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Function tmalloc_large

lib/dlmalloc/malloc.c:4429–4497  ·  view source on GitHub ↗

allocate a large request from the best fitting chunk in a treebin */

Source from the content-addressed store, hash-verified

4427
4428/* allocate a large request from the best fitting chunk in a treebin */
4429static void* tmalloc_large(mstate m, size_t nb) {
4430 tchunkptr v = 0;
4431 size_t rsize = -nb; /* Unsigned negation */
4432 tchunkptr t;
4433 bindex_t idx;
4434 compute_tree_index(nb, idx);
4435 if ((t = *treebin_at(m, idx)) != 0) {
4436 /* Traverse tree for this bin looking for node with size == nb */
4437 size_t sizebits = nb << leftshift_for_tree_index(idx);
4438 tchunkptr rst = 0; /* The deepest untaken right subtree */
4439 for (;;) {
4440 tchunkptr rt;
4441 size_t trem = chunksize(t) - nb;
4442 if (trem < rsize) {
4443 v = t;
4444 if ((rsize = trem) == 0)
4445 break;
4446 }
4447 rt = t->child[1];
4448 t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1];
4449 if (rt != 0 && rt != t)
4450 rst = rt;
4451 if (t == 0) {
4452 t = rst; /* set t to least subtree holding sizes > nb */
4453 break;
4454 }
4455 sizebits <<= 1;
4456 }
4457 }
4458 if (t == 0 && v == 0) { /* set t to root of next non-empty treebin */
4459 binmap_t leftbits = left_bits(idx2bit(idx)) & m->treemap;
4460 if (leftbits != 0) {
4461 bindex_t i;
4462 binmap_t leastbit = least_bit(leftbits);
4463 compute_bit2idx(leastbit, i);
4464 t = *treebin_at(m, i);
4465 }
4466 }
4467
4468 while (t != 0) { /* find smallest of tree or subtree */
4469 size_t trem = chunksize(t) - nb;
4470 if (trem < rsize) {
4471 rsize = trem;
4472 v = t;
4473 }
4474 t = leftmost_child(t);
4475 }
4476
4477 /* If dv is a better fit, return 0 so malloc will use it */
4478 if (v != 0 && rsize < (size_t)(m->dvsize - nb)) {
4479 if (RTCHECK(ok_address(m, v))) { /* split */
4480 mchunkptr r = chunk_plus_offset(v, nb);
4481 assert(chunksize(v) == rsize + nb);
4482 if (RTCHECK(ok_next(v, r))) {
4483 unlink_large_chunk(m, v);
4484 if (rsize < MIN_CHUNK_SIZE)
4485 set_inuse_and_pinuse(m, v, (rsize + nb));
4486 else {

Callers 2

dlmallocFunction · 0.85
mspace_mallocFunction · 0.85

Calls

no outgoing calls

Tested by

no test coverage detected