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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "thread.h"
#include <sys/time.h>
#include <sys/resource.h>
#include <limits.h>
#include <errno.h>
#include <cutils/sched_policy.h>
#include <utils/threads.h>
#include "base/macros.h"
namespace art {
// Conversion map for "nice" values.
//
// We use Android thread priority constants to be consistent with the rest
// of the system. In some cases adjacent entries may overlap.
//
static const int kNiceValues[10] = {
ANDROID_PRIORITY_LOWEST, // 1 (MIN_PRIORITY)
ANDROID_PRIORITY_BACKGROUND + 6,
ANDROID_PRIORITY_BACKGROUND + 3,
ANDROID_PRIORITY_BACKGROUND,
ANDROID_PRIORITY_NORMAL, // 5 (NORM_PRIORITY)
ANDROID_PRIORITY_NORMAL - 2,
ANDROID_PRIORITY_NORMAL - 4,
ANDROID_PRIORITY_URGENT_DISPLAY + 3,
ANDROID_PRIORITY_URGENT_DISPLAY + 2,
ANDROID_PRIORITY_URGENT_DISPLAY // 10 (MAX_PRIORITY)
};
void Thread::SetNativePriority(int newPriority) {
if (newPriority < 1 || newPriority > 10) {
LOG(WARNING) << "bad priority " << newPriority;
newPriority = 5;
}
int newNice = kNiceValues[newPriority-1];
pid_t tid = GetTid();
// TODO: b/18249098 The code below is broken. It uses getpriority() as a proxy for whether a
// thread is already in the SP_FOREGROUND cgroup. This is not necessarily true for background
// processes, where all threads are in the SP_BACKGROUND cgroup. This means that callers will
// have to call setPriority twice to do what they want :
//
// Thread.setPriority(Thread.MIN_PRIORITY); // no-op wrt to cgroups
// Thread.setPriority(Thread.MAX_PRIORITY); // will actually change cgroups.
if (newNice >= ANDROID_PRIORITY_BACKGROUND) {
set_sched_policy(tid, SP_BACKGROUND);
} else if (getpriority(PRIO_PROCESS, tid) >= ANDROID_PRIORITY_BACKGROUND) {
set_sched_policy(tid, SP_FOREGROUND);
}
if (setpriority(PRIO_PROCESS, tid, newNice) != 0) {
PLOG(INFO) << *this << " setPriority(PRIO_PROCESS, " << tid << ", " << newNice << ") failed";
}
}
int Thread::GetNativePriority() {
errno = 0;
int native_priority = getpriority(PRIO_PROCESS, 0);
if (native_priority == -1 && errno != 0) {
PLOG(WARNING) << "getpriority failed";
return kNormThreadPriority;
}
int managed_priority = kMinThreadPriority;
for (size_t i = 0; i < arraysize(kNiceValues); i++) {
if (native_priority >= kNiceValues[i]) {
break;
}
managed_priority++;
}
if (managed_priority > kMaxThreadPriority) {
managed_priority = kMaxThreadPriority;
}
return managed_priority;
}
void Thread::SetUpAlternateSignalStack() {
// Bionic does this for us.
}
void Thread::TearDownAlternateSignalStack() {
// Bionic does this for us.
}
} // namespace art
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