third_party/WebKit/Source/platform/ThreadSafeFunctional.h

   1 // Copyright 2015 The Chromium 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 #ifndef ThreadSafeFunctional_h
   6 #define ThreadSafeFunctional_h
   7
   8 #include "platform/CrossThreadCopier.h"
   9 #include "wtf/Functional.h"
  10
  11 namespace blink {
  12
  13 // threadSafeBind() is bind() for cross-thread task posting.
  14 // threadSafeBind() applies CrossThreadCopier to the arguments.
  15 //
  16 // Example:
  17 //     void func1(int, const String&);
  18 //     f = threadSafeBind(func1, 42, str);
  19 // func1(42, str2) will be called when |f()| is executed,
  20 // where |str2| is a deep copy of |str| (created by str.isolatedCopy()).
  21 //
  22 // threadSafeBind(str) is similar to bind(str.isolatedCopy()), but the latter
  23 // is NOT thread-safe due to temporary objects (https://crbug.com/390851).
  24 //
  25 // Don't (if you pass the task across threads):
  26 //     bind(func1, 42, str);
  27 //     bind(func1, 42, str.isolatedCopy());
  28
  29 template<typename... FreeVariableTypes, typename FunctionType>
  30 PassOwnPtr<Function<typename WTF::FunctionWrapper<FunctionType>::ResultType(FreeVariableTypes...)>> threadSafeBind(
  31     FunctionType function)
  32 {
  33     return bind<FreeVariableTypes...>(function);
  34 }
  35
  36 template<typename... FreeVariableTypes, typename FunctionType, typename P1>
  37 PassOwnPtr<Function<typename WTF::FunctionWrapper<FunctionType>::ResultType(FreeVariableTypes...)>> threadSafeBind(
  38     FunctionType function,
  39     const P1& parameter1)
  40 {
  41     return bind<FreeVariableTypes...>(function,
  42         CrossThreadCopier<P1>::copy(parameter1));
  43 }
  44
  45 template<typename... FreeVariableTypes, typename FunctionType, typename P1, typename P2>
  46 PassOwnPtr<Function<typename WTF::FunctionWrapper<FunctionType>::ResultType(FreeVariableTypes...)>> threadSafeBind(
  47     FunctionType function,
  48     const P1& parameter1, const P2& parameter2)
  49 {
  50     return bind<FreeVariableTypes...>(function,
  51         CrossThreadCopier<P1>::copy(parameter1),
  52         CrossThreadCopier<P2>::copy(parameter2));
  53 }
  54
  55 template<typename... FreeVariableTypes, typename FunctionType, typename P1, typename P2, typename P3>
  56 PassOwnPtr<Function<typename WTF::FunctionWrapper<FunctionType>::ResultType(FreeVariableTypes...)>> threadSafeBind(
  57     FunctionType function,
  58     const P1& parameter1, const P2& parameter2, const P3& parameter3)
  59 {
  60     return bind<FreeVariableTypes...>(function,
  61         CrossThreadCopier<P1>::copy(parameter1),
  62         CrossThreadCopier<P2>::copy(parameter2),
  63         CrossThreadCopier<P3>::copy(parameter3));
  64 }
  65
  66 template<typename... FreeVariableTypes, typename FunctionType, typename P1, typename P2, typename P3, typename P4>
  67 PassOwnPtr<Function<typename WTF::FunctionWrapper<FunctionType>::ResultType(FreeVariableTypes...)>> threadSafeBind(
  68     FunctionType function,
  69     const P1& parameter1, const P2& parameter2, const P3& parameter3, const P4& parameter4)
  70 {
  71     return bind<FreeVariableTypes...>(function,
  72         CrossThreadCopier<P1>::copy(parameter1),
  73         CrossThreadCopier<P2>::copy(parameter2),
  74         CrossThreadCopier<P3>::copy(parameter3),
  75         CrossThreadCopier<P4>::copy(parameter4));
  76 }
  77
  78 template<typename... FreeVariableTypes, typename FunctionType, typename P1, typename P2, typename P3, typename P4, typename P5>
  79 PassOwnPtr<Function<typename WTF::FunctionWrapper<FunctionType>::ResultType(FreeVariableTypes...)>> threadSafeBind(
  80     FunctionType function,
  81     const P1& parameter1, const P2& parameter2, const P3& parameter3, const P4& parameter4, const P5& parameter5)
  82 {
  83     return bind<FreeVariableTypes...>(function,
  84         CrossThreadCopier<P1>::copy(parameter1),
  85         CrossThreadCopier<P2>::copy(parameter2),
  86         CrossThreadCopier<P3>::copy(parameter3),
  87         CrossThreadCopier<P4>::copy(parameter4),
  88         CrossThreadCopier<P5>::copy(parameter5));
  89 }
  90
  91 template<typename... FreeVariableTypes, typename FunctionType, typename P1, typename P2, typename P3, typename P4, typename P5, typename P6>
  92 PassOwnPtr<Function<typename WTF::FunctionWrapper<FunctionType>::ResultType(FreeVariableTypes...)>> threadSafeBind(
  93     FunctionType function,
  94     const P1& parameter1, const P2& parameter2, const P3& parameter3, const P4& parameter4, const P5& parameter5, const P6& parameter6)
  95 {
  96     return bind<FreeVariableTypes...>(function,
  97         CrossThreadCopier<P1>::copy(parameter1),
  98         CrossThreadCopier<P2>::copy(parameter2),
  99         CrossThreadCopier<P3>::copy(parameter3),
 100         CrossThreadCopier<P4>::copy(parameter4),
 101         CrossThreadCopier<P5>::copy(parameter5),
 102         CrossThreadCopier<P6>::copy(parameter6));
 103 }
 104
 105 } // namespace blink
 106
 107 #endif // ThreadSafeFunctional_h