1 /* Copyright (c) 2015, Google Inc.
3 * Permission to use, copy, modify, and/or distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
17 #if defined(OPENSSL_WINDOWS_THREADS)
19 OPENSSL_MSVC_PRAGMA(warning(push, 3))
21 OPENSSL_MSVC_PRAGMA(warning(pop))
26 #include <openssl/mem.h>
27 #include <openssl/type_check.h>
30 OPENSSL_COMPILE_ASSERT(sizeof(CRYPTO_MUTEX) >= sizeof(SRWLOCK),
31 CRYPTO_MUTEX_too_small);
33 static BOOL CALLBACK call_once_init(INIT_ONCE *once, void *arg, void **out) {
34 void (**init)(void) = (void (**)(void))arg;
39 void CRYPTO_once(CRYPTO_once_t *once, void (*init)(void)) {
40 if (!InitOnceExecuteOnce(once, call_once_init, &init, NULL)) {
45 void CRYPTO_MUTEX_init(CRYPTO_MUTEX *lock) {
46 InitializeSRWLock((SRWLOCK *) lock);
49 void CRYPTO_MUTEX_lock_read(CRYPTO_MUTEX *lock) {
50 AcquireSRWLockShared((SRWLOCK *) lock);
53 void CRYPTO_MUTEX_lock_write(CRYPTO_MUTEX *lock) {
54 AcquireSRWLockExclusive((SRWLOCK *) lock);
57 void CRYPTO_MUTEX_unlock_read(CRYPTO_MUTEX *lock) {
58 ReleaseSRWLockShared((SRWLOCK *) lock);
61 void CRYPTO_MUTEX_unlock_write(CRYPTO_MUTEX *lock) {
62 ReleaseSRWLockExclusive((SRWLOCK *) lock);
65 void CRYPTO_MUTEX_cleanup(CRYPTO_MUTEX *lock) {
66 // SRWLOCKs require no cleanup.
69 void CRYPTO_STATIC_MUTEX_lock_read(struct CRYPTO_STATIC_MUTEX *lock) {
70 AcquireSRWLockShared(&lock->lock);
73 void CRYPTO_STATIC_MUTEX_lock_write(struct CRYPTO_STATIC_MUTEX *lock) {
74 AcquireSRWLockExclusive(&lock->lock);
77 void CRYPTO_STATIC_MUTEX_unlock_read(struct CRYPTO_STATIC_MUTEX *lock) {
78 ReleaseSRWLockShared(&lock->lock);
81 void CRYPTO_STATIC_MUTEX_unlock_write(struct CRYPTO_STATIC_MUTEX *lock) {
82 ReleaseSRWLockExclusive(&lock->lock);
85 static CRITICAL_SECTION g_destructors_lock;
86 static thread_local_destructor_t g_destructors[NUM_OPENSSL_THREAD_LOCALS];
88 static CRYPTO_once_t g_thread_local_init_once = CRYPTO_ONCE_INIT;
89 static DWORD g_thread_local_key;
90 static int g_thread_local_failed;
92 static void thread_local_init(void) {
93 if (!InitializeCriticalSectionAndSpinCount(&g_destructors_lock, 0x400)) {
94 g_thread_local_failed = 1;
97 g_thread_local_key = TlsAlloc();
98 g_thread_local_failed = (g_thread_local_key == TLS_OUT_OF_INDEXES);
101 static void NTAPI thread_local_destructor(PVOID module, DWORD reason,
103 // Only free memory on |DLL_THREAD_DETACH|, not |DLL_PROCESS_DETACH|. In
104 // VS2015's debug runtime, the C runtime has been unloaded by the time
105 // |DLL_PROCESS_DETACH| runs. See https://crbug.com/575795. This is consistent
106 // with |pthread_key_create| which does not call destructors on process exit,
108 if (reason != DLL_THREAD_DETACH) {
112 CRYPTO_once(&g_thread_local_init_once, thread_local_init);
113 if (g_thread_local_failed) {
117 void **pointers = (void**) TlsGetValue(g_thread_local_key);
118 if (pointers == NULL) {
122 thread_local_destructor_t destructors[NUM_OPENSSL_THREAD_LOCALS];
124 EnterCriticalSection(&g_destructors_lock);
125 OPENSSL_memcpy(destructors, g_destructors, sizeof(destructors));
126 LeaveCriticalSection(&g_destructors_lock);
129 for (i = 0; i < NUM_OPENSSL_THREAD_LOCALS; i++) {
130 if (destructors[i] != NULL) {
131 destructors[i](pointers[i]);
135 OPENSSL_free(pointers);
138 // Thread Termination Callbacks.
