/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <assert.h>
#include <limits.h>
#include <stdlib.h>
#include "uv.h"
#include "internal.h"
static void uv__once_inner(uv_once_t* guard, void (*callback)(void)) {
DWORD result;
HANDLE existing_event, created_event;
created_event = CreateEvent(NULL, 1, 0, NULL);
if (created_event == 0) {
/* Could fail in a low-memory situation? */
uv_fatal_error(GetLastError(), "CreateEvent");
}
existing_event = InterlockedCompareExchangePointer(&guard->event,
created_event,
NULL);
if (existing_event == NULL) {
/* We won the race */
callback();
result = SetEvent(created_event);
assert(result);
guard->ran = 1;
} else {
/* We lost the race. Destroy the event we created and wait for the existing
* one to become signaled. */
CloseHandle(created_event);
result = WaitForSingleObject(existing_event, INFINITE);
assert(result == WAIT_OBJECT_0);
}
}
void uv_once(uv_once_t* guard, void (*callback)(void)) {
/* Fast case - avoid WaitForSingleObject. */
if (guard->ran) {
return;
}
uv__once_inner(guard, callback);
}
/* Verify that uv_thread_t can be stored in a TLS slot. */
STATIC_ASSERT(sizeof(uv_thread_t) <= sizeof(void*));
static uv_key_t uv__current_thread_key;
static uv_once_t uv__current_thread_init_guard = UV_ONCE_INIT;
static void uv__init_current_thread_key(void) {
if (uv_key_create(&uv__current_thread_key))
abort();
}
struct thread_ctx {
void (*entry)(void* arg);
void* arg;
uv_thread_t self;
};
static UINT __stdcall uv__thread_start(void* arg) {
struct thread_ctx *ctx_p;
struct thread_ctx ctx;
ctx_p = arg;
ctx = *ctx_p;
uv__free(ctx_p);
uv_once(&uv__current_thread_init_guard, uv__init_current_thread_key);
uv_key_set(&uv__current_thread_key, (void*) ctx.self);
ctx.entry(ctx.arg);
return 0;
}
int uv_thread_create(uv_thread_t *tid, void (*entry)(void *arg), void *arg) {
struct thread_ctx* ctx;
int err;
HANDLE thread;
ctx = uv__malloc(sizeof(*ctx));
if (ctx == NULL)
return UV_ENOMEM;
ctx->entry = entry;
ctx->arg = arg;
/* Create the thread in suspended state so we have a chance to pass
* its own creation handle to it */
thread = (HANDLE) _beginthreadex(NULL,
0,
uv__thread_start,
ctx,
CREATE_SUSPENDED,
NULL);
if (thread == NULL) {
err = errno;
uv__free(ctx);
} else {
err = 0;
*tid = thread;
ctx->self = thread;
ResumeThread(thread);
}
switch (err) {
case 0:
return 0;
case EACCES:
return UV_EACCES;
case EAGAIN:
return UV_EAGAIN;
case EINVAL:
return UV_EINVAL;
}
return UV_EIO;
}
uv_thread_t uv_thread_self(void) {
uv_once(&uv__current_thread_init_guard, uv__init_current_thread_key);
return (uv_thread_t) uv_key_get(&uv__current_thread_key);
}
int uv_thread_join(uv_thread_t *tid) {
if (WaitForSingleObject(*tid, INFINITE))
return uv_translate_sys_error(GetLastError());
else {
CloseHandle(*tid);
*tid = 0;
MemoryBarrier(); /* For feature parity with pthread_join(). */
return 0;
}
}
int uv_thread_equal(const uv_thread_t* t1, const uv_thread_t* t2) {
return *t1 == *t2;
}
int uv_mutex_init(uv_mutex_t* mutex) {
InitializeCriticalSection(mutex);
return 0;
}
int uv_mutex_init_recursive(uv_mutex_t* mutex) {
return uv_mutex_init(mutex);
}
