...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
fopen()
.
EAGAIN
as an indication
of an in-progress connect operation.
experimental::basic_channel::reset()
and experimental::basic_concurrent_channel::reset()
so that they work correctly for an unclosed channel.
experimental::promise
operations race()
and all()
.
co_spawn
implementation
to explicitly dispatch cancellation signals through the specified executor,
if the the completion handler has an associated executor of its own.
make_strand()
, make_work_guard()
, ip::address_v4
,
ip::address_v6
, experimental::basic_channel
,
and experimental::basic_concurrent_channel
.
async_compose
, experimental::deferred
, experimental::parallel_group
,
experimental::promise
, channels, and completion token
adapters.
io_context
reference documentation to use executor_work_guard
when preventing the io_context
from running out of work.
deadline_timer
from the Overview documentation.
bind_allocator
, to
simplify associating a custom allocator with a completion token or handler.
file_base::sync_all_on_write
flag, which maps to
O_SYNC
on POSIX and FILE_FLAG_WRITE_THROUGH
on Windows.
basic_file::release()
.
recycling_allocator
as part of the public interface.
nodiscard
attribute
to the following functions:
bind_allocator()
bind_cancellation_slot()
bind_executor()
buffer()
dynamic_buffer()
experimental::append()
experimental::as_single()
experimental::as_tuple()
experimental::make_parallel_group()
experimental::prepend()
get_associated_allocator()
get_associated_cancellation_slot()
get_associated_executor()
make_work_guard()
SSL*
into an ssl::stream<>
.
executor_work_guard<>
even when BOOST_ASIO_NO_TS_EXECUTORS
is defined.
bind_cancellation_slot
compatibility with legacy completion tokens.
bind_executor
compatibility
with legacy completion tokens.
associator
specialisations
for experimental::append
and experimental::prepend
,
to correctly propagate the associated allocator, executor, and cancellation
slot.
awaitable
.
asio/io_context.hpp
is included.
associated_allocator
template was not correctly detecting the nested T::allocator_type
.
io_uring
implementation of async_receive_from
operation for sockets.
io_uring
implementation of write_some_at
operation for files.
io_uring
implementation to correctly check that
it is not the default before registering with reactor.
io_uring
in some build configurations.
experimental::coro
's per-operation cancellation to
clear the slot at completion of each operation.
experimental::promise
's
type-erased completion handlers.
operator=
implementation for ssl::stream
.
any_io_executor
implementation
to work when both BOOST_ASIO_USE_TS_EXECUTOR_AS_DEFAULT
and BOOST_ASIO_SEPARATE_COMPILATION
are defined.
basic_socket::at_mark()
when using the sockatmark()
system call.
dispatch()
, post()
, and defer()
to cover both the old and new executor
forms.
BOOST_ASIO_HAS_IO_URING
and BOOST_ASIO_DISABLE_EPOLL
.BOOST_ASIO_HAS_IO_URING
alone will enable the backend without using it for the existing I/O objects.
This allows it to be used for I/O objects that require io_uring support,
such as files.liburing
library at both compile and link time. Add -luring
to your list of libraries for
linking.
Added support for files. This introduces new classes for stream-oriented
and random-access files. For example, to write to a newly created stream-oriented
file:
asio::stream_file file( my_io_context, "/path/to/file", asio::stream_file::write_only | asio::stream_file::create | asio::stream_file::truncate); file.async_write_some(my_buffer, [](error_code e, size_t n) { // ... });
or to read from a random-access file:
asio::random_access_file file( my_io_context, "/path/to/file", asio::random_access_file::read_only); file.async_read_some_at(1234, my_buffer, [](error_code e, size_t n) { // ... });
This feature currently supports I/O completion ports on Windows,
and io_uring on Linux (define BOOST_ASIO_HAS_IO_URING
to enable).
Added support for portable pipes. This change add supports for pipes on
POSIX and Windows (when I/O completion ports are available). For example,
to create and use a connected pair of pipe objects:
asio::readable_pipe read_end; asio::writable_pipe write_end; asio::connect_pipe(read_end, write_end); write_end.async_write_some(my_write_buffer, [](error_code e, size_t n) { // ... }); read_end.async_read_some(my_read_buffer, [](error_code e, size_t n) { // ... });
Added support for registered buffers. The mutable_registered_buffer
and const_registered_buffer
classes are buffer sequence types that represent 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. For
portability, the facility may be used on other platforms, but the registered
buffers will behave as normal buffers.
