1 // Copyright 2013 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "src/libplatform/default-platform.h"
6 
7 #include <algorithm>
8 #include <queue>
9 
10 #include "src/base/logging.h"
11 #include "src/base/platform/platform.h"
12 #include "src/base/sys-info.h"
13 #include "src/libplatform/worker-thread.h"
14 
15 namespace v8 {
16 namespace platform {
17 
18 
CreateDefaultPlatform(int thread_pool_size)19 v8::Platform* CreateDefaultPlatform(int thread_pool_size) {
20   DefaultPlatform* platform = new DefaultPlatform();
21   platform->SetThreadPoolSize(thread_pool_size);
22   platform->EnsureInitialized();
23   return platform;
24 }
25 
26 
PumpMessageLoop(v8::Platform * platform,v8::Isolate * isolate)27 bool PumpMessageLoop(v8::Platform* platform, v8::Isolate* isolate) {
28   return reinterpret_cast<DefaultPlatform*>(platform)->PumpMessageLoop(isolate);
29 }
30 
31 
32 const int DefaultPlatform::kMaxThreadPoolSize = 4;
33 
34 
DefaultPlatform()35 DefaultPlatform::DefaultPlatform()
36     : initialized_(false), thread_pool_size_(0) {}
37 
38 
~DefaultPlatform()39 DefaultPlatform::~DefaultPlatform() {
40   base::LockGuard<base::Mutex> guard(&lock_);
41   queue_.Terminate();
42   if (initialized_) {
43     for (std::vector<WorkerThread*>::iterator i = thread_pool_.begin();
44          i != thread_pool_.end(); ++i) {
45       delete *i;
46     }
47   }
48   for (std::map<v8::Isolate*, std::queue<Task*> >::iterator i =
49            main_thread_queue_.begin();
50        i != main_thread_queue_.end(); ++i) {
51     while (!i->second.empty()) {
52       delete i->second.front();
53       i->second.pop();
54     }
55   }
56 }
57 
58 
SetThreadPoolSize(int thread_pool_size)59 void DefaultPlatform::SetThreadPoolSize(int thread_pool_size) {
60   base::LockGuard<base::Mutex> guard(&lock_);
61   DCHECK(thread_pool_size >= 0);
62   if (thread_pool_size < 1) {
63     thread_pool_size = base::SysInfo::NumberOfProcessors();
64   }
65   thread_pool_size_ =
66       std::max(std::min(thread_pool_size, kMaxThreadPoolSize), 1);
67 }
68 
69 
EnsureInitialized()70 void DefaultPlatform::EnsureInitialized() {
71   base::LockGuard<base::Mutex> guard(&lock_);
72   if (initialized_) return;
73   initialized_ = true;
74 
75   for (int i = 0; i < thread_pool_size_; ++i)
76     thread_pool_.push_back(new WorkerThread(&queue_));
77 }
78 
79 
PumpMessageLoop(v8::Isolate * isolate)80 bool DefaultPlatform::PumpMessageLoop(v8::Isolate* isolate) {
81   Task* task = NULL;
82   {
83     base::LockGuard<base::Mutex> guard(&lock_);
84     std::map<v8::Isolate*, std::queue<Task*> >::iterator it =
85         main_thread_queue_.find(isolate);
86     if (it == main_thread_queue_.end() || it->second.empty()) {
87       return false;
88     }
89     task = it->second.front();
90     it->second.pop();
91   }
92   task->Run();
93   delete task;
94   return true;
95 }
96 
CallOnBackgroundThread(Task * task,ExpectedRuntime expected_runtime)97 void DefaultPlatform::CallOnBackgroundThread(Task *task,
98                                              ExpectedRuntime expected_runtime) {
99   EnsureInitialized();
100   queue_.Append(task);
101 }
102 
103 
CallOnForegroundThread(v8::Isolate * isolate,Task * task)104 void DefaultPlatform::CallOnForegroundThread(v8::Isolate* isolate, Task* task) {
105   base::LockGuard<base::Mutex> guard(&lock_);
106   main_thread_queue_[isolate].push(task);
107 }
108 
109 } }  // namespace v8::platform
110