void uv_mutex_destroy(uv_mutex_t* mutex) {
DeleteCriticalSection(mutex);
}
void uv_mutex_lock(uv_mutex_t* mutex) {
EnterCriticalSection(mutex);
}
int uv_mutex_trylock(uv_mutex_t* mutex) {
if (TryEnterCriticalSection(mutex))
return 0;
else
return UV_EBUSY;
}
void uv_mutex_unlock(uv_mutex_t* mutex) {
LeaveCriticalSection(mutex);
}
int uv_rwlock_init(uv_rwlock_t* rwlock) {
/* Initialize the semaphore that acts as the write lock. */
HANDLE handle = CreateSemaphoreW(NULL, 1, 1, NULL);
if (handle == NULL)
return uv_translate_sys_error(GetLastError());
rwlock->state_.write_semaphore_ = handle;
/* Initialize the critical section protecting the reader count. */
InitializeCriticalSection(&rwlock->state_.num_readers_lock_);
/* Initialize the reader count. */
rwlock->state_.num_readers_ = 0;
return 0;
}
void uv_rwlock_destroy(uv_rwlock_t* rwlock) {
DeleteCriticalSection(&rwlock->state_.num_readers_lock_);
CloseHandle(rwlock->state_.write_semaphore_);
}
void uv_rwlock_rdlock(uv_rwlock_t* rwlock) {
/* Acquire the lock that protects the reader count. */
EnterCriticalSection(&rwlock->state_.num_readers_lock_);
/* Increase the reader count, and lock for write if this is the first
* reader.
*/
if (++rwlock->state_.num_readers_ == 1) {
DWORD r = WaitForSingleObject(rwlock->state_.write_semaphore_, INFINITE);
if (r != WAIT_OBJECT_0)
uv_fatal_error(GetLastError(), "WaitForSingleObject");
}
/* Release the lock that protects the reader count. */
LeaveCriticalSection(&rwlock->state_.num_readers_lock_);
}
int uv_rwlock_tryrdlock(uv_rwlock_t* rwlock) {
int err;
if (!TryEnterCriticalSection(&rwlock->state_.num_readers_lock_))
return UV_EBUSY;
err = 0;
if (rwlock->state_.num_readers_ == 0) {
/* Currently there are no other readers, which means that the write lock
* needs to be acquired.
*/
DWORD r = WaitForSingleObject(rwlock->state_.write_semaphore_, 0);
if (r == WAIT_OBJECT_0)
rwlock->state_.num_readers_++;
else if (r == WAIT_TIMEOUT)
err = UV_EBUSY;
else if (r == WAIT_FAILED)
uv_fatal_error(GetLastError(), "WaitForSingleObject");
} else {
/* The write lock has already been acquired because there are other
* active readers.
*/
rwlock->state_.num_readers_++;
}
LeaveCriticalSection(&rwlock->state_.num_readers_lock_);
return err;
}
void uv_rwlock_rdunlock(uv_rwlock_t* rwlock) {
EnterCriticalSection(&rwlock->state_.num_readers_lock_);
if (--rwlock->state_.num_readers_ == 0) {
if (!ReleaseSemaphore(rwlock->state_.write_semaphore_, 1, NULL))
uv_fatal_error(GetLastError(), "ReleaseSemaphore");
}
LeaveCriticalSection(&rwlock->state_.num_readers_lock_);
}
void uv_rwlock_wrlock(uv_rwlock_t* rwlock) {
DWORD r = WaitForSingleObject(rwlock->state_.write_semaphore_, INFINITE);
if (r != WAIT_OBJECT_0)
uv_fatal_error(GetLastError(), "WaitForSingleObject");
}
int uv_rwlock_trywrlock(uv_rwlock_t* rwlock) {
DWORD r = WaitForSingleObject(rwlock->state_.write_semaphore_, 0);
if (r == WAIT_OBJECT_0)
return 0;
else if (r == WAIT_TIMEOUT)
return UV_EBUSY;
else
uv_fatal_error(GetLastError(), "WaitForSingleObject");
}
void uv_rwlock_wrunlock(uv_rwlock_t* rwlock) {
if (!ReleaseSemaphore(rwlock->state_.write_semaphore_, 1, NULL))
