1 /*
2 * Copyright (C) 2015-2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "worker.h"
18
19 #include <sys/prctl.h>
20 #include <sys/resource.h>
21
22 namespace android {
23
Worker(const char * name,int priority)24 Worker::Worker(const char *name, int priority)
25 : name_(name), priority_(priority), exit_(false), initialized_(false) {
26 }
27
~Worker()28 Worker::~Worker() {
29 Exit();
30 }
31
InitWorker()32 int Worker::InitWorker() {
33 std::lock_guard<std::mutex> lk(mutex_);
34 if (initialized())
35 return -EALREADY;
36
37 thread_ = std::unique_ptr<std::thread>(
38 new std::thread(&Worker::InternalRoutine, this));
39 initialized_ = true;
40 exit_ = false;
41
42 return 0;
43 }
44
Exit()45 void Worker::Exit() {
46 std::unique_lock<std::mutex> lk(mutex_);
47 exit_ = true;
48 if (initialized()) {
49 lk.unlock();
50 cond_.notify_all();
51 thread_->join();
52 initialized_ = false;
53 }
54 }
55
WaitForSignalOrExitLocked(int64_t max_nanoseconds)56 int Worker::WaitForSignalOrExitLocked(int64_t max_nanoseconds) {
57 int ret = 0;
58 if (should_exit())
59 return -EINTR;
60
61 std::unique_lock<std::mutex> lk(mutex_, std::adopt_lock);
62 if (max_nanoseconds < 0) {
63 cond_.wait(lk);
64 } else if (std::cv_status::timeout ==
65 cond_.wait_for(lk, std::chrono::nanoseconds(max_nanoseconds))) {
66 ret = -ETIMEDOUT;
67 }
68
69 // exit takes precedence on timeout
70 if (should_exit())
71 ret = -EINTR;
72
73 // release leaves mutex locked when going out of scope
74 lk.release();
75
76 return ret;
77 }
78
InternalRoutine()79 void Worker::InternalRoutine() {
80 setpriority(PRIO_PROCESS, 0, priority_);
81 prctl(PR_SET_NAME, name_.c_str());
82
83 std::unique_lock<std::mutex> lk(mutex_, std::defer_lock);
84
85 while (true) {
86 lk.lock();
87 if (should_exit())
88 return;
89 lk.unlock();
90
91 Routine();
92 }
93 }
94 } // namespace android
95