/* "Bag-of-pages" garbage collector for the GNU compiler.
- Copyright (C) 1999, 2000 Free Software Foundation, Inc.
+ Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005
+ Free Software Foundation, Inc.
-This file is part of GNU CC.
+This file is part of GCC.
-GNU CC 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 version.
+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
+version.
-GNU CC is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+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 GNU CC; 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 COPYING. If not, write to the Free
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA. */
#include "config.h"
#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
#include "tree.h"
#include "rtl.h"
#include "tm_p.h"
#include "toplev.h"
-#include "varray.h"
#include "flags.h"
#include "ggc.h"
#include "timevar.h"
+#include "params.h"
+#include "tree-flow.h"
+#ifdef ENABLE_VALGRIND_CHECKING
+# ifdef HAVE_VALGRIND_MEMCHECK_H
+# include <valgrind/memcheck.h>
+# elif defined HAVE_MEMCHECK_H
+# include <memcheck.h>
+# else
+# include <valgrind.h>
+# endif
+#else
+/* Avoid #ifdef:s when we can help it. */
+#define VALGRIND_DISCARD(x)
+#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
+# undef HAVE_MMAP_DEV_ZERO
+
+# include <sys/mman.h>
+# ifndef MAP_FAILED
+# define MAP_FAILED -1
+# endif
+# if !defined (MAP_ANONYMOUS) && defined (MAP_ANON)
+# define MAP_ANONYMOUS MAP_ANON
+# endif
+# define USING_MMAP
-#ifdef HAVE_MMAP_ANYWHERE
-#include <sys/mman.h>
#endif
-#ifndef MAP_FAILED
-#define MAP_FAILED -1
+#ifdef HAVE_MMAP_DEV_ZERO
+
+# include <sys/mman.h>
+# ifndef MAP_FAILED
+# define MAP_FAILED -1
+# endif
+# define USING_MMAP
+
#endif
-#if !defined (MAP_ANONYMOUS) && defined (MAP_ANON)
-#define MAP_ANONYMOUS MAP_ANON
+#ifndef USING_MMAP
+#define USING_MALLOC_PAGE_GROUPS
#endif
-/* Stategy:
+/* Strategy:
This garbage-collecting allocator allocates objects on one of a set
of pages. Each page can allocate objects of a single size only;
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.
+ in the current (highest-numbered) context may be collected.
Page entries are arranged in an array of singly-linked lists. The
array is indexed by the allocation size, in bits, of the pages on
deallocated at the start of the next collection if they haven't
been recycled by then. */
-
-/* Define GGC_POISON to poison memory marked unused by the collector. */
-#undef GGC_POISON
-
-/* Define GGC_ALWAYS_COLLECT to perform collection every time
- ggc_collect is invoked. Otherwise, collection is performed only
- when a significant amount of memory has been allocated since the
- last collection. */
-#undef GGC_ALWAYS_COLLECT
-
-#ifdef ENABLE_GC_CHECKING
-#define GGC_POISON
-#endif
-#ifdef ENABLE_GC_ALWAYS_COLLECT
-#define GGC_ALWAYS_COLLECT
-#endif
-
/* Define GGC_DEBUG_LEVEL to print debugging information.
0: No debugging output.
1: GC statistics only.
2: Page-entry allocations/deallocations as well.
3: Object allocations as well.
- 4: Object marks as well. */
+ 4: Object marks as well. */
#define GGC_DEBUG_LEVEL (0)
\f
#ifndef HOST_BITS_PER_PTR
#define HOST_BITS_PER_PTR HOST_BITS_PER_LONG
#endif
-/* The "" allocated string. */
-char *empty_string;
\f
/* 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 bottommost HOST_PAGE_SIZE_BITS are ignored, since page-entry
pages are aligned on system page boundaries. The next most
significant PAGE_L2_BITS and PAGE_L1_BITS are the second and first
- index values in the lookup table, respectively.
+ index values in the lookup table, respectively.
For 32-bit architectures and the settings below, there are no
leftover bits. For architectures with wider pointers, the lookup
#define LOOKUP_L2(p) \
(((size_t) (p) >> G.lg_pagesize) & ((1 << PAGE_L2_BITS) - 1))
+/* The number of objects per allocation page, for objects on a page of
+ the indicated ORDER. */
+#define OBJECTS_PER_PAGE(ORDER) objects_per_page_table[ORDER]
+
+/* The number of objects in P. */
+#define OBJECTS_IN_PAGE(P) ((P)->bytes / OBJECT_SIZE ((P)->order))
+
+/* The size of an object on a page of the indicated ORDER. */
+#define OBJECT_SIZE(ORDER) object_size_table[ORDER]
+
+/* For speed, we avoid doing a general integer divide to locate the
+ offset in the allocation bitmap, by precalculating numbers M, S
+ such that (O * M) >> S == O / Z (modulo 2^32), for any offset O
+ within the page which is evenly divisible by the object size Z. */
+#define DIV_MULT(ORDER) inverse_table[ORDER].mult
+#define DIV_SHIFT(ORDER) inverse_table[ORDER].shift
+#define OFFSET_TO_BIT(OFFSET, ORDER) \
+ (((OFFSET) * DIV_MULT (ORDER)) >> DIV_SHIFT (ORDER))
+
+/* The number of extra orders, not corresponding to power-of-two sized
+ objects. */
+
+#define NUM_EXTRA_ORDERS ARRAY_SIZE (extra_order_size_table)
+
+#define RTL_SIZE(NSLOTS) \
+ (RTX_HDR_SIZE + (NSLOTS) * sizeof (rtunion))
+
+#define TREE_EXP_SIZE(OPS) \
+ (sizeof (struct tree_exp) + ((OPS) - 1) * sizeof (tree))
+
+/* The Ith entry is the maximum size of an object to be stored in the
+ Ith extra order. Adding a new entry to this array is the *only*
+ thing you need to do to add a new special allocation size. */
+
+static const size_t extra_order_size_table[] = {
+ sizeof (struct stmt_ann_d),
+ sizeof (struct var_ann_d),
+ sizeof (struct tree_decl_non_common),
+ sizeof (struct tree_field_decl),
+ sizeof (struct tree_parm_decl),
+ sizeof (struct tree_var_decl),
+ sizeof (struct tree_list),
+ sizeof (struct tree_ssa_name),
+ sizeof (struct tree_function_decl),
+ sizeof (struct tree_binfo),
+ sizeof (struct function),
+ sizeof (struct basic_block_def),
+ sizeof (bitmap_element),
+ /* PHI nodes with one to three arguments are already covered by the
+ above sizes. */
+ sizeof (struct tree_phi_node) + sizeof (struct phi_arg_d) * 3,
+ TREE_EXP_SIZE (2),
+ RTL_SIZE (2), /* MEM, PLUS, etc. */
+ RTL_SIZE (9), /* INSN */
+};
+
+/* The total number of orders. */
+
+#define NUM_ORDERS (HOST_BITS_PER_PTR + NUM_EXTRA_ORDERS)
+
+/* 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. */
+
+struct max_alignment {
+ char c;
+ union {
+ HOST_WIDEST_INT i;
+ long double d;
+ } u;
+};
+
+/* The biggest alignment required. */
+
+#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))
+
+/* The Ith entry is the number of objects on a page or order I. */
+
+static unsigned objects_per_page_table[NUM_ORDERS];
+
+/* The Ith entry is the size of an object on a page of order I. */
+
+static size_t object_size_table[NUM_ORDERS];
+
+/* The Ith entry is a pair of numbers (mult, shift) such that
+ ((k * mult) >> shift) mod 2^32 == (k / OBJECT_SIZE(I)) mod 2^32,
+ for all k evenly divisible by OBJECT_SIZE(I). */
+
+static struct
+{
+ size_t mult;
+ unsigned int shift;
+}
+inverse_table[NUM_ORDERS];
/* A page_entry records the status of an allocation page. This
structure is dynamically sized to fit the bitmap in_use_p. */
-typedef struct page_entry
+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 previous page-entry with objects of the same size, or NULL if
+ this is the first page-entry. The PREV pointer exists solely to
+ keep the cost of ggc_free manageable. */
+ struct page_entry *prev;
+
/* The number of bytes allocated. (This will always be a multiple
of the host system page size.) */
size_t bytes;
/* The address at which the memory is allocated. */
char *page;
- /* Saved in-use bit vector for pages that aren't in the topmost
- context during collection. */
- unsigned long *save_in_use_p;
+#ifdef USING_MALLOC_PAGE_GROUPS
+ /* Back pointer to the page group this page came from. */
+ struct page_group *group;
+#endif
+
+ /* This is the index in the by_depth varray where this page table
+ can be found. */
+ unsigned long index_by_depth;
/* Context depth of this page. */
unsigned short context_depth;
unsigned long in_use_p[1];
} 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
#if HOST_BITS_PER_PTR <= 32
If there are any pages with free objects, they will be at the
head of the list. NULL if there are no page-entries for this
object size. */
- page_entry *pages[HOST_BITS_PER_PTR];
+ page_entry *pages[NUM_ORDERS];
/* The Nth element in this array is the last page with objects of
size 2^N. NULL if there are no page-entries for this object
size. */
- page_entry *page_tails[HOST_BITS_PER_PTR];
+ page_entry *page_tails[NUM_ORDERS];
/* Lookup table for associating allocation pages with object addresses. */
page_table lookup;
/* Total amount of memory mapped. */
size_t bytes_mapped;
+ /* Bit N set if any allocations have been done at context depth N. */
+ unsigned long context_depth_allocations;
+
+ /* Bit N set if any collections have been done at context depth N. */
+ unsigned long context_depth_collections;
+
/* The current depth in the context stack. */
unsigned short context_depth;
/* A file descriptor open to /dev/zero for reading. */
-#if defined (HAVE_MMAP_ANYWHERE) && !defined(MAP_ANONYMOUS)
+#if defined (HAVE_MMAP_DEV_ZERO)
int dev_zero_fd;
#endif
/* A cache of free system pages. */
page_entry *free_pages;
+#ifdef USING_MALLOC_PAGE_GROUPS
+ page_group *page_groups;
+#endif
+
/* The file descriptor for debugging output. */
FILE *debug_file;
-} G;
+ /* Current number of elements in use in depth below. */
+ unsigned int depth_in_use;
+
+ /* Maximum number of elements that can be used before resizing. */
+ unsigned int depth_max;
+
+ /* Each element of this arry is an index in by_depth where the given
+ depth starts. This structure is indexed by that given depth we
+ are interested in. */
+ unsigned int *depth;
+
+ /* Current number of elements in use in by_depth below. */
+ unsigned int by_depth_in_use;
+
+ /* Maximum number of elements that can be used before resizing. */
+ unsigned int by_depth_max;
+
+ /* Each element of this array is a pointer to a page_entry, all
+ page_entries can be found in here by increasing depth.
