astChannelData

Return a pointer to user-supplied data stored with a Channel

Description:

This macro is intended to be used within the source or sink functions associated with a Channel. It returns any pointer previously stored in the Channel (that is, the Channel that has invoked the source or sink function) using astPutChannelData.

This mechanism is a thread-safe alternative to passing file descriptors, etc, via static global variables.

Synopsis

void astChannelData

Applicability

Channel
This macro applies to all Channels.

Returned Value

astChannelData
The pointer previously stored with the Channel using astPutChannelData. A NULL pointer will be returned if no such pointer has been stored with the Channel.

Notes: