Refactor aset.c and mcxt.c in preparation for Valgrind cooperation.

Move some repeated debugging code into functions and store intermediates
in variables where not presently necessary.  No code-generation changes
in a production build, and no functional changes.  This simplifies and
focuses the main patch.

diff --git a/src/backend/utils/mmgr/aset.c b/src/backend/utils/mmgr/aset.c
index 6a111c78329e7df357ac6e7bb7129e04197b0115..de643779f064957f19dc492cc1c7c7faccd8b079 100644 (file)
--- a/src/backend/utils/mmgr/aset.c
+++ b/src/backend/utils/mmgr/aset.c
@@ -308,6 +308,37 @@ AllocSetFreeIndex(Size size)
    return idx;
 }
 
+#ifdef CLOBBER_FREED_MEMORY
+
+/* Wipe freed memory for debugging purposes */
+static void
+wipe_mem(void *ptr, size_t size)
+{
+   memset(ptr, 0x7F, size);
+}
+#endif
+
+#ifdef MEMORY_CONTEXT_CHECKING
+static void
+set_sentinel(void *base, Size offset)
+{
+   char       *ptr = (char *) base + offset;
+
+   *ptr = 0x7E;
+}
+
+static bool
+sentinel_ok(const void *base, Size offset)
+{
+   const char *ptr = (const char *) base + offset;
+   bool        ret;
+
+   ret = *ptr == 0x7E;
+
+   return ret;
+}
+#endif
+
 #ifdef RANDOMIZE_ALLOCATED_MEMORY
 
 /*
@@ -492,8 +523,7 @@ AllocSetReset(MemoryContext context)
            char       *datastart = ((char *) block) + ALLOC_BLOCKHDRSZ;
 
 #ifdef CLOBBER_FREED_MEMORY
-           /* Wipe freed memory for debugging purposes */
-           memset(datastart, 0x7F, block->freeptr - datastart);
+           wipe_mem(datastart, block->freeptr - datastart);
 #endif
            block->freeptr = datastart;
            block->next = NULL;
@@ -502,8 +532,7 @@ AllocSetReset(MemoryContext context)
        {
            /* Normal case, release the block */
 #ifdef CLOBBER_FREED_MEMORY
-           /* Wipe freed memory for debugging purposes */
-           memset(block, 0x7F, block->freeptr - ((char *) block));
+           wipe_mem(block, block->freeptr - ((char *) block));
 #endif
            free(block);
        }
@@ -545,8 +574,7 @@ AllocSetDelete(MemoryContext context)
        AllocBlock  next = block->next;
 
 #ifdef CLOBBER_FREED_MEMORY
-       /* Wipe freed memory for debugging purposes */
-       memset(block, 0x7F, block->freeptr - ((char *) block));
+       wipe_mem(block, block->freeptr - ((char *) block));
 #endif
        free(block);
        block = next;
@@ -598,7 +626,7 @@ AllocSetAlloc(MemoryContext context, Size size)
        chunk->requested_size = size;
        /* set mark to catch clobber of "unused" space */
        if (size < chunk_size)
-           ((char *) AllocChunkGetPointer(chunk))[size] = 0x7E;
+           set_sentinel(AllocChunkGetPointer(chunk), size);
 #endif
 #ifdef RANDOMIZE_ALLOCATED_MEMORY
        /* fill the allocated space with junk */
@@ -644,7 +672,7 @@ AllocSetAlloc(MemoryContext context, Size size)
        chunk->requested_size = size;
        /* set mark to catch clobber of "unused" space */
        if (size < chunk->size)
-           ((char *) AllocChunkGetPointer(chunk))[size] = 0x7E;
+           set_sentinel(AllocChunkGetPointer(chunk), size);
 #endif
 #ifdef RANDOMIZE_ALLOCATED_MEMORY
        /* fill the allocated space with junk */
@@ -801,7 +829,7 @@ AllocSetAlloc(MemoryContext context, Size size)
    chunk->requested_size = size;
    /* set mark to catch clobber of "unused" space */
    if (size < chunk->size)
-       ((char *) AllocChunkGetPointer(chunk))[size] = 0x7E;
+       set_sentinel(AllocChunkGetPointer(chunk), size);
 #endif
 #ifdef RANDOMIZE_ALLOCATED_MEMORY
    /* fill the allocated space with junk */
@@ -827,7 +855,7 @@ AllocSetFree(MemoryContext context, void *pointer)
 #ifdef MEMORY_CONTEXT_CHECKING
    /* Test for someone scribbling on unused space in chunk */
    if (chunk->requested_size < chunk->size)
-       if (((char *) pointer)[chunk->requested_size] != 0x7E)
+       if (!sentinel_ok(pointer, chunk->requested_size))
            elog(WARNING, "detected write past chunk end in %s %p",
                 set->header.name, chunk);
 #endif
@@ -860,8 +888,7 @@ AllocSetFree(MemoryContext context, void *pointer)
        else
            prevblock->next = block->next;
 #ifdef CLOBBER_FREED_MEMORY
-       /* Wipe freed memory for debugging purposes */
-       memset(block, 0x7F, block->freeptr - ((char *) block));
+       wipe_mem(block, block->freeptr - ((char *) block));
 #endif
        free(block);
    }
@@ -873,8 +900,7 @@ AllocSetFree(MemoryContext context, void *pointer)
        chunk->aset = (void *) set->freelist[fidx];
 
 #ifdef CLOBBER_FREED_MEMORY
-       /* Wipe freed memory for debugging purposes */
-       memset(pointer, 0x7F, chunk->size);
+       wipe_mem(pointer, chunk->size);
 #endif
 
 #ifdef MEMORY_CONTEXT_CHECKING
@@ -901,7 +927,7 @@ AllocSetRealloc(MemoryContext context, void *pointer, Size size)
 #ifdef MEMORY_CONTEXT_CHECKING
    /* Test for someone scribbling on unused space in chunk */
    if (chunk->requested_size < oldsize)
-       if (((char *) pointer)[chunk->requested_size] != 0x7E)
+       if (!sentinel_ok(pointer, chunk->requested_size))
            elog(WARNING, "detected write past chunk end in %s %p",
                 set->header.name, chunk);
 #endif
@@ -924,7 +950,7 @@ AllocSetRealloc(MemoryContext context, void *pointer, Size size)
        chunk->requested_size = size;
        /* set mark to catch clobber of "unused" space */
        if (size < oldsize)
-           ((char *) pointer)[size] = 0x7E;
+           set_sentinel(pointer, size);
 #endif
        return pointer;
    }
@@ -987,7 +1013,7 @@ AllocSetRealloc(MemoryContext context, void *pointer, Size size)
        chunk->requested_size = size;
        /* set mark to catch clobber of "unused" space */
        if (size < chunk->size)
-           ((char *) AllocChunkGetPointer(chunk))[size] = 0x7E;
+           set_sentinel(AllocChunkGetPointer(chunk), size);
 #endif
 
        return AllocChunkGetPointer(chunk);
@@ -1136,11 +1162,9 @@ AllocSetCheck(MemoryContext context)
            AllocChunk  chunk = (AllocChunk) bpoz;
            Size        chsize,
                        dsize;
-           char       *chdata_end;
 
            chsize = chunk->size;       /* aligned chunk size */
            dsize = chunk->requested_size;      /* real data */
-           chdata_end = ((char *) chunk) + (ALLOC_CHUNKHDRSZ + dsize);
 
