blob: 2df190f907dfb7970d95cf690f3fd72e31165af7 [file] [log] [blame]
* Copyright (c) 2016, Alliance for Open Media. All rights reserved
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at
// Multi-threaded worker
// Original source:
#include "config/aom_config.h"
#ifdef __cplusplus
extern "C" {
#define MAX_NUM_THREADS 64
#if defined(_WIN32) && !HAVE_PTHREAD_H
// Prevent leaking max/min macros.
#define NOMINMAX
#include <errno.h> // NOLINT
#include <process.h> // NOLINT
#include <windows.h> // NOLINT
typedef HANDLE pthread_t;
typedef CRITICAL_SECTION pthread_mutex_t;
#if _WIN32_WINNT < 0x0600
#error _WIN32_WINNT must target Windows Vista / Server 2008 or newer.
typedef CONDITION_VARIABLE 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) {
*thread = CreateThread(NULL, /* lpThreadAttributes */
0, /* dwStackSize */
start, arg, 0, /* dwStackSize */
NULL); /* lpThreadId */
*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) {
return (WaitForSingleObjectEx(thread, INFINITE, FALSE /*bAlertable*/) !=
CloseHandle(thread) == 0);
// Mutex
static INLINE int pthread_mutex_init(pthread_mutex_t *const mutex,
void *mutexattr) {
InitializeCriticalSectionEx(mutex, 0 /*dwSpinCount*/, 0 /*Flags*/);
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) {
return 0;
static INLINE int pthread_mutex_unlock(pthread_mutex_t *const mutex) {
return 0;
static INLINE int pthread_mutex_destroy(pthread_mutex_t *const mutex) {
return 0;
// Condition
static INLINE int pthread_cond_destroy(pthread_cond_t *const condition) {
return 0;
static INLINE int pthread_cond_init(pthread_cond_t *const condition,
void *cond_attr) {
return 0;
static INLINE int pthread_cond_signal(pthread_cond_t *const condition) {
return 0;
static INLINE int pthread_cond_broadcast(pthread_cond_t *const condition) {
return 0;
static INLINE int pthread_cond_wait(pthread_cond_t *const condition,
pthread_mutex_t *const mutex) {
int ok;
ok = SleepConditionVariableCS(condition, mutex, INFINITE);
return !ok;
#else // _WIN32
#include <pthread.h> // NOLINT
#define THREADFN void *
#define THREAD_RETURN(val) val
// State of the worker thread object
typedef enum {
NOT_OK = 0, // object is unusable
OK, // ready to work
WORK // busy finishing the current task
} AVxWorkerStatus;
// 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 (*AVxWorkerHook)(void *, void *);
// Platform-dependent implementation details for the worker.
typedef struct AVxWorkerImpl AVxWorkerImpl;
// Synchronization object used to launch job in the worker thread
typedef struct {
AVxWorkerImpl *impl_;
AVxWorkerStatus 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;
AVxWorkerHook 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
} AVxWorker;
// 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)(AVxWorker *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)(AVxWorker *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)(AVxWorker *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)(AVxWorker *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 AVxWorker structs. sync() must
// still be called afterward (for error reporting).
void (*execute)(AVxWorker *const worker);
// Kill the thread and terminate the object. To use the object again, one
// must call reset() again.
void (*end)(AVxWorker *const worker);
} AVxWorkerInterface;
// 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 aom_set_worker_interface(const AVxWorkerInterface *const winterface);
// Retrieve the currently set thread worker interface.
const AVxWorkerInterface *aom_get_worker_interface(void);
#ifdef __cplusplus
} // extern "C"