+ index_by_depth in the page_entry is the index into this data
+ structure where that page_entry can be found. This is used to
+ speed up finding all page_entries at a particular depth. */
+ page_entry **by_depth;
-/* Compute DIVIDEND / DIVISOR, rounded up. */
-#define DIV_ROUND_UP(Dividend, Divisor) \
- (((Dividend) + (Divisor) - 1) / (Divisor))
+ /* Each element is a pointer to the saved in_use_p bits, if any,
+ zero otherwise. We allocate them all together, to enable a
+ better runtime data access pattern. */
+ unsigned long **save_in_use;
-/* The number of objects per allocation page, for objects of size
- 2^ORDER. */
-#define OBJECTS_PER_PAGE(Order) \
- ((Order) >= G.lg_pagesize ? 1 : G.pagesize / ((size_t)1 << (Order)))
+#ifdef ENABLE_GC_ALWAYS_COLLECT
+ /* List of free objects to be verified as actually free on the
+ next collection. */
+ struct free_object
+ {
+ void *object;
+ struct free_object *next;
+ } *free_object_list;
+#endif
+
+#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;
+
+ /* The allocations for each of the allocation orders. */
+ unsigned long long total_allocated_per_order[NUM_ORDERS];
+
+ /* The overhead for each of the allocation orders. */
+ unsigned long long total_overhead_per_order[NUM_ORDERS];
+ } stats;
+#endif
+} G;
/* The size in bytes required to maintain a bitmap for the objects
on a page-entry. */
#define BITMAP_SIZE(Num_objects) \
- (DIV_ROUND_UP ((Num_objects), HOST_BITS_PER_LONG) * sizeof(long))
+ (CEIL ((Num_objects), HOST_BITS_PER_LONG) * sizeof(long))
+
+/* 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. Hosts that need a different value
+ can override this by defining GGC_QUIRE_SIZE explicitly. */
+#ifndef GGC_QUIRE_SIZE
+# ifdef USING_MMAP
+# define GGC_QUIRE_SIZE 256
+# else
+# define GGC_QUIRE_SIZE 16
+# endif
+#endif
-/* Skip garbage collection if the current allocation is not at least
- this factor times the allocation at the end of the last collection.
- In other words, total allocation must expand by (this factor minus
- one) before collection is performed. */
-#define GGC_MIN_EXPAND_FOR_GC (1.3)
+/* Initial guess as to how many page table entries we might need. */
+#define INITIAL_PTE_COUNT 128
+\f
+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);
+#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_page (unsigned);
+static void free_page (struct page_entry *);
+static void release_pages (void);
+static void clear_marks (void);
+static void sweep_pages (void);
+static void ggc_recalculate_in_use_p (page_entry *);
+static void compute_inverse (unsigned);
+static inline void adjust_depth (void);
+static void move_ptes_to_front (int, int);
+
+void debug_print_page_list (int);
+static void push_depth (unsigned int);
+static void push_by_depth (page_entry *, unsigned long *);
+
+/* Push an entry onto G.depth. */
+
+inline static void
+push_depth (unsigned int i)
+{
+ if (G.depth_in_use >= G.depth_max)
+ {
+ G.depth_max *= 2;
+ G.depth = xrealloc (G.depth, G.depth_max * sizeof (unsigned int));
+ }
+ G.depth[G.depth_in_use++] = i;
+}
-/* Bound `allocated_last_gc' to 4MB, to prevent the memory expansion
- test from triggering too often when the heap is small. */
-#define GGC_MIN_LAST_ALLOCATED (4 * 1024 * 1024)
+/* Push an entry onto G.by_depth and G.save_in_use. */
-/* Allocate pages in chunks of this size, to throttle calls to mmap.
- The first page is used, the rest go onto the free list. */
-#define GGC_QUIRE_SIZE 16
+inline static void
+push_by_depth (page_entry *p, unsigned long *s)
+{
+ if (G.by_depth_in_use >= G.by_depth_max)
+ {
+ G.by_depth_max *= 2;
+ G.by_depth = xrealloc (G.by_depth,
+ G.by_depth_max * sizeof (page_entry *));
+ G.save_in_use = xrealloc (G.save_in_use,
+ G.by_depth_max * sizeof (unsigned long *));
+ }
+ G.by_depth[G.by_depth_in_use] = p;
+ G.save_in_use[G.by_depth_in_use++] = s;
+}
-\f
-static int ggc_allocated_p PARAMS ((const void *));
-static page_entry *lookup_page_table_entry PARAMS ((const void *));
-static void set_page_table_entry PARAMS ((void *, page_entry *));
-static char *alloc_anon PARAMS ((char *, size_t));
-static struct page_entry * alloc_page PARAMS ((unsigned));
-static void free_page PARAMS ((struct page_entry *));
-static void release_pages PARAMS ((void));
-static void clear_marks PARAMS ((void));
-static void sweep_pages PARAMS ((void));
-static void ggc_recalculate_in_use_p PARAMS ((page_entry *));
-
-#ifdef GGC_POISON
-static void poison_pages PARAMS ((void));
+#if (GCC_VERSION < 3001)
+#define prefetch(X) ((void) X)
+#else
+#define prefetch(X) __builtin_prefetch (X)
#endif
-void debug_print_page_list PARAMS ((int));
-\f
-/* Returns non-zero if P was allocated in GC'able memory. */
+#define save_in_use_p_i(__i) \
+ (G.save_in_use[__i])
+#define save_in_use_p(__p) \
+ (save_in_use_p_i (__p->index_by_depth))
+
+/* Returns nonzero if P was allocated in GC'able memory. */
static inline int
-ggc_allocated_p (p)
- const void *p;
+ggc_allocated_p (const void *p)
{
page_entry ***base;
size_t L1, L2;
base = &table->table[0];
#endif
- /* Extract the level 1 and 2 indicies. */
+ /* Extract the level 1 and 2 indices. */
L1 = LOOKUP_L1 (p);
L2 = LOOKUP_L2 (p);
return base[L1] && base[L1][L2];
}
-/* Traverse the page table and find the entry for a page.
+/* Traverse the page table and find the entry for a page.
