pSOSystem System Calls - Read

pSOS+ System Calls q_vurgent
Notes
Hex Mnemonic Description
0x31 ERR_MSGSIZ Message is too large.
0x35 ERR_QFULL Message queue at length limit.
0x3B ERR_NOTVARQ Queue is not variable length.
0x65 ERR_STALEID Object's node has failed.
1. q_vurgent() is useful when the message represents an urgent errand and
must be serviced ahead of the normally FIFO ordered messages.
2. If the caller is a task, it may be preempted as a result of this call.
3. The pSOS+ kernel must copy the message into a queue buffer or the receiving
task's buffer. Longer messages take longer to copy. User's should account for
the copy time in their design, especially when calling from an ISR.
4. q_vurgent() sends an urgent message to a variable length message queue.
Use q_urgent() to send an urgent message to an ordinary queue.
Multiprocessor Considerations
1. If qid identifies a global queue residing on another processor node, the local
kernel will internally make an RSC to that remote node to post the input
message to that queue.
2. If a task awakened by this call does not reside on the local node, the local kernel
will internally pass the message to the task's node of residence, whose pSOS+m
kernel will ready the task and give it the relayed message. Thus, a
q_vurgent() call, whether it is on the local or a remote queue, may cause
pSOS+m activities on another processor node.
Callable From
■ Task.
■ ISR, if the target queue is local to the node from which the q_vurgent() call is
made.
■ KI, if the target queue is local to the node from which the q_vurgent() call is
made.
pSOSystem System Calls 1-105
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