threadmessage.h File Reference

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Enumerations
enum	AVThreadMessageFlags { AV_THREAD_MESSAGE_NONBLOCK = 1 }

Functions
int	av_thread_message_queue_alloc (AVThreadMessageQueue **mq, unsigned nelem, unsigned elsize)
	Allocate a new message queue. More...
void	av_thread_message_queue_free (AVThreadMessageQueue **mq)
	Free a message queue. More...
int	av_thread_message_queue_send (AVThreadMessageQueue *mq, void *msg, unsigned flags)
	Send a message on the queue. More...
int	av_thread_message_queue_recv (AVThreadMessageQueue *mq, void *msg, unsigned flags)
	Receive a message from the queue. More...
void	av_thread_message_queue_set_err_send (AVThreadMessageQueue *mq, int err)
	Set the sending error code. More...
void	av_thread_message_queue_set_err_recv (AVThreadMessageQueue *mq, int err)
	Set the receiving error code. More...
void	av_thread_message_queue_set_free_func (AVThreadMessageQueue *mq, void(*free_func)(void *msg))
	Set the optional free message callback function which will be called if an operation is removing messages from the queue. More...
void	av_thread_message_flush (AVThreadMessageQueue *mq)
	Flush the message queue. More...

Enumeration Type Documentation

enum AVThreadMessageFlags

Enumerator
AV_THREAD_MESSAGE_NONBLOCK	Perform non-blocking operation. If this flag is set, send and recv operations are non-blocking and return AVERROR(EAGAIN) immediately if they can not proceed.

Definition at line 24 of file threadmessage.h.

Function Documentation

int av_thread_message_queue_alloc	(	AVThreadMessageQueue **	mq,
		unsigned	nelem,
		unsigned	elsize
	)

Allocate a new message queue.

Parameters

mq	pointer to the message queue
nelem	maximum number of elements in the queue
elsize	size of each element in the queue

Returns

>=0 for success; <0 for error, in particular AVERROR(ENOSYS) if lavu was built without thread support

Definition at line 40 of file threadmessage.c.

Referenced by main().

void av_thread_message_queue_free

(

AVThreadMessageQueue **

mq

)

Free a message queue.

The message queue must no longer be in use by another thread.

Definition at line 91 of file threadmessage.c.

Referenced by main().

int av_thread_message_queue_send	(	AVThreadMessageQueue *	mq,
		void *	msg,
		unsigned	flags
	)

Send a message on the queue.

Definition at line 143 of file threadmessage.c.

Referenced by sender_thread().

int av_thread_message_queue_recv	(	AVThreadMessageQueue *	mq,
		void *	msg,
		unsigned	flags
	)

Receive a message from the queue.

Definition at line 159 of file threadmessage.c.

Referenced by receiver_thread().

void av_thread_message_queue_set_err_send	(	AVThreadMessageQueue *	mq,
		int	err
	)

Set the sending error code.

If the error code is set to non-zero, av_thread_message_queue_recv() will return it immediately when there are no longer available messages. Conventional values, such as AVERROR_EOF or AVERROR(EAGAIN), can be used to cause the receiving thread to stop or suspend its operation.

Definition at line 175 of file threadmessage.c.

Referenced by receiver_thread().

void av_thread_message_queue_set_err_recv	(	AVThreadMessageQueue *	mq,
		int	err
	)

Set the receiving error code.

If the error code is set to non-zero, av_thread_message_queue_send() will return it immediately. Conventional values, such as AVERROR_EOF or AVERROR(EAGAIN), can be used to cause the sending thread to stop or suspend its operation.

Definition at line 186 of file threadmessage.c.

Referenced by sender_thread().

void av_thread_message_queue_set_free_func	(	AVThreadMessageQueue *	mq,
		void(*)(void *msg)	free_func
	)

Set the optional free message callback function which will be called if an operation is removing messages from the queue.

Definition at line 83 of file threadmessage.c.

Referenced by main().

void av_thread_message_flush

(

AVThreadMessageQueue *

mq

)

Flush the message queue.

This function is mostly equivalent to reading and free-ing every message except that it will be done in a single operation (no lock/unlock between reads).

Definition at line 205 of file threadmessage.c.

Referenced by av_thread_message_queue_free(), receiver_thread(), and sender_thread().