Die (probably) if the object wasn't allocated via GC. */
static inline page_entry *
-lookup_page_table_entry(p)
- const void *p;
+lookup_page_table_entry (const void *p)
{
page_entry ***base;
size_t L1, L2;
base = &table->table[0];
#endif
- /* Extract the level 1 and 2 indicies. */
+ /* Extract the level 1 and 2 indices. */
L1 = LOOKUP_L1 (p);
L2 = LOOKUP_L2 (p);
/* Set the page table entry for a page. */
static void
-set_page_table_entry(p, entry)
- void *p;
- page_entry *entry;
+set_page_table_entry (void *p, page_entry *entry)
{
page_entry ***base;
size_t L1, L2;
goto found;
/* Not found -- allocate a new table. */
- table = (page_table) xcalloc (1, sizeof(*table));
+ table = xcalloc (1, sizeof(*table));
table->next = G.lookup;
table->high_bits = high_bits;
G.lookup = table;
base = &table->table[0];
#endif
- /* Extract the level 1 and 2 indicies. */
+ /* Extract the level 1 and 2 indices. */
L1 = LOOKUP_L1 (p);
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;
}
/* Prints the page-entry for object size ORDER, for debugging. */
void
-debug_print_page_list (order)
- int order;
+debug_print_page_list (int order)
{
page_entry *p;
- printf ("Head=%p, Tail=%p:\n", (PTR) G.pages[order],
- (PTR) G.page_tails[order]);
+ printf ("Head=%p, Tail=%p:\n", (void *) G.pages[order],
+ (void *) G.page_tails[order]);
p = G.pages[order];
while (p != NULL)
{
- printf ("%p(%1d|%3d) -> ", (PTR) p, p->context_depth,
+ printf ("%p(%1d|%3d) -> ", (void *) p, p->context_depth,
p->num_free_objects);
p = p->next;
}
fflush (stdout);
}
+#ifdef USING_MMAP
/* Allocate SIZE bytes of anonymous memory, preferably near PREF,
- (if non-null). */
+ (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 (pref, size)
- char *pref ATTRIBUTE_UNUSED;
- size_t size;
+alloc_anon (char *pref ATTRIBUTE_UNUSED, size_t size)
{
- char *page;
-
-#ifdef HAVE_MMAP_ANYWHERE
-#ifdef MAP_ANONYMOUS
- page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE,
- MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-#else
- page = (char *) mmap (pref, size, PROT_READ | PROT_WRITE,
- MAP_PRIVATE, G.dev_zero_fd, 0);
+#ifdef HAVE_MMAP_ANON
+ char *page = mmap (pref, size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+#endif
+#ifdef HAVE_MMAP_DEV_ZERO
+ char *page = mmap (pref, size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE, G.dev_zero_fd, 0);
#endif
+
if (page == (char *) MAP_FAILED)
{
- fputs ("Virtual memory exhausted!\n", stderr);
- exit(1);
+ perror ("virtual memory exhausted");
+ exit (FATAL_EXIT_CODE);
}
-#else
-#ifdef HAVE_VALLOC
- page = (char *) valloc (size);
- if (!page)
- {
- fputs ("Virtual memory exhausted!\n", stderr);
- exit(1);
- }
-#endif /* HAVE_VALLOC */
-#endif /* HAVE_MMAP_ANYWHERE */
/* Remember that we allocated this memory. */
G.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;
}
+#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)
+{
+ return (size_t) (page - allocation) >> G.lg_pagesize;
+}
+
+/* Set and clear the in_use bit for this page in the page group. */
+
+static inline void
+set_page_group_in_use (page_group *group, char *page)
+{
+ group->in_use |= 1 << page_group_index (group->allocation, page);
+}
+
+static inline void
+clear_page_group_in_use (page_group *group, char *page)
+{
+ group->in_use &= ~(1 << page_group_index (group->allocation, page));
+}
+#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. */
static inline struct page_entry *
-alloc_page (order)
- unsigned order;
+alloc_page (unsigned order)
{
struct page_entry *entry, *p, **pp;
char *page;
size_t bitmap_size;
size_t page_entry_size;
size_t entry_size;
+#ifdef USING_MALLOC_PAGE_GROUPS
+ page_group *group;
+#endif
num_objects = OBJECTS_PER_PAGE (order);
bitmap_size = BITMAP_SIZE (num_objects + 1);
page_entry_size = sizeof (page_entry) - sizeof (long) + bitmap_size;
- entry_size = num_objects * (1 << order);
+ entry_size = num_objects * OBJECT_SIZE (order);
+ if (entry_size < G.pagesize)
+ entry_size = G.pagesize;
entry = NULL;
page = NULL;
/* Check the list of free pages for one we can use. */
- for (pp = &G.free_pages, p = *pp; p ; pp = &p->next, p = *pp)
+ for (pp = &G.free_pages, p = *pp; p; pp = &p->next, p = *pp)
if (p->bytes == entry_size)
break;
if (p != NULL)
{
- /* Recycle the allocated memory from this page ... */
+ /* Recycle the allocated memory from this page ... */
*pp = p->next;
page = p->page;
+
+#ifdef USING_MALLOC_PAGE_GROUPS
+ group = p->group;
+#endif
+
/* ... and, if possible, the page entry itself. */
if (p->order == order)
{
else
free (p);
}
-#ifdef HAVE_MMAP_ANYWHERE
+#ifdef USING_MMAP
else if (entry_size == G.pagesize)
{
/* We want just one page. Allocate a bunch of them and put the
struct page_entry *e, *f = G.free_pages;
int i;
- page = alloc_anon (NULL, entry_size * GGC_QUIRE_SIZE);
+ page = alloc_anon (NULL, G.pagesize * GGC_QUIRE_SIZE);
+
/* 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 *) xcalloc (1, sizeof (struct page_entry));
- e->bytes = entry_size;
- e->page = page + i*entry_size;
+ e = xcalloc (1, page_entry_size);
+ e->order = order;
+ e->bytes = G.pagesize;
+ e->page = page + (i << G.lg_pagesize);
e->next = f;
f = e;
}
+
G.free_pages = f;
}
-#endif
else
page = alloc_anon (NULL, entry_size);
+#endif
+#ifdef USING_MALLOC_PAGE_GROUPS
+ else
+ {
+ /* 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. */
+
+ char *allocation, *a, *enda;
+ size_t alloc_size, head_slop, tail_slop;
+ int multiple_pages = (entry_size == G.pagesize);
+
+ if (multiple_pages)
+ alloc_size = GGC_QUIRE_SIZE * G.pagesize;
+ else
+ alloc_size = entry_size + G.pagesize - 1;
+ allocation = xmalloc (alloc_size);
+
+ 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;
+ }
+ gcc_assert (tail_slop >= sizeof (page_group));
+ group = (page_group *)enda;
+ tail_slop -= sizeof (page_group);
+ }
+
+ /* Remember that we allocated this memory. */
+ group->next = G.page_groups;
+ group->allocation = allocation;
+ group->alloc_size = alloc_size;
+ group->in_use = 0;
+ G.page_groups = group;
+ G.bytes_mapped += alloc_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 = xcalloc (1, page_entry_size);
+ e->order = order;
+ e->bytes = G.pagesize;
+ e->page = a;
+ e->group = group;
+ e->next = f;
+ f = e;
+ }
+ G.free_pages = f;
+ }
+ }
+#endif
if (entry == NULL)
- entry = (struct page_entry *) xcalloc (1, page_entry_size);
+ entry = xcalloc (1, page_entry_size);
entry->bytes = entry_size;
entry->page = page;
entry->num_free_objects = num_objects;
entry->next_bit_hint = 1;
+ G.context_depth_allocations |= (unsigned long)1 << G.context_depth;
+
+#ifdef USING_MALLOC_PAGE_GROUPS
+ entry->group = group;
+ set_page_group_in_use (group, page);
+#endif
+
/* Set the one-past-the-end in-use bit. This acts as a sentry as we
increment the hint. */
entry->in_use_p[num_objects / HOST_BITS_PER_LONG]
set_page_table_entry (page, entry);
if (GGC_DEBUG_LEVEL >= 2)
- fprintf (G.debug_file,
- "Allocating page at %p, object size=%d, data %p-%p\n",
- (PTR) entry, 1 << order, page, page + entry_size - 1);
+ fprintf (G.debug_file,
+ "Allocating page at %p, object size=%lu, data %p-%p\n",
+ (void *) entry, (unsigned long) OBJECT_SIZE (order), page,
+ page + entry_size - 1);
return entry;
}
-/* For a page that is no longer needed, put it on the free page list. */
+/* Adjust the size of G.depth so that no index greater than the one
+ used by the top of the G.by_depth is used. */
static inline void
-free_page (entry)
- page_entry *entry;
+adjust_depth (void)
+{
+ page_entry *top;
+
+ if (G.by_depth_in_use)
+ {
+ top = G.by_depth[G.by_depth_in_use-1];
+
+ /* Peel back indices in depth that index into by_depth, so that
+ as new elements are added to by_depth, we note the indices
+ of those elements, if they are for new context depths. */
+ while (G.depth_in_use > (size_t)top->context_depth+1)
+ --G.depth_in_use;
+ }
+}
+
+/* For a page that is no longer needed, put it on the free page list. */
+
+static void
+free_page (page_entry *entry)
{
if (GGC_DEBUG_LEVEL >= 2)
- fprintf (G.debug_file,
- "Deallocating page at %p, data %p-%p\n", (PTR) entry,
+ fprintf (G.debug_file,
+ "Deallocating page at %p, data %p-%p\n", (void *) entry,
entry->page, entry->page + entry->bytes - 1);
+ /* Mark the page as inaccessible. Discard the handle to avoid handle
+ leak. */
+ VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (entry->page, entry->bytes));
