pSOSystem System Calls - Read

ev_receive pSOS+ System Calls
Return Value
Error Codes
Notes
EV_NOWAIT /
EV_WAIT
EV_ANY /
EV_ALL
Return if the event condition is unsatisfied /
block until the event condition is satisfied.
Selecting EV_NOWAIT is a convenient way to reset
all or selected pending events. For example, an
ev_receive() for events 1 and 2
unconditionally resets events 1 and 2.
Wait for ANY / ALL of the desired events.
A successful return with EV_ANY signifies that at
least one specified event was captured. A
successful return with the EV_ALL attribute
signifies that all specified events have been
captured.
timeout If EV_WAIT is set, the timeout parameter specifies the timeout in
units of clock ticks. If the value of timeout is 0, ev_receive()
waits indefinitely.
If EV_NOWAIT is set, the timeout argument is ignored.
events_r Points to the variable where ev_receive() stores the actual events
captured.
This system call returns 0 on success, or an error code on failure.
Hex Mnemonic Description
0x01 ERR_TIMEOUT Timed out; this error code is returned
only if EV_WAIT was used and the
timeout argument was nonzero.
0x3C ERR_NOEVS Selected events not pending; this code
is returned only if the EV_NOWAIT
attribute was selected.
1. Events are not accumulated. No matter how many identical events are sent to
the calling task before it calls ev_receive() for receiving the event, the result
is the same as if one event were pending.
1-28 pSOSystem System Calls