uv_fatal_error(GetLastError(), "ReleaseSemaphore");
}
int uv_sem_init(uv_sem_t* sem, unsigned int value) {
*sem = CreateSemaphore(NULL, value, INT_MAX, NULL);
if (*sem == NULL)
return uv_translate_sys_error(GetLastError());
else
return 0;
}
void uv_sem_destroy(uv_sem_t* sem) {
if (!CloseHandle(*sem))
abort();
}
void uv_sem_post(uv_sem_t* sem) {
if (!ReleaseSemaphore(*sem, 1, NULL))
abort();
}
void uv_sem_wait(uv_sem_t* sem) {
if (WaitForSingleObject(*sem, INFINITE) != WAIT_OBJECT_0)
abort();
}
int uv_sem_trywait(uv_sem_t* sem) {
DWORD r = WaitForSingleObject(*sem, 0);
if (r == WAIT_OBJECT_0)
return 0;
if (r == WAIT_TIMEOUT)
return UV_EAGAIN;
abort();
return -1; /* Satisfy the compiler. */
}
int uv_cond_init(uv_cond_t* cond) {
InitializeConditionVariable(&cond->cond_var);
return 0;
}
void uv_cond_destroy(uv_cond_t* cond) {
/* nothing to do */
(void) &cond;
}
void uv_cond_signal(uv_cond_t* cond) {
WakeConditionVariable(&cond->cond_var);
}
void uv_cond_broadcast(uv_cond_t* cond) {
WakeAllConditionVariable(&cond->cond_var);
}
void uv_cond_wait(uv_cond_t* cond, uv_mutex_t* mutex) {
if (!SleepConditionVariableCS(&cond->cond_var, mutex, INFINITE))
abort();
}
int uv_cond_timedwait(uv_cond_t* cond, uv_mutex_t* mutex, uint64_t timeout) {
if (SleepConditionVariableCS(&cond->cond_var, mutex, (DWORD)(timeout / 1e6)))
return 0;
if (GetLastError() != ERROR_TIMEOUT)
abort();
return UV_ETIMEDOUT;
}
int uv_barrier_init(uv_barrier_t* barrier, unsigned int count) {
int err;
barrier->n = count;
barrier->count = 0;
err = uv_mutex_init(&barrier->mutex);
if (err)
return err;
err = uv_sem_init(&barrier->turnstile1, 0);
if (err)
goto error2;
err = uv_sem_init(&barrier->turnstile2, 1);
if (err)
goto error;
return 0;
error:
uv_sem_destroy(&barrier->turnstile1);
error2:
uv_mutex_destroy(&barrier->mutex);
return err;
}
void uv_barrier_destroy(uv_barrier_t* barrier) {
uv_sem_destroy(&barrier->turnstile2);
uv_sem_destroy(&barrier->turnstile1);
uv_mutex_destroy(&barrier->mutex);
}
int uv_barrier_wait(uv_barrier_t* barrier) {
int serial_thread;
uv_mutex_lock(&barrier->mutex);
if (++barrier->count == barrier->n) {
uv_sem_wait(&barrier->turnstile2);
uv_sem_post(&barrier->turnstile1);
}
uv_mutex_unlock(&barrier->mutex);
uv_sem_wait(&barrier->turnstile1);
uv_sem_post(&barrier->turnstile1);
uv_mutex_lock(&barrier->mutex);
serial_thread = (--barrier->count == 0);
if (serial_thread) {
uv_sem_wait(&barrier->turnstile1);
uv_sem_post(&barrier->turnstile2);
}
uv_mutex_unlock(&barrier->mutex);
uv_sem_wait(&barrier->turnstile2);
uv_sem_post(&barrier->turnstile2);
return serial_thread;
}
int uv_key_create(uv_key_t* key) {
key->tls_index = TlsAlloc();
if (key->tls_index == TLS_OUT_OF_INDEXES)
return UV_ENOMEM;
return 0;
}
void uv_key_delete(uv_key_t* key) {
if (TlsFree(key->tls_index) == FALSE)
abort();
key->tls_index = TLS_OUT_OF_INDEXES;
}
void* uv_key_get(uv_key_t* key) {
void* value;
value = TlsGetValue(key->tls_index);
if (value == NULL)
if (GetLastError() != ERROR_SUCCESS)
abort();
return value;
}
void uv_key_set(uv_key_t* key, void* value) {
if (TlsSetValue(key->tls_index, value) == FALSE)
abort();
}