+
set_page_table_entry (entry->page, NULL);
+#ifdef USING_MALLOC_PAGE_GROUPS
+ clear_page_group_in_use (entry->group, entry->page);
+#endif
+
+ if (G.by_depth_in_use > 1)
+ {
+ page_entry *top = G.by_depth[G.by_depth_in_use-1];
+ int i = entry->index_by_depth;
+
+ /* We cannot free a page from a context deeper than the current
+ one. */
+ gcc_assert (entry->context_depth == top->context_depth);
+
+ /* Put top element into freed slot. */
+ G.by_depth[i] = top;
+ G.save_in_use[i] = G.save_in_use[G.by_depth_in_use-1];
+ top->index_by_depth = i;
+ }
+ --G.by_depth_in_use;
+
+ adjust_depth ();
+
entry->next = G.free_pages;
G.free_pages = entry;
}
/* Release the free page cache to the system. */
static void
-release_pages ()
+release_pages (void)
{
+#ifdef USING_MMAP
page_entry *p, *next;
-
-#ifdef HAVE_MMAP_ANYWHERE
char *start;
size_t len;
munmap (start, len);
G.bytes_mapped -= len;
}
-#else
-#ifdef HAVE_VALLOC
-
- for (p = G.free_pages; p; p = next)
- {
- next = p->next;
- free (p->page);
- G.bytes_mapped -= p->bytes;
- free (p);
- }
-#endif /* HAVE_VALLOC */
-#endif /* HAVE_MMAP_ANYWHERE */
G.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 = &G.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 = &G.page_groups;
+ while ((g = *gp) != NULL)
+ if (g->in_use == 0)
+ {
+ *gp = g->next;
+ G.bytes_mapped -= g->alloc_size;
+ free (g->allocation);
+ }
+ else
+ gp = &g->next;
+#endif
}
/* This table provides a fast way to determine ceil(log_2(size)) for
- allocation requests. The minimum allocation size is four bytes. */
-
-static unsigned char const size_lookup[257] =
-{
- 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4,
- 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
- 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
- 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
- 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
- 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ allocation requests. The minimum allocation size is eight bytes. */
+
+static unsigned char size_lookup[512] =
+{
+ 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4,
+ 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+ 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
- 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
- 8
+ 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9
};
-/* Allocate a chunk of memory of SIZE bytes. If ZERO is non-zero, the
- memory is zeroed; otherwise, its contents are undefined. */
+/* Typed allocation function. Does nothing special in this collector. */
+
+void *
+ggc_alloc_typed_stat (enum gt_types_enum type ATTRIBUTE_UNUSED, size_t size
+ MEM_STAT_DECL)
+{
+ return ggc_alloc_stat (size PASS_MEM_STAT);
+}
+
+/* Allocate a chunk of memory of SIZE bytes. Its contents are undefined. */
void *
-ggc_alloc (size)
- size_t size;
+ggc_alloc_stat (size_t size MEM_STAT_DECL)
{
- unsigned order, word, bit, object_offset;
+ size_t order, word, bit, object_offset, object_size;
struct page_entry *entry;
void *result;
- if (size <= 256)
- order = size_lookup[size];
+ if (size < 512)
+ {
+ order = size_lookup[size];
+ object_size = OBJECT_SIZE (order);
+ }
else
{
- order = 9;
- while (size > ((size_t) 1 << order))
+ order = 10;
+ while (size > (object_size = OBJECT_SIZE (order)))
order++;
}
{
struct page_entry *new_entry;
new_entry = alloc_page (order);
-
- /* If this is the only entry, it's also the tail. */
+
+ new_entry->index_by_depth = G.by_depth_in_use;
+ push_by_depth (new_entry, 0);
+
+ /* We can skip context depths, if we do, make sure we go all the
+ way to the new depth. */
+ while (new_entry->context_depth >= G.depth_in_use)
+ push_depth (G.by_depth_in_use-1);
+
+ /* If this is the only entry, it's also the tail. If it is not
+ the only entry, then we must update the PREV pointer of the
+ ENTRY (G.pages[order]) to point to our new page entry. */
if (entry == NULL)
G.page_tails[order] = new_entry;
-
- /* Put new pages at the head of the page list. */
+ else
+ entry->prev = new_entry;
+
+ /* Put new pages at the head of the page list. By definition the
+ entry at the head of the list always has a NULL pointer. */
new_entry->next = entry;
+ new_entry->prev = NULL;
entry = new_entry;
G.pages[order] = new_entry;
unsigned hint = entry->next_bit_hint;
word = hint / HOST_BITS_PER_LONG;
bit = hint % HOST_BITS_PER_LONG;
-
+
/* If the hint didn't work, scan the bitmap from the beginning. */
if ((entry->in_use_p[word] >> bit) & 1)
{
word = bit = 0;
while (~entry->in_use_p[word] == 0)
++word;
+
+#if GCC_VERSION >= 3004
+ bit = __builtin_ctzl (~entry->in_use_p[word]);
+#else
while ((entry->in_use_p[word] >> bit) & 1)
++bit;
+#endif
+
hint = word * HOST_BITS_PER_LONG + bit;
}
/* Next time, try the next bit. */
entry->next_bit_hint = hint + 1;
- object_offset = hint << order;
+ object_offset = hint * object_size;
}
/* Set the in-use bit. */
&& entry->next != NULL
&& entry->next->num_free_objects > 0)
{
+ /* We have a new head for the list. */
G.pages[order] = entry->next;
+
+ /* We are moving ENTRY to the end of the page table list.
+ The new page at the head of the list will have NULL in
+ its PREV field and ENTRY will have NULL in its NEXT field. */
+ entry->next->prev = NULL;
entry->next = NULL;
+
+ /* Append ENTRY to the tail of the list. */
+ entry->prev = G.page_tails[order];
G.page_tails[order]->next = entry;
G.page_tails[order] = entry;
}
/* Calculate the object's address. */
result = entry->page + object_offset;
+#ifdef GATHER_STATISTICS
+ ggc_record_overhead (OBJECT_SIZE (order), OBJECT_SIZE (order) - size,
+ result PASS_MEM_STAT);
+#endif
+
+#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, object_size));
-#ifdef GGC_POISON
/* `Poison' the entire allocated object, including any padding at
the end. */
- memset (result, 0xaf, 1 << order);
+ memset (result, 0xaf, object_size);
+
+ /* Make the bytes after the end of the object unaccessible. Discard the
+ handle to avoid handle leak. */
+ VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS ((char *) result + size,
+ object_size - 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));
+
/* Keep track of how many bytes are being allocated. This
information is used in deciding when to collect. */
- G.allocated += (size_t) 1 << order;
+ G.allocated += object_size;
+
+ /* For timevar statistics. */
+ timevar_ggc_mem_total += object_size;
+
+#ifdef GATHER_STATISTICS
+ {
+ size_t overhead = object_size - size;
+
+ G.stats.total_overhead += overhead;
+ G.stats.total_allocated += object_size;
+ G.stats.total_overhead_per_order[order] += overhead;
+ G.stats.total_allocated_per_order[order] += object_size;
+
+ if (size <= 32)
+ {
+ G.stats.total_overhead_under32 += overhead;
+ G.stats.total_allocated_under32 += object_size;
+ }
+ if (size <= 64)
+ {
+ G.stats.total_overhead_under64 += overhead;
+ G.stats.total_allocated_under64 += object_size;
+ }
+ if (size <= 128)
+ {
+ G.stats.total_overhead_under128 += overhead;
+ G.stats.total_allocated_under128 += object_size;
+ }
+ }
+#endif
if (GGC_DEBUG_LEVEL >= 3)
- fprintf (G.debug_file,
- "Allocating object, requested size=%d, actual=%d at %p on %p\n",
- (int) size, 1 << order, result, (PTR) entry);
+ fprintf (G.debug_file,
+ "Allocating object, requested size=%lu, actual=%lu at %p on %p\n",
+ (unsigned long) size, (unsigned long) object_size, result,
+ (void *) entry);
return result;
}
static objects, stack variables, or memory allocated with malloc. */
int
-ggc_set_mark (p)
- const void *p;
+ggc_set_mark (const void *p)
{
page_entry *entry;
unsigned bit, word;
/* 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);
-#ifdef ENABLE_CHECKING
- if (entry == NULL)
- abort ();
-#endif
+ gcc_assert (entry);
/* Calculate the index of the object on the page; this is its bit
position in the in_use_p bitmap. */
- bit = (((const char *) p) - entry->page) >> entry->order;
+ bit = OFFSET_TO_BIT (((const char *) p) - entry->page, entry->order);
word = bit / HOST_BITS_PER_LONG;
mask = (unsigned long) 1 << (bit % HOST_BITS_PER_LONG);
-
- /* If the bit was previously set, skip it. */
+
+ /* If the bit was previously set, skip it. */
if (entry->in_use_p[word] & mask)
return 1;
return 0;
}
-/* Mark P, but check first that it was allocated by the collector. */
+/* Return 1 if P has been marked, zero otherwise.
