1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
/*
* Copyright (C) 2014 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 "task_processor.h"
#include "scoped_thread_state_change.h"
namespace art {
namespace gc {
TaskProcessor::TaskProcessor()
: lock_(new Mutex("Task processor lock", kReferenceProcessorLock)), is_running_(false) {
// Piggyback off the reference processor lock level.
cond_.reset(new ConditionVariable("Task processor condition", *lock_));
}
TaskProcessor::~TaskProcessor() {
delete lock_;
}
void TaskProcessor::AddTask(Thread* self, HeapTask* task) {
ScopedThreadStateChange tsc(self, kBlocked);
MutexLock mu(self, *lock_);
tasks_.insert(task);
cond_->Signal(self);
}
HeapTask* TaskProcessor::GetTask(Thread* self) {
ScopedThreadStateChange tsc(self, kBlocked);
MutexLock mu(self, *lock_);
while (true) {
if (tasks_.empty()) {
if (!is_running_) {
return nullptr;
}
cond_->Wait(self); // Empty queue, wait until we are signalled.
} else {
// Non empty queue, look at the top element and see if we are ready to run it.
const uint64_t current_time = NanoTime();
HeapTask* task = *tasks_.begin();
// If we are shutting down, return the task right away without waiting. Otherwise return the
// task if it is late enough.
uint64_t target_time = task->GetTargetRunTime();
if (!is_running_ || target_time <= current_time) {
tasks_.erase(tasks_.begin());
return task;
}
DCHECK_GT(target_time, current_time);
// Wait untl we hit the target run time.
const uint64_t delta_time = target_time - current_time;
const uint64_t ms_delta = NsToMs(delta_time);
const uint64_t ns_delta = delta_time - MsToNs(ms_delta);
cond_->TimedWait(self, static_cast<int64_t>(ms_delta), static_cast<int32_t>(ns_delta));
}
}
UNREACHABLE();
}
void TaskProcessor::UpdateTargetRunTime(Thread* self, HeapTask* task, uint64_t new_target_time) {
MutexLock mu(self, *lock_);
// Find the task.
auto range = tasks_.equal_range(task);
for (auto it = range.first; it != range.second; ++it) {
if (*it == task) {
// Check if the target time was updated, if so re-insert then wait.
if (new_target_time != task->GetTargetRunTime()) {
tasks_.erase(it);
task->SetTargetRunTime(new_target_time);
tasks_.insert(task);
// If we became the first task then we may need to signal since we changed the task that we
// are sleeping on.
if (*tasks_.begin() == task) {
cond_->Signal(self);
}
return;
}
}
}
}
bool TaskProcessor::IsRunning() const {
MutexLock mu(Thread::Current(), *lock_);
return is_running_;
}
void TaskProcessor::Stop(Thread* self) {
MutexLock mu(self, *lock_);
is_running_ = false;
cond_->Broadcast(self);
}
void TaskProcessor::Start(Thread* self) {
MutexLock mu(self, *lock_);
is_running_ = true;
}
void TaskProcessor::RunAllTasks(Thread* self) {
while (true) {
// Wait and get a task, may be interrupted.
HeapTask* task = GetTask(self);
if (task != nullptr) {
task->Run(self);
task->Finalize();
} else if (!IsRunning()) {
break;
}
}
}
} // namespace gc
} // namespace art
|