Added experimental support for channels. This adds templates experimental::basic_channel
and experimental::basic_concurrent_channel
,
with aliases 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 is outstanding 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) { // ... });
experimental::coro
.
co_spawn
for
coro
tasks.
aligned_alloc
on clang
when using an MSVC runtime.
ip::network_v4::canonical()
.
io_context
executors to a single pointer.
execution::any_executor
and any_io_executor
.
gcc
and clang
.
ssl
facilities.
bind_executor
compatibility
with completion tokens.
BOOST_ASIO_USE_TS_EXECUTOR_AS_DEFAULT
is defined.
awaitable<>
.
experimental::parallel_group
that occured when the execution context was shut down with parallel operations
still pending.
CancellationSlot
, a lightweight cancellation
channel that is specified through the new associated_cancellation_slot
associator. A concrete CancellationSlot
implementation is provided in the form of the cancellation_signal
and cancellation_slot
classes.
In conjunction with the bind_cancellation_slot
helper function, these may be used to hook cancellation into asynchronous
operations. However, it should be noted that these classes are the low-level
building blocks of cancellation, and most use cases should use a higher
level abstraction for cancellation, such as experimental::parallel_group
or the new logical operators for awaitable
(see below). The ability to cancel individual operations, or composed operations,
is currently supported by:
async_read
and async_write
async_compose
awaitable
experimental::coro
(see below)
experimental::parallel_group
operation (see below)
experimental::promise
class (see below)
Added the associator
trait.
The associator
trait is
used to generically forward associators, such as associated_executor
and associated_allocator
,
through intermediate completion handlers. For example:
template <typename Handler> struct intermediate_handler { Handler handler_; template <typename... Args> void operator()(Args&... args) { // ... } }; namespace asio { template < template <typename, typename> class Associator, typename Handler, typename DefaultCandidate> struct associator< Associator, intermediate_handler<Handler>, DefaultCandidate> { using type = typename Associator<Handler, DefaultCandidate>::type; static type get( const intermediate_handler<Handler>& h, const DefaultCandidate& c = DefaultCandidate()) noexcept { return Associator<Handler, DefaultCandidate>::get( h.handler_, c); } }; } // namespace asio
Added support for asynchronous operations with multiple completion signatures.
Completion signatures may also specify that they are noexcept
,
and whether they are lvalue-invocable (and thus do not "consume"
the completion handler) or rvalue-invocable (and thus do "consume"
the handler, indicating an end to the asynchronous operation). For example:
auto my_async_operation(..., asio::completion_token_for< void(intermediate_result_type) & noexcept, void(final_result_type) && > auto&& token) { // ... }
Added operator&&
and operator||
for awaitable<>
.
The logical operators ||
and
&&
have been overloaded
for awaitable<>
,
to allow coroutines to be trivially awaited in parallel.
When
awaited using &&
,
the co_await
expression
waits until both operations have completed successfully. As a "short-circuit"
evaluation, if one operation fails with an exception, the other is immediately
cancelled. For example:
std::tuple<std::size_t, std::size_t> results = co_await ( async_read(socket, input_buffer, use_awaitable) && async_write(socket, output_buffer, use_awaitable) );
When awaited using ||
,
the co_await
expression
waits until either operation succeeds. As a "short-circuit" evaluation,
if one operation succeeds without throwing an exception, the other is immediately
cancelled. For example:
std::variant<std::size_t, std::monostate> results = co_await ( async_read(socket, input_buffer, use_awaitable) || timer.async_wait(use_awaitable) );
The operators may be enabled by adding the #include
:
#include <boost/asio/experimental/awaitable_operators.hpp>
and then bringing the contents of the experimental::awaitable_operators
namespace into scope:
using namespace asio::experimental::awaitable_operators;
Added the experimental::as_tuple
completion token adapter. The as_tuple
completion token adapter can be used to specify that the completion handler
arguments should be combined into a single tuple argument. The as_tuple
adapter may be used in conjunction
with use_awaitable
and
structured bindings as follows:
auto [e, n] = co_await socket.async_read_some( asio::buffer(data), as_tuple(use_awaitable));
