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mirror of https://github.com/Llewellynvdm/conky.git synced 2024-11-17 10:35:10 +00:00
conky/src/timed-thread.cc
2010-01-13 10:52:54 -08:00

277 lines
7.1 KiB
C++

/* -*- mode: c++; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: t -*-
* vim: ts=4 sw=4 noet ai cindent syntax=cpp
*
* timed_thread.c: Abstraction layer for timed threads
*
* Copyright (C) 2006-2007 Philip Kovacs pkovacs@users.sourceforge.net
* Copyright (c) 2005-2010 Brenden Matthews, et. al. (see AUTHORS)
* All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
* USA.
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <thread>
#include <list>
#include <chrono>
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <time.h>
#include <unistd.h>
#include "timed-thread.h"
#include "logging.h"
/* Abstraction layer for timed threads */
typedef struct std::chrono::system_clock clk;
/* private */
struct _timed_thread {
std::auto_ptr<std::thread> thread; /* thread itself */
std::mutex cs_mutex; /* critical section mutex */
std::mutex runnable_mutex; /* runnable section mutex */
std::condition_variable runnable_cond; /* signalled to stop the thread */
clk::time_point last_time; /* last time interval */
int pipefd[2];
int die;
_timed_thread() : die(0) {}
};
typedef std::list<timed_thread_ptr> thread_list_t;
thread_list_t thread_list;
/* create a timed thread (object creation only) */
timed_thread::timed_thread(const std::function<void(thread_handle &)> start_routine, unsigned
int interval_usecs) :
p_timed_thread(new _timed_thread), p_thread_handle(this),
interval_usecs(interval_usecs), running(false)
{
#ifdef DEBUG
assert(interval_usecs >= MINIMUM_INTERVAL_USECS);
#endif /* DEBUG */
/* create thread pipe (used to tell threads to die) */
if (pipe(p_timed_thread->pipefd)) {
throw std::runtime_error("couldn't create pipe");
}
/* set initialize to current time */
p_timed_thread->last_time = clk::now();
/* printf("interval_time.tv_sec = %li, .tv_nsec = %li\n",
p_timed_thread->interval_time.tv_sec,
p_timed_thread->interval_time.tv_nsec); */
p_timed_thread->thread = std::auto_ptr<std::thread>(
new std::thread(start_routine, p_thread_handle)
);
DBGP("created thread %ld", (long)p_timed_thread->thread.get());
running = true;
}
/* destroy a timed thread. */
void timed_thread::destroy(bool deregister_this)
{
DBGP("destroying thread %ld", (long)p_timed_thread->thread.get());
#ifdef DEBUG
assert(running && p_timed_thread->thread->joinable());
#endif /* DEBUG */
{
/* signal thread to stop */
std::lock_guard<std::mutex> l(p_timed_thread->runnable_mutex);
p_timed_thread->runnable_cond.notify_one();
p_timed_thread->die = 1;
}
if (write(p_timed_thread->pipefd[1], "die", 3) == -1)
perror("write()");
/* join the terminating thread */
p_timed_thread->thread->join();
close(p_timed_thread->pipefd[0]);
close(p_timed_thread->pipefd[1]);
running = false;
if (deregister_this) deregister(this);
}
/* lock a timed thread for critical section activity */
void timed_thread::lock(void)
{
#ifdef DEBUG
assert(running);
#endif /* DEBUG */
p_timed_thread->cs_mutex.lock();
}
/* unlock a timed thread after critical section activity */
void timed_thread::unlock(void)
{
#ifdef DEBUG
assert(running);
#endif /* DEBUG */
p_timed_thread->cs_mutex.unlock();
}
std::mutex &timed_thread::mutex()
{
#ifdef DEBUG
assert(running);
#endif /* DEBUG */
return p_timed_thread->cs_mutex;
}
int timed_thread::readfd(void) const
{
#ifdef DEBUG
assert(running);
#endif /* DEBUG */
return p_timed_thread->pipefd[0];
}
/* thread waits interval_usecs for runnable_cond to be signaled.
* returns 1 if signaled, -1 on error, and 0 otherwise.
* caller should call timed_thread::exit() on any non-zero return value. */
int timed_thread::test(int override_wait_time)
{
#ifdef DEBUG
assert(running);
#endif /* DEBUG */
bool rc = false;
/* determine when to wait until */
#ifdef _GLIBCXX_USE_CLOCK_REALTIME
clk::time_point wait_time = p_timed_thread->last_time +
clk::duration(interval_usecs * 1000);
#elif defined(_GLIBCXX_USE_GETTIMEOFDAY)
clk::time_point wait_time = p_timed_thread->last_time +
clk::duration(interval_usecs);
#else
clk::time_point wait_time = p_timed_thread->last_time +
clk::duration(interval_usecs / 1000000);
#endif
/* acquire runnable_cond mutex */
{
std::unique_lock<std::mutex> lock(p_timed_thread->runnable_mutex);
if (p_timed_thread->die) {
/* if we were kindly asked to die, then die */
return 1;
}
if (override_wait_time) {
wait_time = clk::now();
}
/* release mutex and wait until future time for runnable_cond to signal */
rc = p_timed_thread->runnable_cond.wait_until(lock, wait_time);
}
p_timed_thread->last_time = clk::now();
#ifdef _GLIBCXX_USE_CLOCK_REALTIME
if (wait_time + clk::duration(interval_usecs * 1000) >
p_timed_thread->last_time) {
p_timed_thread->last_time = wait_time;
}
#elif defined(_GLIBCXX_USE_GETTIMEOFDAY)
if (wait_time + clk::duration(interval_usecs) >
p_timed_thread->last_time) {
p_timed_thread->last_time = wait_time;
}
#else
if (wait_time + clk::duration(interval_usecs / 1000000) >
p_timed_thread->last_time) {
p_timed_thread->last_time = wait_time;
}
#endif
/* if runnable_cond was signaled, tell caller to exit thread */
return rc;
}
/* register a timed thread for future destruction via
* timed_thread::destroy_registered_threads() */
int timed_thread::register_(const timed_thread_ptr &timed_thread)
{
thread_list.push_back(timed_thread);
return 0;
}
void timed_thread::deregister(const timed_thread *timed_thread)
{
for (thread_list_t::iterator i = thread_list.begin(); i != thread_list.end(); i++) {
if (i->get() == timed_thread) {
thread_list.erase(i);
break;
}
}
}
/* destroy all registered timed threads */
void timed_thread::destroy_registered_threads(void)
{
for (thread_list_t::iterator i = thread_list.begin(); i != thread_list.end(); i++) {
// (*i)->destroy(false /* don't deregister */);
#ifdef DEBUG
/* if this assert is ever reached, we have an unreleased shared_ptr
* somewhere holding on to this instance */
assert(i->unique());
#endif /* DEBUG */
}
thread_list.clear(); /* that was easy */
}
int thread_handle::test(int override_wait_time) {
return thread->test(override_wait_time);
}
std::mutex &thread_handle::mutex()
{
#ifdef DEBUG
assert(thread->running);
#endif /* DEBUG */
return thread->p_timed_thread->cs_mutex;
}
void thread_handle::lock(void) {
thread->lock();
}
void thread_handle::unlock(void) {
thread->unlock();
}
int thread_handle::readfd(void) const
{
#ifdef DEBUG
assert(thread->running);
#endif /* DEBUG */
return thread->p_timed_thread->pipefd[0];
}