project-base/server-skynet-source-3rd-jemalloc
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Fix a heap profiling regression.

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Add the prof_tctx_state_destroying transitionary state to fix a race
between a thread destroying a tctx and another thread creating a new
equivalent tctx.

This regression was introduced by
602c8e0971 (Implement per thread heap
profiling.).
This commit is contained in:
Jason Evans 2015-03-14 14:01:35 -07:00
parent d6384b09e1
commit 764b00023f
2 changed files with 32 additions and 13 deletions
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1
include/jemalloc/internal/prof.h
View File

@ -81,6 +81,7 @@ struct prof_cnt_s {
typedef enum {
prof_tctx_state_initializing,
prof_tctx_state_nominal,
prof_tctx_state_destroying,
prof_tctx_state_dumping,
prof_tctx_state_purgatory /* Dumper must finish destroying. */
} prof_tctx_state_t;

44
src/prof.c
View File

@ -642,10 +642,13 @@ prof_tctx_destroy(tsd_t *tsd, prof_tctx_t *tctx)
ckh_remove(tsd, &tdata->bt2tctx, &gctx->bt, NULL, NULL);
destroy_tdata = prof_tdata_should_destroy(tdata, false);
if (tctx->state == prof_tctx_state_nominal)
tctx->state = prof_tctx_state_destroying;
malloc_mutex_unlock(tdata->lock);
malloc_mutex_lock(gctx->lock);
if (tctx->state != prof_tctx_state_dumping) {
switch (tctx->state) {
case prof_tctx_state_destroying:
tctx_tree_remove(&gctx->tctxs, tctx);
destroy_tctx = true;
if (prof_gctx_should_destroy(gctx)) {
@ -667,7 +670,8 @@ prof_tctx_destroy(tsd_t *tsd, prof_tctx_t *tctx)
destroy_gctx = true;
} else
destroy_gctx = false;
} else {
break;
case prof_tctx_state_dumping:
/*
* A dumping thread needs tctx to remain valid until dumping
* has finished. Change state such that the dumping thread will
@ -676,6 +680,9 @@ prof_tctx_destroy(tsd_t *tsd, prof_tctx_t *tctx)
tctx->state = prof_tctx_state_purgatory;
destroy_tctx = false;
destroy_gctx = false;
break;
default:
not_reached();
}
malloc_mutex_unlock(gctx->lock);
if (destroy_gctx) {
@ -1021,21 +1028,30 @@ prof_tctx_merge_tdata(prof_tctx_t *tctx, prof_tdata_t *tdata)
{
malloc_mutex_lock(tctx->gctx->lock);
if (tctx->state == prof_tctx_state_initializing) {
switch (tctx->state) {
case prof_tctx_state_initializing:
case prof_tctx_state_destroying:
malloc_mutex_unlock(tctx->gctx->lock);
return;
}
assert(tctx->state == prof_tctx_state_nominal);
tctx->state = prof_tctx_state_dumping;
malloc_mutex_unlock(tctx->gctx->lock);
case prof_tctx_state_nominal:
tctx->state = prof_tctx_state_dumping;
malloc_mutex_unlock(tctx->gctx->lock);
memcpy(&tctx->dump_cnts, &tctx->cnts, sizeof(prof_cnt_t));
memcpy(&tctx->dump_cnts, &tctx->cnts, sizeof(prof_cnt_t));
tdata->cnt_summed.curobjs += tctx->dump_cnts.curobjs;
tdata->cnt_summed.curbytes += tctx->dump_cnts.curbytes;
if (opt_prof_accum) {
tdata->cnt_summed.accumobjs += tctx->dump_cnts.accumobjs;
tdata->cnt_summed.accumbytes += tctx->dump_cnts.accumbytes;
tdata->cnt_summed.curobjs += tctx->dump_cnts.curobjs;
tdata->cnt_summed.curbytes += tctx->dump_cnts.curbytes;
if (opt_prof_accum) {
tdata->cnt_summed.accumobjs +=
tctx->dump_cnts.accumobjs;
tdata->cnt_summed.accumbytes +=
tctx->dump_cnts.accumbytes;
}
break;
case prof_tctx_state_dumping:
case prof_tctx_state_purgatory:
not_reached();
}
}
@ -1059,6 +1075,7 @@ prof_tctx_merge_iter(prof_tctx_tree_t *tctxs, prof_tctx_t *tctx, void *arg)
switch (tctx->state) {
case prof_tctx_state_nominal:
case prof_tctx_state_destroying:
/* New since dumping started; ignore. */
break;
case prof_tctx_state_dumping:
@ -1094,6 +1111,7 @@ prof_tctx_finish_iter(prof_tctx_tree_t *tctxs, prof_tctx_t *tctx, void *arg)
switch (tctx->state) {
case prof_tctx_state_nominal:
case prof_tctx_state_destroying:
/* New since dumping started; ignore. */
break;
case prof_tctx_state_dumping: