[Emacs-diffs] Changes to emacs/src/gmalloc.c,v

[YAMAMOTO Mitsuharu]

CVSROOT:        /cvsroot/emacs
Module name:    emacs
Changes by:     YAMAMOTO Mitsuharu <mituharu>   07/06/26 03:28:07

Index: gmalloc.c
===================================================================
RCS file: /cvsroot/emacs/emacs/src/gmalloc.c,v
retrieving revision 1.22
retrieving revision 1.23
diff -u -b -r1.22 -r1.23
--- gmalloc.c   20 Jun 2007 12:18:46 -0000      1.22
+++ gmalloc.c   26 Jun 2007 03:28:07 -0000      1.23
@@ -1,9 +1,6 @@
 /* This file is no longer automatically generated from libc.  */
 
 #define _MALLOC_INTERNAL
-#ifdef HAVE_GTK_AND_PTHREAD
-#define USE_PTHREAD
-#endif
 
 /* The malloc headers and source files from the C library follow here.  */
 
@@ -40,6 +37,10 @@
 #include <config.h>
 #endif
 
+#ifdef HAVE_GTK_AND_PTHREAD
+#define USE_PTHREAD
+#endif
+
 #if ((defined __cplusplus || (defined (__STDC__) && __STDC__) \
       || defined STDC_HEADERS || defined PROTOTYPES) \
      && ! defined (BROKEN_PROTOTYPES))
@@ -235,14 +236,21 @@
 extern __ptr_t _malloc_internal PP ((__malloc_size_t __size));
 extern __ptr_t _realloc_internal PP ((__ptr_t __ptr, __malloc_size_t __size));
 extern void _free_internal PP ((__ptr_t __ptr));
+extern __ptr_t _malloc_internal_nolock PP ((__malloc_size_t __size));
+extern __ptr_t _realloc_internal_nolock PP ((__ptr_t __ptr, __malloc_size_t 
__size));
+extern void _free_internal_nolock PP ((__ptr_t __ptr));
 
 #ifdef USE_PTHREAD
-extern pthread_mutex_t _malloc_mutex;
+extern pthread_mutex_t _malloc_mutex, _aligned_blocks_mutex;
 #define LOCK()     pthread_mutex_lock (&_malloc_mutex)
 #define UNLOCK()   pthread_mutex_unlock (&_malloc_mutex)
+#define LOCK_ALIGNED_BLOCKS()     pthread_mutex_lock (&_aligned_blocks_mutex)
+#define UNLOCK_ALIGNED_BLOCKS()   pthread_mutex_unlock (&_aligned_blocks_mutex)
 #else
 #define LOCK()
 #define UNLOCK()
+#define LOCK_ALIGNED_BLOCKS()
+#define UNLOCK_ALIGNED_BLOCKS()
 #endif
 
 #endif /* _MALLOC_INTERNAL.  */
@@ -554,7 +562,8 @@
 
 #ifdef USE_PTHREAD
 static pthread_once_t malloc_init_once_control = PTHREAD_ONCE_INIT;
-pthread_mutex_t _malloc_mutex;
+pthread_mutex_t _malloc_mutex = PTHREAD_MUTEX_INITIALIZER;
+pthread_mutex_t _aligned_blocks_mutex = PTHREAD_MUTEX_INITIALIZER;
 #endif
 
 static void
@@ -567,7 +576,9 @@
   if (__malloc_initialize_hook)
     (*__malloc_initialize_hook) ();
 
-#ifdef USE_PTHREAD
+  /* We don't use recursive mutex because pthread_mutexattr_init may
+     call malloc internally.  */
+#if 0 /* defined (USE_PTHREAD) */
   {
     pthread_mutexattr_t attr;
 
@@ -616,9 +627,9 @@
 
 /* Get neatly aligned memory, initializing or
    growing the heap info table as necessary. */
-static __ptr_t morecore PP ((__malloc_size_t));
+static __ptr_t morecore_nolock PP ((__malloc_size_t));
 static __ptr_t
-morecore (size)
+morecore_nolock (size)
      __malloc_size_t size;
 {
   __ptr_t result;
@@ -661,7 +672,7 @@
             `morecore_recursing' flag and return null.  */
          int save = errno;     /* Don't want to clobber errno with ENOMEM.  */
          morecore_recursing = 1;
-         newinfo = (malloc_info *) _realloc_internal
+         newinfo = (malloc_info *) _realloc_internal_nolock
            (_heapinfo, newsize * sizeof (malloc_info));
          morecore_recursing = 0;
          if (newinfo == NULL)
@@ -717,7 +728,7 @@
       /* Reset _heaplimit so _free_internal never decides
         it can relocate or resize the info table.  */
       _heaplimit = 0;
-      _free_internal (oldinfo);
+      _free_internal_nolock (oldinfo);
       PROTECT_MALLOC_STATE (0);
 
       /* The new heap limit includes the new table just allocated.  */
@@ -732,7 +743,7 @@
 
 /* Allocate memory from the heap.  */
 __ptr_t
-_malloc_internal (size)
+_malloc_internal_nolock (size)
      __malloc_size_t size;
 {
   __ptr_t result;
@@ -752,7 +763,6 @@
     return NULL;
 #endif
 
-  LOCK ();
   PROTECT_MALLOC_STATE (0);
 
   if (size < sizeof (struct list))
@@ -802,8 +812,10 @@
          /* No free fragments of the desired size, so get a new block
             and break it into fragments, returning the first.  */
 #ifdef GC_MALLOC_CHECK
-         result = _malloc_internal (BLOCKSIZE);
+         result = _malloc_internal_nolock (BLOCKSIZE);
          PROTECT_MALLOC_STATE (0);
+#elif defined (USE_PTHREAD)
+         result = _malloc_internal_nolock (BLOCKSIZE);
 #else
          result = malloc (BLOCKSIZE);
 #endif
@@ -874,7 +886,7 @@
                  _heaplimit += wantblocks - lastblocks;
                  continue;
                }
-             result = morecore (wantblocks * BLOCKSIZE);
+             result = morecore_nolock (wantblocks * BLOCKSIZE);
              if (result == NULL)
                goto out;
              block = BLOCK (result);
@@ -932,7 +944,19 @@
 
   PROTECT_MALLOC_STATE (1);
  out:
+  return result;
+}
+
+__ptr_t
+_malloc_internal (size)
+     __malloc_size_t size;
+{
+  __ptr_t result;
+
+  LOCK ();
+  result = _malloc_internal_nolock (size);
   UNLOCK ();
+
   return result;
 }
 
@@ -940,10 +964,21 @@
 malloc (size)
      __malloc_size_t size;
 {
+  __ptr_t (*hook) (__malloc_size_t);
+
   if (!__malloc_initialized && !__malloc_initialize ())
     return NULL;
 
-  return (__malloc_hook != NULL ? *__malloc_hook : _malloc_internal) (size);
+  /* Copy the value of __malloc_hook to an automatic variable in case
+     __malloc_hook is modified in another thread between its
+     NULL-check and the use.
+
+     Note: Strictly speaking, this is not a right solution.  We should
+     use mutexes to access non-read-only variables that are shared
+     among multiple threads.  We just leave it for compatibility with
+     glibc malloc (i.e., assignments to __malloc_hook) for now.  */
+  hook = __malloc_hook;
+  return (hook != NULL ? *hook : _malloc_internal) (size);
 }
 
 #ifndef _LIBC
@@ -1024,9 +1059,9 @@
 struct alignlist *_aligned_blocks = NULL;
 
 /* Return memory to the heap.
-   Like `free' but don't call a __free_hook if there is one.  */
+   Like `_free_internal' but don't lock mutex.  */
 void
-_free_internal (ptr)
+_free_internal_nolock (ptr)
      __ptr_t ptr;
 {
   int type;
@@ -1043,9 +1078,9 @@
   if (ptr == NULL)
     return;
 
-  LOCK ();
   PROTECT_MALLOC_STATE (0);
 
