +#define GGC_PAGE_SIZE 4096 +#define GGC_PAGE_MASK (GGC_PAGE_SIZE - 1) +#define GGC_PAGE_SHIFT 12 + +#if 0 +/* Alternative definitions which use the runtime page size. */ +#define GGC_PAGE_SIZE G.pagesize +#define GGC_PAGE_MASK G.page_mask +#define GGC_PAGE_SHIFT G.lg_pagesize #endif - } u; -} __attribute__ ((packed)); -#define CHUNK_OVERHEAD (offsetof (struct alloc_chunk, u)) +/* The size of a small page managed by the garbage collector. This + must currently be GGC_PAGE_SIZE, but with a few changes could + be any multiple of it to reduce certain kinds of overhead. */ +#define SMALL_PAGE_SIZE GGC_PAGE_SIZE -/* We maintain several bins of free lists for chunks for very small - objects. We never exhaustively search other bins -- if we don't - find one of the proper size, we allocate from the "larger" bin. */ +/* Free bin information. These numbers may be in need of re-tuning. + In general, decreasing the number of free bins would seem to + increase the time it takes to allocate... */ -/* Decreasing the number of free bins increases the time it takes to allocate. - Similar with increasing max_free_bin_size without increasing num_free_bins. +/* FIXME: We can't use anything but MAX_ALIGNMENT for the bin size + today. */ - After much histogramming of allocation sizes and time spent on gc, - on a powerpc G4 7450 - 667 mhz, and an pentium 4 - 2.8ghz, - these were determined to be the optimal values. */ #define NUM_FREE_BINS 64 -#define MAX_FREE_BIN_SIZE 256 -#define FREE_BIN_DELTA (MAX_FREE_BIN_SIZE / NUM_FREE_BINS) -#define SIZE_BIN_UP(SIZE) (((SIZE) + FREE_BIN_DELTA - 1) / FREE_BIN_DELTA) +#define FREE_BIN_DELTA MAX_ALIGNMENT #define SIZE_BIN_DOWN(SIZE) ((SIZE) / FREE_BIN_DELTA) -/* Marker used as chunk->size for a large object. Should correspond - to the size of the bitfield above. */ -#define LARGE_OBJECT_SIZE 0x7fff +/* Allocation and marking parameters. */ + +/* The smallest allocatable unit to keep track of. */ +#define BYTES_PER_ALLOC_BIT MAX_ALIGNMENT + +/* The smallest markable unit. If we require each allocated object + to contain at least two allocatable units, we can use half as many + bits for the mark bitmap. But this adds considerable complexity + to sweeping. */ +#define BYTES_PER_MARK_BIT BYTES_PER_ALLOC_BIT + +#define BYTES_PER_MARK_WORD (8 * BYTES_PER_MARK_BIT * sizeof (mark_type)) /* We use this structure to determine the alignment required for - allocations. For power-of-two sized allocations, that's not a - problem, but it does matter for odd-sized allocations. */ + allocations. + + There are several things wrong with this estimation of alignment. + + The maximum alignment for a structure is often less than the + maximum alignment for a basic data type; for instance, on some + targets long long must be aligned to sizeof (int) in a structure + and sizeof (long long) in a variable. i386-linux is one example; + Darwin is another (sometimes, depending on the compiler in use). + + Also, long double is not included. Nothing in GCC uses long + double, so we assume that this is OK. On powerpc-darwin, adding + long double would bring the maximum alignment up to 16 bytes, + and until we need long double (or to vectorize compiler operations) + that's painfully wasteful. This will need to change, some day. */ struct max_alignment { char c; union { HOST_WIDEST_INT i; -#ifdef HAVE_LONG_DOUBLE - long double d; -#else double d; -#endif } u; }; @@ -202,15 +205,77 @@ struct max_alignment { #define MAX_ALIGNMENT (offsetof (struct max_alignment, u)) -/* Compute the smallest nonnegative number which when added to X gives - a multiple of F. */ - -#define ROUND_UP_VALUE(x, f) ((f) - 1 - ((f) - 1 + (x)) % (f)) - /* Compute the smallest multiple of F that is >= X. */ #define ROUND_UP(x, f) (CEIL (x, f) * (f)) +/* Types to use for the allocation and mark bitmaps. It might be + a good idea to add ffsl to libiberty and use unsigned long + instead; that could speed us up where long is wider than int. */ + +typedef unsigned int alloc_type; +typedef unsigned int mark_type; +#define alloc_ffs(x) ffs(x) + +/* A page_entry records the status of an allocation page. This is the + common data between all three kinds of pages - small, large, and + PCH. */ +typedef struct page_entry +{ + /* The address at which the memory is allocated. */ + char *page; + + /* The zone that this page entry belongs to. */ + struct alloc_zone *zone; + +#ifdef GATHER_STATISTICS + /* How many collections we've survived. */ + size_t survived; +#endif + + /* Does this page contain small objects, or one large object? */ + bool large_p; + + /* Is this page part of the loaded PCH? */ + bool pch_p; +} page_entry; + +/* Additional data needed for small pages. */ +struct small_page_entry +{ + struct page_entry common; + + /* The next small page entry, or NULL if this is the last. */ + struct small_page_entry *next; + + /* If currently marking this zone, a pointer to the mark bits + for this page. If we aren't currently marking this zone, + this pointer may be stale (pointing to freed memory). */ + mark_type *mark_bits; + + /* The allocation bitmap. This array extends far enough to have + one bit for every BYTES_PER_ALLOC_BIT bytes in the page. */ + alloc_type alloc_bits[1]; +}; + +/* Additional data needed for large pages. */ +struct large_page_entry +{ + struct page_entry common; + + /* The next large page entry, or NULL if this is the last. */ + struct large_page_entry *next; + + /* The number of bytes allocated, not including the page entry. */ + size_t bytes; + + /* The previous page in the list, so that we can unlink this one. */ + struct large_page_entry *prev; + + /* During marking, is this object marked? */ + bool mark_p; +}; + /* A two-level tree is used to look up the page-entry for a given pointer. Two chunks of the pointer's bits are extracted to index the first and second levels of the tree, as follows: @@ -234,7 +299,7 @@ struct max_alignment { correct one. */ #define PAGE_L1_BITS (8) -#define PAGE_L2_BITS (32 - PAGE_L1_BITS - G.lg_pagesize) +#define PAGE_L2_BITS (32 - PAGE_L1_BITS - GGC_PAGE_SHIFT) #define PAGE_L1_SIZE ((size_t) 1 << PAGE_L1_BITS) #define PAGE_L2_SIZE ((size_t) 1 << PAGE_L2_BITS) @@ -242,63 +307,7 @@ struct max_alignment { (((size_t) (p) >> (32 - PAGE_L1_BITS)) & ((1 << PAGE_L1_BITS) - 1)) #define LOOKUP_L2(p) \ - (((size_t) (p) >> G.lg_pagesize) & ((1 << PAGE_L2_BITS) - 1)) - -struct alloc_zone; -/* A page_entry records the status of an allocation page. */ -typedef struct page_entry -{ - /* The next page-entry with objects of the same size, or NULL if - this is the last page-entry. */ - struct page_entry *next; - - /* The number of bytes allocated. (This will always be a multiple - of the host system page size.) */ - size_t bytes; - - /* How many collections we've survived. */ - size_t survived; - - /* The address at which the memory is allocated. */ - char *page; - -#ifdef USING_MALLOC_PAGE_GROUPS - /* Back pointer to the page group this page came from. */ - struct page_group *group; -#endif - - /* Number of bytes on the page unallocated. Only used during - collection, and even then large pages merely set this nonzero. */ - size_t bytes_free; - - /* Context depth of this page. */ - unsigned short context_depth; - - /* Does this page contain small objects, or one large object? */ - bool large_p; - - /* The zone that this page entry belongs to. */ - struct alloc_zone *zone; -} page_entry; - -#ifdef USING_MALLOC_PAGE_GROUPS -/* A page_group describes a large allocation from malloc, from which - we parcel out aligned pages. */ -typedef struct page_group -{ - /* A linked list of all extant page groups. */ - struct page_group *next; - - /* The address we received from malloc. */ - char *allocation; - - /* The size of the block. */ - size_t alloc_size; - - /* A bitmask of pages in use. */ - unsigned int in_use; -} page_group; -#endif + (((size_t) (p) >> GGC_PAGE_SHIFT) & ((1 << PAGE_L2_BITS) - 1)) #if HOST_BITS_PER_PTR <= 32 @@ -322,106 +331,161 @@ typedef struct page_table_chain /* The global variables. */ static struct globals { - /* The page lookup table. A single page can only belong to one - zone. This means free pages are zone-specific ATM. */ - page_table lookup; /* The linked list of zones. */ struct alloc_zone *zones; - /* The system's page size. */ + /* Lookup table for associating allocation pages with object addresses. */ + page_table lookup; + + /* The system's page size, and related constants. */ size_t pagesize; size_t lg_pagesize; + size_t page_mask; + + /* The size to allocate for a small page entry. This includes + the size of the structure and the size of the allocation + bitmap. */ + size_t small_page_overhead; - /* A file descriptor open to /dev/zero for reading. */ #if defined (HAVE_MMAP_DEV_ZERO) + /* A file descriptor open to /dev/zero for reading. */ int dev_zero_fd; #endif + /* Allocate pages in chunks of this size, to throttle calls to memory + allocation routines. The first page is used, the rest go onto the + free list. */ + size_t quire_size; + /* The file descriptor for debugging output. */ FILE *debug_file; } G; -/* The zone allocation structure. */ +/* A zone allocation structure. There is one of these for every + distinct allocation zone. */ struct alloc_zone { - /* Name of the zone. */ - const char *name; - - /* Linked list of pages in a zone. */ - page_entry *pages; + /* The most recent free chunk is saved here, instead of in the linked + free list, to decrease list manipulation. It is most likely that we + will want this one. */ + char *cached_free; + size_t cached_free_size; /* Linked lists of free storage. Slots 1 ... NUM_FREE_BINS have chunks of size FREE_BIN_DELTA. All other chunks are in slot 0. */ struct alloc_chunk *free_chunks[NUM_FREE_BINS + 1]; - /* Bytes currently allocated. */ + /* The highest bin index which might be non-empty. It may turn out + to be empty, in which case we have to search downwards. */ + size_t high_free_bin; + + /* Bytes currently allocated in this zone. */ size_t allocated; - /* Bytes currently allocated at the end of the last collection. */ - size_t allocated_last_gc; + /* Linked list of the small pages in this zone. */ + struct small_page_entry *pages; - /* Total amount of memory mapped. */ - size_t bytes_mapped; + /* Doubly linked list of large pages in this zone. */ + struct large_page_entry *large_pages; - /* Bit N set if any allocations have been done at context depth N. */ - unsigned long context_depth_allocations; + /* If we are currently marking this zone, a pointer to the mark bits. */ + mark_type *mark_bits; - /* Bit N set if any collections have been done at context depth N. */ - unsigned long context_depth_collections; + /* Name of the zone. */ + const char *name; - /* The current depth in the context stack. */ - unsigned short context_depth; + /* The number of small pages currently allocated in this zone. */ + size_t n_small_pages; - /* A cache of free system pages. */ - page_entry *free_pages; + /* Bytes allocated at the end of the last collection. */ + size_t allocated_last_gc; -#ifdef USING_MALLOC_PAGE_GROUPS - page_group *page_groups; -#endif + /* Total amount of memory mapped. */ + size_t bytes_mapped; + + /* A cache of free system pages. */ + struct small_page_entry *free_pages; /* Next zone in the linked list of zones. */ struct alloc_zone *next_zone; - /* Return