+ P must have been allocated by the GC allocator; it mustn't point to
+ static objects, stack variables, or memory allocated with malloc. */
-void
-ggc_mark_if_gcable (p)
- const void *p;
+int
+ggc_marked_p (const void *p)
{
- if (p && ggc_allocated_p (p))
- ggc_set_mark (p);
+ page_entry *entry;
+ unsigned bit, word;
+ unsigned long mask;
+
+ /* 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);
+ gcc_assert (entry);
+
+ /* Calculate the index of the object on the page; this is its bit
+ position in the in_use_p bitmap. */
+ bit = OFFSET_TO_BIT (((const char *) p) - entry->page, entry->order);
+ word = bit / HOST_BITS_PER_LONG;
+ mask = (unsigned long) 1 << (bit % HOST_BITS_PER_LONG);
+
+ return (entry->in_use_p[word] & mask) != 0;
}
/* Return the size of the gc-able object P. */
size_t
-ggc_get_size (p)
- const void *p;
+ggc_get_size (const void *p)
{
page_entry *pe = lookup_page_table_entry (p);
- return 1 << pe->order;
+ return OBJECT_SIZE (pe->order);
+}
+
+/* Release the memory for object P. */
+
+void
+ggc_free (void *p)
+{
+ page_entry *pe = lookup_page_table_entry (p);
+ size_t order = pe->order;
+ size_t size = OBJECT_SIZE (order);
+
+#ifdef GATHER_STATISTICS
+ ggc_free_overhead (p);
+#endif
+
+ if (GGC_DEBUG_LEVEL >= 3)
+ fprintf (G.debug_file,
+ "Freeing object, actual size=%lu, at %p on %p\n",
+ (unsigned long) size, p, (void *) pe);
+
+#ifdef ENABLE_GC_CHECKING
+ /* Poison the data, to indicate the data is garbage. */
+ VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (p, size));
+ memset (p, 0xa5, size);
+#endif
+ /* Let valgrind know the object is free. */
+ VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (p, size));
+
+#ifdef ENABLE_GC_ALWAYS_COLLECT
+ /* In the completely-anal-checking mode, we do *not* immediately free
+ the data, but instead verify that the data is *actually* not
+ reachable the next time we collect. */
+ {
+ struct free_object *fo = XNEW (struct free_object);
+ fo->object = p;
+ fo->next = G.free_object_list;
+ G.free_object_list = fo;
+ }
+#else
+ {
+ unsigned int bit_offset, word, bit;
+
+ G.allocated -= size;
+
+ /* Mark the object not-in-use. */
+ bit_offset = OFFSET_TO_BIT (((const char *) p) - pe->page, order);
+ word = bit_offset / HOST_BITS_PER_LONG;
+ bit = bit_offset % HOST_BITS_PER_LONG;
+ pe->in_use_p[word] &= ~(1UL << bit);
+
+ if (pe->num_free_objects++ == 0)
+ {
+ page_entry *p, *q;
+
+ /* If the page is completely full, then it's supposed to
+ be after all pages that aren't. Since we've freed one
+ object from a page that was full, we need to move the
+ page to the head of the list.
+
+ PE is the node we want to move. Q is the previous node
+ and P is the next node in the list. */
+ q = pe->prev;
+ if (q && q->num_free_objects == 0)
+ {
+ p = pe->next;
+
+ q->next = p;
+
+ /* If PE was at the end of the list, then Q becomes the
+ new end of the list. If PE was not the end of the
+ list, then we need to update the PREV field for P. */
+ if (!p)
+ G.page_tails[order] = q;
+ else
+ p->prev = q;
+
+ /* Move PE to the head of the list. */
+ pe->next = G.pages[order];
+ pe->prev = NULL;
+ G.pages[order]->prev = pe;
+ G.pages[order] = pe;
+ }
+
+ /* Reset the hint bit to point to the only free object. */
+ pe->next_bit_hint = bit_offset;
+ }
+ }
+#endif
}
\f
-/* Initialize the ggc-mmap allocator. */
+/* Subroutine of init_ggc which computes the pair of numbers used to
+ perform division by OBJECT_SIZE (order) and fills in inverse_table[].
+ This algorithm is taken from Granlund and Montgomery's paper
+ "Division by Invariant Integers using Multiplication"
+ (Proc. SIGPLAN PLDI, 1994), section 9 (Exact division by
+ constants). */
+
+static void
+compute_inverse (unsigned order)
+{
+ size_t size, inv;
+ unsigned int e;
+
+ size = OBJECT_SIZE (order);
+ e = 0;
+ while (size % 2 == 0)
+ {
+ e++;
+ size >>= 1;
+ }
+
+ inv = size;
+ while (inv * size != 1)
+ inv = inv * (2 - inv*size);
+
+ DIV_MULT (order) = inv;
+ DIV_SHIFT (order) = e;
+}
+
+/* Initialize the ggc-mmap allocator. */
void
-init_ggc ()
+init_ggc (void)
{
+ unsigned order;
+
G.pagesize = getpagesize();
G.lg_pagesize = exact_log2 (G.pagesize);
-#if defined (HAVE_MMAP_ANYWHERE) && !defined(MAP_ANONYMOUS)
+#ifdef HAVE_MMAP_DEV_ZERO
G.dev_zero_fd = open ("/dev/zero", O_RDONLY);
if (G.dev_zero_fd == -1)
- abort ();
+ internal_error ("open /dev/zero: %m");
#endif
#if 0
G.debug_file = stdout;
#endif
- G.allocated_last_gc = GGC_MIN_LAST_ALLOCATED;
-
-#ifdef HAVE_MMAP_ANYWHERE
+#ifdef USING_MMAP
/* StunOS has an amazing off-by-one error for the first mmap allocation
after fiddling with RLIMIT_STACK. The result, as hard as it is to
believe, is an unaligned page allocation, which would cause us to
hork badly if we tried to use it. */
{
char *p = alloc_anon (NULL, G.pagesize);
+ struct 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);
- if ((size_t)p & (G.pagesize - 1))
- abort ();
+ gcc_assert (!((size_t)p & (G.pagesize - 1)));
}
- munmap (p, G.pagesize);
+
+ /* We have a good page, might as well hold onto it... */
+ e = XCNEW (struct page_entry);
+ e->bytes = G.pagesize;
+ e->page = p;
+ e->next = G.free_pages;
+ G.free_pages = e;
}
#endif
- empty_string = ggc_alloc_string ("", 0);
- ggc_add_string_root (&empty_string, 1);
+ /* Initialize the object size table. */
+ for (order = 0; order < HOST_BITS_PER_PTR; ++order)
+ object_size_table[order] = (size_t) 1 << order;
+ for (order = HOST_BITS_PER_PTR; order < NUM_ORDERS; ++order)
+ {
+ size_t s = extra_order_size_table[order - HOST_BITS_PER_PTR];
+ object_size_table[order] = s;
+ }
+
+ /* Initialize the objects-per-page and inverse tables. */
+ for (order = 0; order < NUM_ORDERS; ++order)
+ {
+ objects_per_page_table[order] = G.pagesize / OBJECT_SIZE (order);
+ if (objects_per_page_table[order] == 0)
+ objects_per_page_table[order] = 1;
+ compute_inverse (order);
+ }
+
+ /* Reset the size_lookup array to put appropriately sized objects in
+ the special orders. All objects bigger than the previous power
+ of two, but no greater than the special size, should go in the
+ new order.