140 // Windows doesn't support a per-thread destructor with its TLS primitives.
141 // So, we build it manually by inserting a function to be called on each
142 // thread's exit. This magic is from http://www.codeproject.com/threads/tls.asp
143 // and it works for VC++ 7.0 and later.
145 // Force a reference to _tls_used to make the linker create the TLS directory
146 // if it's not already there. (E.g. if __declspec(thread) is not used). Force
147 // a reference to p_thread_callback_boringssl to prevent whole program
148 // optimization from discarding the variable.
150 #pragma comment(linker, "/INCLUDE:_tls_used")
151 #pragma comment(linker, "/INCLUDE:p_thread_callback_boringssl")
153 #pragma comment(linker, "/INCLUDE:__tls_used")
154 #pragma comment(linker, "/INCLUDE:_p_thread_callback_boringssl")
157 // .CRT$XLA to .CRT$XLZ is an array of PIMAGE_TLS_CALLBACK pointers that are
158 // called automatically by the OS loader code (not the CRT) when the module is
159 // loaded and on thread creation. They are NOT called if the module has been
160 // loaded by a LoadLibrary() call. It must have implicitly been loaded at
163 // By implicitly loaded, I mean that it is directly referenced by the main EXE
164 // or by one of its dependent DLLs. Delay-loaded DLL doesn't count as being
165 // implicitly loaded.
167 // See VC\crt\src\tlssup.c for reference.
169 // The linker must not discard p_thread_callback_boringssl. (We force a
170 // reference to this variable with a linker /INCLUDE:symbol pragma to ensure
171 // that.) If this variable is discarded, the OnThreadExit function will never
175 // .CRT section is merged with .rdata on x64 so it must be constant data.
176 #pragma const_seg(".CRT$XLC")
177 // When defining a const variable, it must have external linkage to be sure the
178 // linker doesn't discard it.
179 extern const PIMAGE_TLS_CALLBACK p_thread_callback_boringssl;
180 const PIMAGE_TLS_CALLBACK p_thread_callback_boringssl = thread_local_destructor;
181 // Reset the default section.
186 #pragma data_seg(".CRT$XLC")
187 PIMAGE_TLS_CALLBACK p_thread_callback_boringssl = thread_local_destructor;
188 // Reset the default section.
193 void *CRYPTO_get_thread_local(thread_local_data_t index) {
194 CRYPTO_once(&g_thread_local_init_once, thread_local_init);
195 if (g_thread_local_failed) {
199 void **pointers = TlsGetValue(g_thread_local_key);
200 if (pointers == NULL) {
203 return pointers[index];
206 int CRYPTO_set_thread_local(thread_local_data_t index, void *value,
207 thread_local_destructor_t destructor) {
208 CRYPTO_once(&g_thread_local_init_once, thread_local_init);
209 if (g_thread_local_failed) {
214 void **pointers = TlsGetValue(g_thread_local_key);
215 if (pointers == NULL) {
216 pointers = OPENSSL_malloc(sizeof(void *) * NUM_OPENSSL_THREAD_LOCALS);
217 if (pointers == NULL) {
221 OPENSSL_memset(pointers, 0, sizeof(void *) * NUM_OPENSSL_THREAD_LOCALS);
222 if (TlsSetValue(g_thread_local_key, pointers) == 0) {
223 OPENSSL_free(pointers);
229 EnterCriticalSection(&g_destructors_lock);
230 g_destructors[index] = destructor;
231 LeaveCriticalSection(&g_destructors_lock);
233 pointers[index] = value;
237 #endif // OPENSSL_WINDOWS_THREADS