Added mq_timedsend() and mq_timedreceive()
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@166 42af7a65-404d-4744-a932-0658087f49c3
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patacongo
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@ -454,6 +454,11 @@ Other memory:
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* mq_receive and mq_send now return errno's appropriately
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* mq_receive and mq_send are now correctly awakened by signals.
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* Fixed an unmatched sched_lock/unlock pair in task_delete().
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* sched_lock must be called in _exit() because operation of
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task_delete() can cause pending tasks to be merged and a
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context switch to occur.
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* Added mq_timedreceive() and mq_timedsend()
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* Started m68322
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</pre></ul>
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@ -1021,10 +1021,12 @@ on this thread of execution.
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<li><a href="#mqclose">2.4.2 mq_close</a></li>
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<li><a href="#mqunlink">2.4.3 mq_unlink</a></li>
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<li><a href="#mqsend">2.4.4 mq_send</a></li>
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<li><a href="#mqreceive">2.4.5 mq_receive</a></li>
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<li><a href="#mqnotify">2.4.6 mq_notify</a></li>
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<li><a href="#mqsetattr">2.4.7 mq_setattr</a></li>
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<li><a href="#mqgetattr">2.4.8 mq_getattr</a></li>
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<li><a href="#mqtimedsend">2.4.5 mq_timedsend</a></li>
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<li><a href="#mqreceive">2.4.6 mq_receive</a></li>
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<li><a href="#mqtimedreceive">2.4.7 mq_timedreceive</a></li>
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<li><a href="#mqnotify">2.4.8 mq_notify</a></li>
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<li><a href="#mqsetattr">2.4.9 mq_setattr</a></li>
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<li><a href="#mqgetattr">2.4.10 mq_getattr</a></li>
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</ul>
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<H3><a name="mqopen">2.4.1 mq_open</a></H3>
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@ -1171,7 +1173,6 @@ closed.
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interface of the same name.
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<H3><a name="mqsend">2.4.4 mq_send</a></H3>
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<p>
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<b>Function Prototype:</b>
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</p>
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@ -1246,13 +1247,96 @@ interface of the same name.
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Comparable to the POSIX interface of the same name.
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</p>
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<h3><a name="mqtimedsend">mq_timedsend</a></h3>
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<b>Function Prototype:</b>
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</p>
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<pre>
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#include <mqueue.h>
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int mq_timedsend(mqd_t mqdes, const char *msg, size_t msglen, int prio,
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const struct timespec *abstime);
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</pre>
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<p>
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<b>Description:</b>
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This function adds the specified message, <code>msg</code>,
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to the message queue, <code>mqdes</code>.
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The <code>msglen</code> parameter specifies the length of the message in bytes pointed to by <code>msg</code>.
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This length must not exceed the maximum message length from the <code>mq_getattr()</code>.
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</p>
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<p>
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If the message queue is not full, <code>mq_timedsend()</code> will place the <code>msg</code>
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in the message queue at the position indicated by the <code>prio</code> argument.
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Messages with higher priority will be inserted before lower priority messages
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The value of <code>prio</code> must not exceed <code>MQ_PRIO_MAX</code>.
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</p>
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<p>
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If the specified message queue is full and <code>O_NONBLOCK</code> is not
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set in the message queue, then <code>mq_send()</code> will block until space
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becomes available to the queue the message or until a timeout occurs.
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</p>
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<p>
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<code>mq_timedsend()</code> behaves just like <code>mq_send()</code>, except
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that if the queue is full and the <code>O_NONBLOCK</code> flag is not enabled
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for the message queue description, then <code>abstime</code> points to a
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structure which specifies a ceiling on the time for which the call will block.
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This ceiling is an absolute timeout in seconds and nanoseconds since the
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Epoch (midnight on the morning of 1 January 1970).
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</p>
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<p>
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If the message queue is full, and the timeout has already expired by the time
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of the call, <code>mq_timedsend()<code> returns immediately.
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</p>
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<p>
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<b>Input Parameters:</b>
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</p>
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<ul>
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<li><code>mqdes</code>. Message queue descriptor.</li>
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<li><code>msg</code>. Message to send.</li>
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<li><code>msglen</code>. The length of the message in bytes.</li>
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<li><code>prio</code>. The priority of the message.</li>
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</ul>
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<p>
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<b>Returned Values:</b>
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On success, <code>mq_send()</code> returns 0 (<code>OK</code>);
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on error, -1 (<code>ERROR</code>) is returned, with <code>errno</code> set
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to indicate the error:
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</p>
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<ul>
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<li>
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<code>EAGAIN</code>.
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The queue was empty, and the <code>O_NONBLOCK</code> flag was set for the message queue description referred to by <code>mqdes</code>.
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</li>
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<li>
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<code>EINVAL</code>.
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Either <code>msg</code> or <code>mqdes</code> is <code>NULL</code> or the value of <code>prio</code> is invalid.
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</li>
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<li>
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<code>EPERM</code>.
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Message queue opened not opened for writing.
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</li>
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<li>
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<code>EMSGSIZE</code>.
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<code>msglen</code> was greater than the <code>maxmsgsize</code> attribute of the message queue.
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</li>
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<li>
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<code>EINTR</code>.
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The call was interrupted by a signal handler.
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</li>
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</ul>
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<p>
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<b>Assumptions/Limitations:</b>
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</p>
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<p>
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<b>POSIX Compatibility:</b>
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Comparable to the POSIX interface of the same name.