+ Enforce alignment during lookup. The resulting bin size must
+ have the same or bigger alignment than the apparent alignment
+ requirement from the size request (but not bigger alignment
+ than MAX_ALIGNMENT). Consider an extra bin of size 76 (in
+ addition to the 64 and 128 byte sized bins). A request of
+ allocation size of 72 bytes must be served from the 128 bytes
+ bin, because 72 bytes looks like a request for 8 byte aligned
+ memory, while the 76 byte bin can only serve chunks with a
+ guaranteed alignment of 4 bytes. */
+ for (order = HOST_BITS_PER_PTR; order < NUM_ORDERS; ++order)
+ {
+ int i, mask;
+
+ /* Build an alignment mask that can be used for testing
+ size % 2*align. If (size | MAX_ALIGNMENT) & mask is non-zero
+ then the requested size apparent alignment requirement
+ (which is at most MAX_ALIGNMENT) is less or equal than what
+ the OBJECT_SIZE bin can guarantee. */
+ mask = ~(((unsigned)-1) << ffs (OBJECT_SIZE (order)));
+ mask &= 2 * MAX_ALIGNMENT - 1;
+
+ /* All objects smaller than the OBJECT_SIZE for this ORDER could go
+ into ORDER. Determine the cases for which that is profitable
+ and fulfilling the alignment requirements. Stop searching
+ once a smaller bin with same or better alignment guarantee is
+ found. */
+ for (i = OBJECT_SIZE (order); ; --i)
+ {
+ unsigned int old_sz = OBJECT_SIZE (size_lookup [i]);
+ if (!(old_sz & (mask >> 1))
+ && old_sz < OBJECT_SIZE (order))
+ break;
+
+ /* If object of size I are presently using a larger bin, we would
+ like to move them to ORDER. However, we can only do that if we
+ can be sure they will be properly aligned. They will be properly
+ aligned if either the ORDER bin is maximally aligned, or if
+ objects of size I cannot be more strictly aligned than the
+ alignment of this order. */
+ if ((i | MAX_ALIGNMENT) & mask
+ && old_sz > OBJECT_SIZE (order))
+ size_lookup[i] = order;
+ }
+ }
+
+ /* Verify we got everything right with respect to alignment requests. */
+ for (order = 1; order < 512; ++order)
+ gcc_assert (ffs (OBJECT_SIZE (size_lookup [order]))
+ >= ffs (order | MAX_ALIGNMENT));
+
+ G.depth_in_use = 0;
+ G.depth_max = 10;
+ G.depth = XNEWVEC (unsigned int, G.depth_max);
+
+ G.by_depth_in_use = 0;
+ G.by_depth_max = INITIAL_PTE_COUNT;
+ G.by_depth = XNEWVEC (page_entry *, G.by_depth_max);
+ G.save_in_use = XNEWVEC (unsigned long *, G.by_depth_max);
}
-/* Increment the `GC context'. Objects allocated in an outer context
- are never freed, eliminating the need to register their roots. */
+/* Start a new GGC zone. */
-void
-ggc_push_context ()
+struct alloc_zone *
+new_ggc_zone (const char *name ATTRIBUTE_UNUSED)
{
- ++G.context_depth;
+ return NULL;
+}
- /* Die on wrap. */
- if (G.context_depth == 0)
- abort ();
+/* Destroy a GGC zone. */
+void
+destroy_ggc_zone (struct alloc_zone *zone ATTRIBUTE_UNUSED)
+{
}
/* Merge the SAVE_IN_USE_P and IN_USE_P arrays in P so that IN_USE_P
reflects reality. Recalculate NUM_FREE_OBJECTS as well. */
static void
-ggc_recalculate_in_use_p (p)
- page_entry *p;
+ggc_recalculate_in_use_p (page_entry *p)
{
unsigned int i;
size_t num_objects;
- /* Because the past-the-end bit in in_use_p is always set, we
+ /* Because the past-the-end bit in in_use_p is always set, we
pretend there is one additional object. */
- num_objects = OBJECTS_PER_PAGE (p->order) + 1;
+ num_objects = OBJECTS_IN_PAGE (p) + 1;
/* Reset the free object count. */
p->num_free_objects = num_objects;
/* Combine the IN_USE_P and SAVE_IN_USE_P arrays. */
- for (i = 0;
- i < DIV_ROUND_UP (BITMAP_SIZE (num_objects),
- sizeof (*p->in_use_p));
+ for (i = 0;
+ i < CEIL (BITMAP_SIZE (num_objects),
+ sizeof (*p->in_use_p));
++i)
{
unsigned long j;
/* Something is in use if it is marked, or if it was in use in a
context further down the context stack. */
- p->in_use_p[i] |= p->save_in_use_p[i];
+ p->in_use_p[i] |= save_in_use_p (p)[i];
/* Decrement the free object count for every object allocated. */
for (j = p->in_use_p[i]; j; j >>= 1)
p->num_free_objects -= (j & 1);
}
- if (p->num_free_objects >= num_objects)
- abort ();
-}
-
-/* Decrement the `GC context'. All objects allocated since the
- previous ggc_push_context are migrated to the outer context. */
-
-void
-ggc_pop_context ()
-{
- unsigned order, depth;
-
- depth = --G.context_depth;
-
- /* 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 (order = 2; order < HOST_BITS_PER_PTR; order++)
- {
- page_entry *p;
-
- for (p = G.pages[order]; p != NULL; p = p->next)
- {
- if (p->context_depth > depth)
- p->context_depth = depth;
-
- /* If this page is now in the topmost context, and we'd
- saved its allocation state, restore it. */
- else if (p->context_depth == depth && p->save_in_use_p)
- {
- ggc_recalculate_in_use_p (p);
- free (p->save_in_use_p);
- p->save_in_use_p = 0;
- }
- }
- }
+ gcc_assert (p->num_free_objects < num_objects);
}
\f
/* Unmark all objects. */
-static inline void
-clear_marks ()
+static void
+clear_marks (void)
{
unsigned order;
- for (order = 2; order < HOST_BITS_PER_PTR; order++)
+ for (order = 2; order < NUM_ORDERS; order++)
{
- size_t num_objects = OBJECTS_PER_PAGE (order);
- size_t bitmap_size = BITMAP_SIZE (num_objects + 1);
page_entry *p;
for (p = G.pages[order]; p != NULL; p = p->next)
{
-#ifdef ENABLE_CHECKING
+ size_t num_objects = OBJECTS_IN_PAGE (p);
+ size_t bitmap_size = BITMAP_SIZE (num_objects + 1);
+
/* The data should be page-aligned. */
- if ((size_t) p->page & (G.pagesize - 1))
- abort ();
-#endif
+ gcc_assert (!((size_t) p->page & (G.pagesize - 1)));
/* Pages that aren't in the topmost context are not collected;
nevertheless, we need their in-use bit vectors to store GC
marks. So, back them up first. */
if (p->context_depth < G.context_depth)
{
- if (! p->save_in_use_p)
- p->save_in_use_p = xmalloc (bitmap_size);
- memcpy (p->save_in_use_p, p->in_use_p, bitmap_size);
+ if (! save_in_use_p (p))
+ save_in_use_p (p) = xmalloc (bitmap_size);
+ memcpy (save_in_use_p (p), p->in_use_p, bitmap_size);
}
/* Reset reset the number of free objects and clear the
memset (p->in_use_p, 0, bitmap_size);
/* Make sure the one-past-the-end bit is always set. */
- p->in_use_p[num_objects / HOST_BITS_PER_LONG]
+ p->in_use_p[num_objects / HOST_BITS_PER_LONG]
= ((unsigned long) 1 << (num_objects % HOST_BITS_PER_LONG));
}
}
/* Free all empty pages. Partially empty pages need no attention
because the `mark' bit doubles as an `unused' bit. */
-static inline void
-sweep_pages ()
+static void
+sweep_pages (void)
{
unsigned order;
- for (order = 2; order < HOST_BITS_PER_PTR; order++)
+ for (order = 2; order < NUM_ORDERS; order++)
{
/* The last page-entry to consider, regardless of entries
placed at the end of the list. */
page_entry * const last = G.page_tails[order];
- size_t num_objects = OBJECTS_PER_PAGE (order);
+ size_t num_objects;
size_t live_objects;
page_entry *p, *previous;
int done;
-
+
p = G.pages[order];
if (p == NULL)
continue;
/* Loop until all entries have been examined. */
done = (p == last);
+ num_objects = OBJECTS_IN_PAGE (p);
+
/* Add all live objects on this page to the count of
allocated memory. */
live_objects = num_objects - p->num_free_objects;
- G.allocated += ((size_t) 1 << order) * live_objects;
+ G.allocated += OBJECT_SIZE (order) * live_objects;
/* Only objects on pages in the topmost context should get
collected. */
/* Remove the page if it's empty. */
else if (live_objects == 0)
{
+ /* If P was the first page in the list, then NEXT
+ becomes the new first page in the list, otherwise
+ splice P out of the forward pointers. */
if (! previous)
G.pages[order] = next;
else
previous->next = next;
+
+ /* Splice P out of the back pointers too. */
+ if (next)
+ next->prev = previous;
/* Are we removing the last element? */
if (p == G.page_tails[order])
{
/* Move p to the end of the list. */
p->next = NULL;
+ p->prev = G.page_tails[order];
G.page_tails[order]->next = p;
/* Update the tail pointer... */
G.pages[order] = next;
else
previous->next = next;
+
