OSDN Git Service

Mark ChangeLog
[pf3gnuchains/gcc-fork.git] / boehm-gc / alloc.c
index 7b92388..9b4869f 100644 (file)
  */
 
 
-# include "gc_priv.h"
+# include "private/gc_priv.h"
 
 # include <stdio.h>
-# ifndef MACOS
+# if !defined(MACOS) && !defined(MSWINCE)
 #   include <signal.h>
 #   include <sys/types.h>
 # endif
@@ -60,9 +60,11 @@ word GC_non_gc_bytes = 0;  /* Number of bytes not intended to be collected */
 word GC_gc_no = 0;
 
 #ifndef SMALL_CONFIG
-  int GC_incremental = 0;    /* By default, stop the world.    */
+  int GC_incremental = 0;  /* By default, stop the world.      */
 #endif
 
+int GC_parallel = FALSE;   /* By default, parallel GC is off.  */
+
 int GC_full_freq = 19;    /* Every 20th collection is a full   */
                           /* collection, whether we need it    */
                           /* or not.                           */
@@ -70,18 +72,36 @@ int GC_full_freq = 19;         /* Every 20th collection is a full   */
 GC_bool GC_need_full_gc = FALSE;
                           /* Need full GC do to heap growth.   */
 
+#ifdef THREADS
+  GC_bool GC_world_stopped = FALSE;
+# define IF_THREADS(x) x
+#else
+# define IF_THREADS(x)
+#endif
+
 word GC_used_heap_size_after_full = 0;
 
 char * GC_copyright[] =
 {"Copyright 1988,1989 Hans-J. Boehm and Alan J. Demers ",
 "Copyright (c) 1991-1995 by Xerox Corporation.  All rights reserved. ",
 "Copyright (c) 1996-1998 by Silicon Graphics.  All rights reserved. ",
+"Copyright (c) 1999-2001 by Hewlett-Packard Company.  All rights reserved. ",
 "THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY",
 " EXPRESSED OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.",
 "See source code for details." };
 
 # include "version.h"
 
+#if defined(SAVE_CALL_CHAIN) && \
+       !(defined(REDIRECT_MALLOC) && defined(GC_HAVE_BUILTIN_BACKTRACE))
+#   define SAVE_CALL_CHAIN_IN_GC
+    /* This is only safe if the call chain save mechanism won't end up */
+    /* calling GC_malloc.  The GNU C library documentation suggests    */
+    /* that backtrace doesn't use malloc, but at least the initial     */
+    /* call in some versions does seem to invoke the dynamic linker,   */
+    /* which uses malloc.                                              */
+#endif
+
 /* some more variables */
 
 extern signed_word GC_mem_found;  /* Number of reclaimed longwords     */
@@ -96,13 +116,15 @@ extern GC_bool GC_collection_in_progress();
 
 int GC_never_stop_func GC_PROTO((void)) { return(0); }
 
+unsigned long GC_time_limit = TIME_LIMIT;
+
 CLOCK_TYPE GC_start_time;      /* Time at which we stopped world.      */
                                /* used only in GC_timeout_stop_func.   */
 
 int GC_n_attempts = 0;         /* Number of attempts at finishing      */
-                               /* collection within TIME_LIMIT         */
+                               /* collection within GC_time_limit.     */
 
-#ifdef SMALL_CONFIG
+#if defined(SMALL_CONFIG) || defined(NO_CLOCK)
 #   define GC_timeout_stop_func GC_never_stop_func
 #else
   int GC_timeout_stop_func GC_PROTO((void))
@@ -112,18 +134,18 @@ int GC_n_attempts = 0;            /* Number of attempts at finishing      */
     unsigned long time_diff;
     
