ceph/branches/riccardo/monitor2/common/Timer.cc

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// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
/*
* Ceph - scalable distributed file system
*
* Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
*
* This is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1, as published by the Free Software
* Foundation. See file COPYING.
*
*/
#include "Timer.h"
#include "Cond.h"
#include "config.h"
#include "include/Context.h"
#undef dout
#define dout(x) if (x <= g_conf.debug) cout << g_clock.now() << " TIMER "
#define derr(x) if (x <= g_conf.debug) cerr << g_clock.now() << " TIMER "
#define DBL 10
#include <signal.h>
#include <sys/time.h>
#include <math.h>
// single global instance
Timer g_timer;
/**** thread solution *****/
bool Timer::get_next_due(utime_t& when)
{
if (scheduled.empty()) {
dout(10) << "get_next_due - nothing scheduled" << endl;
return false;
} else {
map< utime_t, set<Context*> >::iterator it = scheduled.begin();
when = it->first;
dout(10) << "get_next_due - " << when << endl;
return true;
}
}
void Timer::timer_entry()
{
lock.Lock();
while (!thread_stop) {
// now
utime_t now = g_clock.now();
// any events due?
utime_t next;
bool next_due = get_next_due(next);
if (next_due && now >= next) {
// move to pending list
list<Context*> pending;
map< utime_t, set<Context*> >::iterator it = scheduled.begin();
while (it != scheduled.end()) {
if (it->first > now) break;
utime_t t = it->first;
dout(DBL) << "queueing event(s) scheduled at " << t << endl;
for (set<Context*>::iterator cit = it->second.begin();
cit != it->second.end();
cit++) {
pending.push_back(*cit);
event_times.erase(*cit);
num_event--;
}
map< utime_t, set<Context*> >::iterator previt = it;
it++;
scheduled.erase(previt);
}
if (!pending.empty()) {
sleeping = false;
lock.Unlock();
{
// make sure we're not holding any locks while we do callbacks
// make the callbacks myself.
for (list<Context*>::iterator cit = pending.begin();
cit != pending.end();
cit++) {
dout(DBL) << "start callback " << *cit << endl;
(*cit)->finish(0);
dout(DBL) << "finish callback " << *cit << endl;
delete *cit;
}
pending.clear();
assert(pending.empty());
}
lock.Lock();
}
}
else {
// sleep
if (next_due) {
dout(DBL) << "sleeping until " << next << endl;
timed_sleep = true;
sleeping = true;
timeout_cond.WaitUntil(lock, next); // wait for waker or time
utime_t now = g_clock.now();
dout(DBL) << "kicked or timed out at " << now << endl;
} else {
dout(DBL) << "sleeping" << endl;
timed_sleep = false;
sleeping = true;
sleep_cond.Wait(lock); // wait for waker
utime_t now = g_clock.now();
dout(DBL) << "kicked at " << now << endl;
}
}
}
lock.Unlock();
}
/**
* Timer bits
*/
void Timer::register_timer()
{
if (timer_thread.is_started()) {
if (sleeping) {
dout(DBL) << "register_timer kicking thread" << endl;
if (timed_sleep)
timeout_cond.SignalAll();
else
sleep_cond.SignalAll();
} else {
dout(DBL) << "register_timer doing nothing; thread is awake" << endl;
// it's probably doing callbacks.
}
} else {
dout(DBL) << "register_timer starting thread" << endl;
timer_thread.create();
}
}
void Timer::cancel_timer()
{
// clear my callback pointers
if (timer_thread.is_started()) {
dout(10) << "setting thread_stop flag" << endl;
lock.Lock();
thread_stop = true;
if (timed_sleep)
timeout_cond.SignalAll();
else
sleep_cond.SignalAll();
lock.Unlock();
dout(10) << "waiting for thread to finish" << endl;
void *ptr;
timer_thread.join(&ptr);
dout(10) << "thread finished, exit code " << ptr << endl;
}
}
/*
* schedule
*/
void Timer::add_event_after(float seconds,
Context *callback)
{
utime_t when = g_clock.now();
when.sec_ref() += (int)seconds;
add_event_at(when, callback);
}
void Timer::add_event_at(utime_t when,
Context *callback)
{
lock.Lock();
dout(DBL) << "add_event " << callback << " at " << when << endl;
// insert
scheduled[when].insert(callback);
assert(event_times.count(callback) == 0);
event_times[callback] = when;
num_event++;
// make sure i wake up on time
register_timer();
lock.Unlock();
}
bool Timer::cancel_event(Context *callback)
{
lock.Lock();
dout(DBL) << "cancel_event " << callback << endl;
if (!event_times.count(callback)) {
dout(DBL) << "cancel_event " << callback << " isn't scheduled (probably executing)" << endl;
lock.Unlock();
return false; // wasn't scheduled.
}
utime_t tp = event_times[callback];
event_times.erase(callback);
assert(scheduled.count(tp));
assert(scheduled[tp].count(callback));
scheduled[tp].erase(callback);
if (scheduled[tp].empty())
scheduled.erase(tp);
lock.Unlock();
return true;
}
// -------------------------------
void SafeTimer::add_event_after(float seconds, Context *c)
{
assert(lock.is_locked());
Context *w = new EventWrapper(this, c);
dout(DBL) << "SafeTimer.add_event_after wrapping " << c << " with " << w << endl;
scheduled[c] = w;
g_timer.add_event_after(seconds, w);
}
void SafeTimer::add_event_at(utime_t when, Context *c)
{
assert(lock.is_locked());
Context *w = new EventWrapper(this, c);
dout(DBL) << "SafeTimer.add_event_at wrapping " << c << " with " << w << endl;
scheduled[c] = w;
g_timer.add_event_at(when, w);
}
void SafeTimer::EventWrapper::finish(int r)
{
timer->lock.Lock();
if (timer->scheduled.count(actual)) {
// still scheduled. execute.
actual->finish(r);
timer->scheduled.erase(actual);
} else {
// i was canceled.
assert(timer->canceled.count(actual));
}
// did i get canceled?
// (this can happen even if i just executed above. e.g., i may have canceled myself.)
if (timer->canceled.count(actual)) {
timer->canceled.erase(actual);
timer->cond.Signal();
}
// delete the original event
delete actual;
timer->lock.Unlock();
}
void SafeTimer::cancel_event(Context *c)
{
assert(lock.is_locked());
assert(scheduled.count(c));
if (g_timer.cancel_event(scheduled[c])) {
// hosed wrapper. hose original event too.
delete scheduled[c];
} else {
// clean up later.
canceled[c] = scheduled[c];
}
scheduled.erase(c);
}
void SafeTimer::cancel_all()
{
assert(lock.is_locked());
while (!scheduled.empty())
cancel_event(scheduled.begin()->first);
}
void SafeTimer::join()
{
assert(lock.is_locked());
assert(scheduled.empty());
while (!canceled.empty()) {
// wait
dout(-10) << "SafeTimer.join waiting for " << canceled.size() << " to join" << endl;
dout(-10) << canceled << endl;
cond.Wait(lock);
}
}
SafeTimer::~SafeTimer()
{
if (!scheduled.empty() && !canceled.empty()) {
derr(0) << "SafeTimer.~SafeTimer " << scheduled.size() << " events scheduled, "
<< canceled.size() << " canceled but unflushed"
<< endl;
}
}