Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * bump.c
4 : * Bump allocator definitions.
5 : *
6 : * Bump is a MemoryContext implementation designed for memory usages which
7 : * require allocating a large number of chunks, none of which ever need to be
8 : * pfree'd or realloc'd. Chunks allocated by this context have no chunk header
9 : * and operations which ordinarily require looking at the chunk header cannot
10 : * be performed. For example, pfree, realloc, GetMemoryChunkSpace and
11 : * GetMemoryChunkContext are all not possible with bump allocated chunks. The
12 : * only way to release memory allocated by this context type is to reset or
13 : * delete the context.
14 : *
15 : * Portions Copyright (c) 2024, PostgreSQL Global Development Group
16 : *
17 : * IDENTIFICATION
18 : * src/backend/utils/mmgr/bump.c
19 : *
20 : *
21 : * Bump is best suited to cases which require a large number of short-lived
22 : * chunks where performance matters. Because bump allocated chunks don't
23 : * have a chunk header, it can fit more chunks on each block. This means we
24 : * can do more with less memory and fewer cache lines. The reason it's best
25 : * suited for short-lived usages of memory is that ideally, pointers to bump
26 : * allocated chunks won't be visible to a large amount of code. The more
27 : * code that operates on memory allocated by this allocator, the more chances
28 : * that some code will try to perform a pfree or one of the other operations
29 : * which are made impossible due to the lack of chunk header. In order to
30 : * detect accidental usage of the various disallowed operations, we do add a
31 : * MemoryChunk chunk header in MEMORY_CONTEXT_CHECKING builds and have the
32 : * various disallowed functions raise an ERROR.
33 : *
34 : * Allocations are MAXALIGNed.
35 : *
36 : *-------------------------------------------------------------------------
37 : */
38 :
39 : #include "postgres.h"
40 :
41 : #include "lib/ilist.h"
42 : #include "port/pg_bitutils.h"
43 : #include "utils/memdebug.h"
44 : #include "utils/memutils.h"
45 : #include "utils/memutils_memorychunk.h"
46 : #include "utils/memutils_internal.h"
47 :
48 : #define Bump_BLOCKHDRSZ MAXALIGN(sizeof(BumpBlock))
49 :
50 : /* No chunk header unless built with MEMORY_CONTEXT_CHECKING */
51 : #ifdef MEMORY_CONTEXT_CHECKING
52 : #define Bump_CHUNKHDRSZ sizeof(MemoryChunk)
53 : #else
54 : #define Bump_CHUNKHDRSZ 0
55 : #endif
56 :
57 : #define Bump_CHUNK_FRACTION 8
58 :
59 : /* The keeper block is allocated in the same allocation as the set */
60 : #define KeeperBlock(set) ((BumpBlock *) ((char *) (set) + \
61 : MAXALIGN(sizeof(BumpContext))))
62 : #define IsKeeperBlock(set, blk) (KeeperBlock(set) == (blk))
63 :
64 : typedef struct BumpBlock BumpBlock; /* forward reference */
65 :
66 : typedef struct BumpContext
67 : {
68 : MemoryContextData header; /* Standard memory-context fields */
69 :
70 : /* Bump context parameters */
71 : uint32 initBlockSize; /* initial block size */
72 : uint32 maxBlockSize; /* maximum block size */
73 : uint32 nextBlockSize; /* next block size to allocate */
74 : uint32 allocChunkLimit; /* effective chunk size limit */
75 :
76 : dlist_head blocks; /* list of blocks with the block currently
77 : * being filled at the head */
78 : } BumpContext;
79 :
80 : /*
81 : * BumpBlock
82 : * BumpBlock is the unit of memory that is obtained by bump.c from
83 : * malloc(). It contains zero or more allocations, which are the
84 : * units requested by palloc().
85 : */
86 : struct BumpBlock
87 : {
88 : dlist_node node; /* doubly-linked list of blocks */
89 : #ifdef MEMORY_CONTEXT_CHECKING
90 : BumpContext *context; /* pointer back to the owning context */
91 : #endif
92 : char *freeptr; /* start of free space in this block */
93 : char *endptr; /* end of space in this block */
94 : };
95 :
96 : /*
97 : * BumpIsValid
98 : * True iff set is valid bump context.
