poll functions
[Platform]

A mechanism to multiplex input/output over a set of file handles(file descriptors).

For every file handle provided, poll() examines it for any events registered for that particular file handle.

Parameters:

fhs	an array of PollFh struct carrying a FileHandle and bitmasks of events
nfhs	number of file handles
timeout	timer value to timeout or -1 for loop forever

Returns:

number of file handles selected (for which revents is non-zero). 0 if timed out with nothing selected. -1 for error.

TODO Proper wake-up mechanism. In order to correctly detect availability of read/write a FileHandle, we needed a select or poll mechanisms. We opted for poll as POSIX defines in http://pubs.opengroup.org/onlinepubs/009695399/functions/poll.html Currently, mbed::poll() just spins and scans filehandles looking for any events we are interested in. In future, his spinning behaviour will be replaced with condition variables.

TODO Proper wake-up mechanism. In order to correctly detect availability of read/write a FileHandle, we needed a select or poll mechanisms. We opted for poll as POSIX defines in http://pubs.opengroup.org/onlinepubs/009695399/functions/poll.html Currently, mbed::poll() just spins and scans filehandles looking for any events we are interested in. In future, his spinning behaviour will be replaced with condition variables.

Definition at line 26 of file mbed_poll_stub.cpp.