true if this zone was collected during this collection. */ + /* True if this zone was collected during this collection. */ bool was_collected; + + /* True if this zone should be destroyed after the next collection. */ + bool dead; + +#ifdef GATHER_STATISTICS + struct + { + /* Total memory allocated with ggc_alloc. */ + unsigned long long total_allocated; + /* Total overhead for memory to be allocated with ggc_alloc. */ + unsigned long long total_overhead; + + /* Total allocations and overhead for sizes less than 32, 64 and 128. + These sizes are interesting because they are typical cache line + sizes. */ + + unsigned long long total_allocated_under32; + unsigned long long total_overhead_under32; + + unsigned long long total_allocated_under64; + unsigned long long total_overhead_under64; + + unsigned long long total_allocated_under128; + unsigned long long total_overhead_under128; + } stats; +#endif } main_zone; -struct alloc_zone *rtl_zone; -struct alloc_zone *garbage_zone; -struct alloc_zone *tree_zone; +/* Some default zones. */ +struct alloc_zone rtl_zone; +struct alloc_zone tree_zone; +struct alloc_zone tree_id_zone; + +/* The PCH zone does not need a normal zone structure, and it does + not live on the linked list of zones. */ +struct pch_zone +{ + /* The start of the PCH zone. NULL if there is none. */ + char *page; + + /* The end of the PCH zone. NULL if there is none. */ + char *end; + + /* The size of the PCH zone. 0 if there is none. */ + size_t bytes; + + /* The allocation bitmap for the PCH zone. */ + alloc_type *alloc_bits; -/* Allocate pages in chunks of this size, to throttle calls to memory - allocation routines. The first page is used, the rest go onto the - free list. This cannot be larger than HOST_BITS_PER_INT for the - in_use bitmask for page_group. */ -#define GGC_QUIRE_SIZE 16 + /* If we are currently marking, the mark bitmap for the PCH zone. + When it is first read in, we could avoid marking the PCH, + because it will not contain any pointers to GC memory outside + of the PCH; however, the PCH is currently mapped as writable, + so we must mark it in case new pointers are added. */ + mark_type *mark_bits; +} pch_zone; -static int ggc_allocated_p (const void *); -static page_entry *lookup_page_table_entry (const void *); -static void set_page_table_entry (void *, page_entry *); #ifdef USING_MMAP static char *alloc_anon (char *, size_t, struct alloc_zone *); #endif -#ifdef USING_MALLOC_PAGE_GROUPS -static size_t page_group_index (char *, char *); -static void set_page_group_in_use (page_group *, char *); -static void clear_page_group_in_use (page_group *, char *); -#endif -static struct page_entry * alloc_small_page ( struct alloc_zone *); -static struct page_entry * alloc_large_page (size_t, struct alloc_zone *); -static void free_chunk (struct alloc_chunk *, size_t, struct alloc_zone *); -static void free_page (struct page_entry *); +static struct small_page_entry * alloc_small_page (struct alloc_zone *); +static struct large_page_entry * alloc_large_page (size_t, struct alloc_zone *); +static void free_chunk (char *, size_t, struct alloc_zone *); +static void free_small_page (struct small_page_entry *); +static void free_large_page (struct large_page_entry *); static void release_pages (struct alloc_zone *); static void sweep_pages (struct alloc_zone *); -static void * ggc_alloc_zone_1 (size_t, struct alloc_zone *, short); static bool ggc_collect_1 (struct alloc_zone *, bool); -static void check_cookies (void); - +static void new_ggc_zone_1 (struct alloc_zone *, const char *); -/* Returns nonzero if P was allocated in GC'able memory. */ +/* Traverse the page table and find the entry for a page. + Die (probably) if the object wasn't allocated via GC. */ -static inline int -ggc_allocated_p (const void *p) +static inline page_entry * +lookup_page_table_entry (const void *p) { page_entry ***base; size_t L1, L2; @@ -431,14 +495,8 @@ ggc_allocated_p (const void *p) #else page_table table = G.lookup; size_t high_bits = (size_t) p & ~ (size_t) 0xffffffff; - while (1) - { - if (table == NULL) - return 0; - if (table->high_bits == high_bits) - break; - table = table->next; - } + while (table->high_bits != high_bits) + table = table->next; base = &table->table[0]; #endif @@ -446,14 +504,14 @@ ggc_allocated_p (const void *p) L1 = LOOKUP_L1 (p); L2 = LOOKUP_L2 (p); - return base[L1] && base[L1][L2]; + return base[L1][L2]; } /* Traverse the page table and find the entry for a page. - Die (probably) if the object wasn't allocated via GC. */ + Return NULL if the object wasn't allocated via the GC. */ static inline page_entry * -lookup_page_table_entry(const void *p) +lookup_page_table_if_allocated (const void *p) { page_entry ***base; size_t L1, L2; @@ -463,23 +521,38 @@ lookup_page_table_entry(const void *p) #else page_table table = G.lookup; size_t high_bits = (size_t) p & ~ (size_t) 0xffffffff; - while (table->high_bits != high_bits) - table = table->next; + while (1) + { + if (table == NULL) + return NULL; + if (table->high_bits == high_bits) + break; + table = table->next; + } base = &table->table[0]; #endif /* Extract the level 1 and 2 indices. */ L1 = LOOKUP_L1 (p); + if (! base[L1]) + return NULL; + L2 = LOOKUP_L2 (p); + if (L2 >= PAGE_L2_SIZE) + return NULL; + /* We might have a page entry which does not correspond exactly to a + system page. */ + if (base[L1][L2] && (const char *) p < base[L1][L2]->page) + return NULL; return base[L1][L2]; - } -/* Set the page table entry for a page. */ +/* Set the page table entry for the page that starts at P. If ENTRY + is NULL, clear the entry. */ static void -set_page_table_entry(void *p, page_entry *entry) +set_page_table_entry (void *p, page_entry *entry) { page_entry ***base; size_t L1, L2; @@ -494,7 +567,7 @@ set_page_table_entry(void *p, page_entry *entry) goto found; /* Not found -- allocate a new table. */ - table = (page_table) xcalloc (1, sizeof(*table)); + table = XCNEW (struct page_table_chain); table->next = G.lookup; table->high_bits = high_bits; G.lookup = table; @@ -507,248 +580,385 @@ found: L2 = LOOKUP_L2 (p); if (base[L1] == NULL) - base[L1] = (page_entry **) xcalloc (PAGE_L2_SIZE, sizeof (page_entry *)); + base[L1] = XCNEWVEC (page_entry *, PAGE_L2_SIZE); base[L1][L2] = entry; } -#ifdef USING_MMAP -/* Allocate SIZE bytes of anonymous memory, preferably near PREF, - (if non-null). The ifdef structure here is intended to cause a - compile error unless exactly one of the HAVE_* is defined. */ +/* Find the page table entry associated with OBJECT. */ -static inline char * -alloc_anon (char *pref ATTRIBUTE_UNUSED, size_t size, struct alloc_zone *zone) +static inline struct page_entry * +zone_get_object_page (const void *object) { -#ifdef HAVE_MMAP_ANON - char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); -#endif -#ifdef HAVE_MMAP_DEV_ZERO - char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE, - MAP_PRIVATE, G.dev_zero_fd, 0); -#endif - VALGRIND_MALLOCLIKE_BLOCK(page, size, 0, 0); + return lookup_page_table_entry (object); +} - if (page == (char *) MAP_FAILED) - { - perror ("virtual memory exhausted"); - exit (FATAL_EXIT_CODE); - } +/* Find which element of the alloc_bits array OBJECT should be + recorded in. */ +static inline unsigned int +zone_get_object_alloc_word (const void *object) +{ + return (((size_t) object & (GGC_PAGE_SIZE - 1)) + / (8 * sizeof (alloc_type) * BYTES_PER_ALLOC_BIT)); +} - /* Remember that we allocated this memory. */ - zone->bytes_mapped += size; - /* Pretend we don't have access to the allocated pages. We'll enable - access to smaller pieces of the area in ggc_alloc. Discard the - handle to avoid handle leak. */ - VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (page, size)); - return page; +/* Find which bit of the appropriate word in the alloc_bits array + OBJECT should be recorded in. */ +static inline unsigned int +zone_get_object_alloc_bit (const void *object) +{ + return (((size_t) object / BYTES_PER_ALLOC_BIT) + % (8 * sizeof (alloc_type))); } -#endif -#ifdef USING_MALLOC_PAGE_GROUPS -/* Compute the index for this page into the page group. */ -static inline size_t -page_group_index (char *allocation, char *page) +/* Find which element of the mark_bits array OBJECT should be recorded + in. */ +static inline unsigned int +zone_get_object_mark_word (const void *object) { - return (size_t) (page - allocation) >> G.lg_pagesize; + return (((size_t) object & (GGC_PAGE_SIZE - 1)) + / (8 * sizeof (mark_type) * BYTES_PER_MARK_BIT)); } -/* Set and clear the in_use bit for this page in the page group. */ +/* Find which bit of the appropriate word in the mark_bits array + OBJECT should be recorded in. */ +static inline unsigned int +zone_get_object_mark_bit (const void *object) +{ + return (((size_t) object / BYTES_PER_MARK_BIT) + % (8 * sizeof (mark_type))); +} +/* Set the allocation bit corresponding to OBJECT in its page's + bitmap. Used to split this object from the preceding one. */ static inline void -set_page_group_in_use (page_group *group, char *page) +zone_set_object_alloc_bit (const void *object) { - group->in_use |= 1 << page_group_index (group->allocation, page); + struct small_page_entry *page + = (struct small_page_entry *) zone_get_object_page (object); + unsigned int start_word = zone_get_object_alloc_word (object); + unsigned int start_bit = zone_get_object_alloc_bit (object); + + page->alloc_bits[start_word] |= 1L << start_bit; } +/* Clear the allocation bit corresponding to OBJECT in PAGE's + bitmap. Used to coalesce this object with the preceding + one. */ static inline void -clear_page_group_in_use (page_group *group, char *page) +zone_clear_object_alloc_bit (struct small_page_entry *page, + const void *object) { - group->in_use &= ~(1 << page_group_index (group->allocation, page)); + unsigned int start_word = zone_get_object_alloc_word (object); + unsigned int start_bit = zone_get_object_alloc_bit (object); + + /* Would xor be quicker? */ + page->alloc_bits[start_word] &= ~(1L << start_bit); } -#endif -/* Allocate a new page for allocating objects of size 2^ORDER, - and return an entry for it. The entry is not added to the - appropriate page_table list. */ +/* Find the size of the object which starts at START_WORD and + START_BIT in ALLOC_BITS, which is at most MAX_SIZE bytes. + Helper function for ggc_get_size and zone_find_object_size. */ -static inline struct page_entry * -alloc_small_page (struct alloc_zone *zone) +static inline size_t +zone_object_size_1 (alloc_type *alloc_bits, + size_t start_word, size_t start_bit, + size_t max_size) { - struct page_entry *entry; - char *page; -#ifdef USING_MALLOC_PAGE_GROUPS - page_group *group; -#endif - - page = NULL; + size_t size; + alloc_type alloc_word; + int indx; - /* Check the list of free pages for one we can use. */ - entry = zone->free_pages; - if (entry != NULL) - { - /* Recycle the allocated memory from this page ... */ - zone->free_pages = entry->next; - page = entry->page; + /* Load the first word. */ + alloc_word = alloc_bits[start_word++]; -#ifdef USING_MALLOC_PAGE_GROUPS - group = entry->group; -#endif - } -#ifdef USING_MMAP - else + /* If that was the last bit in this word, we'll want to continue + with the next word. Otherwise, handle the rest of this word. */ + if (start_bit) { - /* We want just one page. Allocate a bunch of them