99 : */
100 : #define BumpIsValid(set) \
101 : (PointerIsValid(set) && IsA(set, BumpContext))
102 :
103 : /*
104 : * We always store external chunks on a dedicated block. This makes fetching
105 : * the block from an external chunk easy since it's always the first and only
106 : * chunk on the block.
107 : */
108 : #define ExternalChunkGetBlock(chunk) \
109 : (BumpBlock *) ((char *) chunk - Bump_BLOCKHDRSZ)
110 :
111 : /* Inlined helper functions */
112 : static inline void BumpBlockInit(BumpContext *context, BumpBlock *block,
113 : Size blksize);
114 : static inline bool BumpBlockIsEmpty(BumpBlock *block);
115 : static inline void BumpBlockMarkEmpty(BumpBlock *block);
116 : static inline Size BumpBlockFreeBytes(BumpBlock *block);
117 : static inline void BumpBlockFree(BumpContext *set, BumpBlock *block);
118 :
119 :
120 : /*
121 : * BumpContextCreate
122 : * Create a new Bump context.
123 : *
124 : * parent: parent context, or NULL if top-level context
125 : * name: name of context (must be statically allocated)
126 : * minContextSize: minimum context size
127 : * initBlockSize: initial allocation block size
128 : * maxBlockSize: maximum allocation block size
129 : */
130 : MemoryContext
131 350128 : BumpContextCreate(MemoryContext parent, const char *name, Size minContextSize,
132 : Size initBlockSize, Size maxBlockSize)
133 : {
134 : Size firstBlockSize;
135 : Size allocSize;
136 : BumpContext *set;
137 : BumpBlock *block;
138 :
139 : /* ensure MemoryChunk's size is properly maxaligned */
140 : StaticAssertDecl(Bump_CHUNKHDRSZ == MAXALIGN(Bump_CHUNKHDRSZ),
141 : "sizeof(MemoryChunk) is not maxaligned");
142 :
143 : /*
144 : * First, validate allocation parameters. Asserts seem sufficient because
145 : * nobody varies their parameters at runtime. We somewhat arbitrarily
146 : * enforce a minimum 1K block size. We restrict the maximum block size to
147 : * MEMORYCHUNK_MAX_BLOCKOFFSET as MemoryChunks are limited to this in
148 : * regards to addressing the offset between the chunk and the block that
149 : * the chunk is stored on. We would be unable to store the offset between
150 : * the chunk and block for any chunks that were beyond
151 : * MEMORYCHUNK_MAX_BLOCKOFFSET bytes into the block if the block was to be
152 : * larger than this.
153 : */
154 : Assert(initBlockSize == MAXALIGN(initBlockSize) &&
155 : initBlockSize >= 1024);
156 : Assert(maxBlockSize == MAXALIGN(maxBlockSize) &&
157 : maxBlockSize >= initBlockSize &&
158 : AllocHugeSizeIsValid(maxBlockSize)); /* must be safe to double */
159 : Assert(minContextSize == 0 ||
160 : (minContextSize == MAXALIGN(minContextSize) &&
161 : minContextSize >= 1024 &&
162 : minContextSize <= maxBlockSize));
163 : Assert(maxBlockSize <= MEMORYCHUNK_MAX_BLOCKOFFSET);
164 :
165 : /* Determine size of initial block */
166 350128 : allocSize = MAXALIGN(sizeof(BumpContext)) + Bump_BLOCKHDRSZ +
167 : Bump_CHUNKHDRSZ;
168 350128 : if (minContextSize != 0)
169 0 : allocSize = Max(allocSize, minContextSize);
170 : else
171 350128 : allocSize = Max(allocSize, initBlockSize);
172 :
173 : /*
174 : * Allocate the initial block. Unlike other bump.c blocks, it starts with
175 : * the context header and its block header follows that.
176 : */
177 350128 : set = (BumpContext *) malloc(allocSize);
178 350128 : if (set == NULL)
179 : {
180 0 : MemoryContextStats(TopMemoryContext);
181 0 : ereport(ERROR,
182 : (errcode(ERRCODE_OUT_OF_MEMORY),
183 : errmsg("out of memory"),
184 : errdetail("Failed while creating memory context \"%s\".",
185 : name)));
186 : }
187 :
188 : /*
189 : * Avoid writing code that can fail between here and MemoryContextCreate;
190 : * we'd leak the header and initial block if we ereport in this stretch.
