Method Pike.__Backend()->`()()
- Method
`()
 float|int(0)res =Pike.__Backend()()- Description
 Perform one pass through the backend.
Calls any outstanding call-outs and non-blocking I/O callbacks that are registred in this backend object.
- Parameter 
sleep_time Wait at most
sleep_timeseconds. The default when unspecified or the integer0is no time limit.- Returns
 If the backend did call any callbacks or call outs then the time spent in the backend is returned as a float. Otherwise the integer
0is returned.- Note
 If multiple threads concurrently call this function, then:
One of the threads will be the controlling thread.
All callbacks will be called from the controlling thread.
All threads will be woken up when the controlling thread is done. This may be prematurely if the controlling thread had a shorter timeout.
- Note
 The backend may also be woken up prematurely if the set of events to monitor is changed.
- Note
 Multiple concurrent calls was not supported prior to Pike 8.0.
- See also
 Pike.DefaultBackend,
main()