1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
|
// 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:
// http://git.chromium.org/webm/libwebp.git
// 100644 blob 7bd451b124ae3b81596abfbcc823e3cb129d3a38 src/utils/thread.h
#ifndef VP9_DECODER_VP9_THREAD_H_
#define VP9_DECODER_VP9_THREAD_H_
#include "./vpx_config.h"
#ifdef __cplusplus
extern "C" {
#endif
// Set maximum decode threads to be 8 due to the limit of frame buffers
// and not enough semaphores in the emulation layer on windows.
#define MAX_DECODE_THREADS 8
#if CONFIG_MULTITHREAD
#if defined(_WIN32) && !HAVE_PTHREAD_H
#include <errno.h> // NOLINT
#include <process.h> // NOLINT
#include <windows.h> // NOLINT
typedef HANDLE pthread_t;
typedef CRITICAL_SECTION pthread_mutex_t;
typedef struct {
HANDLE waiting_sem_;
HANDLE received_sem_;
HANDLE signal_event_;
} pthread_cond_t;
//------------------------------------------------------------------------------
// simplistic pthread emulation layer
// _beginthreadex requires __stdcall
#define THREADFN unsigned int __stdcall
#define THREAD_RETURN(val) (unsigned int)((DWORD_PTR)val)
static INLINE int pthread_create(pthread_t* const thread, const void* attr,
unsigned int (__stdcall *start)(void*),
void* arg) {
(void)attr;
*thread = (pthread_t)_beginthreadex(NULL, /* void *security */
0, /* unsigned stack_size */
start,
arg,
0, /* unsigned initflag */
NULL); /* unsigned *thrdaddr */
if (*thread == NULL) return 1;
SetThreadPriority(*thread, THREAD_PRIORITY_ABOVE_NORMAL);
return 0;
}
static INLINE int pthread_join(pthread_t thread, void** value_ptr) {
(void)value_ptr;
return (WaitForSingleObject(thread, INFINITE) != WAIT_OBJECT_0 ||
CloseHandle(thread) == 0);
}
// Mutex
static INLINE int pthread_mutex_init(pthread_mutex_t *const mutex,
void* mutexattr) {
(void)mutexattr;
InitializeCriticalSection(mutex);
return 0;
}
static INLINE int pthread_mutex_trylock(pthread_mutex_t *const mutex) {
return TryEnterCriticalSection(mutex) ? 0 : EBUSY;
}
static INLINE int pthread_mutex_lock(pthread_mutex_t *const mutex) {
EnterCriticalSection(mutex);
return 0;
}
static INLINE int pthread_mutex_unlock(pthread_mutex_t *const mutex) {
LeaveCriticalSection(mutex);
return 0;
}
static INLINE int pthread_mutex_destroy(pthread_mutex_t *const mutex) {
DeleteCriticalSection(mutex);
return 0;
}
// Condition
static INLINE int pthread_cond_destroy(pthread_cond_t *const condition) {
int ok = 1;
ok &= (CloseHandle(condition->waiting_sem_) != 0);
ok &= (CloseHandle(condition->received_sem_) != 0);
ok &= (CloseHandle(condition->signal_event_) != 0);
return !ok;
}
static INLINE int pthread_cond_init(pthread_cond_t *const condition,
void* cond_attr) {
(void)cond_attr;
condition->waiting_sem_ = CreateSemaphore(NULL, 0, MAX_DECODE_THREADS, NULL);
condition->received_sem_ = CreateSemaphore(NULL, 0, MAX_DECODE_THREADS, NULL);
condition->signal_event_ = CreateEvent(NULL, FALSE, FALSE, NULL);
if (condition->waiting_sem_ == NULL ||
condition->received_sem_ == NULL ||
condition->signal_event_ == NULL) {
pthread_cond_destroy(condition);
return 1;
}
return 0;
}
static INLINE int pthread_cond_signal(pthread_cond_t *const condition) {
int ok = 1;
if (WaitForSingleObject(condition->waiting_sem_, 0) == WAIT_OBJECT_0) {
// a thread is waiting in pthread_cond_wait: allow it to be notified
ok = SetEvent(condition->signal_event_);
// wait until the event is consumed so the signaler cannot consume
// the event via its own pthread_cond_wait.
ok &= (WaitForSingleObject(condition->received_sem_, INFINITE) !=
WAIT_OBJECT_0);
}
return !ok;
}
static INLINE int pthread_cond_wait(pthread_cond_t *const condition,
pthread_mutex_t *const mutex) {
int ok;
// note that there is a consumer available so the signal isn't dropped in
// pthread_cond_signal
if (!ReleaseSemaphore(condition->waiting_sem_, 1, NULL))
return 1;
// now unlock the mutex so pthread_cond_signal may be issued
pthread_mutex_unlock(mutex);
ok = (WaitForSingleObject(condition->signal_event_, INFINITE) ==
WAIT_OBJECT_0);
ok &= ReleaseSemaphore(condition->received_sem_, 1, NULL);
pthread_mutex_lock(mutex);
return !ok;
}
#else // _WIN32
#include <pthread.h> // NOLINT
# define THREADFN void*
# define THREAD_RETURN(val) val
#endif
#endif // CONFIG_MULTITHREAD
// State of the worker thread object
typedef enum {
NOT_OK = 0, // object is unusable
OK, // ready to work
WORK // busy finishing the current task
} VP9WorkerStatus;
// Function to be called by the worker thread. Takes two opaque pointers as
// arguments (data1 and data2), and should return false in case of error.
typedef int (*VP9WorkerHook)(void*, void*);
// Platform-dependent implementation details for the worker.
typedef struct VP9WorkerImpl VP9WorkerImpl;
// Synchronization object used to launch job in the worker thread
typedef struct {
VP9WorkerImpl *impl_;
VP9WorkerStatus status_;
VP9WorkerHook hook; // hook to call
void *data1; // first argument passed to 'hook'
void *data2; // second argument passed to 'hook'
int had_error; // return value of the last call to 'hook'
} VP9Worker;
// 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)(VP9Worker *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)(VP9Worker *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)(VP9Worker *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)(VP9Worker *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 VP9Worker structs. sync() must
// still be called afterward (for error reporting).
void (*execute)(VP9Worker *const worker);
// Kill the thread and terminate the object. To use the object again, one
// must call reset() again.
void (*end)(VP9Worker *const worker);
} VP9WorkerInterface;
// 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 vp9_set_worker_interface(const VP9WorkerInterface *const winterface);
// Retrieve the currently set thread worker interface.
const VP9WorkerInterface *vp9_get_worker_interface(void);
//------------------------------------------------------------------------------
#ifdef __cplusplus
} // extern "C"
#endif
#endif // VP9_DECODER_VP9_THREAD_H_
|
