Files
SingularityViewer/indra/llmessage/aicurltimer.cpp
2013-07-08 17:25:06 +02:00

111 lines
3.7 KiB
C++

/**
* @file aicurltimer.cpp
*
* Copyright (c) 2013, Aleric Inglewood.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* There are special exceptions to the terms and conditions of the GPL as
* it is applied to this Source Code. View the full text of the exception
* in the file doc/FLOSS-exception.txt in this software distribution.
*
* CHANGELOG
* and additional copyright holders.
*
* 29/06/2013
* - Initial version, written by Aleric Inglewood @ SL
*/
// An AICurlTimer object provides a callback API for timer events
// by and from the curl thread. It is NOT threadsafe. Everything
// has to be called from the curl thread.
//
// Typical usage:
//
// AICurlTimer timer;
// ...
// // In curl thread (after successful construction is guaranteed).
// timer.create(5.5, boost::bind(&the_callback, <optional params>)); // Call the_callback(<optional params>) in 5.5 seconds.
//
// The callback function is always called by the curl thread.
//
// If timer.cancel() is called before the timer expires, then the callback
// function isn't called. Calling cancel() multiple times is not a problem.
// Note: It is not allowed to call cancel() is from the callback function
// (and rather pointless).
//
// The timer object can be reused (by calling create() again), but
// only after either the callback function was called, or after cancel()
// returned. Most notably, you can call create() again from inside the
// callback function to "restart" the timer.
//
#include "aicurltimer.h"
#include "lltimer.h"
static U64 const NEVER = ((U64)1) << 60; // The year 36,560,871.
//static
F64 const AICurlTimer::sClockWidth_1ms = 1000.0 / calc_clock_frequency(); // Time between two clock ticks, in 1ms units.
U64 AICurlTimer::sTime_1ms; // Time in 1ms units, set once per select() entry.
U64 AICurlTimer::sNextExpiration = NEVER;
AICurlTimer::timer_list_type AICurlTimer::sTimerList;
void AICurlTimer::create(deltams_type expiration, signal_type::slot_type const& slot)
{
AIRunningCurlTimer new_timer(expiration, this);
llassert(mHandle.mRunningTimer == sTimerList.end()); // Create may only be called when the timer isn't already running.
mHandle.init(sTimerList.insert(new_timer), slot);
sNextExpiration = sTimerList.begin()->expiration();
}
void AICurlTimer::cancel(void)
{
if (mHandle.mRunningTimer != sTimerList.end())
{
sTimerList.erase(mHandle.mRunningTimer);
mHandle.mRunningTimer = sTimerList.end();
sNextExpiration = sTimerList.empty() ? NEVER : sTimerList.begin()->expiration();
}
}
void AICurlTimer::handleExpiration(void)
{
for(;;)
{
if (sTimerList.empty())
{
// No running timers left.
sNextExpiration = NEVER;
break;
}
timer_list_type::iterator running_timer = sTimerList.begin();
sNextExpiration = running_timer->expiration();
if (sNextExpiration > sTime_1ms)
{
// Didn't expire yet.
break;
}
Handle& handle(running_timer->getTimer()->mHandle);
llassert_always(running_timer == handle.mRunningTimer);
handle.mRunningTimer = sTimerList.end();
running_timer->do_callback(); // May not throw exceptions.
// Erase the timer from the running list.
sTimerList.erase(running_timer);
}
}