Unblock a client and set its errno
#include <sys/neutrino.h> int MsgError( int rcvid, int error ); int MsgError_r( int rcvid, int error );
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
The MsgError() and MsgError_r() kernel calls unblock the client's MsgSend*() call and set the client's errno to error. No data is transferred.
If error is EOK, the MsgSend*() call returns EOK; if error is any other value, the MsgSend*() call returns -1.
These functions are identical except in the way they indicate errors. See the Returns section for details.
Blocking states
None. In the network case, lower priority threads may run.
Native networking
MsgError() has increased latency when you use it to communicate across a network — the server is now writing the error code to its local lsm-qnet.so, which may need to communicate with the client's lsm-qnet.so to actually transfer the error code.
The only difference between these functions is the way they indicate errors:
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | No |
Signal handler | Yes |
Thread | Yes |