Allow setting a dump hook

If users want to be notified when a heap dump occurs, they can set this hook.
This commit is contained in:
Alex Lapenkou 2021-09-01 13:00:01 -07:00 committed by Alexander Lapenkov
parent f7d46b8119
commit a9031a0970
6 changed files with 178 additions and 11 deletions

View File

@ -48,14 +48,12 @@ extern size_t lg_prof_sample;
extern bool prof_booted;
/*
* A hook to mock out backtrace functionality. This can be handy, since it's
* otherwise difficult to guarantee that two allocations are reported as coming
* from the exact same stack trace in the presence of an optimizing compiler.
*/
void prof_backtrace_hook_set(prof_backtrace_hook_t hook);
prof_backtrace_hook_t prof_backtrace_hook_get();
void prof_dump_hook_set(prof_dump_hook_t hook);
prof_dump_hook_t prof_dump_hook_get();
/* Functions only accessed in prof_inlines.h */
prof_tdata_t *prof_tdata_init(tsd_t *tsd);
prof_tdata_t *prof_tdata_reinit(tsd_t *tsd, prof_tdata_t *tdata);

View File

@ -13,4 +13,9 @@
*/
typedef void (*prof_backtrace_hook_t)(void **, unsigned *, unsigned);
/*
* A callback hook that notifies about recently dumped heap profile.
*/
typedef void (*prof_dump_hook_t)(const char *filename);
#endif /* JEMALLOC_INTERNAL_PROF_HOOK_H */

View File

@ -306,6 +306,7 @@ CTL_PROTO(stats_zero_reallocs)
CTL_PROTO(experimental_hooks_install)
CTL_PROTO(experimental_hooks_remove)
CTL_PROTO(experimental_hooks_prof_backtrace)
CTL_PROTO(experimental_hooks_prof_dump)
CTL_PROTO(experimental_thread_activity_callback)
CTL_PROTO(experimental_utilization_query)
CTL_PROTO(experimental_utilization_batch_query)
@ -835,7 +836,8 @@ static const ctl_named_node_t stats_node[] = {
static const ctl_named_node_t experimental_hooks_node[] = {
{NAME("install"), CTL(experimental_hooks_install)},
{NAME("remove"), CTL(experimental_hooks_remove)},
{NAME("prof_backtrace"), CTL(experimental_hooks_prof_backtrace)}
{NAME("prof_backtrace"), CTL(experimental_hooks_prof_backtrace)},
{NAME("prof_dump"), CTL(experimental_hooks_prof_dump)},
};
static const ctl_named_node_t experimental_thread_node[] = {
@ -3362,6 +3364,34 @@ label_return:
return ret;
}
static int
experimental_hooks_prof_dump_ctl(tsd_t *tsd, const size_t *mib,
size_t miblen, void *oldp, size_t *oldlenp, void *newp, size_t newlen) {
int ret;
if (oldp == NULL && newp == NULL) {
ret = EINVAL;
goto label_return;
}
if (oldp != NULL) {
prof_dump_hook_t old_hook =
prof_dump_hook_get();
READ(old_hook, prof_dump_hook_t);
}
if (newp != NULL) {
if (!opt_prof) {
ret = ENOENT;
goto label_return;
}
prof_dump_hook_t new_hook JEMALLOC_CC_SILENCE_INIT(NULL);
WRITE(new_hook, prof_dump_hook_t);
prof_dump_hook_set(new_hook);
}
ret = 0;
label_return:
return ret;
}
/******************************************************************************/
CTL_RO_CGEN(config_stats, stats_allocated, ctl_stats->allocated, size_t)

View File

@ -73,6 +73,9 @@ bool prof_booted = false;
/* Logically a prof_backtrace_hook_t. */
atomic_p_t prof_backtrace_hook;
/* Logically a prof_dump_hook_t. */
atomic_p_t prof_dump_hook;
/******************************************************************************/
void
@ -533,6 +536,17 @@ prof_backtrace_hook_get() {
ATOMIC_ACQUIRE);
}
void
prof_dump_hook_set(prof_dump_hook_t hook) {
atomic_store_p(&prof_dump_hook, hook, ATOMIC_RELEASE);
}
prof_dump_hook_t
prof_dump_hook_get() {
return (prof_dump_hook_t)atomic_load_p(&prof_dump_hook,
ATOMIC_ACQUIRE);
}
void
prof_boot0(void) {
cassert(config_prof);
@ -672,8 +686,8 @@ prof_boot2(tsd_t *tsd, base_t *base) {
}
}
prof_hooks_init();
prof_unwind_init();
prof_hooks_init();
}
prof_booted = true;

View File

@ -55,6 +55,7 @@ prof_backtrace_impl(void **vec, unsigned *len, unsigned max_len) {
cassert(config_prof);
assert(*len == 0);
assert(vec != NULL);
assert(max_len == PROF_BT_MAX);
nframes = unw_backtrace(vec, PROF_BT_MAX);
if (nframes <= 0) {
@ -95,6 +96,8 @@ prof_backtrace_impl(void **vec, unsigned *len, unsigned max_len) {
prof_unwind_data_t data = {vec, len, max_len};
cassert(config_prof);
assert(vec != NULL);
assert(max_len == PROF_BT_MAX);
_Unwind_Backtrace(prof_unwind_callback, &data);
}
@ -118,6 +121,8 @@ prof_backtrace_impl(void **vec, unsigned *len, unsigned max_len) {
}
cassert(config_prof);
assert(vec != NULL);
assert(max_len == PROF_BT_MAX);
BT_FRAME(0)
BT_FRAME(1)
@ -272,8 +277,10 @@ prof_backtrace_impl(void **vec, unsigned *len, unsigned max_len) {
void
prof_backtrace(tsd_t *tsd, prof_bt_t *bt) {
cassert(config_prof);
pre_reentrancy(tsd, NULL);
prof_backtrace_hook_t prof_backtrace_hook = prof_backtrace_hook_get();
assert(prof_backtrace_hook != NULL);
pre_reentrancy(tsd, NULL);
prof_backtrace_hook(bt->vec, &bt->len, PROF_BT_MAX);
post_reentrancy(tsd);
}
@ -281,6 +288,7 @@ prof_backtrace(tsd_t *tsd, prof_bt_t *bt) {
void
prof_hooks_init() {
prof_backtrace_hook_set(&prof_backtrace_impl);
prof_dump_hook_set(NULL);
}
void
@ -506,6 +514,10 @@ prof_dump(tsd_t *tsd, bool propagate_err, const char *filename,
buf_writer_terminate(tsd_tsdn(tsd), &buf_writer);
prof_dump_close(&arg);
prof_dump_hook_t dump_hook = prof_dump_hook_get();
if (dump_hook != NULL) {
dump_hook(filename);
}
malloc_mutex_unlock(tsd_tsdn(tsd), &prof_dump_mtx);
post_reentrancy(tsd);

