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Diffstat (limited to 'drivers/webpold/utils/thread.c')
-rw-r--r--drivers/webpold/utils/thread.c247
1 files changed, 247 insertions, 0 deletions
diff --git a/drivers/webpold/utils/thread.c b/drivers/webpold/utils/thread.c
new file mode 100644
index 0000000000..ce89cf9dc7
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+++ b/drivers/webpold/utils/thread.c
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+// Copyright 2011 Google Inc. All Rights Reserved.
+//
+// This code is licensed under the same terms as WebM:
+// Software License Agreement: http://www.webmproject.org/license/software/
+// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
+// -----------------------------------------------------------------------------
+//
+// Multi-threaded worker
+//
+// Author: Skal (pascal.massimino@gmail.com)
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <assert.h>
+#include <string.h> // for memset()
+#include "./thread.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+#ifdef WEBP_USE_THREAD
+
+#if defined(_WIN32)
+
+//------------------------------------------------------------------------------
+// simplistic pthread emulation layer
+
+#include <process.h>
+
+// _beginthreadex requires __stdcall
+#define THREADFN unsigned int __stdcall
+#define THREAD_RETURN(val) (unsigned int)((DWORD_PTR)val)
+
+static int pthread_create(pthread_t* const thread, const void* attr,
+ unsigned int (__stdcall *start)(void*), void* arg) {
+ (void)attr;
+ *thread = (pthread_t)_beginthreadex(NULL, /* void *security */
+ 0, /* unsigned stack_size */
+ start,
+ arg,
+ 0, /* unsigned initflag */
+ NULL); /* unsigned *thrdaddr */
+ if (*thread == NULL) return 1;
+ SetThreadPriority(*thread, THREAD_PRIORITY_ABOVE_NORMAL);
+ return 0;
+}
+
+static int pthread_join(pthread_t thread, void** value_ptr) {
+ (void)value_ptr;
+ return (WaitForSingleObject(thread, INFINITE) != WAIT_OBJECT_0 ||
+ CloseHandle(thread) == 0);
+}
+
+// Mutex
+static int pthread_mutex_init(pthread_mutex_t* const mutex, void* mutexattr) {
+ (void)mutexattr;
+ InitializeCriticalSection(mutex);
+ return 0;
+}
+
+static int pthread_mutex_lock(pthread_mutex_t* const mutex) {
+ EnterCriticalSection(mutex);
+ return 0;
+}
+
+static int pthread_mutex_unlock(pthread_mutex_t* const mutex) {
+ LeaveCriticalSection(mutex);
+ return 0;
+}
+
+static int pthread_mutex_destroy(pthread_mutex_t* const mutex) {
+ DeleteCriticalSection(mutex);
+ return 0;
+}
+
+// Condition
+static int pthread_cond_destroy(pthread_cond_t* const condition) {
+ int ok = 1;
+ ok &= (CloseHandle(condition->waiting_sem_) != 0);
+ ok &= (CloseHandle(condition->received_sem_) != 0);
+ ok &= (CloseHandle(condition->signal_event_) != 0);
+ return !ok;
+}
+
+static int pthread_cond_init(pthread_cond_t* const condition, void* cond_attr) {
+ (void)cond_attr;
+ condition->waiting_sem_ = CreateSemaphore(NULL, 0, 1, NULL);
+ condition->received_sem_ = CreateSemaphore(NULL, 0, 1, NULL);
+ condition->signal_event_ = CreateEvent(NULL, FALSE, FALSE, NULL);
+ if (condition->waiting_sem_ == NULL ||
+ condition->received_sem_ == NULL ||
+ condition->signal_event_ == NULL) {
+ pthread_cond_destroy(condition);
+ return 1;
+ }
+ return 0;
+}
+
+static int pthread_cond_signal(pthread_cond_t* const condition) {
+ int ok = 1;
+ if (WaitForSingleObject(condition->waiting_sem_, 0) == WAIT_OBJECT_0) {
+ // a thread is waiting in pthread_cond_wait: allow it to be notified
+ ok = SetEvent(condition->signal_event_);
+ // wait until the event is consumed so the signaler cannot consume
+ // the event via its own pthread_cond_wait.