and put the - extras on the freelist. (Can only do this optimization with - mmap for backing store.) */ - struct page_entry *e, *f = zone->free_pages; - int i; + indx = alloc_ffs (alloc_word >> start_bit); + if (indx) + /* indx is 1-based. We started at the bit after the object's + start, but we also ended at the bit after the object's end. + It cancels out. */ + return indx * BYTES_PER_ALLOC_BIT; - page = alloc_anon (NULL, G.pagesize * GGC_QUIRE_SIZE, zone); + /* The extra 1 accounts for the starting unit, before start_bit. */ + size = (sizeof (alloc_type) * 8 - start_bit + 1) * BYTES_PER_ALLOC_BIT; - /* This loop counts down so that the chain will be in ascending - memory order. */ - for (i = GGC_QUIRE_SIZE - 1; i >= 1; i--) - { - e = (struct page_entry *) xmalloc (sizeof (struct page_entry)); - e->bytes = G.pagesize; - e->page = page + (i << G.lg_pagesize); - e->next = f; - f = e; - } + if (size >= max_size) + return max_size; - zone->free_pages = f; + alloc_word = alloc_bits[start_word++]; } -#endif -#ifdef USING_MALLOC_PAGE_GROUPS else + size = BYTES_PER_ALLOC_BIT; + + while (alloc_word == 0) { - /* Allocate a large block of memory and serve out the aligned - pages therein. This results in much less memory wastage - than the traditional implementation of valloc. */ + size += sizeof (alloc_type) * 8 * BYTES_PER_ALLOC_BIT; + if (size >= max_size) + return max_size; + alloc_word = alloc_bits[start_word++]; + } - char *allocation, *a, *enda; - size_t alloc_size, head_slop, tail_slop; - int multiple_pages = (entry_size == G.pagesize); + indx = alloc_ffs (alloc_word); + return size + (indx - 1) * BYTES_PER_ALLOC_BIT; +} - if (multiple_pages) - alloc_size = GGC_QUIRE_SIZE * G.pagesize; - else - alloc_size = entry_size + G.pagesize - 1; - allocation = xmalloc (alloc_size); - VALGRIND_MALLOCLIKE_BLOCK(addr, alloc_size, 0, 0); - - page = (char *) (((size_t) allocation + G.pagesize - 1) & -G.pagesize); - head_slop = page - allocation; - if (multiple_pages) - tail_slop = ((size_t) allocation + alloc_size) & (G.pagesize - 1); - else - tail_slop = alloc_size - entry_size - head_slop; - enda = allocation + alloc_size - tail_slop; - - /* We allocated N pages, which are likely not aligned, leaving - us with N-1 usable pages. We plan to place the page_group - structure somewhere in the slop. */ - if (head_slop >= sizeof (page_group)) - group = (page_group *)page - 1; - else - { - /* We magically got an aligned allocation. Too bad, we have - to waste a page anyway. */ - if (tail_slop == 0) - { - enda -= G.pagesize; - tail_slop += G.pagesize; - } - if (tail_slop < sizeof (page_group)) - abort (); - group = (page_group *)enda; - tail_slop -= sizeof (page_group); - } +/* Find the size of OBJECT on small page PAGE. */ - /* Remember that we allocated this memory. */ - group->next = G.page_groups; - group->allocation = allocation; - group->alloc_size = alloc_size; - group->in_use = 0; - zone->page_groups = group; - G.bytes_mapped += alloc_size; +static inline size_t +zone_find_object_size (struct small_page_entry *page, + const void *object) +{ + const char *object_midptr = (const char *) object + BYTES_PER_ALLOC_BIT; + unsigned int start_word = zone_get_object_alloc_word (object_midptr); + unsigned int start_bit = zone_get_object_alloc_bit (object_midptr); + size_t max_size = (page->common.page + SMALL_PAGE_SIZE + - (const char *) object); + + return zone_object_size_1 (page->alloc_bits, start_word, start_bit, + max_size); +} - /* If we allocated multiple pages, put the rest on the free list. */ - if (multiple_pages) - { - struct page_entry *e, *f = G.free_pages; - for (a = enda - G.pagesize; a != page; a -= G.pagesize) - { - e = (struct page_entry *) xmalloc (sizeof (struct page_entry)); - e->bytes = G.pagesize; - e->page = a; - e->group = group; - e->next = f; - f = e; - } - zone->free_pages = f; - } - } -#endif +/* highest_bit assumes that alloc_type is 32 bits. */ +extern char check_alloc_type_size[(sizeof (alloc_type) == 4) ? 1 : -1]; - if (entry == NULL) - entry = (struct page_entry *) xmalloc (sizeof (struct page_entry)); - - entry->next = 0; - entry->bytes = G.pagesize; - entry->bytes_free = G.pagesize; - entry->page = page; - entry->context_depth = zone->context_depth; - entry->large_p = false; - entry->zone = zone; - zone->context_depth_allocations |= (unsigned long)1 << zone->context_depth; - -#ifdef USING_MALLOC_PAGE_GROUPS - entry->group = group; - set_page_group_in_use (group, page); -#endif +/* Find the highest set bit in VALUE. Returns the bit number of that + bit, using the same values as ffs. */ +static inline alloc_type +highest_bit (alloc_type value) +{ + /* This also assumes that alloc_type is unsigned. */ + value |= value >> 1; + value |= value >> 2; + value |= value >> 4; + value |= value >> 8; + value |= value >> 16; + value = value ^ (value >> 1); + return alloc_ffs (value); +} - set_page_table_entry (page, entry); +/* Find the offset from the start of an object to P, which may point + into the interior of the object. */ - if (GGC_DEBUG_LEVEL >= 2) - fprintf (G.debug_file, - "Allocating %s page at %p, data %p-%p\n", entry->zone->name, - (PTR) entry, page, page + G.pagesize - 1); +static unsigned long +zone_find_object_offset (alloc_type *alloc_bits, size_t start_word, + size_t start_bit) +{ + unsigned int offset_in_bits; + alloc_type alloc_word = alloc_bits[start_word]; + + /* Mask off any bits after the initial bit, but make sure to include + the initial bit in the result. Note that START_BIT is + 0-based. */ + if (start_bit < 8 * sizeof (alloc_type) - 1) + alloc_word &= (1 << (start_bit + 1)) - 1; + offset_in_bits = start_bit; + + /* Search for the start of the object. */ + while (alloc_word == 0 && start_word > 0) + { + alloc_word = alloc_bits[--start_word]; + offset_in_bits += 8 * sizeof (alloc_type); + } + /* We must always find a set bit. */ + gcc_assert (alloc_word != 0); + /* Note that the result of highest_bit is 1-based. */ + offset_in_bits -= highest_bit (alloc_word) - 1; - return entry; + return BYTES_PER_ALLOC_BIT * offset_in_bits; } -/* Allocate a large page of size SIZE in ZONE. */ +/* Allocate the mark bits for every zone, and set the pointers on each + page. */ +static void +zone_allocate_marks (void) +{ + struct alloc_zone *zone; -static inline struct page_entry * + for (zone = G.zones; zone; zone = zone->next_zone) + { + struct small_page_entry *page; + mark_type *cur_marks; + size_t mark_words, mark_words_per_page; +#ifdef ENABLE_CHECKING + size_t n = 0; +#endif + + mark_words_per_page + = (GGC_PAGE_SIZE + BYTES_PER_MARK_WORD - 1) / BYTES_PER_MARK_WORD; + mark_words = zone->n_small_pages * mark_words_per_page; + zone->mark_bits = (mark_type *) xcalloc (sizeof (mark_type), + mark_words); + cur_marks = zone->mark_bits; + for (page = zone->pages; page; page = page->next) + { + page->mark_bits = cur_marks; + cur_marks += mark_words_per_page; +#ifdef ENABLE_CHECKING + n++; +#endif + } +#ifdef ENABLE_CHECKING + gcc_assert (n == zone->n_small_pages); +#endif + } + + /* We don't collect the PCH zone, but we do have to mark it + (for now). */ + if (pch_zone.bytes) + pch_zone.mark_bits + = (mark_type *) xcalloc (sizeof (mark_type), + CEIL (pch_zone.bytes, BYTES_PER_MARK_WORD)); +} + +/* After marking and sweeping, release the memory used for mark bits. */ +static void +zone_free_marks (void) +{ + struct alloc_zone *zone; + + for (zone = G.zones; zone; zone = zone->next_zone) + if (zone->mark_bits) + { + free (zone->mark_bits); + zone->mark_bits = NULL; + } + + if (pch_zone.bytes) + { + free (pch_zone.mark_bits); + pch_zone.mark_bits = NULL; + } +} + +#ifdef USING_MMAP +/* Allocate SIZE bytes of anonymous memory, preferably near PREF, + (if non-null). The ifdef structure here is intended to cause a + compile error unless exactly one of the HAVE_* is defined. */ + +static inline char * +alloc_anon (char *pref ATTRIBUTE_UNUSED, size_t size, struct alloc_zone *zone) +{ +#ifdef HAVE_MMAP_ANON + char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); +#endif +#ifdef HAVE_MMAP_DEV_ZERO + char *page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE, + MAP_PRIVATE, G.dev_zero_fd, 0); +#endif + + if (page == (char *) MAP_FAILED) + { + perror ("virtual memory exhausted"); + exit (FATAL_EXIT_CODE); + } + + /* Remember that we allocated this memory. */ + zone->bytes_mapped += size; + + /* Pretend we don't have access to the allocated pages. We'll enable + access to smaller pieces of the area in ggc_alloc. Discard the + handle to avoid handle leak. */ + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (page, size)); + + return page; +} +#endif + +/* Allocate a new page for allocating small objects in ZONE, and + return an entry for it. */ + +static struct small_page_entry * +alloc_small_page (struct alloc_zone *zone) +{ + struct small_page_entry *entry; + + /* Check the list of free pages for one we can use. */ + entry = zone->free_pages; + if (entry != NULL) + { + /* Recycle the allocated memory from this page ... */ + zone->free_pages = entry->next; + } + else + { + /* We want just one page. Allocate a bunch of them and put the + extras on the freelist. (Can only do this optimization with + mmap for backing store.) */ + struct small_page_entry *e, *f = zone->free_pages; + int i; + char *page; + + page = alloc_anon (NULL, GGC_PAGE_SIZE * G.quire_size, zone); + + /* This loop counts down so that the chain will be in ascending + memory order. */ + for (i = G.quire_size - 1; i >= 1; i--) + { + e = XCNEWVAR (struct small_page_entry, G.small_page_overhead); + e->common.page = page + (i << GGC_PAGE_SHIFT); + e->common.zone = zone; + e->next = f; + f = e; + set_page_table_entry (e->common.page, &e->common); + } + + zone->free_pages = f; + + entry = XCNEWVAR (struct small_page_entry, G.small_page_overhead); + entry->common.page = page; + entry->common.zone = zone; + set_page_table_entry (page, &entry->common); + } + + zone->n_small_pages++; + + if (GGC_DEBUG_LEVEL >= 2) + fprintf (G.debug_file, + "Allocating %s page at %p, data %p-%p\n", + entry->common.zone->name, (PTR) entry, entry->common.page, + entry->common.page + SMALL_PAGE_SIZE - 1); + + return entry; +} + +/* Allocate a large page of size SIZE in ZONE. */ + +static struct large_page_entry * alloc_large_page (size_t size, struct alloc_zone *zone) { - struct page_entry *entry; + struct large_page_entry *entry; char *page; + size_t needed_size; - page = (char *) xmalloc (size + CHUNK_OVERHEAD + sizeof (struct page_entry)); - entry = (struct page_entry *) (page + size + CHUNK_OVERHEAD); + needed_size = size + sizeof (struct large_page_entry); + page = XNEWVAR (char, needed_size); - entry->next = 0; - entry->bytes = size; - entry->bytes_free = LARGE_OBJECT_SIZE + CHUNK_OVERHEAD; - entry->page = page; - entry->context_depth = zone->context_depth; - entry->large_p = true; - entry->zone = zone; - zone->context_depth_allocations |= (unsigned long)1 << zone->context_depth; - -#ifdef USING_MALLOC_PAGE_GROUPS - entry->group = NULL; + entry = (struct large_page_entry *) page; + + entry->next = NULL; + entry->common.page = page + sizeof (struct large_page_entry); + entry->common.large_p = true; + entry->common.pch_p = false; + entry->common.zone = zone; +#ifdef GATHER_STATISTICS + entry->common.survived = 0; #endif - set_page_table_entry (page, entry); + entry->mark_p = false; + entry->bytes = size; + entry->prev = NULL; + + set_page_table_entry (entry->common.page, &entry->common); if (GGC_DEBUG_LEVEL >= 2) fprintf (G.debug_file, - "Allocating %s large page at %p, data %p-%p\n", entry->zone->name, - (PTR) entry, page, page + size - 1); + "Allocating %s large page at %p, data %p-%p\n", + entry->common.zone->name, (PTR) entry, entry->common.page, + entry->common.page + SMALL_PAGE_SIZE - 1); return entry; } @@ -757,33 +967,41 @@ alloc_large_page (size_t size, struct alloc_zone *zone) /* For a page that is no longer needed, put it on the free page list. */ static inline void -free_page (page_entry *entry) +free_small_page (struct small_page_entry *entry) { if (GGC_DEBUG_LEVEL >= 2) fprintf (G.debug_file, - "Deallocating %s page at %p, data %p-%p\n", entry->zone->name, (PTR) entry, - entry->page, entry->page + entry->bytes - 1); + "Deallocating %s page at %p, data %p-%p\n", + entry->common.zone->name, (PTR) entry, + entry->common.page, entry->common.page + SMALL_PAGE_SIZE - 1); - set_page_table_entry (entry->page, NULL); + gcc_assert (!entry->common.large_p); - if (entry->large_p) - { - free (entry->page); - VALGRIND_FREELIKE_BLOCK (entry->page, entry->bytes); - } - else - { - /* Mark the page as inaccessible. Discard the handle to - avoid handle leak. */ - VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (entry->page, entry->bytes)); + /* Mark the page as inaccessible. Discard the handle to + avoid handle leak. */ + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (entry->common.page, + SMALL_PAGE_SIZE)); -#ifdef USING_MALLOC_PAGE_GROUPS - clear_page_group_in_use (entry->group, entry->page); -#endif + entry->next = entry->common.zone->free_pages; + entry->common.zone->free_pages = entry; + entry->common.zone->n_small_pages--; +} - entry->next = entry->zone->free_pages; - entry->zone->free_pages = entry; - } +/* Release a large page that is no longer needed. */ + +static inline void +free_large_page (struct large_page_entry *entry) +{ + if (GGC_DEBUG_LEVEL >= 2) + fprintf (G.debug_file, + "Deallocating %s page at %p, data %p-%p\n", + entry->common.zone->name, (PTR) entry, + entry->common.page, entry->common.page + SMALL_PAGE_SIZE - 1); + + gcc_assert (entry->common.large_p); + + set_page_table_entry (entry->common.page, NULL); + free (entry); } /* Release the free page cache to the system. */ @@ -792,7 +1010,7 @@ static void release_pages (struct alloc_zone *zone) { #ifdef USING_MMAP - page_entry *p, *next; + struct small_page_entry *p, *next; char *start; size_t len; @@ -801,17 +1019,17 @@ release_pages (struct alloc_zone *zone) while (p) { - start = p->page; + start = p->common.page; next = p->next; - len = p->bytes; - free (p); + len = SMALL_PAGE_SIZE; + set_page_table_entry (p->common.page, NULL); p = next; - while (p && p->page == start + len) + while (p && p->common.page == start + len) { next = p->next; - len += p->bytes; - free (p); + len += SMALL_PAGE_SIZE; + set_page_table_entry (p->common.page, NULL); p = next; } @@ -821,102 +1039,171 @@ release_pages (struct alloc_zone *zone) zone->free_pages = NULL; #endif -#ifdef USING_MALLOC_PAGE_GROUPS - page_entry **pp, *p; - page_group **gp, *g; - - /* Remove all pages from free page groups from the list. */ - pp = &(zone->free_pages); - while ((p = *pp) != NULL) - if (p->group->in_use == 0) - { - *pp = p->next; - free (p); - } - else - pp = &p->next; - - /* Remove all free page groups, and release the storage. */ - gp = &(zone->page_groups); - while ((g = *gp) != NULL) - if (g->in_use == 0) - { - *gp = g->next; - zone->bytes_mapped -= g->alloc_size; - free (g->allocation); - VALGRIND_FREELIKE_BLOCK(g->allocation, 0); - } - else - gp = &g->next; -#endif } -/* Place CHUNK of size SIZE on the free list for ZONE. */ +/* Place the block at PTR of size SIZE on the free list for ZONE. */ static inline void -free_chunk (struct alloc_chunk *chunk, size_t size, struct alloc_zone *zone) +free_chunk (char *ptr, size_t size, struct alloc_zone *zone) { + struct alloc_chunk *chunk = (struct alloc_chunk *) ptr; size_t bin = 0; bin = SIZE_BIN_DOWN (size); - if (bin == 0) - abort (); + gcc_assert (bin != 0); if (bin > NUM_FREE_BINS) - bin = 0; -#ifdef COOKIE_CHECKING - if (chunk->magic != CHUNK_MAGIC && chunk->magic != DEADCHUNK_MAGIC) - abort (); - chunk->magic = DEADCHUNK_MAGIC; -#endif - chunk->u.next_free = zone->free_chunks[bin]; + { + bin = 0; + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (chunk, + sizeof (struct + alloc_chunk))); + chunk->size = size; + chunk->next_free = zone->free_chunks[bin]; + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (ptr + + sizeof (struct + alloc_chunk), + size + - sizeof (struct + alloc_chunk))); + } + else + { + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (chunk, + sizeof (struct + alloc_chunk *))); + chunk->next_free = zone->free_chunks[bin]; + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (ptr + + sizeof (struct + alloc_chunk *), + size + - sizeof (struct + alloc_chunk *))); + } + zone->free_chunks[bin] = chunk; + if (bin > zone->high_free_bin) + zone->high_free_bin = bin; if (GGC_DEBUG_LEVEL >= 3) fprintf (G.debug_file, "Deallocating object, chunk=%p\n", (void *)chunk); - VALGRIND_DISCARD (VALGRIND_MAKE_READABLE (chunk, sizeof (struct alloc_chunk))); } -/* Allocate a chunk of memory of SIZE bytes. */ +/* Allocate a chunk of memory of at least ORIG_SIZE bytes, in ZONE. */ -static void * -ggc_alloc_zone_1 (size_t size, struct alloc_zone *zone, short type) +void * +ggc_alloc_zone_stat (size_t orig_size, struct alloc_zone *zone + MEM_STAT_DECL) { - size_t bin = 0; - size_t lsize = 0; - struct page_entry *entry; - struct alloc_chunk *chunk, *lchunk, **pp; + size_t bin; + size_t csize; + struct small_page_entry *entry; + struct alloc_chunk *chunk, **pp; void *result; + size_t size = orig_size; - /* Align size, so that we're assured of aligned allocations. */ - if (size < FREE_BIN_DELTA) - size = FREE_BIN_DELTA; - size = (size + MAX_ALIGNMENT - 1) & -MAX_ALIGNMENT; + /* Make sure that zero-sized allocations get a unique and freeable + pointer. */ + if (size == 0) + size = MAX_ALIGNMENT; + else + size = (size + MAX_ALIGNMENT - 1) & -MAX_ALIGNMENT; + + /* Try to allocate the object from several different sources. Each + of these cases is responsible for setting RESULT and SIZE to + describe the allocated block, before jumping to FOUND. If a + chunk is split, the allocate bit for the new chunk should also be + set. + + Large objects are handled specially. However, they'll just fail + the next couple of conditions, so we can wait to check for them + below. The large object case is relatively rare (< 1%), so this + is a win. */ + + /* First try to split the last chunk we allocated. For best + fragmentation behavior it would be better to look for a + free bin of the appropriate size for a small object. However, + we're unlikely (1% - 7%) to find one, and this gives better + locality behavior anyway. This case handles the lion's share + of all calls to this function. */ + if (size <= zone->cached_free_size) + { + result = zone->cached_free; - /* Large objects are handled specially. */ - if (size >= G.pagesize - 2*CHUNK_OVERHEAD - FREE_BIN_DELTA) + zone->cached_free_size -= size; + if (zone->cached_free_size) + { + zone->cached_free += size; + zone_set_object_alloc_bit (zone->cached_free); + } + + goto found; + } + + /* Next, try to find a free bin of the exactly correct size. */ + + /* We want to round SIZE up, rather than down, but we know it's + already aligned to at least FREE_BIN_DELTA, so we can just + shift. */ + bin = SIZE_BIN_DOWN (size); + + if (bin <= NUM_FREE_BINS + && (chunk = zone->free_chunks[bin]) != NULL) { - entry = alloc_large_page (size, zone); - entry->survived = 0; - entry->next = entry->zone->pages; - entry->zone->pages = entry; + /* We have a chunk of the right size. Pull it off the free list + and use it. */ + zone->free_chunks[bin] = chunk->next_free; - chunk = (struct alloc_chunk *) entry->page; - VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (chunk, sizeof (struct alloc_chunk))); - chunk->size = LARGE_OBJECT_SIZE; + /* NOTE: SIZE is only guaranteed to be right if MAX_ALIGNMENT + == FREE_BIN_DELTA. */ + result = chunk; + + /* The allocation bits are already set correctly. HIGH_FREE_BIN + may now be wrong, if this was the last chunk in the high bin. + Rather than fixing it up now, wait until we need to search + the free bins. */ goto found; } - /* First look for a tiny object already segregated into its own - size bucket. */ - bin = SIZE_BIN_UP (size); - if (bin <= NUM_FREE_BINS) + /* Next, if there wasn't a chunk of the ideal size, look for a chunk + to split. We can find one in the too-big bin, or in the largest + sized bin with a chunk in it. Try the largest normal-sized bin + first. */ + + if (zone->high_free_bin > bin) { - chunk = zone->free_chunks[bin]; - if (chunk) + /* Find the highest numbered free bin. It will be at or below + the watermark. */ + while (zone->high_free_bin > bin + && zone->free_chunks[zone->high_free_bin] == NULL) + zone->high_free_bin--; + + if (zone->high_free_bin > bin) { - zone->free_chunks[bin] = chunk->u.next_free; - VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (chunk, sizeof (struct alloc_chunk))); + size_t tbin = zone->high_free_bin; + chunk = zone->free_chunks[tbin]; + + /* Remove the chunk from its previous bin. */ + zone->free_chunks[tbin] = chunk->next_free; + + result = (char *) chunk; + + /* Save the rest of the chunk for future allocation. */ + if (zone->cached_free_size) + free_chunk (zone->cached_free, zone->cached_free_size, zone); + + chunk = (struct alloc_chunk *) ((char *) result + size); + zone->cached_free = (char *) chunk; + zone->cached_free_size = (tbin - bin) * FREE_BIN_DELTA; + + /* Mark the new free chunk as an object, so that we can + find the size of the newly allocated object. */ + zone_set_object_alloc_bit (chunk); + + /* HIGH_FREE_BIN may now be wrong, if this was the last + chunk in the high bin. Rather than fixing it up now, + wait until we need to search the free bins. */ + goto found; } } @@ -927,77 +1214,141 @@ ggc_alloc_zone_1 (size_t size, struct alloc_zone *zone, short type) chunk = *pp; while (chunk && chunk->size < size) { - pp = &chunk->u.next_free; + pp = &chunk->next_free; chunk = *pp; } - /* Failing that, allocate new storage. */ - if (!chunk) + if (chunk) { - entry = alloc_small_page (zone); - entry->next = entry->zone->pages; - entry->zone->pages = entry; + /* Remove the chunk from its previous bin. */ + *pp = chunk->next_free; + + result = (char *) chunk; - chunk = (struct alloc_chunk *) entry->page; - VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (chunk, sizeof (struct alloc_chunk))); - chunk->size = G.pagesize - CHUNK_OVERHEAD; + /* Save the rest of the chunk for future allocation, if there's any + left over. */ + csize = chunk->size; + if (csize > size) + { + if (zone->cached_free_size) + free_chunk (zone->cached_free, zone->cached_free_size, zone); + + chunk = (struct alloc_chunk *) ((char *) result + size); + zone->cached_free = (char *) chunk; + zone->cached_free_size = csize - size; + + /* Mark the new free chunk as an object. */ + zone_set_object_alloc_bit (chunk); + } + + goto found; } - else + + /* Handle large allocations. We could choose any threshold between + GGC_PAGE_SIZE - sizeof (struct large_page_entry) and + GGC_PAGE_SIZE. It can't be smaller, because then it wouldn't + be guaranteed to have a unique entry in the lookup table. Large + allocations will always fall through to here. */ + if (size > GGC_PAGE_SIZE) { - *pp = chunk->u.next_free; - VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (chunk, sizeof (struct alloc_chunk))); + struct large_page_entry *entry = alloc_large_page (size, zone); + +#ifdef GATHER_STATISTICS + entry->common.survived = 0; +#endif + + entry->next = zone->large_pages; + if (zone->large_pages) + zone->large_pages->prev = entry; + zone->large_pages = entry; + + result = entry->common.page; + + goto found; } - /* Release extra memory from a chunk that's too big. */ - lsize = chunk->size - size; - if (lsize >= CHUNK_OVERHEAD + FREE_BIN_DELTA) + + /* Failing everything above, allocate a new small page. */ + + entry = alloc_small_page (zone); + entry->next = zone->pages; + zone->pages = entry; + + /* Mark the first chunk in the new page. */ + entry->alloc_bits[0] = 1; + + result = entry->common.page; + if (size < SMALL_PAGE_SIZE) { - VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (chunk, sizeof (struct alloc_chunk))); - chunk->size = size; + if (zone->cached_free_size) + free_chunk (zone->cached_free, zone->cached_free_size, zone); - lsize -= CHUNK_OVERHEAD; - lchunk = (struct alloc_chunk *)(chunk->u.data + size); - VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (lchunk, sizeof (struct alloc_chunk))); -#ifdef COOKIE_CHECKING - lchunk->magic = CHUNK_MAGIC; -#endif - lchunk->type = 0; - lchunk->mark = 0; - lchunk->size = lsize; - free_chunk (lchunk, lsize, zone); + zone->cached_free = (char *) result + size; + zone->cached_free_size = SMALL_PAGE_SIZE - size; + + /* Mark the new free chunk as an object. */ + zone_set_object_alloc_bit (zone->cached_free); } - /* Calculate the object's address. */ + found: -#ifdef COOKIE_CHECKING - chunk->magic = CHUNK_MAGIC; -#endif - chunk->type = 1; - chunk->mark = 0; - chunk->typecode = type; - result = chunk->u.data; -#ifdef ENABLE_GC_CHECKING - /* Keep poisoning-by-writing-0xaf the object, in an attempt to keep the - exact same semantics in presence of memory bugs, regardless of - ENABLE_VALGRIND_CHECKING. We override this request below. Drop the - handle to avoid handle leak. */ - VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (result, size)); + /* We could save TYPE in the chunk, but we don't use that for + anything yet. If we wanted to, we could do it by adding it + either before the beginning of the chunk or after its end, + and adjusting the size and pointer appropriately. */ + + /* We'll probably write to this after we return. */ + prefetchw (result); +#ifdef ENABLE_GC_CHECKING /* `Poison' the entire allocated object. */ + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, size)); memset (result, 0xaf, size); + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (result + orig_size, + size - orig_size)); #endif /* Tell Valgrind that the memory is there, but its content isn't defined. The bytes at the end of the object are still marked unaccessible. */ - VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (result, size)); + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, orig_size)); /* Keep track of how many bytes are being allocated. This information is used in deciding when to collect. */ - zone->allocated += size + CHUNK_OVERHEAD; + zone->allocated += size; + + timevar_ggc_mem_total += size; + +#ifdef GATHER_STATISTICS + ggc_record_overhead (orig_size, size - orig_size, result PASS_MEM_STAT); + + { + size_t object_size = size; + size_t overhead = object_size - orig_size; + + zone->stats.total_overhead += overhead; + zone->stats.total_allocated += object_size; + + if (orig_size <= 32) + { + zone->stats.total_overhead_under32 += overhead; + zone->stats.total_allocated_under32 += object_size; + } + if (orig_size <= 64) + { + zone->stats.total_overhead_under64 += overhead; + zone->stats.total_allocated_under64 += object_size; + } + if (orig_size <= 128) + { + zone->stats.total_overhead_under128 += overhead; + zone->stats.total_allocated_under128 += object_size; + } + } +#endif if (GGC_DEBUG_LEVEL >= 3) - fprintf (G.debug_file, "Allocating object, chunk=%p size=%lu at %p\n", - (void *)chunk, (unsigned long) size, result); + fprintf (G.debug_file, "Allocating object, size=%lu at %p\n", + (unsigned long) size, result); return result; } @@ -1006,38 +1357,150 @@ ggc_alloc_zone_1 (size_t size, struct alloc_zone *zone, short type) for that type. */ void * -ggc_alloc_typed (enum gt_types_enum gte, size_t size) +ggc_alloc_typed_stat (enum gt_types_enum gte, size_t size + MEM_STAT_DECL) { switch (gte) { case gt_ggc_e_14lang_tree_node: - return ggc_alloc_zone_1 (size, tree_zone, gte); + return ggc_alloc_zone_pass_stat (size, &tree_zone); case gt_ggc_e_7rtx_def: - return ggc_alloc_zone_1 (size, rtl_zone, gte); + return ggc_alloc_zone_pass_stat (size, &rtl_zone); case gt_ggc_e_9rtvec_def: - return ggc_alloc_zone_1 (size, rtl_zone, gte); + return ggc_alloc_zone_pass_stat (size, &rtl_zone); default: - return ggc_alloc_zone_1 (size, &main_zone, gte); + return ggc_alloc_zone_pass_stat (size, &main_zone); } } /* Normal ggc_alloc simply allocates into the main zone. */ void * -ggc_alloc (size_t size) +ggc_alloc_stat (size_t size MEM_STAT_DECL) { - return ggc_alloc_zone_1 (size, &main_zone, -1); + return ggc_alloc_zone_pass_stat (size, &main_zone); } -/* Zone allocation allocates into the specified zone. */ +/* Poison the chunk. */ +#ifdef ENABLE_GC_CHECKING +#define poison_region(PTR, SIZE) \ + memset ((PTR), 0xa5, (SIZE)) +#else +#define poison_region(PTR, SIZE) +#endif -void * -ggc_alloc_zone (size_t size, struct alloc_zone *zone) +/* Free the object at P. */ + +void +ggc_free (void *p) +{ + struct page_entry *page; + +#ifdef GATHER_STATISTICS + ggc_free_overhead (p); +#endif + + poison_region (p, ggc_get_size (p)); + + page = zone_get_object_page (p); + + if (page->large_p) + { + struct large_page_entry *large_page + = (struct large_page_entry *) page; + + /* Remove the page from the linked list. */ + if (large_page->prev) + large_page->prev->next = large_page->next; + else + { + gcc_assert (large_page->common.zone->large_pages == large_page); + large_page->common.zone->large_pages = large_page->next; + } + if (large_page->next) + large_page->next->prev = large_page->prev; + + large_page->common.zone->allocated -= large_page->bytes; + + /* Release the memory associated with this object. */ + free_large_page (large_page); + } + else if (page->pch_p) + /* Don't do anything. We won't allocate a new object from the + PCH zone so there's no point in releasing anything. */ + ; + else + { + size_t size = ggc_get_size (p); + + page->zone->allocated -= size; + + /* Add the chunk to the free list. We don't bother with coalescing, + since we are likely to want a chunk of this size again. */ + free_chunk ((char *)p, size, page->zone); + } +} + +/* Mark function for strings. */ + +void +gt_ggc_m_S (const void *p) { - return ggc_alloc_zone_1 (size, zone, -1); + page_entry *entry; + unsigned long offset; + + if (!p) + return; + + /* Look up the page on which the object is alloced. . */ + entry = lookup_page_table_if_allocated (p); + if (! entry) + return; + + if (entry->pch_p) + { + size_t alloc_word, alloc_bit, t; + t = ((const char *) p - pch_zone.page) / BYTES_PER_ALLOC_BIT; + alloc_word = t / (8 * sizeof (alloc_type)); + alloc_bit = t % (8 * sizeof (alloc_type)); + offset = zone_find_object_offset (pch_zone.alloc_bits, alloc_word, + alloc_bit); + } + else if (entry->large_p) + { + struct large_page_entry *le = (struct large_page_entry *) entry; + offset = ((const char *) p) - entry->page; + gcc_assert (offset < le->bytes); + } + else + { + struct small_page_entry *se = (struct small_page_entry *) entry; + unsigned int start_word = zone_get_object_alloc_word (p); + unsigned int start_bit = zone_get_object_alloc_bit (p); + offset = zone_find_object_offset (se->alloc_bits, start_word, start_bit); + + /* On some platforms a char* will not necessarily line up on an + allocation boundary, so we have to update the offset to + account for the leftover bytes. */ + offset += (size_t) p % BYTES_PER_ALLOC_BIT; + } + + if (offset) + { + /* Here we've seen a char* which does not point to the beginning + of an allocated object. We assume it points to the middle of + a STRING_CST. */ + gcc_assert (offset == offsetof (struct tree_string, str)); + p = ((const char *) p) - offset; + gt_ggc_mx_lang_tree_node (CONST_CAST(void *, p)); + return; + } + + /* Inefficient, but also unlikely to matter. */ + ggc_set_mark (p); } /* If P is not marked, mark it and return false. Otherwise return true. @@ -1047,35 +1510,42 @@ ggc_alloc_zone (size_t size, struct alloc_zone *zone) int ggc_set_mark (const void *p) { - page_entry *entry; - struct alloc_chunk *chunk; + struct page_entry *page; + const char *ptr = (const char *) p; -#ifdef ENABLE_CHECKING - /* Look up the page on which the object is alloced. If the object - wasn't allocated by the collector, we'll probably die. */ - entry = lookup_page_table_entry (p); - if (entry == NULL) - abort (); -#endif - chunk = (struct alloc_chunk *) ((char *)p - CHUNK_OVERHEAD); -#ifdef COOKIE_CHECKING - if (chunk->magic != CHUNK_MAGIC) - abort (); -#endif - if (chunk->mark) - return 1; - chunk->mark = 1; + page = zone_get_object_page (p); -#ifndef ENABLE_CHECKING - entry = lookup_page_table_entry (p); -#endif + if (page->pch_p) + { + size_t mark_word, mark_bit, offset; + offset = (ptr - pch_zone.page) / BYTES_PER_MARK_BIT; + mark_word = offset / (8 * sizeof (mark_type)); + mark_bit = offset % (8 * sizeof (mark_type)); + + if (pch_zone.mark_bits[mark_word] & (1 << mark_bit)) + return 1; + pch_zone.mark_bits[mark_word] |= (1 << mark_bit); + } + else if (page->large_p) + { + struct large_page_entry *large_page + = (struct large_page_entry *) page; - /* Large pages are either completely full or completely empty. So if - they are marked, they are completely full. */ - if (entry->large_p) - entry->bytes_free = 0; + if (large_page->mark_p) + return 1; + large_page->mark_p = true; + } else - entry->bytes_free -= chunk->size + CHUNK_OVERHEAD; + { + struct small_page_entry *small_page + = (struct small_page_entry *) page; + + if (small_page->mark_bits[zone_get_object_mark_word (p)] + & (1 << zone_get_object_mark_bit (p))) + return 1; + small_page->mark_bits[zone_get_object_mark_word (p)] + |= (1 << zone_get_object_mark_bit (p)); + } if (GGC_DEBUG_LEVEL >= 4) fprintf (G.debug_file, "Marking %p\n", p); @@ -1090,22 +1560,36 @@ ggc_set_mark (const void *p) int ggc_marked_p (const void *p) { - struct alloc_chunk *chunk; + struct page_entry *page; + const char *ptr = (const char *) p; -#ifdef ENABLE_CHECKING - { - page_entry *entry = lookup_page_table_entry (p); - if (entry == NULL) - abort (); - } -#endif + page = zone_get_object_page (p); - chunk = (struct alloc_chunk *) ((char *)p - CHUNK_OVERHEAD); -#ifdef COOKIE_CHECKING - if (chunk->magic != CHUNK_MAGIC) - abort (); -#endif - return chunk->mark; + if (page->pch_p) + { + size_t mark_word, mark_bit, offset; + offset = (ptr - pch_zone.page) / BYTES_PER_MARK_BIT; + mark_word = offset / (8 * sizeof (mark_type)); + mark_bit = offset % (8 * sizeof (mark_type)); + + return (pch_zone.mark_bits[mark_word] & (1 << mark_bit)) != 0; + } + + if (page->large_p) + { + struct large_page_entry *large_page + = (struct large_page_entry *) page; + + return large_page->mark_p; + } + else + { + struct small_page_entry *small_page + = (struct small_page_entry *) page; + + return 0 != (small_page->mark_bits[zone_get_object_mark_word (p)] + & (1 << zone_get_object_mark_bit (p))); + } } /* Return the size of the gc-able object P. */ @@ -1113,50 +1597,67 @@ ggc_marked_p (const void *p) size_t ggc_get_size (const void *p) { - struct alloc_chunk *chunk; - struct page_entry *entry; + struct page_entry *page; + const char *ptr = (const char *) p; -#ifdef ENABLE_CHECKING - entry = lookup_page_table_entry (p); - if (entry == NULL) - abort (); -#endif + page = zone_get_object_page (p); - chunk = (struct alloc_chunk *) ((char *)p - CHUNK_OVERHEAD); -#ifdef COOKIE_CHECKING - if (chunk->magic != CHUNK_MAGIC) - abort (); -#endif - if (chunk->size == LARGE_OBJECT_SIZE) + if (page->pch_p) { -#ifndef ENABLE_CHECKING - entry = lookup_page_table_entry (p); -#endif - return entry->bytes; + size_t alloc_word, alloc_bit, offset, max_size; + offset = (ptr - pch_zone.page) / BYTES_PER_ALLOC_BIT + 1; + alloc_word = offset / (8 * sizeof (alloc_type)); + alloc_bit = offset % (8 * sizeof (alloc_type)); + max_size = pch_zone.bytes - (ptr - pch_zone.page); + return zone_object_size_1 (pch_zone.alloc_bits, alloc_word, alloc_bit, + max_size); } - return chunk->size; + if (page->large_p) + return ((struct large_page_entry *)page)->bytes; + else + return zone_find_object_size ((struct small_page_entry *) page, p); } /* Initialize the ggc-zone-mmap allocator. */ void init_ggc (void) { + /* The allocation size must be greater than BYTES_PER_MARK_BIT, and + a multiple of both BYTES_PER_ALLOC_BIT and FREE_BIN_DELTA, for + the current assumptions to hold. */ + + gcc_assert (FREE_BIN_DELTA == MAX_ALIGNMENT); + /* Set up the main zone by hand. */ main_zone.name = "Main zone"; G.zones = &main_zone; /* Allocate the default zones. */ - rtl_zone = new_ggc_zone ("RTL zone"); - tree_zone = new_ggc_zone ("Tree zone"); - garbage_zone = new_ggc_zone ("Garbage zone"); + new_ggc_zone_1 (&rtl_zone, "RTL zone"); + new_ggc_zone_1 (&tree_zone, "Tree zone"); + new_ggc_zone_1 (&tree_id_zone, "Tree identifier zone"); G.pagesize = getpagesize(); G.lg_pagesize = exact_log2 (G.pagesize); + G.page_mask = ~(G.pagesize - 1); + + /* Require the system page size to be a multiple of GGC_PAGE_SIZE. */ + gcc_assert ((G.pagesize & (GGC_PAGE_SIZE - 1)) == 0); + + /* Allocate 16 system pages at a time. */ + G.quire_size = 16 * G.pagesize / GGC_PAGE_SIZE; + + /* Calculate the size of the allocation bitmap and other overhead. */ + /* Right now we allocate bits for the page header and bitmap. These + are wasted, but a little tricky to eliminate. */ + G.small_page_overhead + = PAGE_OVERHEAD + (GGC_PAGE_SIZE / BYTES_PER_ALLOC_BIT / 8); + /* G.small_page_overhead = ROUND_UP (G.small_page_overhead, MAX_ALIGNMENT); */ + #ifdef HAVE_MMAP_DEV_ZERO G.dev_zero_fd = open ("/dev/zero", O_RDONLY); - if (G.dev_zero_fd == -1) - abort (); + gcc_assert (G.dev_zero_fd != -1); #endif #if 0 @@ -1173,36 +1674,49 @@ init_ggc (void) hork badly if we tried to use it. */ { char *p = alloc_anon (NULL, G.pagesize, &main_zone); - struct page_entry *e; + struct small_page_entry *e; if ((size_t)p & (G.pagesize - 1)) { /* How losing. Discard this one and try another. If we still can't get something useful, give up. */ p = alloc_anon (NULL, G.pagesize, &main_zone); - if ((size_t)p & (G.pagesize - 1)) - abort (); + gcc_assert (!((size_t)p & (G.pagesize - 1))); } - /* We have a good page, might as well hold onto it... */ - e = (struct page_entry *) xmalloc (sizeof (struct page_entry)); - e->bytes = G.pagesize; - e->page = p; - e->next = main_zone.free_pages; - main_zone.free_pages = e; + if (GGC_PAGE_SIZE == G.pagesize) + { + /* We have a good page, might as well hold onto it... */ + e = XCNEWVAR (struct small_page_entry, G.small_page_overhead); + e->common.page = p; + e->common.zone = &main_zone; + e->next = main_zone.free_pages; + set_page_table_entry (e->common.page, &e->common); + main_zone.free_pages = e; + } + else + { + munmap (p, G.pagesize); + } } #endif } /* Start a new GGC zone. */ -struct alloc_zone * -new_ggc_zone (const char * name) +static void +new_ggc_zone_1 (struct alloc_zone *new_zone, const char * name) { - struct alloc_zone *new_zone = xcalloc (1, sizeof (struct alloc_zone)); new_zone->name = name; new_zone->next_zone = G.zones->next_zone; G.zones->next_zone = new_zone; +} + +struct alloc_zone * +new_ggc_zone (const char * name) +{ + struct alloc_zone *new_zone = XCNEW (struct alloc_zone); + new_ggc_zone_1 (new_zone, name); return new_zone; } @@ -1213,188 +1727,184 @@ destroy_ggc_zone (struct alloc_zone * dead_zone) struct alloc_zone *z; for (z = G.zones; z && z->next_zone != dead_zone; z = z->next_zone) - /* Just find that zone. */ ; - - /* We should have found the zone in the list. Anything else is - fatal. - If we did find the zone, we expect this zone to be empty. - A ggc_collect should have emptied it before we can destroy it. */ - if (!z || dead_zone->allocated != 0) - abort (); - - /* Unchain the dead zone, release all its pages and free it. */ - z->next_zone = z->next_zone->next_zone; - release_pages (dead_zone); - free (dead_zone); -} - -/* Increment the `GC context'. Objects allocated in an outer context - are never freed, eliminating the need to register their roots. */ - -void -ggc_push_context (void) -{ - struct alloc_zone *zone; - for (zone = G.zones; zone; zone = zone->next_zone) - ++(zone->context_depth); - /* Die on wrap. */ - if (main_zone.context_depth >= HOST_BITS_PER_LONG) - abort (); -} - -/* Decrement the `GC context'. All objects allocated since the - previous ggc_push_context are migrated to the outer context. */ - -static void -ggc_pop_context_1 (struct alloc_zone *zone) -{ - unsigned long omask; - unsigned depth; - page_entry *p; - - depth = --(zone->context_depth); - omask = (unsigned long)1 << (depth + 1); - - if (!((zone->context_depth_allocations | zone->context_depth_collections) & omask)) - return; + /* Just find that zone. */ + continue; - zone->context_depth_allocations |= (zone->context_depth_allocations & omask) >> 1; - zone->context_depth_allocations &= omask - 1; - zone->context_depth_collections &= omask - 1; + /* We should have found the zone in the list. Anything else is fatal. */ + gcc_assert (z); - /* Any remaining pages in the popped context are lowered to the new - current context; i.e. objects allocated in the popped context and - left over are imported into the previous context. */ - for (p = zone->pages; p != NULL; p = p->next) - if (p->context_depth > depth) - p->context_depth = depth; + /* z is dead, baby. z is dead. */ + z->dead = true; } -/* Pop all the zone contexts. */ - -void -ggc_pop_context (void) -{ - struct alloc_zone *zone; - for (zone = G.zones; zone; zone = zone->next_zone) - ggc_pop_context_1 (zone); -} - - -/* Poison the chunk. */ -#ifdef ENABLE_GC_CHECKING -#define poison_chunk(CHUNK, SIZE) \ - memset ((CHUNK)->u.data, 0xa5, (SIZE)) -#else -#define poison_chunk(CHUNK, SIZE) -#endif - /* Free all empty pages and objects within a page for a given zone */ static void sweep_pages (struct alloc_zone *zone) { - page_entry **pp, *p, *next; - struct alloc_chunk *chunk, *last_free, *end; - size_t last_free_size, allocated = 0; + struct large_page_entry **lpp, *lp, *lnext; + struct small_page_entry **spp, *sp, *snext; + char *last_free; + size_t allocated = 0; + bool nomarksinpage; /* First, reset the free_chunks lists, since we are going to re-free free chunks in hopes of coalescing them into large chunks. */ memset (zone->free_chunks, 0, sizeof (zone->free_chunks)); - pp = &zone->pages; - for (p = zone->pages; p ; p = next) + zone->high_free_bin = 0; + zone->cached_free = NULL; + zone->cached_free_size = 0; + + /* Large pages are all or none affairs. Either they are completely + empty, or they are completely full. */ + lpp = &zone->large_pages; + for (lp = zone->large_pages; lp != NULL; lp = lnext) { - next = p->next; + gcc_assert (lp->common.large_p); + + lnext = lp->next; + +#ifdef GATHER_STATISTICS + /* This page has now survived another collection. */ + lp->common.survived++; +#endif - /* For empty pages, just free the page. */ - if (p->bytes_free == G.pagesize && p->context_depth == zone->context_depth) + if (lp->mark_p) + { + lp->mark_p = false; + allocated += lp->bytes; + lpp = &lp->next; + } + else { - *pp = next; + *lpp = lnext; #ifdef ENABLE_GC_CHECKING /* Poison the page. */ - memset (p->page, 0xb5, p->bytes); + memset (lp->common.page, 0xb5, SMALL_PAGE_SIZE); #endif - free_page (p); - continue; + if (lp->prev) + lp->prev->next = lp->next; + if (lp->next) + lp->next->prev = lp->prev; + free_large_page (lp); } + } + + spp = &zone->pages; + for (sp = zone->pages; sp != NULL; sp = snext) + { + char *object, *last_object; + char *end; + alloc_type *alloc_word_p; + mark_type *mark_word_p; - /* Large pages are all or none affairs. Either they are - completely empty, or they are completely full. - Thus, if the above didn't catch it, we need not do anything - except remove the mark and reset the bytes_free. + gcc_assert (!sp->common.large_p); - XXX: Should we bother to increment allocated. */ - else if (p->large_p) - { - p->bytes_free = p->bytes; - ((struct alloc_chunk *)p->page)->mark = 0; - continue; - } - pp = &p->next; + snext = sp->next; +#ifdef GATHER_STATISTICS /* This page has now survived another collection. */ - p->survived++; + sp->common.survived++; +#endif - /* Which leaves full and partial pages. Step through all chunks, - consolidate those that are free and insert them into the free - lists. Note that consolidation slows down collection - slightly. */ + /* Step through all chunks, consolidate those that are free and + insert them into the free lists. Note that consolidation + slows down collection slightly. */ - chunk = (struct alloc_chunk *)p->page; - end = (struct alloc_chunk *)(p->page + G.pagesize); + last_object = object = sp->common.page; + end = sp->common.page + SMALL_PAGE_SIZE; last_free = NULL; - last_free_size = 0; + nomarksinpage = true; + mark_word_p = sp->mark_bits; + alloc_word_p = sp->alloc_bits; + + gcc_assert (BYTES_PER_ALLOC_BIT == BYTES_PER_MARK_BIT); + object = sp->common.page; do { - prefetch ((struct alloc_chunk *)(chunk->u.data + chunk->size)); - if (chunk->mark || p->context_depth < zone->context_depth) + unsigned int i, n; + alloc_type alloc_word; + mark_type mark_word; + + alloc_word = *alloc_word_p++; + mark_word = *mark_word_p++; + + if (mark_word) + nomarksinpage = false; + + /* There ought to be some way to do this without looping... */ + i = 0; + while ((n = alloc_ffs (alloc_word)) != 0) { - if (last_free) + /* Extend the current state for n - 1 bits. We can't + shift alloc_word by n, even though it isn't used in the + loop, in case only the highest bit was set. */ + alloc_word >>= n - 1; + mark_word >>= n - 1; + object += BYTES_PER_MARK_BIT * (n - 1); + + if (mark_word & 1) { - last_free->type = 0; - last_free->size = last_free_size; - last_free->mark = 0; - poison_chunk (last_free, last_free_size); - free_chunk (last_free, last_free_size, zone); - last_free = NULL; - } - if (chunk->mark) - { - allocated += chunk->size + CHUNK_OVERHEAD; - p->bytes_free += chunk->size + CHUNK_OVERHEAD; - } - chunk->mark = 0; -#ifdef ENABLE_CHECKING - if (p->bytes_free > p->bytes) - abort (); -#endif - } - else - { - if (last_free) - { - last_free_size += CHUNK_OVERHEAD + chunk->size; + if (last_free) + { + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (last_free, + object + - last_free)); + poison_region (last_free, object - last_free); + free_chunk (last_free, object - last_free, zone); + last_free = NULL; + } + else + allocated += object - last_object; + last_object = object; } else { - last_free = chunk; - last_free_size = chunk->size; + if (last_free == NULL) + { + last_free = object; + allocated += object - last_object; + } + else + zone_clear_object_alloc_bit (sp, object); } + + /* Shift to just after the alloc bit we handled. */ + alloc_word >>= 1; + mark_word >>= 1; + object += BYTES_PER_MARK_BIT; + + i += n; } - chunk = (struct alloc_chunk *)(chunk->u.data + chunk->size); + object += BYTES_PER_MARK_BIT * (8 * sizeof (alloc_type) - i); } - while (chunk < end); + while (object < end); - if (last_free) + if (nomarksinpage) + { + *spp = snext; +#ifdef ENABLE_GC_CHECKING + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (sp->common.page, + SMALL_PAGE_SIZE)); + /* Poison the page. */ + memset (sp->common.page, 0xb5, SMALL_PAGE_SIZE); +#endif + free_small_page (sp); + continue; + } + else if (last_free) { - last_free->type = 0; - last_free->size = last_free_size; - last_free->mark = 0; - poison_chunk (last_free, last_free_size); - free_chunk (last_free, last_free_size, zone); + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (last_free, + object - last_free)); + poison_region (last_free, object - last_free); + free_chunk (last_free, object - last_free, zone); } + else + allocated += object - last_object; + + spp = &sp->next; } zone->allocated = allocated; @@ -1408,19 +1918,34 @@ sweep_pages (struct alloc_zone *zone) static bool ggc_collect_1 (struct alloc_zone *zone, bool need_marking) { - /* Avoid frequent unnecessary work by skipping collection if the - total allocations haven't expanded much since the last - collection. */ - float allocated_last_gc = - MAX (zone->allocated_last_gc, (size_t)PARAM_VALUE (GGC_MIN_HEAPSIZE) * 1024); - - float min_expand = allocated_last_gc * PARAM_VALUE (GGC_MIN_EXPAND) / 100; +#if 0 + /* */ + { + int i; + for (i = 0; i < NUM_FREE_BINS + 1; i++) + { + struct alloc_chunk *chunk; + int n, tot; - if (zone->allocated < allocated_last_gc + min_expand) - return false; + n = 0; + tot = 0; + chunk = zone->free_chunks[i]; + while (chunk) + { + n++; + tot += chunk->size; + chunk = chunk->next_free; + } + fprintf (stderr, "Bin %d: %d free chunks (%d bytes)\n", + i, n, tot); + } + } + /* */ +#endif if (!quiet_flag) - fprintf (stderr, " {%s GC %luk -> ", zone->name, (unsigned long) zone->allocated / 1024); + fprintf (stderr, " {%s GC %luk -> ", + zone->name, (unsigned long) zone->allocated / 1024); /* Zero the total allocated bytes. This will be recalculated in the sweep phase. */ @@ -1430,21 +1955,25 @@ ggc_collect_1 (struct alloc_zone *zone, bool need_marking) reuse in the interim. */ release_pages (zone); - /* Indicate that we've seen collections at this context depth. */ - zone->context_depth_collections - = ((unsigned long)1 << (zone->context_depth + 1)) - 1; if (need_marking) - ggc_mark_roots (); + { + zone_allocate_marks (); + ggc_mark_roots (); +#ifdef GATHER_STATISTICS + ggc_prune_overhead_list (); +#endif + } + sweep_pages (zone); zone->was_collected = true; zone->allocated_last_gc = zone->allocated; - if (!quiet_flag) fprintf (stderr, "%luk}", (unsigned long) zone->allocated / 1024); return true; } +#ifdef GATHER_STATISTICS /* Calculate the average page survival rate in terms of number of collections. */ @@ -1453,59 +1982,56 @@ calculate_average_page_survival (struct alloc_zone *zone) { float count = 0.0; float survival = 0.0; - page_entry *p; + struct small_page_entry *p; + struct large_page_entry *lp; for (p = zone->pages; p; p = p->next) { count += 1.0; - survival += p->survived; + survival += p->common.survived; + } + for (lp = zone->large_pages; lp; lp = lp->next) + { + count += 1.0; + survival += lp->common.survived; } return survival/count; } +#endif -/* Check the magic cookies all of the chunks contain, to make sure we - aren't doing anything stupid, like stomping on alloc_chunk - structures. */ +/* Top level collection routine. */ -static inline void -check_cookies (void) +void +ggc_collect (void) { -#ifdef COOKIE_CHECKING - page_entry *p; struct alloc_zone *zone; + bool marked = false; - for (zone = G.zones; zone; zone = zone->next_zone) + timevar_push (TV_GC); + + if (!ggc_force_collect) { - for (p = zone->pages; p; p = p->next) + float allocated_last_gc = 0, allocated = 0, min_expand; + + for (zone = G.zones; zone; zone = zone->next_zone) { - if (!p->large_p) - { - struct alloc_chunk *chunk = (struct alloc_chunk *)p->page; - struct alloc_chunk *end = (struct alloc_chunk *)(p->page + G.pagesize); - do - { - if (chunk->magic != CHUNK_MAGIC && chunk->magic != DEADCHUNK_MAGIC) - abort (); - chunk = (struct alloc_chunk *)(chunk->u.data + chunk->size); - } - while (chunk < end); - } + allocated_last_gc += zone->allocated_last_gc; + allocated += zone->allocated; } - } -#endif -} + allocated_last_gc = + MAX (allocated_last_gc, + (size_t) PARAM_VALUE (GGC_MIN_HEAPSIZE) * 1024); + min_expand = allocated_last_gc * PARAM_VALUE (GGC_MIN_EXPAND) / 100; -/* Top level collection routine. */ + if (allocated < allocated_last_gc + min_expand) + { + timevar_pop (TV_GC); + return; + } + } -void -ggc_collect (void) -{ - struct alloc_zone *zone; - bool marked = false; - float f; + invoke_plugin_callbacks (PLUGIN_GGC_START, NULL); - timevar_push (TV_GC); - check_cookies (); /* Start by possibly collecting the main zone. */ main_zone.was_collected = false; marked |= ggc_collect_1 (&main_zone, true); @@ -1518,6 +2044,8 @@ ggc_collect (void) marking. So if we mark twice as often as we used to, we'll be twice as slow. Hopefully we'll avoid this cost when we mark zone-at-a-time. */ + /* NOTE drow/2004-07-28: We now always collect the main zone, but + keep this code in case the heuristics are further refined. */ if (main_zone.was_collected) { @@ -1525,12 +2053,12 @@ ggc_collect (void) for (zone = main_zone.next_zone; zone; zone = zone->next_zone) { - check_cookies (); zone->was_collected = false; marked |= ggc_collect_1 (zone, !marked); } } +#ifdef GATHER_STATISTICS /* Print page survival stats, if someone wants them. */ if (GGC_DEBUG_LEVEL >= 2) { @@ -1538,94 +2066,283 @@ ggc_collect (void) { if (zone->was_collected) { - f = calculate_average_page_survival (zone); + float f = calculate_average_page_survival (zone); printf ("Average page survival in zone `%s' is %f\n", zone->name, f); } } } +#endif - /* Since we don't mark zone at a time right now, marking in any - zone means marking in every zone. So we have to clear all the - marks in all the zones that weren't collected already. */ if (marked) + zone_free_marks (); + + /* Free dead zones. */ + for (zone = G.zones; zone && zone->next_zone; zone = zone->next_zone) { - page_entry *p; - for (zone = G.zones; zone; zone = zone->next_zone) - { - if (zone->was_collected) - continue; - for (p = zone->pages; p; p = p->next) - { - if (!p->large_p) - { - struct alloc_chunk *chunk = (struct alloc_chunk *)p->page; - struct alloc_chunk *end = (struct alloc_chunk *)(p->page + G.pagesize); - do - { - prefetch ((struct alloc_chunk *)(chunk->u.data + chunk->size)); - if (chunk->mark || p->context_depth < zone->context_depth) - { - if (chunk->mark) - p->bytes_free += chunk->size + CHUNK_OVERHEAD; -#ifdef ENABLE_CHECKING - if (p->bytes_free > p->bytes) - abort (); -#endif - chunk->mark = 0; - } - chunk = (struct alloc_chunk *)(chunk->u.data + chunk->size); - } - while (chunk < end); - } - else - { - p->bytes_free = p->bytes; - ((struct alloc_chunk *)p->page)->mark = 0; - } - } - } + if (zone->next_zone->dead) + { + struct alloc_zone *dead_zone = zone->next_zone; + + printf ("Zone `%s' is dead and will be freed.\n", dead_zone->name); + + /* The zone must be empty. */ + gcc_assert (!dead_zone->allocated); + + /* Unchain the dead zone, release all its pages and free it. */ + zone->next_zone = zone->next_zone->next_zone; + release_pages (dead_zone); + free (dead_zone); + } } + + invoke_plugin_callbacks (PLUGIN_GGC_END, NULL); + timevar_pop (TV_GC); } /* Print allocation statistics. */ +#define SCALE(x) ((unsigned long) ((x) < 1024*10 \ + ? (x) \ + : ((x) < 1024*1024*10 \ + ? (x) / 1024 \ + : (x) / (1024*1024)))) +#define LABEL(x) ((x) < 1024*10 ? ' ' : ((x) < 1024*1024*10 ? 'k' : 'M')) void ggc_print_statistics (void) { + struct alloc_zone *zone; + struct ggc_statistics stats; + size_t total_overhead = 0, total_allocated = 0, total_bytes_mapped = 0; + size_t pte_overhead, i; + + /* Clear the statistics. */ + memset (&stats, 0, sizeof (stats)); + + /* Make sure collection will really occur. */ + ggc_force_collect = true; + + /* Collect and print the statistics common across collectors. */ + ggc_print_common_statistics (stderr, &stats); + + ggc_force_collect = false; + + /* Release free pages so that we will not count the bytes allocated + there as part of the total allocated memory. */ + for (zone = G.zones; zone; zone = zone->next_zone) + release_pages (zone); + + /* Collect some information about the various sizes of + allocation. */ + fprintf (stderr, + "Memory still allocated at the end of the compilation process\n"); + + fprintf (stderr, "%20s %10s %10s %10s\n", + "Zone", "Allocated", "Used", "Overhead"); + for (zone = G.zones; zone; zone = zone->next_zone) + { + struct large_page_entry *large_page; + size_t overhead, allocated, in_use; + + /* Skip empty zones. */ + if (!zone->pages && !zone->large_pages) + continue; + + allocated = in_use = 0; + + overhead = sizeof (struct alloc_zone); + + for (large_page = zone->large_pages; large_page != NULL; + large_page = large_page->next) + { + allocated += large_page->bytes; + in_use += large_page->bytes; + overhead += sizeof (struct large_page_entry); + } + + /* There's no easy way to walk through the small pages finding + used and unused objects. Instead, add all the pages, and + subtract out the free list. */ + + allocated += GGC_PAGE_SIZE * zone->n_small_pages; + in_use += GGC_PAGE_SIZE * zone->n_small_pages; + overhead += G.small_page_overhead * zone->n_small_pages; + + for (i = 0; i <= NUM_FREE_BINS; i++) + { + struct alloc_chunk *chunk = zone->free_chunks[i]; + while (chunk) + { + in_use -= ggc_get_size (chunk); + chunk = chunk->next_free; + } + } + + fprintf (stderr, "%20s %10lu%c %10lu%c %10lu%c\n", + zone->name, + SCALE (allocated), LABEL (allocated), + SCALE (in_use), LABEL (in_use), + SCALE (overhead), LABEL (overhead)); + + gcc_assert (in_use == zone->allocated); + + total_overhead += overhead; + total_allocated += zone->allocated; + total_bytes_mapped += zone->bytes_mapped; + } + + /* Count the size of the page table as best we can. */ +#if HOST_BITS_PER_PTR <= 32 + pte_overhead = sizeof (G.lookup); + for (i = 0; i < PAGE_L1_SIZE; i++) + if (G.lookup[i]) + pte_overhead += PAGE_L2_SIZE * sizeof (struct page_entry *); +#else + { + page_table table = G.lookup; + pte_overhead = 0; + while (table) + { + pte_overhead += sizeof (*table); + for (i = 0; i < PAGE_L1_SIZE; i++) + if (table->table[i]) + pte_overhead += PAGE_L2_SIZE * sizeof (struct page_entry *); + table = table->next; + } + } +#endif + fprintf (stderr, "%20s %11s %11s %10lu%c\n", "Page Table", + "", "", SCALE (pte_overhead), LABEL (pte_overhead)); + total_overhead += pte_overhead; + + fprintf (stderr, "%20s %10lu%c %10lu%c %10lu%c\n", "Total", + SCALE (total_bytes_mapped), LABEL (total_bytes_mapped), + SCALE (total_allocated), LABEL(total_allocated), + SCALE (total_overhead), LABEL (total_overhead)); + +#ifdef GATHER_STATISTICS + { + unsigned long long all_overhead = 0, all_allocated = 0; + unsigned long long all_overhead_under32 = 0, all_allocated_under32 = 0; + unsigned long long all_overhead_under64 = 0, all_allocated_under64 = 0; + unsigned long long all_overhead_under128 = 0, all_allocated_under128 = 0; + + fprintf (stderr, "\nTotal allocations and overheads during the compilation process\n"); + + for (zone = G.zones; zone; zone = zone->next_zone) + { + all_overhead += zone->stats.total_overhead; + all_allocated += zone->stats.total_allocated; + + all_allocated_under32 += zone->stats.total_allocated_under32; + all_overhead_under32 += zone->stats.total_overhead_under32; + + all_allocated_under64 += zone->stats.total_allocated_under64; + all_overhead_under64 += zone->stats.total_overhead_under64; + + all_allocated_under128 += zone->stats.total_allocated_under128; + all_overhead_under128 += zone->stats.total_overhead_under128; + + fprintf (stderr, "%20s: %10lld\n", + zone->name, zone->stats.total_allocated); + } + + fprintf (stderr, "\n"); + + fprintf (stderr, "Total Overhead: %10lld\n", + all_overhead); + fprintf (stderr, "Total Allocated: %10lld\n", + all_allocated); + + fprintf (stderr, "Total Overhead under 32B: %10lld\n", + all_overhead_under32); + fprintf (stderr, "Total Allocated under 32B: %10lld\n", + all_allocated_under32); + fprintf (stderr, "Total Overhead under 64B: %10lld\n", + all_overhead_under64); + fprintf (stderr, "Total Allocated under 64B: %10lld\n", + all_allocated_under64); + fprintf (stderr, "Total Overhead under 128B: %10lld\n", + all_overhead_under128); + fprintf (stderr, "Total Allocated under 128B: %10lld\n", + all_allocated_under128); + } +#endif } +/* Precompiled header support. */ + +/* For precompiled headers, we sort objects based on their type. We + also sort various objects into their own buckets; currently this + covers strings and IDENTIFIER_NODE trees. The choices of how + to sort buckets have not yet been tuned. */ + +#define NUM_PCH_BUCKETS (gt_types_enum_last + 3) + +#define OTHER_BUCKET (gt_types_enum_last + 0) +#define IDENTIFIER_BUCKET (gt_types_enum_last + 1) +#define STRING_BUCKET (gt_types_enum_last + 2) + +struct ggc_pch_ondisk +{ + size_t total; + size_t type_totals[NUM_PCH_BUCKETS]; +}; + struct ggc_pch_data { - struct ggc_pch_ondisk - { - unsigned total; - } d; + struct ggc_pch_ondisk d; size_t base; - size_t written; + size_t orig_base; + size_t alloc_size; + alloc_type *alloc_bits; + size_t type_bases[NUM_PCH_BUCKETS]; + size_t start_offset; }; -/* Initialize the PCH datastructure. */ +/* Initialize the PCH data structure. */ struct ggc_pch_data * init_ggc_pch (void) { - return xcalloc (sizeof (struct ggc_pch_data), 1); + return XCNEW (struct ggc_pch_data); +} + +/* Return which of the page-aligned buckets the object at X, with type + TYPE, should be sorted into in the PCH. Strings will have + IS_STRING set and TYPE will be gt_types_enum_last. Other objects + of unknown type will also have TYPE equal to gt_types_enum_last. */ + +static int +pch_bucket (void *x, enum gt_types_enum type, + bool is_string) +{ + /* Sort identifiers into their own bucket, to improve locality + when searching the identifier hash table. */ + if (type == gt_ggc_e_14lang_tree_node + && TREE_CODE ((tree) x) == IDENTIFIER_NODE) + return IDENTIFIER_BUCKET; + else if (type == gt_types_enum_last) + { + if (is_string) + return STRING_BUCKET; + return OTHER_BUCKET; + } + return type; } /* Add the size of object X to the size of the PCH data. */ void ggc_pch_count_object (struct ggc_pch_data *d, void *x ATTRIBUTE_UNUSED, - size_t size, bool is_string) + size_t size, bool is_string, enum gt_types_enum type) { - if (!is_string) - { - d->d.total += size + CHUNK_OVERHEAD; - } - else - d->d.total += size; + /* NOTE: Right now we don't need to align up the size of any objects. + Strings can be unaligned, and everything else is allocated to a + MAX_ALIGNMENT boundary already. */ + + d->d.type_totals[pch_bucket (x, type, is_string)] += size; } /* Return the total size of the PCH data. */ @@ -1633,102 +2350,181 @@ ggc_pch_count_object (struct ggc_pch_data *d, void *x ATTRIBUTE_UNUSED, size_t ggc_pch_total_size (struct ggc_pch_data *d) { - return d->d.total; + enum gt_types_enum i; + size_t alloc_size, total_size; + + total_size = 0; + for (i = 0; i < NUM_PCH_BUCKETS; i++) + { + d->d.type_totals[i] = ROUND_UP (d->d.type_totals[i], GGC_PAGE_SIZE); + total_size += d->d.type_totals[i]; + } + d->d.total = total_size; + + /* Include the size of the allocation bitmap. */ + alloc_size = CEIL (d->d.total, BYTES_PER_ALLOC_BIT * 8); + alloc_size = ROUND_UP (alloc_size, MAX_ALIGNMENT); + d->alloc_size = alloc_size; + + return d->d.total + alloc_size; } /* Set the base address for the objects in the PCH file. */ void -ggc_pch_this_base (struct ggc_pch_data *d, void *base) +ggc_pch_this_base (struct ggc_pch_data *d, void *base_) { - d->base = (size_t) base; + int i; + size_t base = (size_t) base_; + + d->base = d->orig_base = base; + for (i = 0; i < NUM_PCH_BUCKETS; i++) + { + d->type_bases[i] = base; + base += d->d.type_totals[i]; + } + + if (d->alloc_bits == NULL) + d->alloc_bits = XCNEWVAR (alloc_type, d->alloc_size); } /* Allocate a place for object X of size SIZE in the PCH file. */ char * ggc_pch_alloc_object (struct ggc_pch_data *d, void *x, - size_t size, bool is_string) + size_t size, bool is_string, + enum gt_types_enum type) { + size_t alloc_word, alloc_bit; char *result; - result = (char *)d->base; - if (!is_string) - { - struct alloc_chunk *chunk = (struct alloc_chunk *) ((char *)x - CHUNK_OVERHEAD); - if (chunk->size == LARGE_OBJECT_SIZE) - d->base += ggc_get_size (x) + CHUNK_OVERHEAD; - else - d->base += chunk->size + CHUNK_OVERHEAD; - return result + CHUNK_OVERHEAD; - } - else - { - d->base += size; - return result; - } - + int bucket = pch_bucket (x, type, is_string); + + /* Record the start of the object in the allocation bitmap. We + can't assert that the allocation bit is previously clear, because + strings may violate the invariant that they are at least + BYTES_PER_ALLOC_BIT long. This is harmless - ggc_get_size + should not be called for strings. */ + alloc_word = ((d->type_bases[bucket] - d->orig_base) + / (8 * sizeof (alloc_type) * BYTES_PER_ALLOC_BIT)); + alloc_bit = ((d->type_bases[bucket] - d->orig_base) + / BYTES_PER_ALLOC_BIT) % (8 * sizeof (alloc_type)); + d->alloc_bits[alloc_word] |= 1L << alloc_bit; + + /* Place the object at the current pointer for this bucket. */ + result = (char *) d->type_bases[bucket]; + d->type_bases[bucket] += size; + return result; } /* Prepare to write out the PCH data to file F. */ void -ggc_pch_prepare_write (struct ggc_pch_data *d ATTRIBUTE_UNUSED, - FILE *f ATTRIBUTE_UNUSED) +ggc_pch_prepare_write (struct ggc_pch_data *d, + FILE *f) { - /* Nothing to do. */ + /* We seek around a lot while writing. Record where the end + of the padding in the PCH file is, so that we can + locate each object's offset. */ + d->start_offset = ftell (f); } /* Write out object X of SIZE to file F. */ void -ggc_pch_write_object (struct ggc_pch_data *d ATTRIBUTE_UNUSED, - FILE *f, void *x, void *newx ATTRIBUTE_UNUSED, - size_t size, bool is_string) +ggc_pch_write_object (struct ggc_pch_data *d, + FILE *f, void *x, void *newx, + size_t size, bool is_string ATTRIBUTE_UNUSED) { - if (!is_string) - { - struct alloc_chunk *chunk = (struct alloc_chunk *) ((char *)x - CHUNK_OVERHEAD); - size = ggc_get_size (x); - if (fwrite (chunk, size + CHUNK_OVERHEAD, 1, f) != 1) - fatal_error ("can't write PCH file: %m"); - d->written += size + CHUNK_OVERHEAD; - } - else - { - if (fwrite (x, size, 1, f) != 1) - fatal_error ("can't write PCH file: %m"); - d->written += size; - } - if (d->written == d->d.total - && fseek (f, ROUND_UP_VALUE (d->d.total, G.pagesize), SEEK_CUR) != 0) + if (fseek (f, (size_t) newx - d->orig_base + d->start_offset, SEEK_SET) != 0) + fatal_error ("can't seek PCH file: %m"); + + if (fwrite (x, size, 1, f) != 1) fatal_error ("can't write PCH file: %m"); } void ggc_pch_finish (struct ggc_pch_data *d, FILE *f) { + /* Write out the allocation bitmap. */ + if (fseek (f, d->start_offset + d->d.total, SEEK_SET) != 0) + fatal_error ("can't seek PCH file: %m"); + + if (fwrite (d->alloc_bits, d->alloc_size, 1, f) != 1) + fatal_error ("can't write PCH file: %m"); + + /* Done with the PCH, so write out our footer. */ if (fwrite (&d->d, sizeof (d->d), 1, f) != 1) fatal_error ("can't write PCH file: %m"); + + free (d->alloc_bits); free (d); } +/* The PCH file from F has been mapped at ADDR. Read in any + additional data from the file and set up the GC state. */ void ggc_pch_read (FILE *f, void *addr) { struct ggc_pch_ondisk d; - struct page_entry *entry; - char *pte; + size_t alloc_size; + struct alloc_zone *zone; + struct page_entry *pch_page; + char *p; + if (fread (&d, sizeof (d), 1, f) != 1) fatal_error ("can't read PCH file: %m"); - entry = xcalloc (1, sizeof (struct page_entry)); - entry->bytes = d.total; - entry->page = addr; - entry->context_depth = 0; - entry->zone = &main_zone; - for (pte = entry->page; - pte < entry->page + entry->bytes; - pte += G.pagesize) - set_page_table_entry (pte, entry); + alloc_size = CEIL (d.total, BYTES_PER_ALLOC_BIT * 8); + alloc_size = ROUND_UP (alloc_size, MAX_ALIGNMENT); + + pch_zone.bytes = d.total; + pch_zone.alloc_bits = (alloc_type *) ((char *) addr + pch_zone.bytes); + pch_zone.page = (char *) addr; + pch_zone.end = (char *) pch_zone.alloc_bits; + + /* We've just read in a PCH file. So, every object that used to be + allocated is now free. */ + for (zone = G.zones; zone; zone = zone->next_zone) + { + struct small_page_entry *page, *next_page; + struct large_page_entry *large_page, *next_large_page; + + zone->allocated = 0; + + /* Clear the zone's free chunk list. */ + memset (zone->free_chunks, 0, sizeof (zone->free_chunks)); + zone->high_free_bin = 0; + zone->cached_free = NULL; + zone->cached_free_size = 0; + + /* Move all the small pages onto the free list. */ + for (page = zone->pages; page != NULL; page = next_page) + { + next_page = page->next; + memset (page->alloc_bits, 0, + G.small_page_overhead - PAGE_OVERHEAD); + free_small_page (page); + } + + /* Discard all the large pages. */ + for (large_page = zone->large_pages; large_page != NULL; + large_page = next_large_page) + { + next_large_page = large_page->next; + free_large_page (large_page); + } + + zone->pages = NULL; + zone->large_pages = NULL; + } + + /* Allocate the dummy page entry for the PCH, and set all pages + mapped into the PCH to reference it. */ + pch_page = XCNEW (struct page_entry); + pch_page->page = pch_zone.page; + pch_page->pch_p = true; + + for (p = pch_zone.page; p < pch_zone.end; p += GGC_PAGE_SIZE) + set_page_table_entry (p, pch_page); }