summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorRemko Tronçon <git@el-tramo.be>2009-06-01 08:48:42 (GMT)
committerRemko Tronçon <git@el-tramo.be>2009-06-01 09:24:28 (GMT)
commit2812bddd81f8a1b804c7460f4e14cd0aa393d129 (patch)
treed46294f35150c4f0f43deaf2d31fceaf945ae715 /3rdParty/Boost/boost/asio/detail/strand_service.hpp
downloadswift-contrib-2812bddd81f8a1b804c7460f4e14cd0aa393d129.zip
swift-contrib-2812bddd81f8a1b804c7460f4e14cd0aa393d129.tar.bz2
Import.
Diffstat (limited to '3rdParty/Boost/boost/asio/detail/strand_service.hpp')
-rw-r--r--3rdParty/Boost/boost/asio/detail/strand_service.hpp532
1 files changed, 532 insertions, 0 deletions
diff --git a/3rdParty/Boost/boost/asio/detail/strand_service.hpp b/3rdParty/Boost/boost/asio/detail/strand_service.hpp
new file mode 100644
index 0000000..2c89a61
--- /dev/null
+++ b/3rdParty/Boost/boost/asio/detail/strand_service.hpp
@@ -0,0 +1,532 @@
+//
+// strand_service.hpp
+// ~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2008 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_STRAND_SERVICE_HPP
+#define BOOST_ASIO_DETAIL_STRAND_SERVICE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/push_options.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+#include <boost/aligned_storage.hpp>
+#include <boost/assert.hpp>
+#include <boost/detail/atomic_count.hpp>
+#include <boost/intrusive_ptr.hpp>
+#include <boost/asio/detail/pop_options.hpp>
+
+#include <boost/asio/io_service.hpp>
+#include <boost/asio/detail/bind_handler.hpp>
+#include <boost/asio/detail/call_stack.hpp>
+#include <boost/asio/detail/handler_alloc_helpers.hpp>
+#include <boost/asio/detail/handler_invoke_helpers.hpp>
+#include <boost/asio/detail/mutex.hpp>
+#include <boost/asio/detail/noncopyable.hpp>
+#include <boost/asio/detail/service_base.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+// Default service implementation for a strand.
+class strand_service
+ : public boost::asio::detail::service_base<strand_service>
+{
+public:
+ class handler_base;
+ class invoke_current_handler;
+ class post_next_waiter_on_exit;
+
+ // The underlying implementation of a strand.
+ class strand_impl
+ {
+#if defined (__BORLANDC__)
+ public:
+#else
+ private:
+#endif
+ void add_ref()
+ {
+ ++ref_count_;
+ }
+
+ void release()
+ {
+ if (--ref_count_ == 0)
+ delete this;
+ }
+
+ private:
+ // Only this service will have access to the internal values.
+ friend class strand_service;
+ friend class post_next_waiter_on_exit;
+ friend class invoke_current_handler;
+
+ strand_impl(strand_service& owner)
+ : owner_(owner),
+ current_handler_(0),
+ first_waiter_(0),
+ last_waiter_(0),
+ ref_count_(0)
+ {
+ // Insert implementation into linked list of all implementations.
+ boost::asio::detail::mutex::scoped_lock lock(owner_.mutex_);
+ next_ = owner_.impl_list_;
+ prev_ = 0;
+ if (owner_.impl_list_)
+ owner_.impl_list_->prev_ = this;
+ owner_.impl_list_ = this;
+ }
+
+ ~strand_impl()
+ {
+ // Remove implementation from linked list of all implementations.
+ boost::asio::detail::mutex::scoped_lock lock(owner_.mutex_);
+ if (owner_.impl_list_ == this)
+ owner_.impl_list_ = next_;
+ if (prev_)
+ prev_->next_ = next_;
+ if (next_)
+ next_->prev_= prev_;
+ next_ = 0;
+ prev_ = 0;
+ lock.unlock();
+
+ if (current_handler_)
+ {
+ current_handler_->destroy();
+ }
+
+ while (first_waiter_)
+ {
+ handler_base* next = first_waiter_->next_;
+ first_waiter_->destroy();
+ first_waiter_ = next;
+ }
+ }
+
+ // Mutex to protect access to internal data.
+ boost::asio::detail::mutex mutex_;
+
+ // The service that owns this implementation.
+ strand_service& owner_;
+
+ // The handler that is ready to execute. If this pointer is non-null then it
+ // indicates that a handler holds the lock.
+ handler_base* current_handler_;
+
+ // The start of the list of waiting handlers for the strand.
+ handler_base* first_waiter_;
+
+ // The end of the list of waiting handlers for the strand.
+ handler_base* last_waiter_;
+
+ // Storage for posted handlers.
+ typedef boost::aligned_storage<128> handler_storage_type;
+#if defined(__BORLANDC__)
+ boost::aligned_storage<128> handler_storage_;
+#else
+ handler_storage_type handler_storage_;
+#endif
+
+ // Pointers to adjacent socket implementations in linked list.
+ strand_impl* next_;
+ strand_impl* prev_;
+
+ // The reference count on the strand implementation.
+ boost::detail::atomic_count ref_count_;
+
+#if !defined(__BORLANDC__)
+ friend void intrusive_ptr_add_ref(strand_impl* p)
+ {
+ p->add_ref();
+ }
+
+ friend void intrusive_ptr_release(strand_impl* p)
+ {
+ p->release();
+ }
+#endif
+ };
+
+ friend class strand_impl;
+
+ typedef boost::intrusive_ptr<strand_impl> implementation_type;
+
+ // Base class for all handler types.
+ class handler_base
+ {
+ public:
+ typedef void (*invoke_func_type)(handler_base*,
+ strand_service&, implementation_type&);
+ typedef void (*destroy_func_type)(handler_base*);
+
+ handler_base(invoke_func_type invoke_func, destroy_func_type destroy_func)
+ : next_(0),
+ invoke_func_(invoke_func),
+ destroy_func_(destroy_func)
+ {
+ }
+
+ void invoke(strand_service& service_impl, implementation_type& impl)
+ {
+ invoke_func_(this, service_impl, impl);
+ }
+
+ void destroy()
+ {
+ destroy_func_(this);
+ }
+
+ protected:
+ ~handler_base()
+ {
+ }
+
+ private:
+ friend class strand_service;
+ friend class strand_impl;
+ friend class post_next_waiter_on_exit;
+ handler_base* next_;
+ invoke_func_type invoke_func_;
+ destroy_func_type destroy_func_;
+ };
+
+ // Helper class to allow handlers to be dispatched.
+ class invoke_current_handler
+ {
+ public:
+ invoke_current_handler(strand_service& service_impl,
+ const implementation_type& impl)
+ : service_impl_(service_impl),
+ impl_(impl)
+ {
+ }
+
+ void operator()()
+ {
+ impl_->current_handler_->invoke(service_impl_, impl_);
+ }
+
+ friend void* asio_handler_allocate(std::size_t size,
+ invoke_current_handler* this_handler)
+ {
+ return this_handler->do_handler_allocate(size);
+ }
+
+ friend void asio_handler_deallocate(void*, std::size_t,
+ invoke_current_handler*)
+ {
+ }
+
+ void* do_handler_allocate(std::size_t size)
+ {
+#if defined(__BORLANDC__)
+ BOOST_ASSERT(size <= boost::aligned_storage<128>::size);
+#else
+ BOOST_ASSERT(size <= strand_impl::handler_storage_type::size);
+#endif
+ (void)size;
+ return impl_->handler_storage_.address();
+ }
+
+ // The asio_handler_invoke hook is not defined here since the default one
+ // provides the correct behaviour, and including it here breaks MSVC 7.1
+ // in some situations.
+
+ private:
+ strand_service& service_impl_;
+ implementation_type impl_;
+ };
+
+ // Helper class to automatically enqueue next waiter on block exit.
+ class post_next_waiter_on_exit
+ {
+ public:
+ post_next_waiter_on_exit(strand_service& service_impl,
+ implementation_type& impl)
+ : service_impl_(service_impl),
+ impl_(impl),
+ cancelled_(false)
+ {
+ }
+
+ ~post_next_waiter_on_exit()
+ {
+ if (!cancelled_)
+ {
+ boost::asio::detail::mutex::scoped_lock lock(impl_->mutex_);
+ impl_->current_handler_ = impl_->first_waiter_;
+ if (impl_->current_handler_)
+ {
+ impl_->first_waiter_ = impl_->first_waiter_->next_;
+ if (impl_->first_waiter_ == 0)
+ impl_->last_waiter_ = 0;
+ lock.unlock();
+ service_impl_.get_io_service().post(
+ invoke_current_handler(service_impl_, impl_));
+ }
+ }
+ }
+
+ void cancel()
+ {
+ cancelled_ = true;
+ }
+
+ private:
+ strand_service& service_impl_;
+ implementation_type& impl_;
+ bool cancelled_;
+ };
+
+ // Class template for a waiter.
+ template <typename Handler>
+ class handler_wrapper
+ : public handler_base
+ {
+ public:
+ handler_wrapper(Handler handler)
+ : handler_base(&handler_wrapper<Handler>::do_invoke,
+ &handler_wrapper<Handler>::do_destroy),
+ handler_(handler)
+ {
+ }
+
+ static void do_invoke(handler_base* base,
+ strand_service& service_impl, implementation_type& impl)
+ {
+ // Take ownership of the handler object.
+ typedef handler_wrapper<Handler> this_type;
+ this_type* h(static_cast<this_type*>(base));
+ typedef handler_alloc_traits<Handler, this_type> alloc_traits;
+ handler_ptr<alloc_traits> ptr(h->handler_, h);
+
+ post_next_waiter_on_exit p1(service_impl, impl);
+
+ // Make a copy of the handler so that the memory can be deallocated before
+ // the upcall is made.
+ Handler handler(h->handler_);
+
+ // A handler object must still be valid when the next waiter is posted
+ // since destroying the last handler might cause the strand object to be
+ // destroyed. Therefore we create a second post_next_waiter_on_exit object
+ // that will be destroyed before the handler object.
+ p1.cancel();
+ post_next_waiter_on_exit p2(service_impl, impl);
+
+ // Free the memory associated with the handler.
+ ptr.reset();
+
+ // Indicate that this strand is executing on the current thread.
+ call_stack<strand_impl>::context ctx(impl.get());
+
+ // Make the upcall.
+ boost_asio_handler_invoke_helpers::invoke(handler, &handler);
+ }
+
+ static void do_destroy(handler_base* base)
+ {
+ // Take ownership of the handler object.
+ typedef handler_wrapper<Handler> this_type;
+ this_type* h(static_cast<this_type*>(base));
+ typedef handler_alloc_traits<Handler, this_type> alloc_traits;
+ handler_ptr<alloc_traits> ptr(h->handler_, h);
+
+ // A sub-object of the handler may be the true owner of the memory
+ // associated with the handler. Consequently, a local copy of the handler
+ // is required to ensure that any owning sub-object remains valid until
+ // after we have deallocated the memory here.
+ Handler handler(h->handler_);
+ (void)handler;
+
+ // Free the memory associated with the handler.
+ ptr.reset();
+ }
+
+ private:
+ Handler handler_;
+ };
+
+ // Construct a new strand service for the specified io_service.
+ explicit strand_service(boost::asio::io_service& io_service)
+ : boost::asio::detail::service_base<strand_service>(io_service),
+ mutex_(),
+ impl_list_(0)
+ {
+ }
+
+ // Destroy all user-defined handler objects owned by the service.
+ void shutdown_service()
+ {
+ // Construct a list of all handlers to be destroyed.
+ boost::asio::detail::mutex::scoped_lock lock(mutex_);
+ strand_impl* impl = impl_list_;
+ handler_base* first_handler = 0;
+ while (impl)
+ {
+ if (impl->current_handler_)
+ {
+ impl->current_handler_->next_ = first_handler;
+ first_handler = impl->current_handler_;
+ impl->current_handler_ = 0;
+ }
+ if (impl->first_waiter_)
+ {
+ impl->last_waiter_->next_ = first_handler;
+ first_handler = impl->first_waiter_;
+ impl->first_waiter_ = 0;
+ impl->last_waiter_ = 0;
+ }
+ impl = impl->next_;
+ }
+
+ // Destroy all handlers without holding the lock.
+ lock.unlock();
+ while (first_handler)
+ {
+ handler_base* next = first_handler->next_;
+ first_handler->destroy();
+ first_handler = next;
+ }
+ }
+
+ // Construct a new strand implementation.
+ void construct(implementation_type& impl)
+ {
+ impl = implementation_type(new strand_impl(*this));
+ }
+
+ // Destroy a strand implementation.
+ void destroy(implementation_type& impl)
+ {
+ implementation_type().swap(impl);
+ }
+
+ // Request the io_service to invoke the given handler.
+ template <typename Handler>
+ void dispatch(implementation_type& impl, Handler handler)
+ {
+ if (call_stack<strand_impl>::contains(impl.get()))
+ {
+ boost_asio_handler_invoke_helpers::invoke(handler, &handler);
+ }
+ else
+ {
+ // Allocate and construct an object to wrap the handler.
+ typedef handler_wrapper<Handler> value_type;
+ typedef handler_alloc_traits<Handler, value_type> alloc_traits;
+ raw_handler_ptr<alloc_traits> raw_ptr(handler);
+ handler_ptr<alloc_traits> ptr(raw_ptr, handler);
+
+ boost::asio::detail::mutex::scoped_lock lock(impl->mutex_);
+
+ if (impl->current_handler_ == 0)
+ {
+ // This handler now has the lock, so can be dispatched immediately.
+ impl->current_handler_ = ptr.release();
+ lock.unlock();
+ this->get_io_service().dispatch(invoke_current_handler(*this, impl));
+ }
+ else
+ {
+ // Another handler already holds the lock, so this handler must join
+ // the list of waiters. The handler will be posted automatically when
+ // its turn comes.
+ if (impl->last_waiter_)
+ {
+ impl->last_waiter_->next_ = ptr.get();
+ impl->last_waiter_ = impl->last_waiter_->next_;
+ }
+ else
+ {
+ impl->first_waiter_ = ptr.get();
+ impl->last_waiter_ = ptr.get();
+ }
+ ptr.release();
+ }
+ }
+ }
+
+ // Request the io_service to invoke the given handler and return immediately.
+ template <typename Handler>
+ void post(implementation_type& impl, Handler handler)
+ {
+ // Allocate and construct an object to wrap the handler.
+ typedef handler_wrapper<Handler> value_type;
+ typedef handler_alloc_traits<Handler, value_type> alloc_traits;
+ raw_handler_ptr<alloc_traits> raw_ptr(handler);
+ handler_ptr<alloc_traits> ptr(raw_ptr, handler);
+
+ boost::asio::detail::mutex::scoped_lock lock(impl->mutex_);
+
+ if (impl->current_handler_ == 0)
+ {
+ // This handler now has the lock, so can be dispatched immediately.
+ impl->current_handler_ = ptr.release();
+ lock.unlock();
+ this->get_io_service().post(invoke_current_handler(*this, impl));
+ }
+ else
+ {
+ // Another handler already holds the lock, so this handler must join the
+ // list of waiters. The handler will be posted automatically when its turn
+ // comes.
+ if (impl->last_waiter_)
+ {
+ impl->last_waiter_->next_ = ptr.get();
+ impl->last_waiter_ = impl->last_waiter_->next_;
+ }
+ else
+ {
+ impl->first_waiter_ = ptr.get();
+ impl->last_waiter_ = ptr.get();
+ }
+ ptr.release();
+ }
+ }
+
+private:
+ // Mutex to protect access to the linked list of implementations.
+ boost::asio::detail::mutex mutex_;
+
+ // The head of a linked list of all implementations.
+ strand_impl* impl_list_;
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#if defined(__BORLANDC__)
+
+namespace boost {
+
+inline void intrusive_ptr_add_ref(
+ boost::asio::detail::strand_service::strand_impl* p)
+{
+ p->add_ref();
+}
+
+inline void intrusive_ptr_release(
+ boost::asio::detail::strand_service::strand_impl* p)
+{
+ p->release();
+}
+
+} // namespace boost
+
+#endif // defined(__BORLANDC__)
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_STRAND_SERVICE_HPP