     if ((count++ & 3) != 0) return(0);
-#ifndef NO_CLOCK
     GET_TIME(current_time);
     time_diff = MS_TIME_DIFF(current_time,GC_start_time);
-    if (time_diff >= TIME_LIMIT) {
-#      ifdef PRINTSTATS
+    if (time_diff >= GC_time_limit) {
+#      ifdef CONDPRINT
+         if (GC_print_stats) {
            GC_printf0("Abandoning stopped marking after ");
            GC_printf1("%lu msecs", (unsigned long)time_diff);
-           GC_printf1("(attempt %d)\n", (unsigned long) GC_n_attempts);
+           GC_printf1("(attempt %ld)\n", (unsigned long) GC_n_attempts);
+         }
 #      endif
        return(1);
     }
-#endif
     return(0);
   }
 #endif /* !SMALL_CONFIG */
@@ -151,7 +173,7 @@ static word min_words_allocd()
                               + (GC_large_free_bytes >> 2)
                                   /* use a bit more of large empty heap */
                               + total_root_size);
-    if (GC_incremental) {
+    if (TRUE_INCREMENTAL) {
         return scan_size / (2 * GC_free_space_divisor);
     } else {
         return scan_size / GC_free_space_divisor;
@@ -173,7 +195,8 @@ word GC_adj_words_allocd()
     /* managed object should not alter result, assuming the client     */
     /* is playing by the rules.                                                */
     result = (signed_word)GC_words_allocd
-            - (signed_word)GC_mem_freed - expl_managed;
+            - (signed_word)GC_mem_freed 
+            + (signed_word)GC_finalizer_mem_freed - expl_managed;
     if (result > (signed_word)GC_words_allocd) {
         result = GC_words_allocd;
        /* probably client bug or unfortunate scheduling */
@@ -183,7 +206,8 @@ word GC_adj_words_allocd()
        /* had been reallocated this round. Finalization is user        */
        /* visible progress.  And if we don't count this, we have       */
        /* stability problems for programs that finalize all objects.   */
-    result += GC_words_wasted;
+    if ((GC_words_wasted >> 3) < result)
+        result += GC_words_wasted;
        /* This doesn't reflect useful work.  But if there is lots of   */
        /* new fragmentation, the same is probably true of the heap,    */
        /* and the collection will be correspondingly cheaper.          */
@@ -208,21 +232,28 @@ void GC_clear_a_few_frames()
 {
 #   define NWORDS 64
     word frames[NWORDS];
+    /* Some compilers will warn that frames was set but never used.    */
+    /* That's the whole idea ...                                       */
     register int i;
     
     for (i = 0; i < NWORDS; i++) frames[i] = 0;
 }
 
+/* Heap size at which we need a collection to avoid expanding past     */
+/* limits used by blacklisting.                                                */
+static word GC_collect_at_heapsize = (word)(-1);
+
 /* Have we allocated enough to amortize a collection? */
 GC_bool GC_should_collect()
 {
-    return(GC_adj_words_allocd() >= min_words_allocd());
+    return(GC_adj_words_allocd() >= min_words_allocd()
+          || GC_heapsize >= GC_collect_at_heapsize);
 }
 
 
 void GC_notify_full_gc()
 {
-    if (GC_start_call_back != (void (*)())0) {
+    if (GC_start_call_back != (void (*) GC_PROTO((void)))0) {
        (*GC_start_call_back)();
     }
 }
@@ -241,16 +272,21 @@ void GC_maybe_gc()
 
     if (GC_should_collect()) {
         if (!GC_incremental) {
-           GC_notify_full_gc();
             GC_gcollect_inner();
             n_partial_gcs = 0;
             return;
-        } else if (GC_need_full_gc || n_partial_gcs >= GC_full_freq) {
-#          ifdef PRINTSTATS
-             GC_printf2(
-               "***>Full mark for collection %lu after %ld allocd bytes\n",
-               (unsigned long) GC_gc_no+1,
-               (long)WORDS_TO_BYTES(GC_words_allocd));
+        } else {
+#        ifdef PARALLEL_MARK
+           GC_wait_for_reclaim();
+#        endif
+         if (GC_need_full_gc || n_partial_gcs >= GC_full_freq) {
+#          ifdef CONDPRINT
+             if (GC_print_stats) {
+               GC_printf2(
+                 "***>Full mark for collection %lu after %ld allocd bytes\n",
+                 (unsigned long) GC_gc_no+1,
+                 (long)WORDS_TO_BYTES(GC_words_allocd));
+             }
 #           endif
            GC_promote_black_lists();
            (void)GC_reclaim_all((GC_stop_func)0, TRUE);
@@ -258,17 +294,19 @@ void GC_maybe_gc()
             n_partial_gcs = 0;
            GC_notify_full_gc();
            GC_is_full_gc = TRUE;
-        } else {
+          } else {
             n_partial_gcs++;
-        }
+          }
+       }
         /* We try to mark with the world stopped.      */
         /* If we run out of time, this turns into      */
         /* incremental marking.                        */
-#ifndef NO_CLOCK
-        GET_TIME(GC_start_time);
-#endif
-        if (GC_stopped_mark(GC_timeout_stop_func)) {
-#           ifdef SAVE_CALL_CHAIN
+#      ifndef NO_CLOCK
+          if (GC_time_limit != GC_TIME_UNLIMITED) { GET_TIME(GC_start_time); }
+#      endif
+        if (GC_stopped_mark(GC_time_limit == GC_TIME_UNLIMITED? 
+                           GC_never_stop_func : GC_timeout_stop_func)) {
+#           ifdef SAVE_CALL_CHAIN_IN_GC
                 GC_save_callers(GC_last_stack);
 #           endif
             GC_finish_collection();
@@ -285,39 +323,55 @@ void GC_maybe_gc()
 /*
  * Stop the world garbage collection.  Assumes lock held, signals disabled.
  * If stop_func is not GC_never_stop_func, then abort if stop_func returns TRUE.
+ * Return TRUE if we successfully completed the collection.
  */
 GC_bool GC_try_to_collect_inner(stop_func)
 GC_stop_func stop_func;
 {
+#   ifdef CONDPRINT
+        CLOCK_TYPE start_time, current_time;
+#   endif
+    if (GC_dont_gc) return FALSE;
     if (GC_incremental && GC_collection_in_progress()) {
-#   ifdef PRINTSTATS
+#   ifdef CONDPRINT
+      if (GC_print_stats) {
        GC_printf0(
            "GC_try_to_collect_inner: finishing collection in progress\n");
-#    endif /* PRINTSTATS */
+      }
+#   endif /* CONDPRINT */
       /* Just finish collection already in progress.   */
        while(GC_collection_in_progress()) {
            if (stop_func()) return(FALSE);
            GC_collect_a_little_inner(1);
        }
     }
-#   ifdef PRINTSTATS
+    if (stop_func == GC_never_stop_func) GC_notify_full_gc();
+#   ifdef CONDPRINT
+      if (GC_print_stats) {
+        if (GC_print_stats) GET_TIME(start_time);
        GC_printf2(
           "Initiating full world-stop collection %lu after %ld allocd bytes\n",
           (unsigned long) GC_gc_no+1,
           (long)WORDS_TO_BYTES(GC_words_allocd));
+      }
 #   endif
     GC_promote_black_lists();
     /* Make sure all blocks have been reclaimed, so sweep routines     */
     /* don't see cleared mark bits.                                    */
     /* If we're guaranteed to finish, then this is unnecessary.                */
-       if (stop_func != GC_never_stop_func
+    /* In the find_leak case, we have to finish to guarantee that      */
+    /* previously unmarked objects are not reported as leaks.          */
+#       ifdef PARALLEL_MARK
+           GC_wait_for_reclaim();
+#       endif
+       if ((GC_find_leak || stop_func != GC_never_stop_func)
            && !GC_reclaim_all(stop_func, FALSE)) {
            /* Aborted.  So far everything is still consistent. */
            return(FALSE);
        }
     GC_invalidate_mark_state();  /* Flush mark stack.  */
     GC_clear_marks();
-#   ifdef SAVE_CALL_CHAIN
+#   ifdef SAVE_CALL_CHAIN_IN_GC
         GC_save_callers(GC_last_stack);
 #   endif
     GC_is_full_gc = TRUE;
@@ -333,6 +387,13 @@ GC_stop_func stop_func;
       return(FALSE);
     }
     GC_finish_collection();
+#   if defined(CONDPRINT)
+      if (GC_print_stats) {
+        GET_TIME(current_time);
+        GC_printf1("Complete collection took %lu msecs\n",
+                   MS_TIME_DIFF(current_time,start_time));
+      }
+#   endif
     return(TRUE);
 }
 
@@ -348,7 +409,7 @@ GC_stop_func stop_func;
 # define GC_RATE 10 
 # define MAX_PRIOR_ATTEMPTS 1
        /* Maximum number of prior attempts at world stop marking       */
-       /* A value of 1 means that we finish the seconf time, no matter */
+       /* A value of 1 means that we finish the second time, no matter */
        /* how long it takes.  Doesn't count the initial root scan      */
        /* for a full GC.                                               */
 
@@ -360,14 +421,19 @@ int n;
 {
     register int i;
     
+    if (GC_dont_gc) return;
     if (GC_incremental && GC_collection_in_progress()) {
        for (i = GC_deficit; i < GC_RATE*n; i++) {
            if (GC_mark_some((ptr_t)0)) {
                /* Need to finish a collection */
-#              ifdef SAVE_CALL_CHAIN
+#              ifdef SAVE_CALL_CHAIN_IN_GC
                    GC_save_callers(GC_last_stack);
 #              endif
-               if (GC_n_attempts < MAX_PRIOR_ATTEMPTS) {
+#              ifdef PARALLEL_MARK
+                   GC_wait_for_reclaim();
+#              endif
+               if (GC_n_attempts < MAX_PRIOR_ATTEMPTS
+                   && GC_time_limit != GC_TIME_UNLIMITED) {
                  GET_TIME(GC_start_time);
                  if (!GC_stopped_mark(GC_timeout_stop_func)) {
                    GC_n_attempts++;
@@ -398,6 +464,7 @@ int GC_collect_a_little GC_PROTO(())
     result = (int)GC_collection_in_progress();
     UNLOCK();
     ENABLE_SIGNALS();
+    if (!result && GC_debugging_started) GC_print_all_smashed();
     return(result);
 }
 
@@ -412,18 +479,34 @@ GC_stop_func stop_func;
 {
     register int i;
     int dummy;
-#   ifdef PRINTSTATS
+#   if defined(PRINTTIMES) || defined(CONDPRINT)
        CLOCK_TYPE start_time, current_time;
 #   endif
        
-    STOP_WORLD();
-#   ifdef PRINTSTATS
+#   ifdef PRINTTIMES
        GET_TIME(start_time);
+#   endif
+#   if defined(CONDPRINT) && !defined(PRINTTIMES)
+       if (GC_print_stats) GET_TIME(start_time);
+#   endif
+#   if defined(REGISTER_LIBRARIES_EARLY)
+        GC_cond_register_dynamic_libraries();
+#   endif
+    STOP_WORLD();
+    IF_THREADS(GC_world_stopped = TRUE);
+#   ifdef CONDPRINT
+      if (GC_print_stats) {
        GC_printf1("--> Marking for collection %lu ",
                   (unsigned long) GC_gc_no + 1);
        GC_printf2("after %lu allocd bytes + %lu wasted bytes\n",
                   (unsigned long) WORDS_TO_BYTES(GC_words_allocd),
                   (unsigned long) WORDS_TO_BYTES(GC_words_wasted));
+      }
+#   endif
+#   ifdef MAKE_BACK_GRAPH
+      if (GC_print_back_height) {
+        GC_build_back_graph();
+      }
 #   endif
 
     /* Mark from all roots.  */
@@ -433,12 +516,15 @@ GC_stop_func stop_func;
        GC_initiate_gc();
        for(i = 0;;i++) {
            if ((*stop_func)()) {
-#                  ifdef PRINTSTATS
+#                  ifdef CONDPRINT
+                     if (GC_print_stats) {
                        GC_printf0("Abandoned stopped marking after ");
                        GC_printf1("%lu iterations\n",
                                   (unsigned long)i);
+                     }
 #                  endif
                    GC_deficit = i; /* Give the mutator a chance. */
+                    IF_THREADS(GC_world_stopped = FALSE);
                    START_WORLD();
                    return(FALSE);
            }
@@ -450,27 +536,97 @@ GC_stop_func stop_func;
       GC_printf2("Collection %lu reclaimed %ld bytes",
                  (unsigned long) GC_gc_no - 1,
                  (long)WORDS_TO_BYTES(GC_mem_found));
-      GC_printf1(" ---> heapsize = %lu bytes\n",
-               (unsigned long) GC_heapsize);
-      /* Printf arguments may be pushed in funny places.  Clear the    */
-      /* space.                                                                */
-      GC_printf0("");
-#   endif      
+#   else
+#     ifdef CONDPRINT
+        if (GC_print_stats) {
+         GC_printf1("Collection %lu finished", (unsigned long) GC_gc_no - 1);
+       }
+#     endif
+#   endif /* !PRINTSTATS */
+#   ifdef CONDPRINT
+      if (GC_print_stats) {
+        GC_printf1(" ---> heapsize = %lu bytes\n",
+                  (unsigned long) GC_heapsize);
+        /* Printf arguments may be pushed in funny places.  Clear the  */
+        /* space.                                                      */
+        GC_printf0("");
+      }
+#   endif  /* CONDPRINT  */
 
     /* Check all debugged objects for consistency */
         if (GC_debugging_started) {
             (*GC_check_heap)();
         }
     
+    IF_THREADS(GC_world_stopped = FALSE);
+    START_WORLD();
 #   ifdef PRINTTIMES
        GET_TIME(current_time);
        GC_printf1("World-stopped marking took %lu msecs\n",
                   MS_TIME_DIFF(current_time,start_time));
+#   else
+#     ifdef CONDPRINT
+       if (GC_print_stats) {
+         GET_TIME(current_time);
+         GC_printf1("World-stopped marking took %lu msecs\n",
+                    MS_TIME_DIFF(current_time,start_time));
+       }
+#     endif
 #   endif
-    START_WORLD();
     return(TRUE);
 }
 
+/* Set all mark bits for the free list whose first entry is q  */
+#ifdef __STDC__
+  void GC_set_fl_marks(ptr_t q)
+#else
+  void GC_set_fl_marks(q)
+  ptr_t q;
+#endif
+{
+   ptr_t p;
+   struct hblk * h, * last_h = 0;
+   hdr *hhdr;
+   int word_no;
+
+   for (p = q; p != 0; p = obj_link(p)){
+       h = HBLKPTR(p);
+       if (h != last_h) {
+         last_h = h; 
+         hhdr = HDR(h);
+       }
+       word_no = (((word *)p) - ((word *)h));
+       set_mark_bit_from_hdr(hhdr, word_no);
+   }
+}
+
+/* Clear all mark bits for the free list whose first entry is q        */
+/* Decrement GC_mem_found by number of words on free list.     */
+#ifdef __STDC__
+  void GC_clear_fl_marks(ptr_t q)
+#else
+  void GC_clear_fl_marks(q)
+  ptr_t q;
+#endif
+{
+   ptr_t p;
+   struct hblk * h, * last_h = 0;
+   hdr *hhdr;
+   int word_no;
+
+   for (p = q; p != 0; p = obj_link(p)){
+       h = HBLKPTR(p);
+       if (h != last_h) {
+         last_h = h; 
+         hhdr = HDR(h);
+       }
+       word_no = (((word *)p) - ((word *)h));
+       clear_mark_bit_from_hdr(hhdr, word_no);
+#      ifdef GATHERSTATS
+           GC_mem_found -= hhdr -> hb_sz;
+#      endif
+   }
+}
 
 /* Finish up a collection.  Assumes lock is held, signals are disabled,        */
 /* but the world is otherwise running.                                 */
@@ -488,26 +644,24 @@ void GC_finish_collection()
 #   ifdef GATHERSTATS
         GC_mem_found = 0;
 #   endif
+#   if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
+       if (getenv("GC_PRINT_ADDRESS_MAP") != 0) {
+         GC_print_address_map();
+       }
+#   endif
+    COND_DUMP;
     if (GC_find_leak) {
       /* Mark all objects on the free list.  All objects should be */
       /* marked when we're done.                                  */
        {
          register word size;           /* current object size          */
-         register ptr_t p;     /* pointer to current object    */
-         register struct hblk * h;     /* pointer to block containing *p */
-         register hdr * hhdr;
-         register int word_no;           /* "index" of *p in *q          */
          int kind;
+         ptr_t q;
 
          for (kind = 0; kind < GC_n_kinds; kind++) {
            for (size = 1; size <= MAXOBJSZ; size++) {
-             for (p= GC_obj_kinds[kind].ok_freelist[size];
-                  p != 0; p=obj_link(p)){
-               h = HBLKPTR(p);
-               hhdr = HDR(h);
-               word_no = (((word *)p) - ((word *)h));
-               set_mark_bit_from_hdr(hhdr, word_no);
-             }
+             q = GC_obj_kinds[kind].ok_freelist[size];
+             if (q != 0) GC_set_fl_marks(q);
            }
          }
        }
@@ -524,33 +678,32 @@ void GC_finish_collection()
       GET_TIME(finalize_time);
 #   endif
 
