1a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// Copyright 2011 Google Inc. All Rights Reserved.
2a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora//
30406ce1417f76f2034833414dcecc9f56253640cVikas Arora// Use of this source code is governed by a BSD-style license
40406ce1417f76f2034833414dcecc9f56253640cVikas Arora// that can be found in the COPYING file in the root of the source
50406ce1417f76f2034833414dcecc9f56253640cVikas Arora// tree. An additional intellectual property rights grant can be found
60406ce1417f76f2034833414dcecc9f56253640cVikas Arora// in the file PATENTS. All contributing project authors may
70406ce1417f76f2034833414dcecc9f56253640cVikas Arora// be found in the AUTHORS file in the root of the source tree.
8a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// -----------------------------------------------------------------------------
9a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora//
10a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// Multi-threaded worker
11a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora//
12a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// Author: Skal (pascal.massimino@gmail.com)
13a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora
14a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora#ifndef WEBP_UTILS_THREAD_H_
15a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora#define WEBP_UTILS_THREAD_H_
16a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora
171e7bf8805bd030c19924a5306837ecd72c295751Vikas Arora#ifdef HAVE_CONFIG_H
181e7bf8805bd030c19924a5306837ecd72c295751Vikas Arora#include "config.h"
191e7bf8805bd030c19924a5306837ecd72c295751Vikas Arora#endif
201e7bf8805bd030c19924a5306837ecd72c295751Vikas Arora
21af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora#include "webp/types.h"
22af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora
238b720228d581a84fd173b6dcb2fa295b59db489aVikas Arora#ifdef __cplusplus
24a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Aroraextern "C" {
25a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora#endif
26a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora
27a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// State of the worker thread object
28a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Aroratypedef enum {
29a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora  NOT_OK = 0,   // object is unusable
30a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora  OK,           // ready to work
31a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora  WORK          // busy finishing the current task
32a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} WebPWorkerStatus;
33a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora
34a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// Function to be called by the worker thread. Takes two opaque pointers as
35a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora// arguments (data1 and data2), and should return false in case of error.
36a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Aroratypedef int (*WebPWorkerHook)(void*, void*);
37a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora
38af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora// Platform-dependent implementation details for the worker.
39af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Aroratypedef struct WebPWorkerImpl WebPWorkerImpl;
40af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora
41af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora// Synchronization object used to launch job in the worker thread
42a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Aroratypedef struct {
43af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  WebPWorkerImpl* impl_;
44a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora  WebPWorkerStatus status_;
45a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora  WebPWorkerHook hook;    // hook to call
46a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora  void* data1;            // first argument passed to 'hook'
47a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora  void* data2;            // second argument passed to 'hook'
48a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora  int had_error;          // return value of the last call to 'hook'
49a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora} WebPWorker;
50a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora
51af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora// The interface for all thread-worker related functions. All these functions
52af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora// must be implemented.
53af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Aroratypedef struct {
54af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // Must be called first, before any other method.
55af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  void (*Init)(WebPWorker* const worker);
56af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // Must be called to initialize the object and spawn the thread. Re-entrant.
57af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // Will potentially launch the thread. Returns false in case of error.
58af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  int (*Reset)(WebPWorker* const worker);
59af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // Makes sure the previous work is finished. Returns true if worker->had_error
60af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // was not set and no error condition was triggered by the working thread.
61af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  int (*Sync)(WebPWorker* const worker);
62af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // Triggers the thread to call hook() with data1 and data2 arguments. These
63af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // hook/data1/data2 values can be changed at any time before calling this
64af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // function, but not be changed afterward until the next call to Sync().
65af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  void (*Launch)(WebPWorker* const worker);
66af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // This function is similar to Launch() except that it calls the
67af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // hook directly instead of using a thread. Convenient to bypass the thread
68af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // mechanism while still using the WebPWorker structs. Sync() must
69af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // still be called afterward (for error reporting).
70af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  void (*Execute)(WebPWorker* const worker);
71af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // Kill the thread and terminate the object. To use the object again, one
72af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  // must call Reset() again.
73af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora  void (*End)(WebPWorker* const worker);
74af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora} WebPWorkerInterface;
75af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora
76af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora// Install a new set of threading functions, overriding the defaults. This
77af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora// should be done before any workers are started, i.e., before any encoding or
78af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora// decoding takes place. The contents of the interface struct are copied, it
79af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora// is safe to free the corresponding memory after this call. This function is
80af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora// not thread-safe. Return false in case of invalid pointer or methods.
81af51b94a435132e9014c324e25fb686b3d07a8c8Vikas AroraWEBP_EXTERN(int) WebPSetWorkerInterface(
82af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora    const WebPWorkerInterface* const interface);
83af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora
84af51b94a435132e9014c324e25fb686b3d07a8c8Vikas Arora// Retrieve the currently set thread worker interface.
85af51b94a435132e9014c324e25fb686b3d07a8c8Vikas AroraWEBP_EXTERN(const WebPWorkerInterface*) WebPGetWorkerInterface(void);
86a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora
87a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora//------------------------------------------------------------------------------
88a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora
898b720228d581a84fd173b6dcb2fa295b59db489aVikas Arora#ifdef __cplusplus
90a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora}    // extern "C"
91a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora#endif
92a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora
93a2415724fb3466168b2af5b08bd94ba732c0e753Vikas Arora#endif  /* WEBP_UTILS_THREAD_H_ */
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