third_party/WebKit/Source/core/dom/ExecutionContextTask.h

   1 /*
   2  * Copyright (C) 2013 Google Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Neither the name of Google Inc. nor the names of its
  11  * contributors may be used to endorse or promote products derived from
  12  * this software without specific prior written permission.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  15  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  16  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  17  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  18  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  19  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  20  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #ifndef ExecutionContextTask_h
  28 #define ExecutionContextTask_h
  29
  30 #include "core/CoreExport.h"
  31 #include "wtf/FastAllocBase.h"
  32 #include "wtf/Functional.h"
  33 #include "wtf/Noncopyable.h"
  34 #include "wtf/PassOwnPtr.h"
  35 #include "wtf/text/WTFString.h"
  36
  37 namespace blink {
  38
  39 class ExecutionContext;
  40
  41 class CORE_EXPORT ExecutionContextTask {
  42     WTF_MAKE_NONCOPYABLE(ExecutionContextTask);
  43     WTF_MAKE_FAST_ALLOCATED(ExecutionContextTask);
  44 public:
  45     ExecutionContextTask() { }
  46     virtual ~ExecutionContextTask() { }
  47     virtual void performTask(ExecutionContext*) = 0;
  48     virtual String taskNameForInstrumentation() const { return String(); }
  49 };
  50
  51 namespace internal {
  52
  53 template<typename T>
  54 class CallClosureTaskBase : public ExecutionContextTask {
  55 protected:
  56     CallClosureTaskBase(PassOwnPtr<Function<T>> closure, bool isSameThread)
  57         : m_closure(closure)
  58 #if ENABLE(ASSERT)
  59         , m_isSameThread(isSameThread)
  60         , m_createdThread(currentThread())
  61 #endif
  62     {
  63     }
  64
  65     void checkThread()
  66     {
  67 #if ENABLE(ASSERT)
  68         if (m_isSameThread) {
  69             RELEASE_ASSERT(m_createdThread == currentThread());
  70         }
  71 #endif
  72     }
  73
  74     OwnPtr<Function<T>> m_closure;
  75
  76 private:
  77 #if ENABLE(ASSERT)
  78     bool m_isSameThread;
  79     ThreadIdentifier m_createdThread;
  80 #endif
  81 };
  82
  83 class CallClosureTask final : public CallClosureTaskBase<void()> {
  84 public:
  85     // Do not use |create| other than in createCrossThreadTask and
  86     // createSameThreadTask.
  87     // See http://crbug.com/390851
  88     static PassOwnPtr<CallClosureTask> create(PassOwnPtr<Closure> closure, bool isSameThread = false)
  89     {
  90         return adoptPtr(new CallClosureTask(closure, isSameThread));
  91     }
  92
  93     void performTask(ExecutionContext*) override
  94     {
  95         checkThread();
  96         (*m_closure)();
  97     }
  98
  99 private:
 100     CallClosureTask(PassOwnPtr<Closure> closure, bool isSameThread)
 101         : CallClosureTaskBase<void()>(closure, isSameThread)
 102     {
 103     }
 104 };
 105
 106 } // namespace internal
 107
 108 // Create tasks passed within a single thread.
 109 // When posting tasks within a thread, use |createSameThreadTask| instead
 110 // of using |bind| directly to state explicitly that there is no need to care
 111 // about thread safety when posting the task.
 112 // When posting tasks across threads, use |createCrossThreadTask|.
 113 template<typename FunctionType, typename... P>
 114 PassOwnPtr<ExecutionContextTask> createSameThreadTask(
 115     FunctionType function, const P&... parameters)
 116 {
 117     return internal::CallClosureTask::create(bind(function, parameters...), true);
 118 }
 119
 120 } // namespace
 121
 122 #endif