+  LOCK_ALIGNED_BLOCKS ();
   for (l = _aligned_blocks; l != NULL; l = l->next)
     if (l->aligned == ptr)
       {
@@ -1053,6 +1088,7 @@
        ptr = l->exact;
        break;
       }
+  UNLOCK_ALIGNED_BLOCKS ();
 
   block = BLOCK (ptr);
 
@@ -1158,7 +1194,7 @@
                 table's blocks to the system before we have copied them to
                 the new location.  */
              _heaplimit = 0;
-             _free_internal (_heapinfo);
+             _free_internal_nolock (_heapinfo);
              _heaplimit = oldlimit;
 
              /* Tell malloc to search from the beginning of the heap for
@@ -1166,7 +1202,7 @@
              _heapindex = 0;
 
              /* Allocate new space for the info table and move its data.  */
-             newinfo = (malloc_info *) _malloc_internal (info_blocks
+             newinfo = (malloc_info *) _malloc_internal_nolock (info_blocks
                                                          * BLOCKSIZE);
              PROTECT_MALLOC_STATE (0);
              memmove (newinfo, _heapinfo, info_blocks * BLOCKSIZE);
@@ -1230,8 +1266,8 @@
          _chunks_free -= BLOCKSIZE >> type;
          _bytes_free -= BLOCKSIZE;
 
-#ifdef GC_MALLOC_CHECK
-         _free_internal (ADDRESS (block));
+#if defined (GC_MALLOC_CHECK) || defined (USE_PTHREAD)
+         _free_internal_nolock (ADDRESS (block));
 #else
          free (ADDRESS (block));
 #endif
@@ -1269,6 +1305,16 @@
     }
 
   PROTECT_MALLOC_STATE (1);
+}
+
+/* Return memory to the heap.
+   Like `free' but don't call a __free_hook if there is one.  */
+void
+_free_internal (ptr)
+     __ptr_t ptr;
+{
+  LOCK ();
+  _free_internal_nolock (ptr);
   UNLOCK ();
 }
 
@@ -1278,8 +1324,10 @@
 free (ptr)
      __ptr_t ptr;
 {
-  if (__free_hook != NULL)
-    (*__free_hook) (ptr);
+  void (*hook) (__ptr_t) = __free_hook;
+
+  if (hook != NULL)
+    (*hook) (ptr);
   else
     _free_internal (ptr);
 }
@@ -1415,7 +1463,7 @@
    new region.  This module has incestuous knowledge of the
    internals of both free and malloc. */
 __ptr_t
-_realloc_internal (ptr, size)
+_realloc_internal_nolock (ptr, size)
      __ptr_t ptr;
      __malloc_size_t size;
 {
@@ -1425,15 +1473,14 @@
 
   if (size == 0)
     {
-      _free_internal (ptr);
-      return _malloc_internal (0);
+      _free_internal_nolock (ptr);
+      return _malloc_internal_nolock (0);
     }
   else if (ptr == NULL)
-    return _malloc_internal (size);
+    return _malloc_internal_nolock (size);
 
   block = BLOCK (ptr);
 
-  LOCK ();
   PROTECT_MALLOC_STATE (0);
 