191 : */
192 350128 : dlist_init(&set->blocks);
193 :
194 : /* Fill in the initial block's block header */
195 350128 : block = KeeperBlock(set);
196 : /* determine the block size and initialize it */
197 350128 : firstBlockSize = allocSize - MAXALIGN(sizeof(BumpContext));
198 350128 : BumpBlockInit(set, block, firstBlockSize);
199 :
200 : /* add it to the doubly-linked list of blocks */
201 350128 : dlist_push_head(&set->blocks, &block->node);
202 :
203 : /*
204 : * Fill in BumpContext-specific header fields. The Asserts above should
205 : * ensure that these all fit inside a uint32.
206 : */
207 350128 : set->initBlockSize = (uint32) initBlockSize;
208 350128 : set->maxBlockSize = (uint32) maxBlockSize;
209 350128 : set->nextBlockSize = (uint32) initBlockSize;
210 :
211 : /*
212 : * Compute the allocation chunk size limit for this context.
213 : *
214 : * Limit the maximum size a non-dedicated chunk can be so that we can fit
215 : * at least Bump_CHUNK_FRACTION of chunks this big onto the maximum sized
216 : * block. We must further limit this value so that it's no more than
217 : * MEMORYCHUNK_MAX_VALUE. We're unable to have non-external chunks larger
218 : * than that value as we store the chunk size in the MemoryChunk 'value'
219 : * field in the call to MemoryChunkSetHdrMask().
220 : */
221 350128 : set->allocChunkLimit = Min(maxBlockSize, MEMORYCHUNK_MAX_VALUE);
222 350128 : while ((Size) (set->allocChunkLimit + Bump_CHUNKHDRSZ) >
223 1750640 : (Size) ((Size) (maxBlockSize - Bump_BLOCKHDRSZ) / Bump_CHUNK_FRACTION))
224 1400512 : set->allocChunkLimit >>= 1;
225 :
226 : /* Finally, do the type-independent part of context creation */
227 350128 : MemoryContextCreate((MemoryContext) set, T_BumpContext, MCTX_BUMP_ID,
228 : parent, name);
229 :
230 350128 : ((MemoryContext) set)->mem_allocated = allocSize;
231 :
232 350128 : return (MemoryContext) set;
233 : }
234 :
235 : /*
236 : * BumpReset
237 : * Frees all memory which is allocated in the given set.
238 : *
239 : * The code simply frees all the blocks in the context apart from the keeper
240 : * block.
241 : */
242 : void
243 352184 : BumpReset(MemoryContext context)
244 : {
245 352184 : BumpContext *set = (BumpContext *) context;
246 : dlist_mutable_iter miter;
247 :
248 : Assert(BumpIsValid(set));
249 :
250 : #ifdef MEMORY_CONTEXT_CHECKING
251 : /* Check for corruption and leaks before freeing */
252 : BumpCheck(context);
253 : #endif
254 :
255 724444 : dlist_foreach_modify(miter, &set->blocks)
256 : {
257 372260 : BumpBlock *block = dlist_container(BumpBlock, node, miter.cur);
258 :
259 372260 : if (IsKeeperBlock(set, block))
260 352184 : BumpBlockMarkEmpty(block);
261 : else
262 20076 : BumpBlockFree(set, block);
263 : }
264 :
265 : /* Reset block size allocation sequence, too */
266 352184 : set->nextBlockSize = set->initBlockSize;
267 :
268 : /* Ensure there is only 1 item in the dlist */
269 : Assert(!dlist_is_empty(&set->blocks));
270 : Assert(!dlist_has_next(&set->blocks, dlist_head_node(&set->blocks)));
271 352184 : }
272 :
273 : /*
274 : * BumpDelete
275 : * Free all memory which is allocated in the given context.