+    if (GC_print_back_height) {
+#     ifdef MAKE_BACK_GRAPH
+       GC_traverse_back_graph();
+#     else
+#      ifndef SMALL_CONFIG
+         GC_err_printf0("Back height not available: "
+                        "Rebuild collector with -DMAKE_BACK_GRAPH\n");
+#      endif
+#     endif
+    }
+
     /* Clear free list mark bits, in case they got accidentally marked   */
-    /* Note: HBLKPTR(p) == pointer to head of block containing *p        */
-    /* (or GC_find_leak is set and they were intentionally marked.)     */
+    /* (or GC_find_leak is set and they were intentionally marked).     */
     /* Also subtract memory remaining from GC_mem_found count.           */
     /* Note that composite objects on free list are cleared.             */
     /* Thus accidentally marking a free list is not a problem;  only     */
     /* objects on the list itself will be marked, and that's fixed here. */
       {
        register word size;             /* current object size          */
-       register ptr_t p;       /* pointer to current object    */
-       register struct hblk * h;       /* pointer to block containing *p */
-       register hdr * hhdr;
-       register int word_no;           /* "index" of *p in *q          */
+       register ptr_t q;       /* pointer to current object    */
        int kind;
 
        for (kind = 0; kind < GC_n_kinds; kind++) {
          for (size = 1; size <= MAXOBJSZ; size++) {
-           for (p= GC_obj_kinds[kind].ok_freelist[size];
-                p != 0; p=obj_link(p)){
-               h = HBLKPTR(p);
-               hhdr = HDR(h);
-               word_no = (((word *)p) - ((word *)h));
-               clear_mark_bit_from_hdr(hhdr, word_no);
-#              ifdef GATHERSTATS
-                   GC_mem_found -= size;
-#              endif
-           }
+           q = GC_obj_kinds[kind].ok_freelist[size];
+           if (q != 0) GC_clear_fl_marks(q);
          }
        }
       }
@@ -593,6 +746,7 @@ void GC_finish_collection()
       GC_words_allocd = 0;
       GC_words_wasted = 0;
       GC_mem_freed = 0;
+      GC_finalizer_mem_freed = 0;
       
 #   ifdef USE_MUNMAP
       GC_unmap_old();
@@ -616,6 +770,7 @@ void GC_finish_collection()
     int result;
     DCL_LOCK_STATE;
     
+    if (GC_debugging_started) GC_print_all_smashed();
     GC_INVOKE_FINALIZERS();
     DISABLE_SIGNALS();
     LOCK();
@@ -627,14 +782,17 @@ void GC_finish_collection()
     EXIT_GC();
     UNLOCK();
     ENABLE_SIGNALS();
-    if(result) GC_INVOKE_FINALIZERS();
+    if(result) {
+        if (GC_debugging_started) GC_print_all_smashed();
+        GC_INVOKE_FINALIZERS();
+    }
     return(result);
 }
 
 void GC_gcollect GC_PROTO(())
 {
-    GC_notify_full_gc();
     (void)GC_try_to_collect(GC_never_stop_func);
+    if (GC_have_errors) GC_print_all_errors();
 }
 
 word GC_n_heap_sects = 0;      /* Number of sections currently in heap. */
@@ -663,22 +821,22 @@ word bytes;
     GC_heap_sects[GC_n_heap_sects].hs_start = (ptr_t)p;
     GC_heap_sects[GC_n_heap_sects].hs_bytes = bytes;
     GC_n_heap_sects++;
-    words = BYTES_TO_WORDS(bytes - HDR_BYTES);
+    words = BYTES_TO_WORDS(bytes);
     phdr -> hb_sz = words;
-    phdr -> hb_map = (char *)1;   /* A value != GC_invalid_map */
+    phdr -> hb_map = (unsigned char *)1;   /* A value != GC_invalid_map        */
     phdr -> hb_flags = 0;
     GC_freehblk(p);
     GC_heapsize += bytes;
-    if ((ptr_t)p <= GC_least_plausible_heap_addr
+    if ((ptr_t)p <= (ptr_t)GC_least_plausible_heap_addr
         || GC_least_plausible_heap_addr == 0) {
-        GC_least_plausible_heap_addr = (ptr_t)p - sizeof(word);
+        GC_least_plausible_heap_addr = (GC_PTR)((ptr_t)p - sizeof(word));
                /* Making it a little smaller than necessary prevents   */
                /* us from getting a false hit from the variable        */
                /* itself.  There's some unintentional reflection       */
                /* here.                                                */
     }
-    if ((ptr_t)p + bytes >= GC_greatest_plausible_heap_addr) {
-        GC_greatest_plausible_heap_addr = (ptr_t)p + bytes;
+    if ((ptr_t)p + bytes >= (ptr_t)GC_greatest_plausible_heap_addr) {
+        GC_greatest_plausible_heap_addr = (GC_PTR)((ptr_t)p + bytes);
     }
 }
 
@@ -705,8 +863,8 @@ void GC_print_heap_sects()
 }
 # endif
 
-ptr_t GC_least_plausible_heap_addr = (ptr_t)ONES;
-ptr_t GC_greatest_plausible_heap_addr = 0;
+GC_PTR GC_least_plausible_heap_addr = (GC_PTR)ONES;
+GC_PTR GC_greatest_plausible_heap_addr = 0;
 
 ptr_t GC_max(x,y)
 ptr_t x, y;
@@ -762,9 +920,16 @@ word n;
     }
     space = GET_MEM(bytes);
     if( space == 0 ) {
+#      ifdef CONDPRINT
+         if (GC_print_stats) {
+           GC_printf1("Failed to expand heap by %ld bytes\n",
+                      (unsigned long)bytes);
+         }
+#       endif
        return(FALSE);
     }
-#   ifdef PRINTSTATS
+#   ifdef CONDPRINT
+      if (GC_print_stats) {
        GC_printf2("Increasing heap size by %lu after %lu allocated bytes\n",
                   (unsigned long)bytes,
                   (unsigned long)WORDS_TO_BYTES(GC_words_allocd));
@@ -773,26 +938,39 @@ word n;
          GC_print_block_list(); GC_print_hblkfreelist();
          GC_printf0("\n");
 #      endif
+      }
 #   endif
-    expansion_slop = 8 * WORDS_TO_BYTES(min_words_allocd());
-    if (5 * HBLKSIZE * MAXHINCR > expansion_slop) {
-        expansion_slop = 5 * HBLKSIZE * MAXHINCR;
-    }
+    expansion_slop = WORDS_TO_BYTES(min_words_allocd()) + 4*MAXHINCR*HBLKSIZE;
     if (GC_last_heap_addr == 0 && !((word)space & SIGNB)
-        || GC_last_heap_addr != 0 && GC_last_heap_addr < (ptr_t)space) {
+        || (GC_last_heap_addr != 0 && GC_last_heap_addr < (ptr_t)space)) {
         /* Assume the heap is growing up */
         GC_greatest_plausible_heap_addr =
-            GC_max(GC_greatest_plausible_heap_addr,
-                   (ptr_t)space + bytes + expansion_slop);
+            (GC_PTR)GC_max((ptr_t)GC_greatest_plausible_heap_addr,
+                           (ptr_t)space + bytes + expansion_slop);
     } else {
         /* Heap is growing down */
         GC_least_plausible_heap_addr =
-            GC_min(GC_least_plausible_heap_addr,
-                   (ptr_t)space - expansion_slop);
+            (GC_PTR)GC_min((ptr_t)GC_least_plausible_heap_addr,
+                           (ptr_t)space - expansion_slop);
     }
+#   if defined(LARGE_CONFIG)
+      if (((ptr_t)GC_greatest_plausible_heap_addr <= (ptr_t)space + bytes
+           || (ptr_t)GC_least_plausible_heap_addr >= (ptr_t)space)
+         && GC_heapsize > 0) {
+       /* GC_add_to_heap will fix this, but ... */
+       WARN("Too close to address space limit: blacklisting ineffective\n", 0);
+      }
+#   endif
     GC_prev_heap_addr = GC_last_heap_addr;
     GC_last_heap_addr = (ptr_t)space;
     GC_add_to_heap(space, bytes);
+    /* Force GC before we are likely to allocate past expansion_slop */
+      GC_collect_at_heapsize =
+         GC_heapsize + expansion_slop - 2*MAXHINCR*HBLKSIZE;
+#     if defined(LARGE_CONFIG)
+        if (GC_collect_at_heapsize < GC_heapsize /* wrapped */)
+         GC_collect_at_heapsize = (word)(-1);
+#     endif
     return(TRUE);
 }
 