Alternatively, it may be used as a default completion token like
so:
using default_token = as_tuple_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(asio::buffer(data)); // ... }
Added the experimental::append
completion token adapter. The append
completion token adapter can be used to pass additional completion handler
arguments at the end of the completion signature. For example:
timer.async_wait( asio::experimental::append( [](boost::system::error_code ec, int i) { // ... }, 42) ); std::future<int> f = timer.async_wait( asio::experimental::append( asio::use_future, 42 ) );
Added the experimental::prepend
completion token adapter. The prepend
completion token adapter can be used to pass additional arguments before
the existing completion handler arguments. For example:
timer.async_wait( asio::experimental::prepend( [](int i, boost::system::error_code ec) { // ... }, 42) ); std::future<std::tuple<int, boost::system::error_code>> f = timer.async_wait( asio::experimental::prepend( asio::use_future, 42 ) );
Added the experimental::deferred
completion token. The deferred
completion token takes a call to an asynchronous operation's initiating
function and turns it into a function object that accepts a completion
token. For example:
auto deferred_op = timer.async_wait( asio::experimental::deferred); ... std::move(deferred_op)( [](boost::system::error_code ec){ ... });
or:
auto deferred_op = timer.async_wait( asio::experimental::deferred); ... std::future<void> = std::move(deferred_op)( asio::use_future);
The deferred token also supports chaining, to create simple compositions:
auto deferred_op = timer.async_wait( asio::experimental::deferred( [&](boost::system::error_code ec) { timer.expires_after( std::chrono::seconds(1)); return timer.async_wait( asio::experimental::deferred); }); ... std::future<void> = std::move(deferred_op)(asio::use_future);
Added the experimental::parallel_group
class and experimental::make_parallel_group
function. This utility may be used to launch work that is performed in
parallel, and wait for one or all of the operations to complete. A parallel_group
implements automatic cancellation
of incomplete operations. For example:
experimental::make_parallel_group( [&](auto token) { return stream.async_read_some(asio::buffer(data), token); }, [&](auto token) { return timer.async_wait(token); } ).async_wait( experimental::wait_for_one(), []( std::array<std::size_t, 2> completion_order, boost::system::error_code ec1, std::size_t n1, boost::system::error_code ec2 ) { // ... } );
The conditions for completion of the group may be specified using
one of the four provided function objects wait_for_all
,
wait_for_one
, wait_for_one_success
, and wait_for_one_error
, or with a custom
function. The parallel_group
class can also be combined with deferred
as follows:
experimental::make_parallel_group( stream.async_read_some(asio::buffer(data), experimental::deferred), timer.async_wait(experimental::deferred) ).async_wait( // ... );
Note: for maximum flexibility, parallel_group
does not propagate the executor automatically to the operations within
the group.
Added experimental::promise
. The promise
type allows eager execution and synchronisation of async operations. For
example:
auto promise = async_read( stream, asio::buffer(my_buffer), asio::experimental::use_promise); ... do other stuff while the read is going on ... promise.async_wait( // completion the operation [](error_code ec, std::size_t bytes_read) { ... });
Promises can be safely disregarded if the result is no longer required.
Different operations can be combined to either wait for all to complete
or for one to complete (and cancel the rest). For example, to wait for
one to complete:
auto timeout_promise = timer.async_wait( asio::experimental::use_promise); auto read_promise = async_read( stream, asio::buffer(my_buffer), asio::experimental::use_promise); auto promise = asio::experimental::promise<>::race( timeout_promise, read_promise); promise.async_wait( [](std::variant<error_code, std::tuple<error_code, std::size_t>> v) { if (v.index() == 0) {} //timed out else if (v.index() == 1) // completed in time });
or to wait for all to complete:
auto write_promise = async_write( stream, asio::buffer(my_write_buffer), asio::experimental::use_promise); auto read_promise = async_read( stream, asio::buffer(my_buffer), asio::experimental::use_promise); auto promise = asio::experimental::promise<>::all( write_promise, read_promise); promise.async_wait( [](std::tuple<error_code, std::size_t> write_result, std::tuple<error_code, std::size_t> read_result) { });
Thanks go to Klemens Morgenstern for contributing this feature.
