putbq(D3)putbq(D3)NAMEputbq - place a message at the head of a queue
SYNOPSIS
#include <sys/stream.h>
#include <sys/ddi.h>
int putbq(queue_t *q, mblk_t *bp);
Arguments
q Pointer to the queue.
bp Pointer to the message.
DESCRIPTIONputbq puts a message back at the head of a queue. If messages of a
higher priority are on the queue, then bp is placed at the head of its
corresponding priority band. See srv(D2) for more information about
message priorities.
All flow control parameters are updated. The queue's service routine is
scheduled if it has not been disabled by a previous call to noenable(D3).
Return Values
putbq returns 1 on success and 0 on failure.
USAGEputbq is usually called when bcanput(D3) or canput(D3) determines that
the message cannot be passed on to the next stream component.
putbq can fail if there is not enough memory to allocate the accounting
data structures used with messages whose priority bands are greater than
zero.
High priority messages should never be put back on a queue from within a
service routine.
Level
Base or Interrupt.
Synchronization Constraints
Does not sleep.
Driver-defined basic locks, read/write locks, and sleep locks may be held
across calls to this function.
Examples
See bufcall(D3) for an example of putbq.
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putbq(D3)putbq(D3)REFERENCESbcanput(D3), canput(D3), getq(D3), insq(D3), msgb(D4), putq(D3),
queue(D4), rmvq(D3), srv(D2)
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