Process a message again in a resource manager
Synopsis:
#include <sys/iofunc.h>
#include <sys/resmgr.h>
int resmgr_msg_again( resmgr_context_t *ctp,
int rcvid);
Arguments:
- ctp
- A pointer to a
resmgr_context_t
structure that the resource-manager library uses to pass context information between functions.
- rcvid
- The receive ID of the message that you want to process again.
Library:
libc
Use the -l c option to
qcc
to link against this library.
This library is usually included automatically.
Description:
The resmgr_msg_again() function reprocesses the message
corresponding to the given rcvid.
It does this by:
- calling
MsgInfo()
and
MsgRead()
to refresh the resmgr_context_t structure to be as it
was as when you originally received the message
- calling
MsgCurrent()
to adjust your server threads' priority to that of the blocked client
- processing the message as if it had just arrived
You use this function if your resource manager can't process a message right away.
For example, if a read operation is blocked, your io_read handler would
save the rcvid of the request, and then return
_RESMGR_NOREPLY, leaving the client blocked.
Later, when the resource manager can handle the request, it can call
resmgr_msg_again() to reprocess the message.
Returns:
- -1
- Failure.
- 0
- Success.
Errors:
- EFAULT
- A fault occurred when the kernel tried to access the buffers provided.
- ESRCH
- The thread indicated by rcvid doesn't exist, has had its
connection detached, or isn't in either STATE_REPLY or
STATE_NET_REPLY, or it isn't blocked on the connection
associated with the rcvid.
- ESRVRFAULT
- The receive side of a message transfer encountered a memory fault accessing the receive/reply buffer.
Classification:
QNX Neutrino
| Safety: |
|
|---|
| Cancellation point |
No |
| Interrupt handler |
No |
| Signal handler |
No |
| Thread |
Yes |