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Adresses pr #165 and issue #164 by @colesbury:

Browse Source 
On Mac OS, the thread-local _mi_default_heap may get reset before
_mi_thread_done is called, leaking the default heap on non-main threads.

Now the current default heap is also stored in mi_pthread_key (or mi_fls_key
on Windows). The _mi_thread_done function is called with this value.
This commit is contained in:
daan 2019-11-13 17:22:03 -08:00
parent f0e02bab03
commit a4ed63d127
3 changed files with 38 additions and 28 deletions
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1
include/mimalloc-internal.h
View File

@ -101,6 +101,7 @@ uint8_t _mi_bsr(uintptr_t x); // bit-scan-right, used on BSD i
void _mi_heap_destroy_pages(mi_heap_t* heap);
void _mi_heap_collect_abandon(mi_heap_t* heap);
uintptr_t _mi_heap_random(mi_heap_t* heap);
void _mi_heap_set_default_direct(mi_heap_t* heap);
// "stats.c"
void _mi_stats_done(mi_stats_t* stats);

6
src/heap.c
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@ -223,7 +223,7 @@ static void mi_heap_free(mi_heap_t* heap) {
// reset default
if (mi_heap_is_default(heap)) {
_mi_heap_default = heap->tld->heap_backing;
_mi_heap_set_default_direct(heap->tld->heap_backing);
}
// and free the used memory
mi_free(heap);
@ -354,8 +354,8 @@ mi_heap_t* mi_heap_set_default(mi_heap_t* heap) {
mi_assert(mi_heap_is_initialized(heap));
if (!mi_heap_is_initialized(heap)) return NULL;
mi_assert_expensive(mi_heap_is_valid(heap));
mi_heap_t* old = _mi_heap_default;
_mi_heap_default = heap;
mi_heap_t* old = mi_get_default_heap();
_mi_heap_set_default_direct(heap);
return old;
}

