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
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
//
// detail/impl/strand_executor_service.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef BOOST_ASIO_DETAIL_IMPL_STRAND_EXECUTOR_SERVICE_HPP
#define BOOST_ASIO_DETAIL_IMPL_STRAND_EXECUTOR_SERVICE_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include <boost/asio/detail/call_stack.hpp>
#include <boost/asio/detail/fenced_block.hpp>
#include <boost/asio/detail/handler_invoke_helpers.hpp>
#include <boost/asio/detail/recycling_allocator.hpp>
#include <boost/asio/executor_work_guard.hpp>
#include <boost/asio/detail/push_options.hpp>
namespace boost {
namespace asio {
namespace detail {
template <typename Executor>
class strand_executor_service::invoker
{
public:
invoker(const implementation_type& impl, Executor& ex)
: impl_(impl),
work_(ex)
{
}
invoker(const invoker& other)
: impl_(other.impl_),
work_(other.work_)
{
}
#if defined(BOOST_ASIO_HAS_MOVE)
invoker(invoker&& other)
: impl_(BOOST_ASIO_MOVE_CAST(implementation_type)(other.impl_)),
work_(BOOST_ASIO_MOVE_CAST(executor_work_guard<Executor>)(other.work_))
{
}
#endif // defined(BOOST_ASIO_HAS_MOVE)
struct on_invoker_exit
{
invoker* this_;
~on_invoker_exit()
{
this_->impl_->mutex_->lock();
this_->impl_->ready_queue_.push(this_->impl_->waiting_queue_);
bool more_handlers = this_->impl_->locked_ =
!this_->impl_->ready_queue_.empty();
this_->impl_->mutex_->unlock();
if (more_handlers)
{
Executor ex(this_->work_.get_executor());
recycling_allocator<void> allocator;
ex.post(BOOST_ASIO_MOVE_CAST(invoker)(*this_), allocator);
}
}
};
void operator()()
{
// Indicate that this strand is executing on the current thread.
call_stack<strand_impl>::context ctx(impl_.get());
// Ensure the next handler, if any, is scheduled on block exit.
on_invoker_exit on_exit = { this };
(void)on_exit;
// Run all ready handlers. No lock is required since the ready queue is
// accessed only within the strand.
boost::system::error_code ec;
while (scheduler_operation* o = impl_->ready_queue_.front())
{
impl_->ready_queue_.pop();
o->complete(impl_.get(), ec, 0);
}
}
private:
implementation_type impl_;
executor_work_guard<Executor> work_;
};
template <typename Executor, typename Function, typename Allocator>
void strand_executor_service::dispatch(const implementation_type& impl,
Executor& ex, BOOST_ASIO_MOVE_ARG(Function) function, const Allocator& a)
{
typedef typename decay<Function>::type function_type;
// If we are already in the strand then the function can run immediately.
if (call_stack<strand_impl>::contains(impl.get()))
{
// Make a local, non-const copy of the function.
function_type tmp(BOOST_ASIO_MOVE_CAST(Function)(function));
fenced_block b(fenced_block::full);
boost_asio_handler_invoke_helpers::invoke(tmp, tmp);
return;
}
// Allocate and construct an operation to wrap the function.
typedef executor_op<function_type, Allocator> op;
typename op::ptr p = { detail::addressof(a), op::ptr::allocate(a), 0 };
p.p = new (p.v) op(BOOST_ASIO_MOVE_CAST(Function)(function), a);
BOOST_ASIO_HANDLER_CREATION((impl->service_->context(), *p.p,
"strand_executor", impl.get(), 0, "dispatch"));
// Add the function to the strand and schedule the strand if required.
bool first = enqueue(impl, p.p);
p.v = p.p = 0;
if (first)
ex.dispatch(invoker<Executor>(impl, ex), a);
}
// Request invocation of the given function and return immediately.
template <typename Executor, typename Function, typename Allocator>
void strand_executor_service::post(const implementation_type& impl,
Executor& ex, BOOST_ASIO_MOVE_ARG(Function) function, const Allocator& a)
{
typedef typename decay<Function>::type function_type;
// Allocate and construct an operation to wrap the function.
typedef executor_op<function_type, Allocator> op;
typename op::ptr p = { detail::addressof(a), op::ptr::allocate(a), 0 };
p.p = new (p.v) op(BOOST_ASIO_MOVE_CAST(Function)(function), a);
BOOST_ASIO_HANDLER_CREATION((impl->service_->context(), *p.p,
"strand_executor", impl.get(), 0, "post"));
// Add the function to the strand and schedule the strand if required.
bool first = enqueue(impl, p.p);
p.v = p.p = 0;
if (first)
ex.post(invoker<Executor>(impl, ex), a);
}
// Request invocation of the given function and return immediately.
template <typename Executor, typename Function, typename Allocator>
void strand_executor_service::defer(const implementation_type& impl,
Executor& ex, BOOST_ASIO_MOVE_ARG(Function) function, const Allocator& a)
{
typedef typename decay<Function>::type function_type;
// Allocate and construct an operation to wrap the function.
typedef executor_op<function_type, Allocator> op;
typename op::ptr p = { detail::addressof(a), op::ptr::allocate(a), 0 };
p.p = new (p.v) op(BOOST_ASIO_MOVE_CAST(Function)(function), a);
BOOST_ASIO_HANDLER_CREATION((impl->service_->context(), *p.p,
"strand_executor", impl.get(), 0, "defer"));
// Add the function to the strand and schedule the strand if required.
bool first = enqueue(impl, p.p);
p.v = p.p = 0;
if (first)
ex.defer(invoker<Executor>(impl, ex), a);
}
} // namespace detail
} // namespace asio
} // namespace boost
#include <boost/asio/detail/pop_options.hpp>
#endif // BOOST_ASIO_DETAIL_IMPL_STRAND_EXECUTOR_SERVICE_HPP
|
