修复C++11 thread_local对象析构函数与实际内存释放动作顺序相反问题

This commit is contained in:
atwww 2024-05-12 01:50:02 +08:00 committed by GitHub
parent f55187f830
commit b421b4e1f4
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
3 changed files with 71 additions and 10 deletions

View File

@ -9,6 +9,8 @@
* thread.
* 2019-02-07 Bernard Add _pthread_destroy to release pthread resource.
* 2022-05-10 xiangxistu Modify the recycle logic about resource of pthread.
* 2024-04-15 atwww Modify the recycle logic of TLS in function _pthread_data_destroy,
* make it safe for C++11's thread_local destructors.
*/
#include <rthw.h>
@ -85,9 +87,27 @@ pthread_t _pthread_data_create(void)
return index;
}
void _pthread_data_destroy(_pthread_data_t *ptd)
static inline void _destroy_item(int index, _pthread_data_t *ptd)
{
extern _pthread_key_data_t _thread_keys[PTHREAD_KEY_MAX];
void *data;
if (_thread_keys[index].is_used)
{
data = ptd->tls[index];
if (data && _thread_keys[index].destructor)
{
_thread_keys[index].destructor(data);
}
}
}
#ifdef RT_USING_CPLUSPLUS11
#define NOT_USE_CXX_TLS -1
#endif
void _pthread_data_destroy(_pthread_data_t *ptd)
{
pthread_t pth;
if (ptd)
@ -97,18 +117,37 @@ void _pthread_data_destroy(_pthread_data_t *ptd)
*/
if (ptd->tls != RT_NULL)
{
void *data;
rt_uint32_t index;
for (index = 0; index < PTHREAD_KEY_MAX; index ++)
int index;
#ifdef RT_USING_CPLUSPLUS11
/* If C++11 is enabled and emutls is used,
* destructors of C++ object must be called safely.
*/
extern pthread_key_t emutls_get_pthread_key(void);
pthread_key_t emutls_pthread_key = emutls_get_pthread_key();
if (emutls_pthread_key != NOT_USE_CXX_TLS)
{
if (_thread_keys[index].is_used)
/* If execution reaches here, C++ 'thread_local' may be used.
* Destructors of c++ class object must be called before emutls_key_destructor.
*/
int start = ((emutls_pthread_key - 1 + PTHREAD_KEY_MAX) % PTHREAD_KEY_MAX);
int i = 0;
for (index = start; i < PTHREAD_KEY_MAX; index = (index - 1 + PTHREAD_KEY_MAX) % PTHREAD_KEY_MAX, i ++)
{
data = ptd->tls[index];
if (data && _thread_keys[index].destructor)
_thread_keys[index].destructor(data);
_destroy_item(index, ptd);
}
}
else
#endif
{
/* If only C TLS is used, that is, POSIX TLS or __Thread_local,
* just iterate the _thread_keys from index 0.
*/
for (index = 0; index < PTHREAD_KEY_MAX; index ++)
{
_destroy_item(index, ptd);
}
}
/* release tls area */
rt_free(ptd->tls);
ptd->tls = RT_NULL;

View File

@ -0,0 +1,9 @@
from building import *
cwd = GetCurrentDir()
src = Glob('*.c')
CPPPATH = [cwd]
group = DefineGroup('POSIX', src, depend = ['RT_USING_PTHREADS'], CPPPATH = CPPPATH)
Return('group')

View File

@ -6,6 +6,10 @@
* Change Logs:
* Date Author Notes
* 2021-04-27 peterfan Add copyright header.
* 2024-04-15 atwww Add emutls_get_pthread_key to make c++11's thread_local destructe safely.
* Use emutls_pthread_key to determine whether C++11 thread_local is used.
* Move this file from components\libc\cplusplus\cpp11 to components\libc\posix\tls,
* because _Thread_local in C will also use emutls.
*/
/* ===---------- emutls.c - Implements __emutls_get_address ---------------===
@ -109,7 +113,16 @@ typedef struct emutls_address_array
void *data[];
} emutls_address_array;
static pthread_key_t emutls_pthread_key;
static pthread_key_t emutls_pthread_key = -1; /* -1 means that TLS in C or C++ is not used. */
pthread_key_t emutls_get_pthread_key(void)
{
/* If program uses C or C++ TLS keyword, _Thread_local、__thread or thread_local,
* the function emutls_get_index will ensure that emutls_pthread_key is initialized once
* when it is first used. Therefore, there is no need to use synchronization measures here.
*/
return emutls_pthread_key;
}
static void emutls_key_destructor(void *ptr)
{