Destroy a communications channel
#include <sys/neutrino.h> int ChannelDestroy( int chid ); int ChannelDestroy_r( int chid );
- The channel ID, returned by ChannelCreate(), of the channel that you want to destroy.
Use the -l c option to qcc to link against this library. This library is usually included automatically.
These kernel calls remove a channel specified by the channel ID chid argument. Once destroyed, any attempt to receive messages or pulses on the channel will fail. Any threads that are blocked on the channel by calling MsgReceivev() or MsgSendv() will be unblocked and return with an error.
The ChannelDestroy() and ChannelDestroy_r() functions are identical except in the way they indicate errors. See the Returns section for details.
When the channel is destroyed, all server connection IDs become invalid. The client connections are also marked invalid but remain in existence until the client removes them by calling ConnectDetach(). An attempt by the client to use one of these invalid connections using MsgSendv() or MsgSendPulse() will return with an error.
A server typically destroys its channels prior to its termination. If it fails to do so, the kernel destroys them automatically when the process dies.
These calls don't block.
The only difference between these functions is the way they indicate errors:
- If an error occurs, the function returns -1 and sets errno. Any other value returned indicates success.
- EOK is returned on success. This function does NOT set errno. If an error occurs, the function may return any value in the Errors section.
- The channel specified by chid doesn't exist.
Message Passing chapter of Getting Started with QNX Neutrino