| // Copyright 2013 Google Inc. All Rights Reserved. |
| // |
| // Use of this source code is governed by a BSD-style license |
| // that can be found in the COPYING file in the root of the source |
| // tree. An additional intellectual property rights grant can be found |
| // in the file PATENTS. All contributing project authors may |
| // be found in the AUTHORS file in the root of the source tree. |
| // ----------------------------------------------------------------------------- |
| // |
| // Multi-threaded worker |
| // |
| // Original source: |
| // https://chromium.googlesource.com/webm/libwebp |
| |
| #ifndef VPX_VPX_UTIL_VPX_THREAD_H_ |
| #define VPX_VPX_UTIL_VPX_THREAD_H_ |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| #define MAX_NUM_THREADS 64 |
| |
| // State of the worker thread object |
| typedef enum { |
| VPX_WORKER_STATUS_NOT_OK = 0, // object is unusable |
| VPX_WORKER_STATUS_OK, // ready to work |
| VPX_WORKER_STATUS_WORKING // busy finishing the current task |
| } VPxWorkerStatus; |
| |
| // Function to be called by the worker thread. Takes two opaque pointers as |
| // arguments (data1 and data2). Should return true on success and return false |
| // in case of error. |
| typedef int (*VPxWorkerHook)(void *, void *); |
| |
| // Platform-dependent implementation details for the worker. |
| typedef struct VPxWorkerImpl VPxWorkerImpl; |
| |
| // Synchronization object used to launch job in the worker thread |
| typedef struct { |
| VPxWorkerImpl *impl_; |
| VPxWorkerStatus status_; |
| // Thread name for the debugger. If not NULL, must point to a string that |
| // outlives the worker thread. For portability, use a name <= 15 characters |
| // long (not including the terminating NUL character). |
| const char *thread_name; |
| VPxWorkerHook hook; // hook to call |
| void *data1; // first argument passed to 'hook' |
| void *data2; // second argument passed to 'hook' |
| int had_error; // true if a call to 'hook' returned false |
| } VPxWorker; |
| |
| // The interface for all thread-worker related functions. All these functions |
| // must be implemented. |
| typedef struct { |
| // Must be called first, before any other method. |
| void (*init)(VPxWorker *const worker); |
| // Must be called to initialize the object and spawn the thread. Re-entrant. |
| // Will potentially launch the thread. Returns false in case of error. |
| int (*reset)(VPxWorker *const worker); |
| // Makes sure the previous work is finished. Returns true if worker->had_error |
| // was not set and no error condition was triggered by the working thread. |
| int (*sync)(VPxWorker *const worker); |
| // Triggers the thread to call hook() with data1 and data2 arguments. These |
| // hook/data1/data2 values can be changed at any time before calling this |
| // function, but not be changed afterward until the next call to Sync(). |
| void (*launch)(VPxWorker *const worker); |
| // This function is similar to launch() except that it calls the |
| // hook directly instead of using a thread. Convenient to bypass the thread |
| // mechanism while still using the VPxWorker structs. sync() must |
| // still be called afterward (for error reporting). |
| void (*execute)(VPxWorker *const worker); |
| // Kill the thread and terminate the object. To use the object again, one |
| // must call reset() again. |
| void (*end)(VPxWorker *const worker); |
| } VPxWorkerInterface; |
| |
| // Install a new set of threading functions, overriding the defaults. This |
| // should be done before any workers are started, i.e., before any encoding or |
| // decoding takes place. The contents of the interface struct are copied, it |
| // is safe to free the corresponding memory after this call. This function is |
| // not thread-safe. Return false in case of invalid pointer or methods. |
| int vpx_set_worker_interface(const VPxWorkerInterface *const winterface); |
| |
| // Retrieve the currently set thread worker interface. |
| const VPxWorkerInterface *vpx_get_worker_interface(void); |
| |
| //------------------------------------------------------------------------------ |
| |
| #ifdef __cplusplus |
| } // extern "C" |
| #endif |
| |
| #endif // VPX_VPX_UTIL_VPX_THREAD_H_ |