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 #define MAX_NUM_THREADS 64 25 26 // State of the worker thread object 27 typedef enum { 28 AVX_WORKER_STATUS_NOT_OK = 0, // object is unusable 29 AVX_WORKER_STATUS_OK, // ready to work 30 AVX_WORKER_STATUS_WORKING // busy finishing the current task 31 } AVxWorkerStatus; 32 33 // Function to be called by the worker thread. Takes two opaque pointers as 34 // arguments (data1 and data2). Should return true on success and return false 35 // in case of error. 36 typedef int (*AVxWorkerHook)(void *, void *); 37 38 // Platform-dependent implementation details for the worker. 39 typedef struct AVxWorkerImpl AVxWorkerImpl; 40 41 // Synchronization object used to launch job in the worker thread 42 typedef struct { 43 AVxWorkerImpl *impl_; 44 AVxWorkerStatus status_; 45 // Thread name for the debugger. If not NULL, must point to a string that 46 // outlives the worker thread. For portability, use a name <= 15 characters 47 // long (not including the terminating NUL character). 48 const char *thread_name; 49 AVxWorkerHook hook; // hook to call 50 void *data1; // first argument passed to 'hook' 51 void *data2; // second argument passed to 'hook' 52 int had_error; // true if a call to 'hook' returned false 53 } AVxWorker; 54 55 // The interface for all thread-worker related functions. All these functions 56 // must be implemented. 57 typedef struct { 58 // Must be called first, before any other method. 59 void (*init)(AVxWorker *const worker); 60 // Must be called to initialize the object and spawn the thread. Re-entrant. 61 // Will potentially launch the thread. Returns false in case of error. 62 int (*reset)(AVxWorker *const worker); 63 // Makes sure the previous work is finished. Returns true if worker->had_error 64 // was not set and no error condition was triggered by the working thread. 65 int (*sync)(AVxWorker *const worker); 66 // Triggers the thread to call hook() with data1 and data2 arguments. These 67 // hook/data1/data2 values can be changed at any time before calling this 68 // function, but not be changed afterward until the next call to Sync(). 69 void (*launch)(AVxWorker *const worker); 70 // This function is similar to launch() except that it calls the 71 // hook directly instead of using a thread. Convenient to bypass the thread 72 // mechanism while still using the AVxWorker structs. sync() must 73 // still be called afterward (for error reporting). 74 void (*execute)(AVxWorker *const worker); 75 // Kill the thread and terminate the object. To use the object again, one 76 // must call reset() again. 77 void (*end)(AVxWorker *const worker); 78 } AVxWorkerInterface; 79 80 // Install a new set of threading functions, overriding the defaults. This 81 // should be done before any workers are started, i.e., before any encoding or 82 // decoding takes place. The contents of the interface struct are copied, it 83 // is safe to free the corresponding memory after this call. This function is 84 // not thread-safe. Return false in case of invalid pointer or methods. 85 int aom_set_worker_interface(const AVxWorkerInterface *const winterface); 86 87 // Retrieve the currently set thread worker interface. 88 const AVxWorkerInterface *aom_get_worker_interface(void); 89 90 //------------------------------------------------------------------------------ 91 92 #ifdef __cplusplus 93 } // extern "C" 94 #endif 95 96 #endif // AOM_AOM_UTIL_AOM_THREAD_H_ 97