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Postgres FD Implementation
Commit a855148a authored by Noah Misch's avatar Noah Misch
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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.
parent 1d96bb96
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Showing with 73 additions and 38 deletions
src/backend/utils/mmgr/aset.c
View file @ a855148a
......@@ -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);
......
src/backend/utils/mmgr/mcxt.c
View file @ a855148a
......@@ -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;
}
/*
......
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