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author | Edward Thomson <ethomson@edwardthomson.com> | 2019-12-01 14:38:54 +1100 |
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committer | GitHub <noreply@github.com> | 2019-12-01 14:38:54 +1100 |
commit | 36bfc27a45ac34e8425271c9d3c79ce62564e195 (patch) | |
tree | 3e99e9063a9ea639c6a752a09e1c898332dcf82d | |
parent | d298f9b2879170612dff7512c8c20e64baad69d1 (diff) | |
parent | 5c6180b5a0e9f9bd1c82938137582720d7a2e6e6 (diff) | |
download | libgit2-36bfc27a45ac34e8425271c9d3c79ce62564e195.tar.gz |
Merge pull request #5314 from pks-t/pks/dll-main-removal
global: convert to fiber-local storage to fix exit races
-rw-r--r-- | src/global.c | 52 | ||||
-rw-r--r-- | src/global.h | 2 | ||||
-rw-r--r-- | src/win32/thread.c | 5 |
3 files changed, 12 insertions, 47 deletions
diff --git a/src/global.c b/src/global.c index 418c036c1..5af35aa62 100644 --- a/src/global.c +++ b/src/global.c @@ -141,14 +141,21 @@ static void shutdown_common(void) */ #if defined(GIT_THREADS) && defined(GIT_WIN32) -static DWORD _tls_index; +static DWORD _fls_index; static volatile LONG _mutex = 0; +static void WINAPI fls_free(void *st) +{ + git__global_state_cleanup(st); + git__free(st); +} + static int synchronized_threads_init(void) { int error; - _tls_index = TlsAlloc(); + if ((_fls_index = FlsAlloc(fls_free)) == FLS_OUT_OF_INDEXES) + return -1; git_threads_init(); @@ -190,9 +197,7 @@ int git_libgit2_shutdown(void) if ((ret = git_atomic_dec(&git__n_inits)) == 0) { shutdown_common(); - git__free_tls_data(); - - TlsFree(_tls_index); + FlsFree(_fls_index); git_mutex_free(&git__mwindow_mutex); #if defined(GIT_MSVC_CRTDBG) @@ -213,7 +218,7 @@ git_global_st *git__global_state(void) assert(git_atomic_get(&git__n_inits) > 0); - if ((ptr = TlsGetValue(_tls_index)) != NULL) + if ((ptr = FlsGetValue(_fls_index)) != NULL) return ptr; ptr = git__calloc(1, sizeof(git_global_st)); @@ -222,43 +227,10 @@ git_global_st *git__global_state(void) git_buf_init(&ptr->error_buf, 0); - TlsSetValue(_tls_index, ptr); + FlsSetValue(_fls_index, ptr); return ptr; } -/** - * Free the TLS data associated with this thread. - * This should only be used by the thread as it - * is exiting. - */ -void git__free_tls_data(void) -{ - void *ptr = TlsGetValue(_tls_index); - if (!ptr) - return; - - git__global_state_cleanup(ptr); - git__free(ptr); - TlsSetValue(_tls_index, NULL); -} - -BOOL WINAPI DllMain(HINSTANCE hInstDll, DWORD fdwReason, LPVOID lpvReserved) -{ - GIT_UNUSED(hInstDll); - GIT_UNUSED(lpvReserved); - - /* This is how Windows lets us know our thread is being shut down */ - if (fdwReason == DLL_THREAD_DETACH) { - git__free_tls_data(); - } - - /* - * Windows pays attention to this during library loading. We don't do anything - * so we trivially succeed. - */ - return TRUE; -} - #elif defined(GIT_THREADS) && defined(_POSIX_THREADS) static pthread_key_t _tls_key; diff --git a/src/global.h b/src/global.h index 3c0559c68..db41dad1f 100644 --- a/src/global.h +++ b/src/global.h @@ -35,8 +35,6 @@ typedef void (*git_global_shutdown_fn)(void); extern void git__on_shutdown(git_global_shutdown_fn callback); -extern void git__free_tls_data(void); - extern const char *git_libgit2__user_agent(void); extern const char *git_libgit2__ssl_ciphers(void); diff --git a/src/win32/thread.c b/src/win32/thread.c index c3a6c0e28..42dba7f97 100644 --- a/src/win32/thread.c +++ b/src/win32/thread.c @@ -32,8 +32,6 @@ static DWORD WINAPI git_win32__threadproc(LPVOID lpParameter) thread->result = thread->proc(thread->param); - git__free_tls_data(); - return CLEAN_THREAD_EXIT; } @@ -103,9 +101,6 @@ void git_thread_exit(void *value) { assert(GIT_GLOBAL->current_thread); GIT_GLOBAL->current_thread->result = value; - - git__free_tls_data(); - ExitThread(CLEAN_THREAD_EXIT); } |