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</p>
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<h3><a name="mqreceive">2.4.5 mq_receive</a></h3>
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<p>
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<b>Function Prototype:</b>
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</p>
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<pre>
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#include <mqueue.h>
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int mq_receive(mqd_t mqdes, void *msg, size_t msglen, int *prio);
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ssize_t mq_receive(mqd_t mqdes, void *msg, size_t msglen, int *prio);
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</pre>
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<p>
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<b>Description:</b>
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@ -1316,7 +1400,92 @@ interface of the same name.
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Comparable to the POSIX interface of the same name.
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</p>
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<H3><a name="mqnotify">2.4.6 mq_notify</a></H3>
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<h3><a name="mqtimedreceive">2.4.6 mq_timedreceive</a></h3>
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<p>
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<b>Function Prototype:</b>
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</p>
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<pre>
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#include <mqueue.h>
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ssize_t mq_timedreceive(mqd_t mqdes, void *msg, size_t msglen,
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int *prio, const struct timespec *abstime);
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</pre>
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<p>
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<b>Description:</b>
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This function receives the oldest of the highest priority messages from the message
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queue specified by <code>mqdes</code>.
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If the size of the buffer in bytes, <code>msgLen</code>, is less than the
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<code>mq_msgsize</code> attribute of the message queue, <code>mq_timedreceive()</code> will
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return an error.
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Otherwise, the selected message is removed from the queue and copied to <code>msg</code>.
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</p>
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<p>
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If the message queue is empty and <code>O_NONBLOCK</code> was not set, <code>mq_timedreceive()</code>
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will block until a message is added to the message queue (or until a timeout occurs).
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If more than one task is waiting to receive a message, only the task with the highest
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priority that has waited the longest will be unblocked.
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</p>
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<p>
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<code>mq_timedreceive()</code> behaves just like <code>mq_receive()<code>, except
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that if the queue is empty and the <code>O_NONBLOCK<c/ode> flag is not enabled
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for the message queue description, then <code>abstime</code> points to a structure
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which specifies a ceiling on the time for which the call will block.
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This ceiling is an absolute timeout in seconds and nanoseconds since the Epoch
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(midnight on the morning of 1 January 1970).
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</p>
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<p>
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If no message is available, and the timeout has already expired by the time of
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the call, <code>mq_timedreceive()</code> returns immediately.
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</p>
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<p>
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<b>Input Parameters:</b>
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</p>
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<ul>
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<li><code>mqdes</code>. Message Queue Descriptor.</li>
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<li><code>msg</code>. Buffer to receive the message.</li>
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<li><code>msglen</code>. Size of the buffer in bytes.</li>
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<li><code>prio</code>. If not NULL, the location to store message priority.
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<li><code>abstime</code>. The absolute time to wait until a timeout is declared.
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</ul>
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<p>
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<b>Returned Values:</b>.
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One success, the length of the selected message in bytes is returned.
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On failure, -1 (<code>ERROR</code>) is returned and the <code>errno</code> is set appropriately:
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</p>
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<ul>
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<li>
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<code>EAGAIN</code>:
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The queue was empty and the <code>O_NONBLOCK</code> flag was set for the message queue description referred to by <code>mqdes</code>.
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</li>
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<li>
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<code>EPERM</code>:
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Message queue opened not opened for reading.
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</li>
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<li>
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<code>EMSGSIZE</code>:
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<code>msglen</code> was less than the <code>maxmsgsize</code> attribute of the message queue.
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</li>
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<li>
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<code>EINTR</code>:
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The call was interrupted by a signal handler.
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</li>
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<li>
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<code>EINVAL</code>:
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Invalid <code>msg</code> or <code>mqdes</code> or <code>abstime</code>
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</li>
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<li>
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<code>ETIMEDOUT</code>:
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The call timed out before a message could be transferred.
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</li>
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</ul>
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<p>
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<b>Assumptions/Limitations:</b>
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</p>
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<p>
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<b>POSIX Compatibility:</b>
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Comparable to the POSIX interface of the same name.
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</p>
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<h3><a name="mqnotify">2.4.7 mq_notify</a></h3>
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<p>
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<b>Function Prototype:</b>
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@ -1372,7 +1541,7 @@ appropriate <I>mq_receive()</I> ... The resulting behavior is as if the
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message queue remains empty, and no notification shall be sent."
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</ul>
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<H3><a name="mqsetattr">2.4.7 mq_setattr</a></H3>
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<H3><a name="mqsetattr">2.4.8 mq_setattr</a></H3>
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<p>
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<b>Function Prototype:</b>
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@ -1411,7 +1580,7 @@ would have been returned by mq_getattr()).
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<b> POSIX Compatibility:</b> Comparable to the POSIX
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interface of the same name.
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<H3><a name="mqgetattr">2.4.8 mq_getattr</a></H3>
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<H3><a name="mqgetattr">2.4.9 mq_getattr</a></H3>
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<p>
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<b>Function Prototype:</b>
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@ -5641,6 +5810,8 @@ notify a task when a message is available on a queue.
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<li><a href="#mqreceive">mq_receive</a></li>
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<li><a href="#mqsend">mq_send</a></li>
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<li><a href="#mqsetattr">mq_setattr</a></li>
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<li><a href="#mqtimedreceive">mq_timedreceive</a></li>
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<li><a href="#mqtimedsend">mq_timedsend</a></li>
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<li><a href="#mqunlink">mq_unlink</a></li>
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<li><a href="#OS_Interfaces">OS Interfaces</a>
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<li><a href="#Pthread">Pthread Interfaces</a>
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