The awaitable<>, co_spawn(), this_coro, detached, and redirect_error
facilities have been moved from the asio::experimental namespace to
namespace asio. As part of this change, the this_coro::token() awaitable
has been superseded by the asio::use_awaitable completion token.
Please note that the use_awaitable and redirect_error completion tokens
work only with asynchronous operations that use the new form of
async_result with member function initiate(). Furthermore, when using
use_awaitable, please be aware that the asynchronous operation is not
initiated until co_await is applied to the awaitable<>.
All I/O objects now have an additional Executor template parameter. This
template parameter defaults to the asio::executor type (the polymorphic
executor wrapper) but can be used to specify a user-defined executor
type.
I/O objects' constructors and functions that previously took an
asio::io_context& now accept either an Executor or a reference to a
concrete ExecutionContext (such as asio::io_context or
asio::thread_pool).
One potential point of breakage in existing user code is when reusing an
I/O object's io_context for constructing another I/O object, as in:
asio::steady_timer my_timer(my_socket.get_executor().context());
To fix this, either construct the second I/O object using the first I/O
object's executor:
asio::steady_timer my_timer(my_socket.get_executor());
or otherwise explicitly pass the io_context:
asio::steady_timer my_timer(my_io_context);
Four new protocol classes have been added:
- asio::generic::datagram_protocol
- asio::generic::raw_protocol
- asio::generic::seq_packet_protocol
- asio::generic::stream_protocol
These classes implement the Protocol type requirements, but allow the
user to specify the address family (e.g. AF_INET) and protocol type
(e.g. IPPROTO_TCP) at runtime.
A new endpoint class template, asio::generic::basic_endpoint, has been
added to support these new protocol classes. This endpoint can hold any
other endpoint type, provided its native representation fits into a
sockaddr_storage object.
When using C++11, it is now possible to perform move construction from a
socket (or acceptor) object to convert to the more generic protocol's
socket (or acceptor) type. If the protocol conversion is valid:
Protocol1 p1 = ...;
Protocol2 p2(p1);
then the corresponding socket conversion is allowed:
Protocol1::socket socket1(io_service);
...
Protocol2::socket socket2(std::move(socket1));
For example, one possible conversion is from a TCP socket to a generic
stream-oriented socket:
asio::ip::tcp::socket socket1(io_service);
...
asio::generic::stream_protocol::socket socket2(std::move(socket1));
The conversion is also available for move-assignment. Note that these
conversions are not limited to the newly added generic protocol classes.
User-defined protocols may take advantage of this feature by similarly
ensuring the conversion from Protocol1 to Protocol2 is valid, as above.
As a convenience, the socket acceptor's accept() and async_accept()
functions have been changed so that they can directly accept into a
different protocol's socket type, provided the protocol conversion is
valid. For example, the following is now possible:
asio::ip::tcp::acceptor acceptor(io_service);
...
asio::generic::stream_protocol::socket socket1(io_service);
acceptor.accept(socket1);
[SVN r84363]
* 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]
- It is now evaluated before the first call to the underlying
*_some() operation, as well as after every operation.
- The return value is a number of bytes, which indicates the maximum
length to be transferred on the subsequent *_some() operation. If
the return value is 0 then the composed operation completes.
Add missing unit tests for read_at and write_at.
[SVN r48418]