View File

@ -1,6 +1,11 @@
#include "test/jemalloc_test.h"
const char *dump_filename = "/dev/null";
prof_backtrace_hook_t default_hook;
bool mock_bt_hook_called = false;
bool mock_dump_hook_called = false;
void
mock_bt_hook(void **vec, unsigned *len, unsigned max_len) {
@ -11,7 +16,38 @@ mock_bt_hook(void **vec, unsigned *len, unsigned max_len) {
mock_bt_hook_called = true;
}
TEST_BEGIN(test_prof_backtrace_hook) {
void
mock_bt_augmenting_hook(void **vec, unsigned *len, unsigned max_len) {
default_hook(vec, len, max_len);
expect_u_gt(*len, 0, "Default backtrace hook returned empty backtrace");
expect_u_lt(*len, max_len,
"Default backtrace hook returned too large backtrace");
/* Add a separator between default frames and augmented */
vec[*len] = (void *)0x030303030;
(*len)++;
/* Add more stack frames */
for (unsigned i = 0; i < 3; ++i) {
if (*len == max_len) {
break;
}
vec[*len] = (void *)((uintptr_t)i);
(*len)++;
}
mock_bt_hook_called = true;
}
void
mock_dump_hook(const char *filename) {
mock_dump_hook_called = true;
expect_str_eq(filename, dump_filename,
"Incorrect file name passed to the dump hook");
}
TEST_BEGIN(test_prof_backtrace_hook_replace) {
test_skip_if(!config_prof);
@ -27,7 +63,6 @@ TEST_BEGIN(test_prof_backtrace_hook) {
NULL, 0, (void *)&null_hook, sizeof(null_hook)),
EINVAL, "Incorrectly allowed NULL backtrace hook");
prof_backtrace_hook_t default_hook;
size_t default_hook_sz = sizeof(prof_backtrace_hook_t);
prof_backtrace_hook_t hook = &mock_bt_hook;
expect_d_eq(mallctl("experimental.hooks.prof_backtrace",
@ -54,8 +89,81 @@ TEST_BEGIN(test_prof_backtrace_hook) {
}
TEST_END
TEST_BEGIN(test_prof_backtrace_hook_augment) {
test_skip_if(!config_prof);
mock_bt_hook_called = false;
void *p0 = mallocx(1, 0);
assert_ptr_not_null(p0, "Failed to allocate");
expect_false(mock_bt_hook_called, "Called mock hook before it's set");
size_t default_hook_sz = sizeof(prof_backtrace_hook_t);
prof_backtrace_hook_t hook = &mock_bt_augmenting_hook;
expect_d_eq(mallctl("experimental.hooks.prof_backtrace",
(void *)&default_hook, &default_hook_sz, (void *)&hook,
sizeof(hook)), 0, "Unexpected mallctl failure setting hook");
void *p1 = mallocx(1, 0);
assert_ptr_not_null(p1, "Failed to allocate");
expect_true(mock_bt_hook_called, "Didn't call mock hook");
prof_backtrace_hook_t current_hook;
size_t current_hook_sz = sizeof(prof_backtrace_hook_t);
expect_d_eq(mallctl("experimental.hooks.prof_backtrace",
(void *)&current_hook, &current_hook_sz, (void *)&default_hook,
sizeof(default_hook)), 0,
"Unexpected mallctl failure resetting hook to default");
expect_ptr_eq(current_hook, hook,
"Hook returned by mallctl is not equal to mock hook");
dallocx(p1, 0);
dallocx(p0, 0);
}
TEST_END
TEST_BEGIN(test_prof_dump_hook) {
test_skip_if(!config_prof);
mock_dump_hook_called = false;
expect_d_eq(mallctl("prof.dump", NULL, NULL, (void *)&dump_filename,
sizeof(dump_filename)), 0, "Failed to dump heap profile");
expect_false(mock_dump_hook_called, "Called dump hook before it's set");
size_t default_hook_sz = sizeof(prof_dump_hook_t);
prof_dump_hook_t hook = &mock_dump_hook;
expect_d_eq(mallctl("experimental.hooks.prof_dump",
(void *)&default_hook, &default_hook_sz, (void *)&hook,
sizeof(hook)), 0, "Unexpected mallctl failure setting hook");
expect_d_eq(mallctl("prof.dump", NULL, NULL, (void *)&dump_filename,
sizeof(dump_filename)), 0, "Failed to dump heap profile");
expect_true(mock_dump_hook_called, "Didn't call mock hook");
prof_dump_hook_t current_hook;
size_t current_hook_sz = sizeof(prof_dump_hook_t);
expect_d_eq(mallctl("experimental.hooks.prof_dump",
(void *)&current_hook, &current_hook_sz, (void *)&default_hook,
sizeof(default_hook)), 0,
"Unexpected mallctl failure resetting hook to default");
expect_ptr_eq(current_hook, hook,
"Hook returned by mallctl is not equal to mock hook");
}
TEST_END
int
main(void) {
return test(
test_prof_backtrace_hook);
test_prof_backtrace_hook_replace,
test_prof_backtrace_hook_augment,
test_prof_dump_hook);
}