276 : */
277 : void
278 350128 : BumpDelete(MemoryContext context)
279 : {
280 : /* Reset to release all releasable BumpBlocks */
281 350128 : BumpReset(context);
282 : /* And free the context header and keeper block */
283 350128 : free(context);
284 350128 : }
285 :
286 : /*
287 : * Helper for BumpAlloc() that allocates an entire block for the chunk.
288 : *
289 : * BumpAlloc()'s comment explains why this is separate.
290 : */
291 : pg_noinline
292 : static void *
293 18 : BumpAllocLarge(MemoryContext context, Size size, int flags)
294 : {
295 18 : BumpContext *set = (BumpContext *) context;
296 : BumpBlock *block;
297 : #ifdef MEMORY_CONTEXT_CHECKING
298 : MemoryChunk *chunk;
299 : #endif
300 : Size chunk_size;
301 : Size required_size;
302 : Size blksize;
303 :
304 : /* validate 'size' is within the limits for the given 'flags' */
305 18 : MemoryContextCheckSize(context, size, flags);
306 :
307 : #ifdef MEMORY_CONTEXT_CHECKING
308 : /* ensure there's always space for the sentinel byte */
309 : chunk_size = MAXALIGN(size + 1);
310 : #else
311 18 : chunk_size = MAXALIGN(size);
312 : #endif
313 :
314 18 : required_size = chunk_size + Bump_CHUNKHDRSZ;
315 18 : blksize = required_size + Bump_BLOCKHDRSZ;
316 :
317 18 : block = (BumpBlock *) malloc(blksize);
318 18 : if (block == NULL)
319 0 : return NULL;
320 :
321 18 : context->mem_allocated += blksize;
322 :
323 : /* the block is completely full */
324 18 : block->freeptr = block->endptr = ((char *) block) + blksize;
325 :
326 : #ifdef MEMORY_CONTEXT_CHECKING
327 : /* block with a single (used) chunk */
328 : block->context = set;
329 :
330 : chunk = (MemoryChunk *) (((char *) block) + Bump_BLOCKHDRSZ);
331 :
332 : /* mark the MemoryChunk as externally managed */
333 : MemoryChunkSetHdrMaskExternal(chunk, MCTX_BUMP_ID);
334 :
335 : chunk->requested_size = size;
336 : /* set mark to catch clobber of "unused" space */
337 : Assert(size < chunk_size);
338 : set_sentinel(MemoryChunkGetPointer(chunk), size);
339 : #endif
340 : #ifdef RANDOMIZE_ALLOCATED_MEMORY
341 : /* fill the allocated space with junk */
342 : randomize_mem((char *) MemoryChunkGetPointer(chunk), size);
343 : #endif
344 :
345 : /*
346 : * Add the block to the tail of allocated blocks list. The current block
347 : * is left at the head of the list as it may still have space for
348 : * non-large allocations.
349 : */
350 18 : dlist_push_tail(&set->blocks, &block->node);
351 :
352 : #ifdef MEMORY_CONTEXT_CHECKING
353 : /* Ensure any padding bytes are marked NOACCESS. */
354 : VALGRIND_MAKE_MEM_NOACCESS((char *) MemoryChunkGetPointer(chunk) + size,
355 : chunk_size - size);
356 :
357 : /* Disallow access to the chunk header. */
358 : VALGRIND_MAKE_MEM_NOACCESS(chunk, Bump_CHUNKHDRSZ);
359 :
360 : return MemoryChunkGetPointer(chunk);
361 : #else
362 18 : return (void *) (((char *) block) + Bump_BLOCKHDRSZ);
363 : #endif
364 : }
365 :
366 : /*
367 : * Small helper for allocating a new chunk from a chunk, to avoid duplicating
368 : * the code between BumpAlloc() and BumpAllocFromNewBlock().
369 : */
370 : static inline void *
371 23355612 : BumpAllocChunkFromBlock(MemoryContext context, BumpBlock *block, Size size,
372 : Size chunk_size)
373 : {
374 : #ifdef MEMORY_CONTEXT_CHECKING
375 : MemoryChunk *chunk;
376 : #else
377 : void *ptr;
378 : #endif
379 :
380 : /* validate we've been given a block with enough free space */
381 : Assert(block != NULL);
382 : Assert((block->endptr - block->freeptr) >= Bump_CHUNKHDRSZ + chunk_size);
383 :
384 : #ifdef MEMORY_CONTEXT_CHECKING
385 : chunk = (MemoryChunk *) block->freeptr;
386 : #else
387 23355612 : ptr = (void *) block->freeptr;
388 : #endif
389 :
390 : /* point the freeptr beyond this chunk */
391 23355612 : block->freeptr += (Bump_CHUNKHDRSZ + chunk_size);
392 : Assert(block->freeptr <= block->endptr);
393 :
394 : #ifdef MEMORY_CONTEXT_CHECKING
395 : /* Prepare to initialize the chunk header. */
396 : VALGRIND_MAKE_MEM_UNDEFINED(chunk, Bump_CHUNKHDRSZ);
397 :
398 : MemoryChunkSetHdrMask(chunk, block, chunk_size, MCTX_BUMP_ID);
399 : chunk->requested_size = size;
400 : /* set mark to catch clobber of "unused" space */
401 : Assert(size < chunk_size);
402 : set_sentinel(MemoryChunkGetPointer(chunk), size);
403 :
404 : #ifdef RANDOMIZE_ALLOCATED_MEMORY
405 : /* fill the allocated space with junk */
406 : randomize_mem((char *) MemoryChunkGetPointer(chunk), size);
407 : #endif
408 :
409 : /* Ensure any padding bytes are marked NOACCESS. */
410 : VALGRIND_MAKE_MEM_NOACCESS((char *) MemoryChunkGetPointer(chunk) + size,
411 : chunk_size - size);
412 :
413 : /* Disallow access to the chunk header. */
414 : VALGRIND_MAKE_MEM_NOACCESS(chunk, Bump_CHUNKHDRSZ);
415 :
416 : return MemoryChunkGetPointer(chunk);
417 : #else
418 23355612 : return ptr;
419 : #endif /* MEMORY_CONTEXT_CHECKING */
420 : }
421 :
422 : /*
423 : * Helper for BumpAlloc() that allocates a new block and returns a chunk
424 : * allocated from it.
425 : *
426 : * BumpAlloc()'s comment explains why this is separate.
427 : */
428 : pg_noinline
429 : static void *
430 20058 : BumpAllocFromNewBlock(MemoryContext context, Size size, int flags,
431 : Size chunk_size)
432 : {
433 20058 : BumpContext *set = (BumpContext *) context;
434 : BumpBlock *block;
435 : Size blksize;
436 : Size required_size;
437 :
438 : /*
439 : * The first such block has size initBlockSize, and we double the space in
440 : * each succeeding block, but not more than maxBlockSize.
441 : */
442 20058 : blksize = set->nextBlockSize;
443 20058 : set->nextBlockSize <<= 1;
444 20058 : if (set->nextBlockSize > set->maxBlockSize)
445 2 : set->nextBlockSize = set->maxBlockSize;
446 :
447 : /* we'll need space for the chunk, chunk hdr and block hdr */
448 20058 : required_size = chunk_size + Bump_CHUNKHDRSZ + Bump_BLOCKHDRSZ;
449 : /* round the size up to the next power of 2 */
450 20058 : if (blksize < required_size)
451 0 : blksize = pg_nextpower2_size_t(required_size);
452 :
453 20058 : block = (BumpBlock *) malloc(blksize);
454 :
455 20058 : if (block == NULL)
456 0 : return MemoryContextAllocationFailure(context, size, flags);
457 :
458 20058 : context->mem_allocated += blksize;
459 :
460 : /* initialize the new block */
461 20058 : BumpBlockInit(set, block, blksize);
462 :
463 : /* add it to the doubly-linked list of blocks */
464 20058 : dlist_push_head(&set->blocks, &block->node);
465 :
466 20058 : return BumpAllocChunkFromBlock(context, block, size, chunk_size);
467 : }
468 :
469 : /*
470 : * BumpAlloc
471 : * Returns a pointer to allocated memory of given size or raises an ERROR
472 : * on allocation failure, or returns NULL when flags contains
473 : * MCXT_ALLOC_NO_OOM.
474 : *
475 : * No request may exceed:
476 : * MAXALIGN_DOWN(SIZE_MAX) - Bump_BLOCKHDRSZ - Bump_CHUNKHDRSZ
477 : * All callers use a much-lower limit.
