#include <nitro/os.h>
BOOL OS_ReadMessage(
OSMessageQueue* mq,
OSMessage* msg,
s32 flags );
mq | Pointer to the message queue |
msg | Viewed message |
flags | If OS_MESSAGE_BLOCK is set up, OS_ReceiveMessage blocks empty queues. If OS_MESSAGE_NOBLOCK is set up, OS_ReceiveMessage returns immediately whether or not the queue is empty. |
Returns TRUE
if the message was removed without any problems. If OS_MESSAGE_NOBLOCK
was specified and the queue was empty, FALSE is returned.
Copies the starting message of the message queue The status of the message queue does not change. This function differs from OS_ReceiveMessage()
in that a wait status thread is not activated to send a message to this queue. In a manner of speaking, OS_ReadMessage()
is a function for looking at the starting message of the message queue.
If OS_MESSAGE_BLOCK
is set up in flags
, the thread that called this function will be paused if the queue is empty. The thread resumes once the message is sent to the queue. If another receiving thread with a higher priority is present, those threads are executed first so be aware of the point at which messages are removed. If the message queue is empty when this thread is executed, it will be paused again until another message is sent to the queue.
If OS_MESSAGE_NOBLOCK
is set up in flags
, the process immediately returns to the thread that was called. If the queue is not empty, TRUE
is returned. If it is empty, FALSE
is returned.
OS_InitMessageQueue
, OS_SendMessage
, OS_ReceiveMessage
03/12/2004 Initial Version