+ /* And update the backpointer in NEXT if necessary. */
+ if (next)
+ next->prev = previous;
+
p = previous;
}
}
else if (p != G.pages[order])
{
previous->next = p->next;
+
+ /* Update the backchain in the next node if it exists. */
+ if (p->next)
+ p->next->prev = previous;
+
+ /* Move P to the head of the list. */
p->next = G.pages[order];
+ p->prev = NULL;
+ G.pages[order]->prev = p;
+
+ /* Update the head pointer. */
G.pages[order] = p;
+
/* Are we moving the last element? */
if (G.page_tails[order] == p)
G.page_tails[order] = previous;
previous = p;
p = next;
- }
+ }
while (! done);
/* Now, restore the in_use_p vectors for any pages from contexts
}
}
-#ifdef GGC_POISON
+#ifdef ENABLE_GC_CHECKING
/* Clobber all free objects. */
-static inline void
-poison_pages ()
+static void
+poison_pages (void)
{
unsigned order;
- for (order = 2; order < HOST_BITS_PER_PTR; order++)
+ for (order = 2; order < NUM_ORDERS; order++)
{
- size_t num_objects = OBJECTS_PER_PAGE (order);
- size_t size = (size_t) 1 << order;
+ size_t size = OBJECT_SIZE (order);
page_entry *p;
for (p = G.pages[order]; p != NULL; p = p->next)
{
+ size_t num_objects;
size_t i;
if (p->context_depth != G.context_depth)
contexts. */
continue;
+ num_objects = OBJECTS_IN_PAGE (p);
for (i = 0; i < num_objects; i++)
{
size_t word, bit;
word = i / HOST_BITS_PER_LONG;
bit = i % HOST_BITS_PER_LONG;
if (((p->in_use_p[word] >> bit) & 1) == 0)
- memset (p->page + i * size, 0xa5, size);
+ {
+ char *object = p->page + i * size;
+
+ /* Keep poison-by-write when we expect to use Valgrind,
+ so the exact same memory semantics is kept, in case
+ there are memory errors. We override this request
+ below. */
+ VALGRIND_DISCARD (VALGRIND_MAKE_WRITABLE (object, size));
+ memset (object, 0xa5, size);
+
+ /* Drop the handle to avoid handle leak. */
+ VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (object, size));
+ }
}
}
}
}
+#else
+#define poison_pages()
+#endif
+
+#ifdef ENABLE_GC_ALWAYS_COLLECT
+/* Validate that the reportedly free objects actually are. */
+
+static void
+validate_free_objects (void)
+{
+ struct free_object *f, *next, *still_free = NULL;
+
+ for (f = G.free_object_list; f ; f = next)
+ {
+ page_entry *pe = lookup_page_table_entry (f->object);
+ size_t bit, word;
+
+ bit = OFFSET_TO_BIT ((char *)f->object - pe->page, pe->order);
+ word = bit / HOST_BITS_PER_LONG;
+ bit = bit % HOST_BITS_PER_LONG;
+ next = f->next;
+
+ /* Make certain it isn't visible from any root. Notice that we
+ do this check before sweep_pages merges save_in_use_p. */
+ gcc_assert (!(pe->in_use_p[word] & (1UL << bit)));
+
+ /* If the object comes from an outer context, then retain the
+ free_object entry, so that we can verify that the address
+ isn't live on the stack in some outer context. */
+ if (pe->context_depth != G.context_depth)
+ {
+ f->next = still_free;
+ still_free = f;
+ }
+ else
+ free (f);
+ }
+
+ G.free_object_list = still_free;
+}
+#else
+#define validate_free_objects()
#endif
/* Top level mark-and-sweep routine. */
void
-ggc_collect ()
+ggc_collect (void)
{
/* Avoid frequent unnecessary work by skipping collection if the
total allocations haven't expanded much since the last
collection. */
-#ifndef GGC_ALWAYS_COLLECT
- if (G.allocated < GGC_MIN_EXPAND_FOR_GC * G.allocated_last_gc)
+ float allocated_last_gc =
+ MAX (G.allocated_last_gc, (size_t)PARAM_VALUE (GGC_MIN_HEAPSIZE) * 1024);
+
+ float min_expand = allocated_last_gc * PARAM_VALUE (GGC_MIN_EXPAND) / 100;
+
+ if (G.allocated < allocated_last_gc + min_expand && !ggc_force_collect)
return;
-#endif
timevar_push (TV_GC);
if (!quiet_flag)
fprintf (stderr, " {GC %luk -> ", (unsigned long) G.allocated / 1024);
+ if (GGC_DEBUG_LEVEL >= 2)
+ fprintf (G.debug_file, "BEGIN COLLECTING\n");
/* Zero the total allocated bytes. This will be recalculated in the
sweep phase. */
G.allocated = 0;
- /* Release the pages we freed the last time we collected, but didn't
+ /* Release the pages we freed the last time we collected, but didn't
reuse in the interim. */
release_pages ();
+ /* Indicate that we've seen collections at this context depth. */
+ G.context_depth_collections = ((unsigned long)1 << (G.context_depth + 1)) - 1;
+
clear_marks ();
ggc_mark_roots ();
-
-#ifdef GGC_POISON
- poison_pages ();
+#ifdef GATHER_STATISTICS
+ ggc_prune_overhead_list ();
#endif
-
+ poison_pages ();
+ validate_free_objects ();
sweep_pages ();
G.allocated_last_gc = G.allocated;
- if (G.allocated_last_gc < GGC_MIN_LAST_ALLOCATED)
- G.allocated_last_gc = GGC_MIN_LAST_ALLOCATED;
timevar_pop (TV_GC);
if (!quiet_flag)
fprintf (stderr, "%luk}", (unsigned long) G.allocated / 1024);
+ if (GGC_DEBUG_LEVEL >= 2)
+ fprintf (G.debug_file, "END COLLECTING\n");
}
/* Print allocation statistics. */
+#define SCALE(x) ((unsigned long) ((x) < 1024*10 \
+ ? (x) \
+ : ((x) < 1024*1024*10 \
+ ? (x) / 1024 \
+ : (x) / (1024*1024))))
+#define STAT_LABEL(x) ((x) < 1024*10 ? ' ' : ((x) < 1024*1024*10 ? 'k' : 'M'))
void
-ggc_page_print_statistics ()
+ggc_print_statistics (void)
{
struct ggc_statistics stats;
unsigned int i;
+ size_t total_overhead = 0;
/* Clear the statistics. */
memset (&stats, 0, sizeof (stats));
-
+
/* Make sure collection will really occur. */
G.allocated_last_gc = 0;
/* Collect and print the statistics common across collectors. */
- ggc_print_statistics (stderr, &stats);
+ ggc_print_common_statistics (stderr, &stats);
/* Release free pages so that we will not count the bytes allocated
there as part of the total allocated memory. */
release_pages ();
- /* Collect some information about the various sizes of
+ /* Collect some information about the various sizes of
allocation. */
- fprintf (stderr, "\n%-4s%-16s%-16s\n", "Log", "Allocated", "Used");
- for (i = 0; i < HOST_BITS_PER_PTR; ++i)
+ fprintf (stderr,
+ "Memory still allocated at the end of the compilation process\n");
+ fprintf (stderr, "%-5s %10s %10s %10s\n",
+ "Size", "Allocated", "Used", "Overhead");
+ for (i = 0; i < NUM_ORDERS; ++i)
{
page_entry *p;
size_t allocated;
size_t in_use;
+ size_t overhead;
/* Skip empty entries. */
if (!G.pages[i])
continue;
- allocated = in_use = 0;
+ overhead = allocated = in_use = 0;
/* Figure out the total number of bytes allocated for objects of
- this size, and how many of them are actually in use. */
+ this size, and how many of them are actually in use. Also figure
+ out how much memory the page table is using. */
for (p = G.pages[i]; p; p = p->next)
{
allocated += p->bytes;
- in_use +=
- (OBJECTS_PER_PAGE (i) - p->num_free_objects) * (1 << i);
+ in_use +=
+ (OBJECTS_IN_PAGE (p) - p->num_free_objects) * OBJECT_SIZE (i);
+
+ overhead += (sizeof (page_entry) - sizeof (long)
+ + BITMAP_SIZE (OBJECTS_IN_PAGE (p) + 1));
}
- fprintf (stderr, "%-3d %-15lu %-15lu\n", i,
- (unsigned long) allocated, (unsigned long) in_use);
+ fprintf (stderr, "%-5lu %10lu%c %10lu%c %10lu%c\n",
+ (unsigned long) OBJECT_SIZE (i),
+ SCALE (allocated), STAT_LABEL (allocated),
+ SCALE (in_use), STAT_LABEL (in_use),
+ SCALE (overhead), STAT_LABEL (overhead));
+ total_overhead += overhead;
+ }
+ fprintf (stderr, "%-5s %10lu%c %10lu%c %10lu%c\n", "Total",
+ SCALE (G.bytes_mapped), STAT_LABEL (G.bytes_mapped),
+ SCALE (G.allocated), STAT_LABEL(G.allocated),
+ SCALE (total_overhead), STAT_LABEL (total_overhead));
+
+#ifdef GATHER_STATISTICS
+ {
+ fprintf (stderr, "\nTotal allocations and overheads during the compilation process\n");
+
+ fprintf (stderr, "Total Overhead: %10lld\n",
+ G.stats.total_overhead);
+ fprintf (stderr, "Total Allocated: %10lld\n",
+ G.stats.total_allocated);
+
+ fprintf (stderr, "Total Overhead under 32B: %10lld\n",
+ G.stats.total_overhead_under32);
+ fprintf (stderr, "Total Allocated under 32B: %10lld\n",
+ G.stats.total_allocated_under32);
+ fprintf (stderr, "Total Overhead under 64B: %10lld\n",
+ G.stats.total_overhead_under64);
+ fprintf (stderr, "Total Allocated under 64B: %10lld\n",
+ G.stats.total_allocated_under64);
+ fprintf (stderr, "Total Overhead under 128B: %10lld\n",
