This adds experimental::channel and experimental::concurrent_channel.
Channels may be used to send completions as messages. For example:
// Create a channel with no buffer space.
channel<void(error_code, size_t)> ch(ctx);
// The call to try_send fails as there is no buffer
// space and no waiting receive operations.
bool ok = ch.try_send(asio::error::eof, 123);
assert(!ok);
// The async_send operation blocks until a receive
// operation consumes the message.
ch.async_send(asio::error::eof, 123,
[](error_code ec)
{
// ...
});
// The async_receive consumes the message. Both the
// async_send and async_receive operations complete
// immediately.
ch.async_receive(
[](error_code ec, size_t n)
{
// ...
});
The mutable_registered_buffer and const_registered_buffer classes are
buffer sequence types that represented registered buffers. These buffers
are obtained by first performing a buffer registration:
auto my_registration =
asio::register_buffers(
my_execution_context,
my_buffer_sequence);
The registration object must be maintained for as long as the buffer
registration is required. The supplied buffer sequence represents the
memory location or locations that will be registered, and the caller
must ensure they remain valid for as long as they are registered. The
registration is automatically removed when the registration object is
destroyed. There can be at most one active registration per execution
context.
The registration object is a container of registered buffers. Buffers
may be obtained from it by iterating over the container, or via direct
index access:
asio::mutable_registered_buffer my_buffer
= my_registration[i];
The registered buffers may then be passed directly to operations:
asio::async_read(my_socket, my_buffer,
[](error_code ec, size_t n)
{
// ...
});
Buffer registration supports the io_uring backend when used with read
and write operations on descriptors, files, pipes, and sockets.
The as_single completion token adapter can be used to specify that the
completion handler arguments should be combined into a single argument.
For completion signatures with a single parameter, the argument is
passed through as-is. For signatures with two or more parameters, the
arguments are combined into a tuple.
The as_single adapter may be used in conjunction with use_awaitable and
structured bindings as follows:
auto [e, n] = co_await socket.async_read_some(
boost::asio::buffer(data), as_single(use_awaitable));
Alternatively, it may be used as a default completion token like so:
using default_token = as_single_t<use_awaitable_t<>>;
using tcp_socket = default_token::as_default_on_t<tcp::socket>;
// ...
awaitable<void> do_read(tcp_socket socket)
{
// ...
auto [e, n] = co_await socket.async_read_some(boost::asio::buffer(data));
// ...
}
The ssl::host_name_verification class is a drop-in replacement for
ssl::rfc2818_verification, which it supersedes. The
ssl::rfc2818_verification class has been marked as deprecated.
Thanks to Arvid Norberg for providing the implementation.
* Improve backward compatibility of the new SSL implementation.
* Add wrapper for SSL_CTX_set_default_verify_paths().
* Document which OpenSSL functions the ssl::context member functions use.
* Add SSL certificate verification callbacks, and add a new
ssl::rfc2818_verification function object for simple peer certificate
verification based on the host name.
* Use std::atomic<> when available.
* Prefer to use std::array when it is available.
* Use std::shared_ptr and std::weak_ptr when available.
* Use a lightweight scoped smart pointer.
* Fix some shadow variable warnings with g++ 4.6.
[SVN r70384]
* Added support for signal handling, using a new class called
signal_set. Programs may add one or more signals to the set, and then
perform an async_wait() operation. The specified handler will be
called when one of the signals occurs. The same signal number may
registered with multiple signal_set objects, however the signal number
must be used only with Asio.
* Added handler tracking, a new debugging aid. When enabled by defining
BOOST_ASIO_ENABLE_HANDLER_TRACKING, Asio writes debugging output to
the standard error stream. The output records asynchronous operations
and the relationships between their handlers. It may be post-processed
using the included [^handlerviz.pl] tool to create a visual
representation of the handlers (requires GraphViz).
* Fixed a bug in asio::streambuf where the consume() function did not
always update the internal buffer pointers correctly. The problem may
occur when the asio::streambuf is filled with data using the standard
C++ member functions such as sputn(). (Note: the problem does not
manifest when the streambuf is populated by the Asio free functions
read(), async_read(), read_until() or async_read_until().)
* Fixed a bug on kqueue-based platforms, where reactor read operations
that return false from their perform() function are not correctly
re-registered with kqueue.
