1 /* 2 * Copyright (c) 2016, Alliance for Open Media. All rights reserved. 3 * 4 * This source code is subject to the terms of the BSD 2 Clause License and 5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License 6 * was not distributed with this source code in the LICENSE file, you can 7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open 8 * Media Patent License 1.0 was not distributed with this source code in the 9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent. 10 */ 11 // 12 // Multi-threaded worker 13 // 14 // Original source: 15 // https://chromium.googlesource.com/webm/libwebp 16 17 #ifndef AOM_AOM_UTIL_AOM_THREAD_H_ 18 #define AOM_AOM_UTIL_AOM_THREAD_H_ 19 20 #ifdef __cplusplus 21 extern "C" { 22 #endif 23 24 // State of the worker thread object 25 typedef enum { 26 AVX_WORKER_STATUS_NOT_OK = 0, // object is unusable 27 AVX_WORKER_STATUS_OK, // ready to work 28 AVX_WORKER_STATUS_WORKING // busy finishing the current task 29 } AVxWorkerStatus; 30 31 // Function to be called by the worker thread. Takes two opaque pointers as 32 // arguments (data1 and data2). Should return true on success and return false 33 // in case of error. 34 typedef int (*AVxWorkerHook)(void *, void *); 35 36 // Platform-dependent implementation details for the worker. 37 typedef struct AVxWorkerImpl AVxWorkerImpl; 38 39 // Synchronization object used to launch job in the worker thread 40 typedef struct { 41 AVxWorkerImpl *impl_; 42 AVxWorkerStatus status_; 43 // Thread name for the debugger. If not NULL, must point to a string that 44 // outlives the worker thread. For portability, use a name <= 15 characters 45 // long (not including the terminating NUL character). 46 const char *thread_name; 47 AVxWorkerHook hook; // hook to call 48 void *data1; // first argument passed to 'hook' 49 void *data2; // second argument passed to 'hook' 50 int had_error; // true if a call to 'hook' returned false 51 } AVxWorker; 52 53 // The interface for all thread-worker related functions. All these functions 54 // must be implemented. 55 typedef struct { 56 // Must be called first, before any other method. 57 void (*init)(AVxWorker *const worker); 58 // Must be called to initialize the object and spawn the thread. Re-entrant. 59 // Will potentially launch the thread. Returns false in case of error. 60 int (*reset)(AVxWorker *const worker); 61 // Makes sure the previous work is finished. Returns true if worker->had_error 62 // was not set and no error condition was triggered by the working thread. 63 int (*sync)(AVxWorker *const worker); 64 // Triggers the thread to call hook() with data1 and data2 arguments. These 65 // hook/data1/data2 values can be changed at any time before calling this 66 // function, but not be changed afterward until the next call to Sync(). 67 void (*launch)(AVxWorker *const worker); 68 // This function is similar to launch() except that it calls the 69 // hook directly instead of using a thread. Convenient to bypass the thread 70 // mechanism while still using the AVxWorker structs. sync() must 71 // still be called afterward (for error reporting). 72 void (*execute)(AVxWorker *const worker); 73 // Kill the thread and terminate the object. To use the object again, one 74 // must call reset() again. 75 void (*end)(AVxWorker *const worker); 76 } AVxWorkerInterface; 77 78 // Install a new set of threading functions, overriding the defaults. This 79 // should be done before any workers are started, i.e., before any encoding or 80 // decoding takes place. The contents of the interface struct are copied, it 81 // is safe to free the corresponding memory after this call. This function is 82 // not thread-safe. Return false in case of invalid pointer or methods. 83 int aom_set_worker_interface(const AVxWorkerInterface *const winterface); 84 85 // Retrieve the currently set thread worker interface. 86 const AVxWorkerInterface *aom_get_worker_interface(void); 87 88 //------------------------------------------------------------------------------ 89 90 #ifdef __cplusplus 91 } // extern "C" 92 #endif 93 94 #endif // AOM_AOM_UTIL_AOM_THREAD_H_ 95