+ G.stats.total_overhead_under128);
+ fprintf (stderr, "Total Allocated under 128B: %10lld\n",
+ G.stats.total_allocated_under128);
+
+ for (i = 0; i < NUM_ORDERS; i++)
+ if (G.stats.total_allocated_per_order[i])
+ {
+ fprintf (stderr, "Total Overhead page size %7d: %10lld\n",
+ OBJECT_SIZE (i), G.stats.total_overhead_per_order[i]);
+ fprintf (stderr, "Total Allocated page size %7d: %10lld\n",
+ OBJECT_SIZE (i), G.stats.total_allocated_per_order[i]);
+ }
+ }
+#endif
+}
+\f
+struct ggc_pch_data
+{
+ struct ggc_pch_ondisk
+ {
+ unsigned totals[NUM_ORDERS];
+ } d;
+ size_t base[NUM_ORDERS];
+ size_t written[NUM_ORDERS];
+};
+
+struct ggc_pch_data *
+init_ggc_pch (void)
+{
+ return XCNEW (struct ggc_pch_data);
+}
+
+void
+ggc_pch_count_object (struct ggc_pch_data *d, void *x ATTRIBUTE_UNUSED,
+ size_t size, bool is_string ATTRIBUTE_UNUSED,
+ enum gt_types_enum type ATTRIBUTE_UNUSED)
+{
+ unsigned order;
+
+ if (size < 512)
+ order = size_lookup[size];
+ else
+ {
+ order = 10;
+ while (size > OBJECT_SIZE (order))
+ order++;
+ }
+
+ d->d.totals[order]++;
+}
+
+size_t
+ggc_pch_total_size (struct ggc_pch_data *d)
+{
+ size_t a = 0;
+ unsigned i;
+
+ for (i = 0; i < NUM_ORDERS; i++)
+ a += ROUND_UP (d->d.totals[i] * OBJECT_SIZE (i), G.pagesize);
+ return a;
+}
+
+void
+ggc_pch_this_base (struct ggc_pch_data *d, void *base)
+{
+ size_t a = (size_t) base;
+ unsigned i;
+
+ for (i = 0; i < NUM_ORDERS; i++)
+ {
+ d->base[i] = a;
+ a += ROUND_UP (d->d.totals[i] * OBJECT_SIZE (i), G.pagesize);
+ }
+}
+
+
+char *
+ggc_pch_alloc_object (struct ggc_pch_data *d, void *x ATTRIBUTE_UNUSED,
+ size_t size, bool is_string ATTRIBUTE_UNUSED,
+ enum gt_types_enum type ATTRIBUTE_UNUSED)
+{
+ unsigned order;
+ char *result;
+
+ if (size < 512)
+ order = size_lookup[size];
+ else
+ {
+ order = 10;
+ while (size > OBJECT_SIZE (order))
+ order++;
+ }
+
+ result = (char *) d->base[order];
+ d->base[order] += OBJECT_SIZE (order);
+ return result;
+}
+
+void
+ggc_pch_prepare_write (struct ggc_pch_data *d ATTRIBUTE_UNUSED,
+ FILE *f ATTRIBUTE_UNUSED)
+{
+ /* Nothing to do. */
+}
+
+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 ATTRIBUTE_UNUSED)
+{
+ unsigned order;
+ static const char emptyBytes[256];
+
+ if (size < 512)
+ order = size_lookup[size];
+ else
+ {
+ order = 10;
+ while (size > OBJECT_SIZE (order))
+ order++;
+ }
+
+ if (fwrite (x, size, 1, f) != 1)
+ fatal_error ("can't write PCH file: %m");
+
+ /* If SIZE is not the same as OBJECT_SIZE(order), then we need to pad the
+ object out to OBJECT_SIZE(order). This happens for strings. */
+
+ if (size != OBJECT_SIZE (order))
+ {
+ unsigned padding = OBJECT_SIZE(order) - size;
+
+ /* To speed small writes, we use a nulled-out array that's larger
+ than most padding requests as the source for our null bytes. This
+ permits us to do the padding with fwrite() rather than fseek(), and
+ limits the chance the OS may try to flush any outstanding writes. */
+ if (padding <= sizeof(emptyBytes))
+ {
+ if (fwrite (emptyBytes, 1, padding, f) != padding)
+ fatal_error ("can't write PCH file");
+ }
+ else
+ {
+ /* Larger than our buffer? Just default to fseek. */
+ if (fseek (f, padding, SEEK_CUR) != 0)
+ fatal_error ("can't write PCH file");
+ }
+ }
+
+ d->written[order]++;
+ if (d->written[order] == d->d.totals[order]
+ && fseek (f, ROUND_UP_VALUE (d->d.totals[order] * OBJECT_SIZE (order),
+ G.pagesize),
+ SEEK_CUR) != 0)
+ fatal_error ("can't write PCH file: %m");
+}
+
+void
+ggc_pch_finish (struct ggc_pch_data *d, FILE *f)
+{
+ if (fwrite (&d->d, sizeof (d->d), 1, f) != 1)
+ fatal_error ("can't write PCH file: %m");
+ free (d);
+}
+
+/* Move the PCH PTE entries just added to the end of by_depth, to the
+ front. */
+
+static void
+move_ptes_to_front (int count_old_page_tables, int count_new_page_tables)
+{
+ unsigned i;
+
+ /* First, we swap the new entries to the front of the varrays. */
+ page_entry **new_by_depth;
+ unsigned long **new_save_in_use;
+
+ new_by_depth = XNEWVEC (page_entry *, G.by_depth_max);
+ new_save_in_use = XNEWVEC (unsigned long *, G.by_depth_max);
+
+ memcpy (&new_by_depth[0],
+ &G.by_depth[count_old_page_tables],
+ count_new_page_tables * sizeof (void *));
+ memcpy (&new_by_depth[count_new_page_tables],
+ &G.by_depth[0],
+ count_old_page_tables * sizeof (void *));
+ memcpy (&new_save_in_use[0],
+ &G.save_in_use[count_old_page_tables],
+ count_new_page_tables * sizeof (void *));
+ memcpy (&new_save_in_use[count_new_page_tables],
+ &G.save_in_use[0],
+ count_old_page_tables * sizeof (void *));
+
+ free (G.by_depth);
+ free (G.save_in_use);
+
+ G.by_depth = new_by_depth;
+ G.save_in_use = new_save_in_use;
+
+ /* Now update all the index_by_depth fields. */
+ for (i = G.by_depth_in_use; i > 0; --i)
+ {
+ page_entry *p = G.by_depth[i-1];
+ p->index_by_depth = i-1;
}
- /* Print out some global information. */
- fprintf (stderr, "\nTotal bytes marked: %lu\n",
- (unsigned long) G.allocated);
- fprintf (stderr, "Total bytes mapped: %lu\n",
- (unsigned long) G.bytes_mapped);
+ /* And last, we update the depth pointers in G.depth. The first
+ entry is already 0, and context 0 entries always start at index
+ 0, so there is nothing to update in the first slot. We need a
+ second slot, only if we have old ptes, and if we do, they start
+ at index count_new_page_tables. */
+ if (count_old_page_tables)
+ push_depth (count_new_page_tables);
+}
+
+void
+ggc_pch_read (FILE *f, void *addr)
+{
+ struct ggc_pch_ondisk d;
+ unsigned i;
+ char *offs = addr;
+ unsigned long count_old_page_tables;
+ unsigned long count_new_page_tables;
+
+ count_old_page_tables = G.by_depth_in_use;
+
+ /* We've just read in a PCH file. So, every object that used to be
+ allocated is now free. */
+ clear_marks ();
+#ifdef ENABLE_GC_CHECKING
+ poison_pages ();
+#endif
+
+ /* No object read from a PCH file should ever be freed. So, set the
+ context depth to 1, and set the depth of all the currently-allocated
+ pages to be 1 too. PCH pages will have depth 0. */
+ gcc_assert (!G.context_depth);
+ G.context_depth = 1;
+ for (i = 0; i < NUM_ORDERS; i++)
+ {
+ page_entry *p;
+ for (p = G.pages[i]; p != NULL; p = p->next)
+ p->context_depth = G.context_depth;
+ }
+
+ /* Allocate the appropriate page-table entries for the pages read from
+ the PCH file. */
+ if (fread (&d, sizeof (d), 1, f) != 1)
+ fatal_error ("can't read PCH file: %m");
+
+ for (i = 0; i < NUM_ORDERS; i++)
+ {
+ struct page_entry *entry;
+ char *pte;
+ size_t bytes;
+ size_t num_objs;
+ size_t j;
+
+ if (d.totals[i] == 0)
+ continue;
+
+ bytes = ROUND_UP (d.totals[i] * OBJECT_SIZE (i), G.pagesize);
+ num_objs = bytes / OBJECT_SIZE (i);
+ entry = xcalloc (1, (sizeof (struct page_entry)
+ - sizeof (long)
+ + BITMAP_SIZE (num_objs + 1)));
+ entry->bytes = bytes;
+ entry->page = offs;
+ entry->context_depth = 0;
+ offs += bytes;
+ entry->num_free_objects = 0;
+ entry->order = i;
+
+ for (j = 0;
+ j + HOST_BITS_PER_LONG <= num_objs + 1;
+ j += HOST_BITS_PER_LONG)
+ entry->in_use_p[j / HOST_BITS_PER_LONG] = -1;
+ for (; j < num_objs + 1; j++)
+ entry->in_use_p[j / HOST_BITS_PER_LONG]
+ |= 1L << (j % HOST_BITS_PER_LONG);
+
+ for (pte = entry->page;
+ pte < entry->page + entry->bytes;
+ pte += G.pagesize)
+ set_page_table_entry (pte, entry);
+
+ if (G.page_tails[i] != NULL)
+ G.page_tails[i]->next = entry;
+ else
+ G.pages[i] = entry;
+ G.page_tails[i] = entry;
+
+ /* We start off by just adding all the new information to the
+ end of the varrays, later, we will move the new information
+ to the front of the varrays, as the PCH page tables are at
+ context 0. */
+ push_by_depth (entry, 0);
+ }
+
+ /* Now, we update the various data structures that speed page table
+ handling. */
+ count_new_page_tables = G.by_depth_in_use - count_old_page_tables;
+
+ move_ptes_to_front (count_old_page_tables, count_new_page_tables);
+
+ /* Update the statistics. */
+ G.allocated = G.allocated_last_gc = offs - (char *)addr;
}
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