ref: 2bbc75bddc6f2a07056ff017108e35f14061041b
dir: /third_party/boringssl/src/crypto/thread_win.c/
/* Copyright (c) 2015, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include "internal.h"
#if defined(OPENSSL_WINDOWS_THREADS)
OPENSSL_MSVC_PRAGMA(warning(push, 3))
#include <windows.h>
OPENSSL_MSVC_PRAGMA(warning(pop))
#include <stdlib.h>
#include <string.h>
#include <openssl/mem.h>
#include <openssl/type_check.h>
OPENSSL_STATIC_ASSERT(sizeof(CRYPTO_MUTEX) >= sizeof(SRWLOCK),
"CRYPTO_MUTEX is too small");
#if defined(__GNUC__) || defined(__clang__)
OPENSSL_STATIC_ASSERT(alignof(CRYPTO_MUTEX) >= alignof(SRWLOCK),
"CRYPTO_MUTEX has insufficient alignment");
#endif
static BOOL CALLBACK call_once_init(INIT_ONCE *once, void *arg, void **out) {
void (**init)(void) = (void (**)(void))arg;
(**init)();
return TRUE;
}
void CRYPTO_once(CRYPTO_once_t *once, void (*init)(void)) {
if (!InitOnceExecuteOnce(once, call_once_init, &init, NULL)) {
abort();
}
}
void CRYPTO_MUTEX_init(CRYPTO_MUTEX *lock) {
InitializeSRWLock((SRWLOCK *) lock);
}
void CRYPTO_MUTEX_lock_read(CRYPTO_MUTEX *lock) {
AcquireSRWLockShared((SRWLOCK *) lock);
}
void CRYPTO_MUTEX_lock_write(CRYPTO_MUTEX *lock) {
AcquireSRWLockExclusive((SRWLOCK *) lock);
}
void CRYPTO_MUTEX_unlock_read(CRYPTO_MUTEX *lock) {
ReleaseSRWLockShared((SRWLOCK *) lock);
}
void CRYPTO_MUTEX_unlock_write(CRYPTO_MUTEX *lock) {
ReleaseSRWLockExclusive((SRWLOCK *) lock);
}
void CRYPTO_MUTEX_cleanup(CRYPTO_MUTEX *lock) {
// SRWLOCKs require no cleanup.
}
void CRYPTO_STATIC_MUTEX_lock_read(struct CRYPTO_STATIC_MUTEX *lock) {
AcquireSRWLockShared(&lock->lock);
}
void CRYPTO_STATIC_MUTEX_lock_write(struct CRYPTO_STATIC_MUTEX *lock) {
AcquireSRWLockExclusive(&lock->lock);
}
void CRYPTO_STATIC_MUTEX_unlock_read(struct CRYPTO_STATIC_MUTEX *lock) {
ReleaseSRWLockShared(&lock->lock);
}
void CRYPTO_STATIC_MUTEX_unlock_write(struct CRYPTO_STATIC_MUTEX *lock) {
ReleaseSRWLockExclusive(&lock->lock);
}
static SRWLOCK g_destructors_lock = SRWLOCK_INIT;
static thread_local_destructor_t g_destructors[NUM_OPENSSL_THREAD_LOCALS];
static CRYPTO_once_t g_thread_local_init_once = CRYPTO_ONCE_INIT;
static DWORD g_thread_local_key;
static int g_thread_local_failed;
static void thread_local_init(void) {
g_thread_local_key = TlsAlloc();
g_thread_local_failed = (g_thread_local_key == TLS_OUT_OF_INDEXES);
}
static void NTAPI thread_local_destructor(PVOID module, DWORD reason,
PVOID reserved) {
// Only free memory on |DLL_THREAD_DETACH|, not |DLL_PROCESS_DETACH|. In
// VS2015's debug runtime, the C runtime has been unloaded by the time
// |DLL_PROCESS_DETACH| runs. See https://crbug.com/575795. This is consistent
// with |pthread_key_create| which does not call destructors on process exit,
// only thread exit.
if (reason != DLL_THREAD_DETACH) {
return;
}
CRYPTO_once(&g_thread_local_init_once, thread_local_init);
if (g_thread_local_failed) {
return;
}
void **pointers = (void**) TlsGetValue(g_thread_local_key);
if (pointers == NULL) {
return;
}
thread_local_destructor_t destructors[NUM_OPENSSL_THREAD_LOCALS];
AcquireSRWLockExclusive(&g_destructors_lock);
OPENSSL_memcpy(destructors, g_destructors, sizeof(destructors));
ReleaseSRWLockExclusive(&g_destructors_lock);
for (unsigned i = 0; i < NUM_OPENSSL_THREAD_LOCALS; i++) {
if (destructors[i] != NULL) {
destructors[i](pointers[i]);
}
}
OPENSSL_free(pointers);
}
// Thread Termination Callbacks.
//
// Windows doesn't support a per-thread destructor with its TLS primitives.
// So, we build it manually by inserting a function to be called on each
// thread's exit. This magic is from http://www.codeproject.com/threads/tls.asp
// and it works for VC++ 7.0 and later.
//
// Force a reference to _tls_used to make the linker create the TLS directory
// if it's not already there. (E.g. if __declspec(thread) is not used). Force
// a reference to p_thread_callback_boringssl to prevent whole program
// optimization from discarding the variable.
//
// Note, in the prefixed build, |p_thread_callback_boringssl| may be a macro.
#define STRINGIFY(x) #x
#define EXPAND_AND_STRINGIFY(x) STRINGIFY(x)
#ifdef _WIN64
__pragma(comment(linker, "/INCLUDE:_tls_used"))
__pragma(comment(
linker, "/INCLUDE:" EXPAND_AND_STRINGIFY(p_thread_callback_boringssl)))
#else
__pragma(comment(linker, "/INCLUDE:__tls_used"))
__pragma(comment(
linker, "/INCLUDE:_" EXPAND_AND_STRINGIFY(p_thread_callback_boringssl)))
#endif
// .CRT$XLA to .CRT$XLZ is an array of PIMAGE_TLS_CALLBACK pointers that are
// called automatically by the OS loader code (not the CRT) when the module is
// loaded and on thread creation. They are NOT called if the module has been
// loaded by a LoadLibrary() call. It must have implicitly been loaded at
// process startup.
//
// By implicitly loaded, I mean that it is directly referenced by the main EXE
// or by one of its dependent DLLs. Delay-loaded DLL doesn't count as being
// implicitly loaded.
//
// See VC\crt\src\tlssup.c for reference.
// The linker must not discard p_thread_callback_boringssl. (We force a
// reference to this variable with a linker /INCLUDE:symbol pragma to ensure
// that.) If this variable is discarded, the OnThreadExit function will never
// be called.
#ifdef _WIN64
// .CRT section is merged with .rdata on x64 so it must be constant data.
#pragma const_seg(".CRT$XLC")
// When defining a const variable, it must have external linkage to be sure the
// linker doesn't discard it.
extern const PIMAGE_TLS_CALLBACK p_thread_callback_boringssl;
const PIMAGE_TLS_CALLBACK p_thread_callback_boringssl = thread_local_destructor;
// Reset the default section.
#pragma const_seg()
#else
#pragma data_seg(".CRT$XLC")
PIMAGE_TLS_CALLBACK p_thread_callback_boringssl = thread_local_destructor;
// Reset the default section.
#pragma data_seg()
#endif // _WIN64
static void **get_thread_locals(void) {
// |TlsGetValue| clears the last error even on success, so that callers may
// distinguish it successfully returning NULL or failing. It is documented to
// never fail if the argument is a valid index from |TlsAlloc|, so we do not
// need to handle this.
//
// However, this error-mangling behavior interferes with the caller's use of
// |GetLastError|. In particular |SSL_get_error| queries the error queue to
// determine whether the caller should look at the OS's errors. To avoid
// destroying state, save and restore the Windows error.
//
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms686812(v=vs.85).aspx
DWORD last_error = GetLastError();
void **ret = TlsGetValue(g_thread_local_key);
SetLastError(last_error);
return ret;
}
void *CRYPTO_get_thread_local(thread_local_data_t index) {
CRYPTO_once(&g_thread_local_init_once, thread_local_init);
if (g_thread_local_failed) {
return NULL;
}
void **pointers = get_thread_locals();
if (pointers == NULL) {
return NULL;
}
return pointers[index];
}
int CRYPTO_set_thread_local(thread_local_data_t index, void *value,
thread_local_destructor_t destructor) {
CRYPTO_once(&g_thread_local_init_once, thread_local_init);
if (g_thread_local_failed) {
destructor(value);
return 0;
}
void **pointers = get_thread_locals();
if (pointers == NULL) {
pointers = OPENSSL_malloc(sizeof(void *) * NUM_OPENSSL_THREAD_LOCALS);
if (pointers == NULL) {
destructor(value);
return 0;
}
OPENSSL_memset(pointers, 0, sizeof(void *) * NUM_OPENSSL_THREAD_LOCALS);
if (TlsSetValue(g_thread_local_key, pointers) == 0) {
OPENSSL_free(pointers);
destructor(value);
return 0;
}
}
AcquireSRWLockExclusive(&g_destructors_lock);
g_destructors[index] = destructor;
ReleaseSRWLockExclusive(&g_destructors_lock);
pointers[index] = value;
return 1;
}
#endif // OPENSSL_WINDOWS_THREADS