1 // Copyright 2011 Google Inc. All Rights Reserved. 2 // 3 // Use of this source code is governed by a BSD-style license 4 // that can be found in the COPYING file in the root of the source 5 // tree. An additional intellectual property rights grant can be found 6 // in the file PATENTS. All contributing project authors may 7 // be found in the AUTHORS file in the root of the source tree. 8 // ----------------------------------------------------------------------------- 9 // 10 // Multi-threaded worker 11 // 12 // Author: Skal (pascal.massimino (at) gmail.com) 13 14 #ifndef WEBP_UTILS_THREAD_H_ 15 #define WEBP_UTILS_THREAD_H_ 16 17 #ifdef HAVE_CONFIG_H 18 #include "config.h" 19 #endif 20 21 #if defined(__cplusplus) || defined(c_plusplus) 22 extern "C" { 23 #endif 24 25 #if WEBP_USE_THREAD 26 27 #if defined(_WIN32) 28 29 #include <windows.h> 30 typedef HANDLE pthread_t; 31 typedef CRITICAL_SECTION pthread_mutex_t; 32 typedef struct { 33 HANDLE waiting_sem_; 34 HANDLE received_sem_; 35 HANDLE signal_event_; 36 } pthread_cond_t; 37 38 #else 39 40 #include <pthread.h> 41 42 #endif /* _WIN32 */ 43 #endif /* WEBP_USE_THREAD */ 44 45 // State of the worker thread object 46 typedef enum { 47 NOT_OK = 0, // object is unusable 48 OK, // ready to work 49 WORK // busy finishing the current task 50 } WebPWorkerStatus; 51 52 // Function to be called by the worker thread. Takes two opaque pointers as 53 // arguments (data1 and data2), and should return false in case of error. 54 typedef int (*WebPWorkerHook)(void*, void*); 55 56 // Synchronize object used to launch job in the worker thread 57 typedef struct { 58 #if WEBP_USE_THREAD 59 pthread_mutex_t mutex_; 60 pthread_cond_t condition_; 61 pthread_t thread_; 62 #endif 63 WebPWorkerStatus status_; 64 WebPWorkerHook hook; // hook to call 65 void* data1; // first argument passed to 'hook' 66 void* data2; // second argument passed to 'hook' 67 int had_error; // return value of the last call to 'hook' 68 } WebPWorker; 69 70 // Must be called first, before any other method. 71 void WebPWorkerInit(WebPWorker* const worker); 72 // Must be called to initialize the object and spawn the thread. Re-entrant. 73 // Will potentially launch the thread. Returns false in case of error. 74 int WebPWorkerReset(WebPWorker* const worker); 75 // Makes sure the previous work is finished. Returns true if worker->had_error 76 // was not set and no error condition was triggered by the working thread. 77 int WebPWorkerSync(WebPWorker* const worker); 78 // Triggers the thread to call hook() with data1 and data2 argument. These 79 // hook/data1/data2 can be changed at any time before calling this function, 80 // but not be changed afterward until the next call to WebPWorkerSync(). 81 void WebPWorkerLaunch(WebPWorker* const worker); 82 // Kill the thread and terminate the object. To use the object again, one 83 // must call WebPWorkerReset() again. 84 void WebPWorkerEnd(WebPWorker* const worker); 85 86 //------------------------------------------------------------------------------ 87 88 #if defined(__cplusplus) || defined(c_plusplus) 89 } // extern "C" 90 #endif 91 92 #endif /* WEBP_UTILS_THREAD_H_ */ 93