59
src/init.c
View File

@ -90,6 +90,7 @@ const mi_heap_t _mi_heap_empty = {
false
};
// the thread-local default heap for allocation
mi_decl_thread mi_heap_t* _mi_heap_default = (mi_heap_t*)&_mi_heap_empty;
@ -198,8 +199,8 @@ static bool _mi_heap_init(void) {
if (mi_heap_is_initialized(_mi_heap_default)) return true;
if (_mi_is_main_thread()) {
// the main heap is statically allocated
_mi_heap_default = &_mi_heap_main;
mi_assert_internal(_mi_heap_default->tld->heap_backing == _mi_heap_default);
_mi_heap_set_default_direct(&_mi_heap_main);
mi_assert_internal(_mi_heap_default->tld->heap_backing == mi_get_default_heap());
}
else {
// use `_mi_os_alloc` to allocate directly from the OS
@ -219,18 +220,17 @@ static bool _mi_heap_init(void) {
tld->heap_backing = heap;
tld->segments.stats = &tld->stats;
tld->os.stats = &tld->stats;
_mi_heap_default = heap;
_mi_heap_set_default_direct(heap);
}
return false;
}
// Free the thread local default heap (called from `mi_thread_done`)
static bool _mi_heap_done(void) {
mi_heap_t* heap = _mi_heap_default;
static bool _mi_heap_done(mi_heap_t* heap) {
if (!mi_heap_is_initialized(heap)) return true;
// reset default heap
_mi_heap_default = (_mi_is_main_thread() ? &_mi_heap_main : (mi_heap_t*)&_mi_heap_empty);
_mi_heap_set_default_direct(_mi_is_main_thread() ? &_mi_heap_main : (mi_heap_t*)&_mi_heap_empty);
// todo: delete all non-backing heaps?
@ -277,6 +277,8 @@ static bool _mi_heap_done(void) {
// to set up the thread local keys.
// --------------------------------------------------------
static void _mi_thread_done(mi_heap_t* default_heap);
#ifdef __wasi__
// no pthreads in the WebAssembly Standard Interface
#elif !defined(_WIN32)
@ -291,14 +293,14 @@ static bool _mi_heap_done(void) {
#include <fibersapi.h>
static DWORD mi_fls_key;
static void NTAPI mi_fls_done(PVOID value) {
if (value!=NULL) mi_thread_done();
if (value!=NULL) _mi_thread_done((mi_heap_t*)value);
}
#elif defined(MI_USE_PTHREADS)
// use pthread locol storage keys to detect thread ending
#include <pthread.h>
static pthread_key_t mi_pthread_key;
static void mi_pthread_done(void* value) {
if (value!=NULL) mi_thread_done();
if (value!=NULL) _mi_thread_done((mi_heap_t*)value);
}
#elif defined(__wasi__)
// no pthreads in the WebAssembly Standard Interface
@ -332,6 +334,8 @@ void mi_thread_init(void) mi_attr_noexcept
mi_process_init();
// initialize the thread local default heap
// (this will call `_mi_heap_set_default_direct` and thus set the
// fiber/pthread key to a non-zero value, ensuring `_mi_thread_done` is called)
if (_mi_heap_init()) return; // returns true if already initialized
// don't further initialize for the main thread
@ -339,33 +343,38 @@ void mi_thread_init(void) mi_attr_noexcept
_mi_stat_increase(&mi_get_default_heap()->tld->stats.threads, 1);
// set hooks so our mi_thread_done() will be called
#if defined(_WIN32) && defined(MI_SHARED_LIB)
// nothing to do as it is done in DllMain
#elif defined(_WIN32) && !defined(MI_SHARED_LIB)
FlsSetValue(mi_fls_key, (void*)(_mi_thread_id()|1)); // set to a dummy value so that `mi_fls_done` is called
#elif defined(MI_USE_PTHREADS)
pthread_setspecific(mi_pthread_key, (void*)(_mi_thread_id()|1)); // set to a dummy value so that `mi_pthread_done` is called
#endif
//_mi_verbose_message("thread init: 0x%zx\n", _mi_thread_id());
}
void mi_thread_done(void) mi_attr_noexcept {
_mi_thread_done(mi_get_default_heap());
}
static void _mi_thread_done(mi_heap_t* heap) {
// stats
mi_heap_t* heap = mi_get_default_heap();
if (!_mi_is_main_thread() && mi_heap_is_initialized(heap)) {
_mi_stat_decrease(&heap->tld->stats.threads, 1);
}
// abandon the thread local heap
if (_mi_heap_done()) return; // returns true if already ran
//if (!_mi_is_main_thread()) {
// _mi_verbose_message("thread done: 0x%zx\n", _mi_thread_id());
//}
if (_mi_heap_done(heap)) return; // returns true if already ran
}
void _mi_heap_set_default_direct(mi_heap_t* heap) {
mi_assert_internal(heap != NULL);
_mi_heap_default = heap;
// ensure the default heap is passed to `_mi_thread_done`
// setting to a non-NULL value also ensures `mi_thread_done` is called.
#if defined(_WIN32) && defined(MI_SHARED_LIB)
// nothing to do as it is done in DllMain
#elif defined(_WIN32) && !defined(MI_SHARED_LIB)
FlsSetValue(mi_fls_key, heap);
#elif defined(MI_USE_PTHREADS)
pthread_setspecific(mi_pthread_key, heap);
#endif
}
// --------------------------------------------------------
// Run functions on process init/done, and thread init/done
@ -446,7 +455,7 @@ void mi_process_init(void) mi_attr_noexcept {
// access _mi_heap_default before setting _mi_process_is_initialized to ensure
// that the TLS slot is allocated without getting into recursion on macOS
// when using dynamic linking with interpose.
mi_heap_t* h = _mi_heap_default;
mi_heap_t* h = mi_get_default_heap();
_mi_process_is_initialized = true;
_mi_heap_main.thread_id = _mi_thread_id();