478 : *
479 : *
480 : * Note: when using valgrind, it doesn't matter how the returned allocation
481 : * is marked, as mcxt.c will set it to UNDEFINED.
482 : * This function should only contain the most common code paths. Everything
483 : * else should be in pg_noinline helper functions, thus avoiding the overhead
484 : * of creating a stack frame for the common cases. Allocating memory is often
485 : * a bottleneck in many workloads, so avoiding stack frame setup is
486 : * worthwhile. Helper functions should always directly return the newly
487 : * allocated memory so that we can just return that address directly as a tail
488 : * call.
489 : */
490 : void *
491 23355630 : BumpAlloc(MemoryContext context, Size size, int flags)
492 : {
493 23355630 : BumpContext *set = (BumpContext *) context;
494 : BumpBlock *block;
495 : Size chunk_size;
496 : Size required_size;
497 :
498 : Assert(BumpIsValid(set));
499 :
500 : #ifdef MEMORY_CONTEXT_CHECKING
501 : /* ensure there's always space for the sentinel byte */
502 : chunk_size = MAXALIGN(size + 1);
503 : #else
504 23355630 : chunk_size = MAXALIGN(size);
505 : #endif
506 :
507 : /*
508 : * If requested size exceeds maximum for chunks we hand the request off to
509 : * BumpAllocLarge().
510 : */
511 23355630 : if (chunk_size > set->allocChunkLimit)
512 18 : return BumpAllocLarge(context, size, flags);
513 :
514 23355612 : required_size = chunk_size + Bump_CHUNKHDRSZ;
515 :
516 : /*
517 : * Not an oversized chunk. We try to first make use of the latest block,
518 : * but if there's not enough space in it we must allocate a new block.
519 : */
520 23355612 : block = dlist_container(BumpBlock, node, dlist_head_node(&set->blocks));
521 :
522 23355612 : if (BumpBlockFreeBytes(block) < required_size)
523 20058 : return BumpAllocFromNewBlock(context, size, flags, chunk_size);
524 :
525 : /* The current block has space, so just allocate chunk there. */
526 23335554 : return BumpAllocChunkFromBlock(context, block, size, chunk_size);
527 : }
528 :
529 : /*
530 : * BumpBlockInit
531 : * Initializes 'block' assuming 'blksize'. Does not update the context's
532 : * mem_allocated field.
533 : */
534 : static inline void
535 370186 : BumpBlockInit(BumpContext *context, BumpBlock *block, Size blksize)
536 : {
537 : #ifdef MEMORY_CONTEXT_CHECKING
538 : block->context = context;
539 : #endif
540 370186 : block->freeptr = ((char *) block) + Bump_BLOCKHDRSZ;
541 370186 : block->endptr = ((char *) block) + blksize;
542 :
543 : /* Mark unallocated space NOACCESS. */
544 : VALGRIND_MAKE_MEM_NOACCESS(block->freeptr, blksize - Bump_BLOCKHDRSZ);
545 370186 : }
546 :
547 : /*
548 : * BumpBlockIsEmpty
549 : * Returns true iff 'block' contains no chunks
550 : */
551 : static inline bool
552 0 : BumpBlockIsEmpty(BumpBlock *block)
553 : {
554 : /* it's empty if the freeptr has not moved */
555 0 : return (block->freeptr == ((char *) block + Bump_BLOCKHDRSZ));
556 : }
557 :
558 : /*
559 : * BumpBlockMarkEmpty
560 : * Set a block as empty. Does not free the block.
