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win: simplify uv_rwlock_t type

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PR-URL: https://github.com/libuv/libuv/pull/989
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
This commit is contained in:
Saúl Ibarra Corretgé 2016-08-10 13:20:30 +01:00
parent b3c9902dfc
commit 56292929ac
2 changed files with 26 additions and 28 deletions
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10
include/uv-win.h
View File

@ -217,12 +217,10 @@ typedef CRITICAL_SECTION uv_mutex_t;
typedef CONDITION_VARIABLE uv_cond_t;
typedef union {
struct {
unsigned int num_readers_;
CRITICAL_SECTION num_readers_lock_;
HANDLE write_semaphore_;
} state_;
typedef struct {
unsigned int num_readers_;
CRITICAL_SECTION num_readers_lock_;
HANDLE write_semaphore_;
} uv_rwlock_t;
typedef struct {

44
src/win/thread.c
View File

@ -207,57 +207,57 @@ int uv_rwlock_init(uv_rwlock_t* rwlock) {
HANDLE handle = CreateSemaphoreW(NULL, 1, 1, NULL);
if (handle == NULL)
return uv_translate_sys_error(GetLastError());
rwlock->state_.write_semaphore_ = handle;
rwlock->write_semaphore_ = handle;
/* Initialize the critical section protecting the reader count. */
InitializeCriticalSection(&rwlock->state_.num_readers_lock_);
InitializeCriticalSection(&rwlock->num_readers_lock_);
/* Initialize the reader count. */
rwlock->state_.num_readers_ = 0;
rwlock->num_readers_ = 0;
return 0;
}
void uv_rwlock_destroy(uv_rwlock_t* rwlock) {
DeleteCriticalSection(&rwlock->state_.num_readers_lock_);
CloseHandle(rwlock->state_.write_semaphore_);
DeleteCriticalSection(&rwlock->num_readers_lock_);
CloseHandle(rwlock->write_semaphore_);
}
void uv_rwlock_rdlock(uv_rwlock_t* rwlock) {
/* Acquire the lock that protects the reader count. */
EnterCriticalSection(&rwlock->state_.num_readers_lock_);
EnterCriticalSection(&rwlock->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 (++rwlock->num_readers_ == 1) {
DWORD r = WaitForSingleObject(rwlock->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_);
LeaveCriticalSection(&rwlock->num_readers_lock_);
}
int uv_rwlock_tryrdlock(uv_rwlock_t* rwlock) {
int err;
if (!TryEnterCriticalSection(&rwlock->state_.num_readers_lock_))
if (!TryEnterCriticalSection(&rwlock->num_readers_lock_))
return UV_EBUSY;
err = 0;
if (rwlock->state_.num_readers_ == 0) {
if (rwlock->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);
DWORD r = WaitForSingleObject(rwlock->write_semaphore_, 0);
if (r == WAIT_OBJECT_0)
rwlock->state_.num_readers_++;
rwlock->num_readers_++;
else if (r == WAIT_TIMEOUT)
err = UV_EBUSY;
else if (r == WAIT_FAILED)
@ -267,35 +267,35 @@ int uv_rwlock_tryrdlock(uv_rwlock_t* rwlock) {
/* The write lock has already been acquired because there are other
* active readers.
*/
rwlock->state_.num_readers_++;
rwlock->num_readers_++;
}
LeaveCriticalSection(&rwlock->state_.num_readers_lock_);
LeaveCriticalSection(&rwlock->num_readers_lock_);
return err;
}
void uv_rwlock_rdunlock(uv_rwlock_t* rwlock) {
EnterCriticalSection(&rwlock->state_.num_readers_lock_);
EnterCriticalSection(&rwlock->num_readers_lock_);
if (--rwlock->state_.num_readers_ == 0) {
if (!ReleaseSemaphore(rwlock->state_.write_semaphore_, 1, NULL))
if (--rwlock->num_readers_ == 0) {
if (!ReleaseSemaphore(rwlock->write_semaphore_, 1, NULL))
uv_fatal_error(GetLastError(), "ReleaseSemaphore");
}
LeaveCriticalSection(&rwlock->state_.num_readers_lock_);
LeaveCriticalSection(&rwlock->num_readers_lock_);
}
void uv_rwlock_wrlock(uv_rwlock_t* rwlock) {
DWORD r = WaitForSingleObject(rwlock->state_.write_semaphore_, INFINITE);
DWORD r = WaitForSingleObject(rwlock->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);
DWORD r = WaitForSingleObject(rwlock->write_semaphore_, 0);
if (r == WAIT_OBJECT_0)
return 0;
else if (r == WAIT_TIMEOUT)
@ -306,7 +306,7 @@ int uv_rwlock_trywrlock(uv_rwlock_t* rwlock) {
void uv_rwlock_wrunlock(uv_rwlock_t* rwlock) {
if (!ReleaseSemaphore(rwlock->state_.write_semaphore_, 1, NULL))
if (!ReleaseSemaphore(rwlock->write_semaphore_, 1, NULL))
uv_fatal_error(GetLastError(), "ReleaseSemaphore");
}