            /*
             * Check chunk size
@@ -1170,7 +1194,8 @@ AllocSetCheck(MemoryContext context)
            /*
             * Check for overwrite of "unallocated" space in chunk
             */
-           if (dsize > 0 && dsize < chsize && *chdata_end != 0x7E)
+           if (dsize > 0 && dsize < chsize &&
+               !sentinel_ok(chunk, ALLOC_CHUNKHDRSZ + dsize))
                elog(WARNING, "problem in alloc set %s: detected write past chunk end in block %p, chunk %p",
                     name, block, chunk);
 

diff --git a/src/backend/utils/mmgr/mcxt.c b/src/backend/utils/mmgr/mcxt.c
index 8dd3cf488964afaa3801b7b64c4b1ac1f9fa1157..c72e3470004bb4d51ab48a727e138da5194f771a 100644 (file)
--- a/src/backend/utils/mmgr/mcxt.c
+++ b/src/backend/utils/mmgr/mcxt.c
@@ -569,6 +569,8 @@ MemoryContextCreate(NodeTag tag, Size size,
 void *
 MemoryContextAlloc(MemoryContext context, Size size)
 {
+   void       *ret;
+
    AssertArg(MemoryContextIsValid(context));
 
    if (!AllocSizeIsValid(size))
@@ -577,7 +579,9 @@ MemoryContextAlloc(MemoryContext context, Size size)
 
    context->isReset = false;
 
-   return (*context->methods->alloc) (context, size);
+   ret = (*context->methods->alloc) (context, size);
+
+   return ret;
 }
 
 /*
@@ -638,6 +642,8 @@ void *
 palloc(Size size)
 {
    /* duplicates MemoryContextAlloc to avoid increased overhead */
+   void       *ret;
+
    AssertArg(MemoryContextIsValid(CurrentMemoryContext));
 
    if (!AllocSizeIsValid(size))
@@ -646,7 +652,9 @@ palloc(Size size)
 
    CurrentMemoryContext->isReset = false;
 
-   return (*CurrentMemoryContext->methods->alloc) (CurrentMemoryContext, size);
+   ret = (*CurrentMemoryContext->methods->alloc) (CurrentMemoryContext, size);
+
+   return ret;
 }
 
 void *
@@ -677,7 +685,7 @@ palloc0(Size size)
 void
 pfree(void *pointer)
 {
-   StandardChunkHeader *header;
+   MemoryContext context;
 
    /*
     * Try to detect bogus pointers handed to us, poorly though we can.
@@ -690,12 +698,12 @@ pfree(void *pointer)
    /*
     * OK, it's probably safe to look at the chunk header.
     */
-   header = (StandardChunkHeader *)
-       ((char *) pointer - STANDARDCHUNKHEADERSIZE);
+   context = ((StandardChunkHeader *)
+              ((char *) pointer - STANDARDCHUNKHEADERSIZE))->context;
 
-   AssertArg(MemoryContextIsValid(header->context));
+   AssertArg(MemoryContextIsValid(context));
 
-   (*header->context->methods->free_p) (header->context, pointer);
+   (*context->methods->free_p) (context, pointer);
 }
 
 /*
@@ -705,7 +713,12 @@ pfree(void *pointer)
 void *
 repalloc(void *pointer, Size size)
 {
-   StandardChunkHeader *header;
+   MemoryContext context;
+   void       *ret;
+
+   if (!AllocSizeIsValid(size))
+       elog(ERROR, "invalid memory alloc request size %lu",
+            (unsigned long) size);
 
    /*
     * Try to detect bogus pointers handed to us, poorly though we can.
@@ -718,20 +731,17 @@ repalloc(void *pointer, Size size)
    /*
     * OK, it's probably safe to look at the chunk header.
     */
-   header = (StandardChunkHeader *)
-       ((char *) pointer - STANDARDCHUNKHEADERSIZE);
+   context = ((StandardChunkHeader *)
+              ((char *) pointer - STANDARDCHUNKHEADERSIZE))->context;
 
-   AssertArg(MemoryContextIsValid(header->context));
-
-   if (!AllocSizeIsValid(size))
-       elog(ERROR, "invalid memory alloc request size %lu",
-            (unsigned long) size);
+   AssertArg(MemoryContextIsValid(context));
 
    /* isReset must be false already */
-   Assert(!header->context->isReset);
+   Assert(!context->isReset);
+
+   ret = (*context->methods->realloc) (context, pointer, size);
 
-   return (*header->context->methods->realloc) (header->context,
-                                                pointer, size);
+   return ret;
 }
 
 /*