561 : */
562 : static inline void
563 352184 : BumpBlockMarkEmpty(BumpBlock *block)
564 : {
565 : #if defined(USE_VALGRIND) || defined(CLOBBER_FREED_MEMORY)
566 : char *datastart = ((char *) block) + Bump_BLOCKHDRSZ;
567 : #endif
568 :
569 : #ifdef CLOBBER_FREED_MEMORY
570 : wipe_mem(datastart, block->freeptr - datastart);
571 : #else
572 : /* wipe_mem() would have done this */
573 : VALGRIND_MAKE_MEM_NOACCESS(datastart, block->freeptr - datastart);
574 : #endif
575 :
576 : /* Reset the block, but don't return it to malloc */
577 352184 : block->freeptr = ((char *) block) + Bump_BLOCKHDRSZ;
578 352184 : }
579 :
580 : /*
581 : * BumpBlockFreeBytes
582 : * Returns the number of bytes free in 'block'
583 : */
584 : static inline Size
585 23355612 : BumpBlockFreeBytes(BumpBlock *block)
586 : {
587 23355612 : return (block->endptr - block->freeptr);
588 : }
589 :
590 : /*
591 : * BumpBlockFree
592 : * Remove 'block' from 'set' and release the memory consumed by it.
593 : */
594 : static inline void
595 20076 : BumpBlockFree(BumpContext *set, BumpBlock *block)
596 : {
597 : /* Make sure nobody tries to free the keeper block */
598 : Assert(!IsKeeperBlock(set, block));
599 :
600 : /* release the block from the list of blocks */
601 20076 : dlist_delete(&block->node);
602 :
603 20076 : ((MemoryContext) set)->mem_allocated -= ((char *) block->endptr - (char *) block);
604 :
605 : #ifdef CLOBBER_FREED_MEMORY
606 : wipe_mem(block, ((char *) block->endptr - (char *) block));
607 : #endif
608 :
609 20076 : free(block);
610 20076 : }
611 :
612 : /*
613 : * BumpFree
614 : * Unsupported.
615 : */
616 : void
617 0 : BumpFree(void *pointer)
618 : {
619 0 : elog(ERROR, "%s is not supported by the bump memory allocator", "pfree");
620 : }
621 :
622 : /*
623 : * BumpRealloc
624 : * Unsupported.
625 : */
626 : void *
627 0 : BumpRealloc(void *pointer, Size size, int flags)
628 : {
629 0 : elog(ERROR, "%s is not supported by the bump memory allocator", "realloc");
630 : return NULL; /* keep compiler quiet */
631 : }
632 :
633 : /*
634 : * BumpGetChunkContext
635 : * Unsupported.
636 : */
637 : MemoryContext
638 0 : BumpGetChunkContext(void *pointer)
639 : {
640 0 : elog(ERROR, "%s is not supported by the bump memory allocator", "GetMemoryChunkContext");
641 : return NULL; /* keep compiler quiet */
642 : }
643 :
644 : /*
645 : * BumpGetChunkSpace
646 : * Unsupported.
647 : */
648 : Size
649 0 : BumpGetChunkSpace(void *pointer)
650 : {
651 0 : elog(ERROR, "%s is not supported by the bump memory allocator", "GetMemoryChunkSpace");
652 : return 0; /* keep compiler quiet */
653 : }
654 :
655 : /*
656 : * BumpIsEmpty
657 : * Is a BumpContext empty of any allocated space?
658 : */
659 : bool
660 0 : BumpIsEmpty(MemoryContext context)
661 : {
662 0 : BumpContext *set = (BumpContext *) context;
663 : dlist_iter iter;
664 :
665 : Assert(BumpIsValid(set));
666 :
667 0 : dlist_foreach(iter, &set->blocks)
668 : {
669 0 : BumpBlock *block = dlist_container(BumpBlock, node, iter.cur);
670 :
671 0 : if (!BumpBlockIsEmpty(block))
672 0 : return false;
673 : }
674 :
675 0 : return true;
676 : }
677 :
678 : /*
679 : * BumpStats
680 : * Compute stats about memory consumption of a Bump context.
681 : *
682 : * printfunc: if not NULL, pass a human-readable stats string to this.
683 : * passthru: pass this pointer through to printfunc.
684 : * totals: if not NULL, add stats about this context into *totals.
685 : * print_to_stderr: print stats to stderr if true, elog otherwise.
