added WebP library

3rdparty/libwebp/utils/thread.h

@@ -0,0 +1,86 @@
+// 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)
+
+#ifndef WEBP_UTILS_THREAD_H_
+#define WEBP_UTILS_THREAD_H_
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+#if WEBP_USE_THREAD
+
+#if defined(_WIN32)
+
+#include <windows.h>
+typedef HANDLE pthread_t;
+typedef CRITICAL_SECTION pthread_mutex_t;
+typedef struct {
+  HANDLE waiting_sem_;
+  HANDLE received_sem_;
+  HANDLE signal_event_;
+} pthread_cond_t;
+
+#else
+
+#include <pthread.h>
+
+#endif    /* _WIN32 */
+#endif    /* WEBP_USE_THREAD */
+
+// State of the worker thread object
+typedef enum {
+  NOT_OK = 0,   // object is unusable
+  OK,           // ready to work
+  WORK          // busy finishing the current task
+} WebPWorkerStatus;
+
+// Function to be called by the worker thread. Takes two opaque pointers as
+// arguments (data1 and data2), and should return false in case of error.
+typedef int (*WebPWorkerHook)(void*, void*);
+
+// Synchronize object used to launch job in the worker thread
+typedef struct {
+#if WEBP_USE_THREAD
+  pthread_mutex_t mutex_;
+  pthread_cond_t  condition_;
+  pthread_t       thread_;
+#endif
+  WebPWorkerStatus status_;
+  WebPWorkerHook hook;    // hook to call
+  void* data1;            // first argument passed to 'hook'
+  void* data2;            // second argument passed to 'hook'
+  int had_error;          // return value of the last call to 'hook'
+} WebPWorker;
+
+// Must be called first, before any other method.
+void WebPWorkerInit(WebPWorker* const worker);
+// Must be called initialize the object and spawn the thread. Re-entrant.
+// Will potentially launch the thread. Returns false in case of error.
+int WebPWorkerReset(WebPWorker* const worker);
+// Make sure the previous work is finished. Returns true if worker->had_error
+// was not set and not error condition was triggered by the working thread.
+int WebPWorkerSync(WebPWorker* const worker);
+// Trigger the thread to call hook() with data1 and data2 argument. These
+// hook/data1/data2 can be changed at any time before calling this function,
+// but not be changed afterward until the next call to WebPWorkerSync().
+void WebPWorkerLaunch(WebPWorker* const worker);
+// Kill the thread and terminate the object. To use the object again, one
+// must call WebPWorkerReset() again.
+void WebPWorkerEnd(WebPWorker* const worker);
+
+//------------------------------------------------------------------------------
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}    // extern "C"
+#endif
+
+#endif  /* WEBP_UTILS_THREAD_H_ */