Code Confidencebuild

Enhanced Select()

The network stack supports an extension to the standard select semantics which allows all threads that are waiting to be restarted even if the select conditions are not satisfied.

The standard select() API:

select(int nfd,
       fd_set *in, fd_set *out, fd_set *ex,
       struct timeval *tv); 

does not support the restart.

The additional API:

cyg_select_with_abort(int nfd,
       fd_set *in, fd_set *out, fd_set *ex,
       struct timeval *tv)

behaves exactly as select() with the additional feature that a call to

void cyg_select_abort(void)

will cause all threads waiting in any cyg_select_with_abort() call to cease waiting and continue execution.