UpdateGlue: let the update thread run at "idle" priority

The update thread should not affect the rest of the system, therefore
set "idle" priority, and let it only run when nobody else is using the
resources.
This commit is contained in:
Max Kellermann 2014-01-14 09:09:52 +01:00
parent 07a7fde825
commit 5d17731b73
4 changed files with 77 additions and 0 deletions

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@ -285,6 +285,7 @@ libutil_a_SOURCES = \
# Multi-threading library
libthread_a_SOURCES = \
src/thread/Util.hxx \
src/thread/Mutex.hxx \
src/thread/PosixMutex.hxx \
src/thread/CriticalSection.hxx \

1
NEWS
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@ -17,6 +17,7 @@ ver 0.19 (not yet released)
* encoder:
- shine: new encoder plugin
* new resampler option using libsoxr
* the update thread runs at "idle" priority
ver 0.18.7 (2013/01/13)
* playlist

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@ -34,6 +34,7 @@
#include "system/FatalError.hxx"
#include "thread/Id.hxx"
#include "thread/Thread.hxx"
#include "thread/Util.hxx"
#include <assert.h>
@ -68,6 +69,8 @@ update_task(gcc_unused void *ctx)
else
LogDebug(update_domain, "starting");
SetThreadIdlePriority();
modified = update_walk(next.path_utf8.c_str(), next.discard);
if (modified || !db_exists()) {

72
src/thread/Util.hxx Normal file
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@ -0,0 +1,72 @@
/*
* Copyright (C) 2003-2014 The Music Player Daemon Project
* http://www.musicpd.org
*
* 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, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_THREAD_UTIL_HXX
#define MPD_THREAD_UTIL_HXX
#ifdef __linux__
#include <sched.h>
#include <sys/syscall.h>
#include <unistd.h>
#elif defined(WIN32)
#include <windows.h>
#endif
#ifdef __linux__
static int
ioprio_set(int which, int who, int ioprio)
{
return syscall(SYS_ioprio_set, which, who, ioprio);
}
static void
ioprio_set_idle()
{
static constexpr int _IOPRIO_WHO_PROCESS = 1;
static constexpr int _IOPRIO_CLASS_IDLE = 3;
static constexpr int _IOPRIO_CLASS_SHIFT = 13;
static constexpr int _IOPRIO_IDLE =
(_IOPRIO_CLASS_IDLE << _IOPRIO_CLASS_SHIFT) | 7;
ioprio_set(_IOPRIO_WHO_PROCESS, 0, _IOPRIO_IDLE);
}
#endif
/**
* Lower the current thread's priority to "idle" (very low).
*/
static inline void
SetThreadIdlePriority()
{
#ifdef __linux__
#ifdef SCHED_IDLE
static struct sched_param sched_param;
sched_setscheduler(0, SCHED_IDLE, &sched_param);
#endif
ioprio_set_idle();
#elif defined(WIN32)
SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_IDLE);
#endif
};
#endif