   type = _heapinfo[block].busy.type;
@@ -1443,11 +1490,11 @@
       /* Maybe reallocate a large block to a small fragment.  */
       if (size <= BLOCKSIZE / 2)
        {
-         result = _malloc_internal (size);
+         result = _malloc_internal_nolock (size);
          if (result != NULL)
            {
              memcpy (result, ptr, size);
-             _free_internal (ptr);
+             _free_internal_nolock (ptr);
              goto out;
            }
        }
@@ -1467,7 +1514,7 @@
             Now we will free this chunk; increment the statistics counter
             so it doesn't become wrong when _free_internal decrements it.  */
          ++_chunks_used;
-         _free_internal (ADDRESS (block + blocks));
+         _free_internal_nolock (ADDRESS (block + blocks));
          result = ptr;
        }
       else if (blocks == _heapinfo[block].busy.info.size)
@@ -1482,8 +1529,8 @@
          /* Prevent free from actually returning memory to the system.  */
          oldlimit = _heaplimit;
          _heaplimit = 0;
-         _free_internal (ptr);
-         result = _malloc_internal (size);
+         _free_internal_nolock (ptr);
+         result = _malloc_internal_nolock (size);
          PROTECT_MALLOC_STATE (0);
          if (_heaplimit == 0)
            _heaplimit = oldlimit;
@@ -1493,13 +1540,13 @@
                 the thing we just freed.  Unfortunately it might
                 have been coalesced with its neighbors.  */
              if (_heapindex == block)
-               (void) _malloc_internal (blocks * BLOCKSIZE);
+               (void) _malloc_internal_nolock (blocks * BLOCKSIZE);
              else
                {
                  __ptr_t previous
-                   = _malloc_internal ((block - _heapindex) * BLOCKSIZE);
-                 (void) _malloc_internal (blocks * BLOCKSIZE);
-                 _free_internal (previous);
+                   = _malloc_internal_nolock ((block - _heapindex) * 
BLOCKSIZE);
+                 (void) _malloc_internal_nolock (blocks * BLOCKSIZE);
+                 _free_internal_nolock (previous);
                }
              goto out;
            }
@@ -1519,18 +1566,31 @@
        {
          /* The new size is different; allocate a new space,
             and copy the lesser of the new size and the old. */
-         result = _malloc_internal (size);
+         result = _malloc_internal_nolock (size);
          if (result == NULL)
            goto out;
          memcpy (result, ptr, min (size, (__malloc_size_t) 1 << type));
-         _free_internal (ptr);
+         _free_internal_nolock (ptr);
        }
       break;
     }
 
   PROTECT_MALLOC_STATE (1);
  out:
+  return result;
+}
+
+__ptr_t
+_realloc_internal (ptr, size)
+     __ptr_t ptr;
+     __malloc_size_t size;
+{
+  __ptr_t result;
+
+  LOCK();
+  result = _realloc_internal_nolock (ptr, size);
   UNLOCK ();
+
   return result;
 }
 
@@ -1539,11 +1599,13 @@
      __ptr_t ptr;
      __malloc_size_t size;
 {
+  __ptr_t (*hook) (__ptr_t, __malloc_size_t);
+
   if (!__malloc_initialized && !__malloc_initialize ())
     return NULL;
 
-  return (__realloc_hook != NULL ? *__realloc_hook : _realloc_internal)
-    (ptr, size);
+  hook = __realloc_hook;
+  return (hook != NULL ? *hook : _realloc_internal) (ptr, size);
 }
 /* Copyright (C) 1991, 1992, 1994 Free Software Foundation, Inc.
 
@@ -1681,9 +1743,10 @@
 {
   __ptr_t result;
   unsigned long int adj, lastadj;
+  __ptr_t (*hook) (__malloc_size_t, __malloc_size_t) = __memalign_hook;
 
-  if (__memalign_hook)
-    return (*__memalign_hook) (alignment, size);
+  if (hook)
+    return (*hook) (alignment, size);
 
   /* Allocate a block with enough extra space to pad the block with up to
      (ALIGNMENT - 1) bytes if necessary.  */
@@ -1718,6 +1781,7 @@
         of an allocated block.  */
 
       struct alignlist *l;
+      LOCK_ALIGNED_BLOCKS ();
       for (l = _aligned_blocks; l != NULL; l = l->next)
        if (l->aligned == NULL)
          /* This slot is free.  Use it.  */
@@ -1725,17 +1789,24 @@
       if (l == NULL)
        {
          l = (struct alignlist *) malloc (sizeof (struct alignlist));
-         if (l == NULL)
+         if (l != NULL)
            {
-             free (result);
-             return NULL;
-           }
          l->next = _aligned_blocks;
          _aligned_blocks = l;
        }
+       }
+      if (l != NULL)
+       {
       l->exact = result;
       result = l->aligned = (char *) result + alignment - adj;
     }
+      UNLOCK_ALIGNED_BLOCKS ();
+      if (l == NULL)
+       {
+         free (result);
+         result = NULL;
+       }
+    }
 
   return result;
 }