* Modified the buffers_iterator<> and ip::basic_resolver_iterator
classes so that the value_type typedefs are non-const byte types.
[SVN r69198]
* Added support for timeouts on socket iostreams, such as
ip::tcp::iostream. A timeout is set by calling expires_at() or
expires_from_now() to establish a deadline. Any socket operations
which occur past the deadline will put the iostream into a bad state.
* Added a new error() member function to socket iostreams, for
retrieving the error code from the most recent system call.
* Added a new basic_deadline_timer::cancel_one() function. This function
lets you cancel a single waiting handler on a timer. Handlers are
cancelled in FIFO order.
* Added a new transfer_exactly() completion condition. This can be used
to send or receive a specified number of bytes even if the total size
of the buffer (or buffer sequence) is larger.
* Added new free functions connect() and async_connect(). These
operations try each endpoint in a list until the socket is
successfully connected.
* Extended the buffer_size() function so that it works for buffer
sequences in addition to individual buffers.
* Added a new buffer_copy() function that can be used to copy the raw
bytes between individual buffers and buffer sequences.
* Added new non-throwing overloads of read(), read_at(), write() and
write_at() that do not require a completion condition.
* Added friendlier compiler errors for when a completion handler does
not meet the necessary type requirements. When C++0x is available
(currently supported for g++ 4.5 or later, and MSVC 10), static_assert
is also used to generate an informative error message. Checking may be
disabled by defining BOOST_ASIO_DISABLE_HANDLER_TYPE_REQUIREMENTS.
* Made the is_loopback(), is_unspecified() and is_multicast() functions
consistently available across the ip::address, ip::address_v4 and
ip::address_v6 classes. Refs #3939.
* Added new non_blocking() functions for managing the non-blocking
behaviour of a socket or descriptor. The io_control() commands named
non_blocking_io are now deprecated in favour of these new functions.
* Added new native_non_blocking() functions for managing the
non-blocking mode of the underlying socket or descriptor. These
functions are intended to allow the encapsulation of arbitrary
non-blocking system calls as asynchronous operations, in a way that is
transparent to the user of the socket object. The functions have no
effect on the behaviour of the synchronous operations of the socket or
descriptor. Refs #3307.
* Added the io_control() member function for socket acceptors.
Refs #3297.
* For consistency with the C++0x standard library, deprecated the
native_type typedefs in favour of native_handle_type, and the native()
member functions in favour of native_handle().
* Added a release() member function to posix descriptors. This function
releases ownership of the underlying native descriptor to the caller.
Refs #3900.
* Added support for sequenced packet sockets (SOCK_SEQPACKET).
* Added a new io_service::stopped() function that can be used to
determine whether the io_service has stopped (i.e. a reset() call is
needed prior to any further calls to run(), run_one(), poll() or
poll_one()).
* Reduced the copying of handler function objects.
* Added support for C++0x move construction to further reduce copying of
handler objects. Move support is enabled when compiling in -std=c++0x
mode on g++ 4.5 or higher, or when using MSVC10.
* Removed the dependency on OS-provided macros for the well-known IPv4
and IPv6 addresses. This should eliminate the annoying "missing braces
around initializer" warnings. Refs #3741.
* Reduced the size of ip::basic_endpoint<> objects (such as
ip::tcp::endpoint and ip::udp::endpoint).
* Changed the reactor backends to assume that any descriptors or sockets
added using assign() may have been dup()-ed, and so require explicit
deregistration from the reactor. Refs #4971.
* Changed the SSL error category to return error strings from the
OpenSSL library.
* Changed the separate compilation support such that, to use Asio's SSL
capabilities, you should also include 'asio/ssl/impl/src.hpp in one
source file in your program.
* Removed the deprecated member functions named io_service(). The
get_io_service() member functions should be used instead.
* Removed the deprecated typedefs resolver_query and resolver_iterator
from the ip::tcp, ip::udp and ip::icmp classes.
* Fixed a compile error on some versions of g++ due to anonymous enums.
Refs #4883.
* Added an explicit cast to the FIONBIO constant to int to suppress a
compiler warning on some platforms. Refs #5128.
* Fixed warnings reported by g++'s -Wshadow compiler option. Refs #3905.
[SVN r69194]
