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@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) 22extern "C" { 23#endif 24 25#if WEBP_USE_THREAD 26 27#if defined(_WIN32) 28 29#include <windows.h> 30typedef HANDLE pthread_t; 31typedef CRITICAL_SECTION pthread_mutex_t; 32typedef 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 46typedef 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. 54typedef int (*WebPWorkerHook)(void*, void*); 55 56// Synchronize object used to launch job in the worker thread 57typedef 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. 71void 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. 74int 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. 77int 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(). 81void WebPWorkerLaunch(WebPWorker* const worker); 82// Kill the thread and terminate the object. To use the object again, one 83// must call WebPWorkerReset() again. 84void 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