686 : */
687 : void
688 6 : BumpStats(MemoryContext context, MemoryStatsPrintFunc printfunc,
689 : void *passthru, MemoryContextCounters *totals, bool print_to_stderr)
690 : {
691 6 : BumpContext *set = (BumpContext *) context;
692 6 : Size nblocks = 0;
693 6 : Size totalspace = 0;
694 6 : Size freespace = 0;
695 : dlist_iter iter;
696 :
697 : Assert(BumpIsValid(set));
698 :
699 18 : dlist_foreach(iter, &set->blocks)
700 : {
701 12 : BumpBlock *block = dlist_container(BumpBlock, node, iter.cur);
702 :
703 12 : nblocks++;
704 12 : totalspace += (block->endptr - (char *) block);
705 12 : freespace += (block->endptr - block->freeptr);
706 : }
707 :
708 6 : if (printfunc)
709 : {
710 : char stats_string[200];
711 :
712 0 : snprintf(stats_string, sizeof(stats_string),
713 : "%zu total in %zu blocks; %zu free; %zu used",
714 : totalspace, nblocks, freespace, totalspace - freespace);
715 0 : printfunc(context, passthru, stats_string, print_to_stderr);
716 : }
717 :
718 6 : if (totals)
719 : {
720 6 : totals->nblocks += nblocks;
721 6 : totals->totalspace += totalspace;
722 6 : totals->freespace += freespace;
723 : }
724 6 : }
725 :
726 :
727 : #ifdef MEMORY_CONTEXT_CHECKING
728 :
729 : /*
730 : * BumpCheck
731 : * Walk through chunks and check consistency of memory.
732 : *
733 : * NOTE: report errors as WARNING, *not* ERROR or FATAL. Otherwise you'll
734 : * find yourself in an infinite loop when trouble occurs, because this
735 : * routine will be entered again when elog cleanup tries to release memory!
736 : */
737 : void
738 : BumpCheck(MemoryContext context)
739 : {
740 : BumpContext *bump = (BumpContext *) context;
741 : const char *name = context->name;
742 : dlist_iter iter;
743 : Size total_allocated = 0;
744 :
745 : /* walk all blocks in this context */
746 : dlist_foreach(iter, &bump->blocks)
747 : {
748 : BumpBlock *block = dlist_container(BumpBlock, node, iter.cur);
749 : int nchunks;
750 : char *ptr;
751 : bool has_external_chunk = false;
752 :
753 : if (IsKeeperBlock(bump, block))
754 : total_allocated += block->endptr - (char *) bump;
755 : else
756 : total_allocated += block->endptr - (char *) block;
757 :
758 : /* check block belongs to the correct context */
759 : if (block->context != bump)
760 : elog(WARNING, "problem in Bump %s: bogus context link in block %p",
761 : name, block);
762 :
763 : /* now walk through the chunks and count them */
764 : nchunks = 0;
765 : ptr = ((char *) block) + Bump_BLOCKHDRSZ;
766 :
767 : while (ptr < block->freeptr)
768 : {
769 : MemoryChunk *chunk = (MemoryChunk *) ptr;
770 : BumpBlock *chunkblock;
771 : Size chunksize;
772 :
773 : /* allow access to the chunk header */
774 : VALGRIND_MAKE_MEM_DEFINED(chunk, Bump_CHUNKHDRSZ);
775 :
776 : if (MemoryChunkIsExternal(chunk))
777 : {
778 : chunkblock = ExternalChunkGetBlock(chunk);
779 : chunksize = block->endptr - (char *) MemoryChunkGetPointer(chunk);
780 : has_external_chunk = true;
781 : }
782 : else
783 : {
784 : chunkblock = MemoryChunkGetBlock(chunk);
785 : chunksize = MemoryChunkGetValue(chunk);
786 : }
787 :
788 : /* move to the next chunk */
789 : ptr += (chunksize + Bump_CHUNKHDRSZ);
790 :
791 : nchunks += 1;
792 :
793 : /* chunks have both block and context pointers, so check both */
794 : if (chunkblock != block)
795 : elog(WARNING, "problem in Bump %s: bogus block link in block %p, chunk %p",
796 : name, block, chunk);
797 : }
798 :
799 : if (has_external_chunk && nchunks > 1)
800 : elog(WARNING, "problem in Bump %s: external chunk on non-dedicated block %p",
801 : name, block);
802 :
803 : }
804 :
805 : Assert(total_allocated == context->mem_allocated);
806 : }
807 :
808 : #endif /* MEMORY_CONTEXT_CHECKING */
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