http://www.ousob.com --- Legacy Redefined OuSob - File: /wwwroot/clipx/usr/include/wvstreams/wvtimestream.h

/* -*- Mode: C++ -*- * Worldvisions Weaver Software: * Copyright (C) 1997-2002 Net Integration Technologies, Inc. * */ #ifndef __WVTIMESTREAM_H #define __WVTIMESTREAM_H #include "wvtimeutils.h" #include "wvstream.h" /** * WvTimeStream causes select() to be true after a configurable number * of milliseconds. Because programs using WvStream make no guarantees * about how often select() will be called, WvTimeStream tries to adjust * its timing to a correct _average_ number of milliseconds per tick. * * For example, if ms_per_tick=100, WvTimeStream will tick 10 times in one * second. However, there may be a few milliseconds of difference * ("jitter") for each individual tick, due to random system delays. */ class WvTimeStream : public WvStream { WvTime last; WvTime next; time_t ms_per_tick; public: WvTimeStream(); /** * Every 'msec' milliseconds, select() will return true on this * stream. if 'msec' is 0 (or less), the timer is disabled. * * Be careful when mixing alarm() with this. You can know whether * it was the alarm or if you had a timer event by looking at * alarm_was_ticking. But the alarm() has priority, so if there's * always an alarm, the timer event never gets to run. Calling * alarm(0) in the callback unconditionally would thus be a bad * idea, or even with an unsuitably small number (say, less than * the time it takes to go back into select()). So don't do it. */ void set_timer(time_t msec); virtual bool isok() const; virtual bool pre_select(SelectInfo &si); virtual bool post_select(SelectInfo &si); virtual void execute(); }; #endif // __WVTIMESTREAM_H