+ ok &= (WaitForSingleObject(condition->received_sem_, INFINITE) !=
+ WAIT_OBJECT_0);
+ }
+ return !ok;
+}
+
+static int pthread_cond_wait(pthread_cond_t* const condition,
+ pthread_mutex_t* const mutex) {
+ int ok;
+ // note that there is a consumer available so the signal isn't dropped in
+ // pthread_cond_signal
+ if (!ReleaseSemaphore(condition->waiting_sem_, 1, NULL))
+ return 1;
+ // now unlock the mutex so pthread_cond_signal may be issued
+ pthread_mutex_unlock(mutex);
+ ok = (WaitForSingleObject(condition->signal_event_, INFINITE) ==
+ WAIT_OBJECT_0);
+ ok &= ReleaseSemaphore(condition->received_sem_, 1, NULL);
+ pthread_mutex_lock(mutex);
+ return !ok;
+}
+
+#else // _WIN32
+# define THREADFN void*
+# define THREAD_RETURN(val) val
+#endif
+
+//------------------------------------------------------------------------------
+
+static THREADFN WebPWorkerThreadLoop(void *ptr) { // thread loop
+ WebPWorker* const worker = (WebPWorker*)ptr;
+ int done = 0;
+ while (!done) {
+ pthread_mutex_lock(&worker->mutex_);
+ while (worker->status_ == OK) { // wait in idling mode
+ pthread_cond_wait(&worker->condition_, &worker->mutex_);
+ }
+ if (worker->status_ == WORK) {
+ if (worker->hook) {
+ worker->had_error |= !worker->hook(worker->data1, worker->data2);
+ }
+ worker->status_ = OK;
+ } else if (worker->status_ == NOT_OK) { // finish the worker
+ done = 1;
+ }
+ // signal to the main thread that we're done (for Sync())
+ pthread_cond_signal(&worker->condition_);
+ pthread_mutex_unlock(&worker->mutex_);
+ }
+ return THREAD_RETURN(NULL); // Thread is finished
+}
+
+// main thread state control
+static void WebPWorkerChangeState(WebPWorker* const worker,
+ WebPWorkerStatus new_status) {
+ // no-op when attempting to change state on a thread that didn't come up
+ if (worker->status_ < OK) return;
+
+ pthread_mutex_lock(&worker->mutex_);
+ // wait for the worker to finish
+ while (worker->status_ != OK) {
+ pthread_cond_wait(&worker->condition_, &worker->mutex_);
+ }
+ // assign new status and release the working thread if needed
+ if (new_status != OK) {
+ worker->status_ = new_status;
+ pthread_cond_signal(&worker->condition_);
+ }
+ pthread_mutex_unlock(&worker->mutex_);
+}
+
+#endif
+
+//------------------------------------------------------------------------------
+
+void WebPWorkerInit(WebPWorker* const worker) {
+ memset(worker, 0, sizeof(*worker));
+ worker->status_ = NOT_OK;
+}
+
+int WebPWorkerSync(WebPWorker* const worker) {
+#ifdef WEBP_USE_THREAD
+ WebPWorkerChangeState(worker, OK);
+#endif
+ assert(worker->status_ <= OK);
+ return !worker->had_error;
+}
+
+int WebPWorkerReset(WebPWorker* const worker) {
+ int ok = 1;
+ worker->had_error = 0;
+ if (worker->status_ < OK) {
+#ifdef WEBP_USE_THREAD
+ if (pthread_mutex_init(&worker->mutex_, NULL) ||
+ pthread_cond_init(&worker->condition_, NULL)) {
+ return 0;
+ }
+ pthread_mutex_lock(&worker->mutex_);
+ ok = !pthread_create(&worker->thread_, NULL, WebPWorkerThreadLoop, worker);
+ if (ok) worker->status_ = OK;
+ pthread_mutex_unlock(&worker->mutex_);
+#else
+ worker->status_ = OK;
+#endif
+ } else if (worker->status_ > OK) {
+ ok = WebPWorkerSync(worker);
+ }
+ assert(!ok || (worker->status_ == OK));
+ return ok;
+}
+
+void WebPWorkerLaunch(WebPWorker* const worker) {
+#ifdef WEBP_USE_THREAD
+ WebPWorkerChangeState(worker, WORK);
+#else
+ if (worker->hook)
+ worker->had_error |= !worker->hook(worker->data1, worker->data2);
+#endif
+}
+
+void WebPWorkerEnd(WebPWorker* const worker) {
+ if (worker->status_ >= OK) {
+#ifdef WEBP_USE_THREAD
+ WebPWorkerChangeState(worker, NOT_OK);
+ pthread_join(worker->thread_, NULL);
+ pthread_mutex_destroy(&worker->mutex_);
+ pthread_cond_destroy(&worker->condition_);
+#else
+ worker->status_ = NOT_OK;
+#endif
+ }
+ assert(worker->status_ == NOT_OK);
+}
+
+//------------------------------------------------------------------------------
+
+#if defined(__cplusplus) || defined(c_plusplus)
+} // extern "C"
+#endif