@@ -827,8 +1005,7 @@ word needed_blocks;
 GC_bool ignore_off_page;
 {
     if (!GC_incremental && !GC_dont_gc &&
-       (GC_dont_expand && GC_words_allocd > 0 || GC_should_collect())) {
-      GC_notify_full_gc();
+       ((GC_dont_expand && GC_words_allocd > 0) || GC_should_collect())) {
       GC_gcollect_inner();
     } else {
       word blocks_to_get = GC_heapsize/(HBLKSIZE*GC_free_space_divisor)
@@ -837,6 +1014,9 @@ GC_bool ignore_off_page;
       if (blocks_to_get > MAXHINCR) {
           word slop;
           
+         /* Get the minimum required to make it likely that we         */
+         /* can satisfy the current request in the presence of black-  */
+         /* listing.  This will probably be more than MAXHINCR.        */
           if (ignore_off_page) {
               slop = 4;
           } else {
@@ -853,15 +1033,16 @@ GC_bool ignore_off_page;
         && !GC_expand_hp_inner(needed_blocks)) {
        if (GC_fail_count++ < GC_max_retries) {
            WARN("Out of Memory!  Trying to continue ...\n", 0);
-           GC_notify_full_gc();
            GC_gcollect_inner();
        } else {
-           WARN("Out of Memory!  Returning NIL!\n", 0);
+#          if !defined(AMIGA) || !defined(GC_AMIGA_FASTALLOC)
+             WARN("Out of Memory!  Returning NIL!\n", 0);
+#          endif
            return(FALSE);
        }
       } else {
-#        ifdef PRINTSTATS
-            if (GC_fail_count) {
+#        ifdef CONDPRINT
+            if (GC_fail_count && GC_print_stats) {
              GC_printf0("Memory available again ...\n");
            }
 #        endif
@@ -881,29 +1062,38 @@ ptr_t GC_allocobj(sz, kind)
 word sz;
 int kind;
 {
-    register ptr_t * flh = &(GC_obj_kinds[kind].ok_freelist[sz]);
+    ptr_t * flh = &(GC_obj_kinds[kind].ok_freelist[sz]);
+    GC_bool tried_minor = FALSE;
     
     if (sz == 0) return(0);
 
     while (*flh == 0) {
       ENTER_GC();
       /* Do our share of marking work */
-        if(GC_incremental && !GC_dont_gc) GC_collect_a_little_inner(1);
+        if(TRUE_INCREMENTAL) GC_collect_a_little_inner(1);
       /* Sweep blocks for objects of this size */
-          GC_continue_reclaim(sz, kind);
+        GC_continue_reclaim(sz, kind);
       EXIT_GC();
       if (*flh == 0) {
         GC_new_hblk(sz, kind);
       }
       if (*flh == 0) {
         ENTER_GC();
-        if (!GC_collect_or_expand((word)1,FALSE)) {
+       if (GC_incremental && GC_time_limit == GC_TIME_UNLIMITED
+           && ! tried_minor ) {
+           GC_collect_a_little_inner(1);
+           tried_minor = TRUE;
+       } else {
+          if (!GC_collect_or_expand((word)1,FALSE)) {
            EXIT_GC();
            return(0);
+         }
        }
        EXIT_GC();
       }
     }
+    /* Successful allocation; reset failure count.     */
+    GC_fail_count = 0;
     
     return(*flh);
 }