1 /*
2  * Copyright 2014 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #ifndef SkTaskGroup_DEFINED
9 #define SkTaskGroup_DEFINED
10 
11 #include <functional>
12 
13 #include "SkTypes.h"
14 #include "SkAtomics.h"
15 #include "SkTemplates.h"
16 
17 class SkTaskGroup : SkNoncopyable {
18 public:
19     // Create one of these in main() to enable SkTaskGroups globally.
20     struct Enabler : SkNoncopyable {
21         explicit Enabler(int threads = -1);  // Default is system-reported core count.
22         ~Enabler();
23     };
24 
25     SkTaskGroup();
~SkTaskGroup()26     ~SkTaskGroup() { this->wait(); }
27 
28     // Add a task to this SkTaskGroup.  It will likely run on another thread.
29     void add(std::function<void(void)> fn);
30 
31     // Add a batch of N tasks, all calling fn with different arguments.
32     void batch(int N, std::function<void(int)> fn);
33 
34     // Block until all Tasks previously add()ed to this SkTaskGroup have run.
35     // You may safely reuse this SkTaskGroup after wait() returns.
36     void wait();
37 
38 private:
39     SkAtomic<int32_t> fPending;
40 };
41 
42 // Returns best estimate of number of CPU cores available to use.
43 int sk_num_cores();
44 
45 #endif//SkTaskGroup_DEFINED
46