Added the experimental::coro
class template. The coro
type is a C++20 coroutine primitive for resumable functions, with the ability
to combine both asynchronous waiting (co_await
)
and yielding (co_yield
)
into a single, stateful control flow. For example:
#include <boost/asio.hpp> #include <boost/asio/experimental/coro.hpp> using asio::ip::tcp; asio::experimental::coro<std::string> reader(tcp::socket& sock) { std::string buf; while (sock.is_open()) { std::size_t n = co_await asio::async_read_until( sock, asio::dynamic_buffer(buf), '\n', asio::experimental::use_coro); co_yield buf.substr(0, n); buf.erase(0, n); } } asio::awaitable<void> consumer(tcp::socket sock) { auto r = reader(sock); auto msg1 = co_await r.async_resume(asio::use_awaitable); std::cout << "Message 1: " << msg1.value_or("\n"); auto msg2 = co_await r.async_resume(asio::use_awaitable); std::cout << "Message 2: " << msg2.value_or("\n"); } asio::awaitable<void> listen(tcp::acceptor& acceptor) { for (;;) { co_spawn( acceptor.get_executor(), consumer(co_await acceptor.async_accept(asio::use_awaitable)), asio::detached); } } int main() { asio::io_context ctx; tcp::acceptor acceptor(ctx, {tcp::v4(), 54321}); co_spawn(ctx, listen(acceptor), asio::detached); ctx.run(); }
Thanks go to Klemens Morgenstern for contributing this feature.
ssl::stream<>
.
co_spawn
to dispatch
the coroutine's initial step
to the executor, and to only post
the completion handler if the coroutine did not otherwise perform a context
switch (i.e. a co_await
on an asynchronous operation).
any_executor
and any_io_executor
when
used with asynchronous operations.
nodiscard
attribute
to awaitable<>
.
BOOST_ASIO_RECYCLING_ALLOCATOR_CACHE_SIZE
macro.
std::system_error
message workaround for recent
MSVC.
use_awaitable_t::executor_with_default
.
any_io_executor
equality operators to correctly return a result based on the target executor.
strand<>
to avoid using a potentially moved-from executor.
gcc
tests are not used for clang
when detecting compiler features.
clang
shipped with
MSVC.
OPENSSL_NO_SSL_INTERN
is defined.
posix::basic_stream_descriptor
move operations
to work with non-defaulted executors.
ip::scope_id_type
type alias.
ip::port_type
type alias.
std::hash
specialisations for IP addresses.
std::hash
specialisations for ip::basic_endpoint<>
.
any_io_executor
to a "strong typedef"-style class.
experimental::as_single
to work with handler hook deprecation.
errno
is not overwritten
if socket()
fails on macOS/FreeBSD.
io_context
and thread_pool
executors
when move-assigned.
call_stack
objects are accessed only from implementation files.
blocking.always
property from being used with strand<>
, as it did not produce the correct
semantics.
asio/impl/src.cpp
.
connect_pair
function (which will fail with an operation_not_supported error).
ip::basic_resolver
.
Added the experimental::as_single
completion token adapter. 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)); // ... }
MSG_NOSIGNAL
on more platforms by using _POSIX_VERSION
to detect whether it is supported.
executor
concept
to test for a const-qualified execute()
.
any_executor
support
for builds without RTTI support.
thread_pool
unit
test to work without RTTI support.
asio::query
.
push/pop_options.hpp
includes.
select
reactor is used on Windows.
any_executor
comparisons and conversion.
strand<>
adaptation of Networking TS executors when targeting older C++ versions
or less conformant compilers.
io_context::executor_type
, thread_pool::executor_type
,
system_executor
,
and strand
executors
now meet the requirements for the proposed standard executors. These
classes also continue to meet the existing requirements for the Networking
TS model of executors.
dispatch
, post
, defer
,
get_associated_executor
,
bind_executor
, make_work_guard
, spawn
, co_spawn
,
async_compose
, use_future
, etc., can interoperate
with both new proposed standard executors, and with existing Networking
TS executors. The implementation determines at compile time which
model a particular executor meets; the proposed standard executor
model is used in preference if both are detected.
any_io_executor
type alias has been introduced as the new default runtime-polymorphic
executor for all I/O objects. This type alias points to the execution::any_executor<>
template with a set of supportable properties specified for use with
I/O. This change may break existing code that directly uses the old
polymorphic wrapper, executor
.
If required for backward compatibility, BOOST_ASIO_USE_TS_EXECUTOR_AS_DEFAULT
can be defined, which changes the any_io_executor
type alias to instead point to the executor
polymorphic wrapper.
BOOST_ASIO_NO_TS_EXECUTORS
.
Added converting move construction and assignment to basic_waitable_timer
.
This enables move construction and assignment between different timer types,
provided the executor types are convertible. For example:
basic_waitable_timer< clock_type, traits_type, io_context::executor_type > timer1(my_io_context); basic_waitable_timer< clock_type, traits_type, any_io_executor // polymorphic wrapper > timer2(std::move(timer1));
gcc
10.
Added overloads of co_spawn
that launch an awaitable. This change allows us to write:
co_spawn(executor, echo(std::move(socket)), detached);
instead of:
co_spawn(executor, [socket = std::move(socket)]() mutable { return echo(std::move(socket)); }, detached);
use_awaitable_t
's
default executor adapter, to enable conversion between executor types.
detached_t
as a default completion token, by adding members as_default_on()
and as_default_on_t<>
.
ssl::stream<>
.
ssl::stream<>
write operations to linearise gather-write buffer sequences.
asio_handler_invoke
hook. This hook was deprecated with the introduction of the Networking
TS trait associated_executor
and function get_associated_executor()
. Compiling an application with BOOST_ASIO_NO_DEPRECATED
will now trigger
a compile error if any handler implements the asio_handler_invoke
hook.
asio_handler_allocate
and asio_handle_deallocate
hooks. These hooks were deprecated with the introduction of the Networking
TS trait associated_allocator
and function get_associated_allocator()
. Compiling an application with BOOST_ASIO_NO_DEPRECATED
will now trigger
a compile error if any handler implements the asio_handler_allocate
or asio_handler_deallocate
hooks.
recv
rather than recvmsg
,
send
rather than
sendmsg
, read
rather than readv
, and write
rather than writev
.
executor
.
errno
and error codes when on an error path.
io_context::exeutor_type
)
is detected.
Added source location support to handler tracking. The new BOOST_ASIO_HANDLER_LOCATION((file_name,
line,
function_name))
macro may be used to inform the handler tracking mechanism of a source
location. This macro declares an object that is placed on the stack. Then,
when an asynchronous operation is launched with location information, it
outputs lines using the <action>
n^m
, prior to the n*m
line that signifies
the beginning of the asynchronous operation. For example:
@asio|1589423304.861944|>7|ec=system:0,bytes_transferred=5
@asio|1589423304.861952|7^8|in 'async_write' (...../../include/asio/impl/write.hpp:330)
@asio|1589423304.861952|7^8|called from 'do_write' (handler_tracking/async_tcp_echo_server.cpp:62)
@asio|1589423304.861952|7^8|called from 'operator()' (handler_tracking/async_tcp_echo_server.cpp:51)
@asio|1589423304.861952|7*8|socket@0x7ff61c008230.async_send
@asio|1589423304.861975|.8|non_blocking_send,ec=system:0,bytes_transferred=5
@asio|1589423304.861980|<7|
If std::source_location
or std::experimental::source_location
are available, the use_awaitable_t
token (when default-constructed or used as a default completion token)
will also cause handler tracking to output a source location for each newly
created asynchronous operation. A use_awaitable_t
object may also be explicitly constructed with location information.
handlerviz.pl
tool.
Added the handlerlive.pl
tool, which processes handler
tracking output to produce a list of "live" handlers. Live handlers
are those that are associated with pending asynchronous operations, as
well as handlers that are currently executing. For example:
cat output.txt | perl handlerlive.pl
or:
perl handerlive.pl < output.txt
or:
perl handlerlive.pl output.txt
Added the handlertree.pl
tool, which filters handler
tracking output to include only those events in the tree that produced
the nominated handlers. For example, to filter the output to include only
the events associated with handlers 123
,
456
, and their predecessors:
cat output.txt | perl handlertree.pl 123 456
or:
perl handlertree.pl 123 456 < output.txt
This script may be combined with handerlive.pl and handlerviz.pl
to produce a graph of the "live" asynchronous operation chains.
For example:
cat output.txt | \
perl handlertree.pl perl handlerlive.pl output.txt
| \
perl handlerviz.pl | \
dot -Tsvg > output.svg
async_compose
to
work with copyable handlers when passed by lvalue.
co_spawn
.
Executor
base class from the executor_binder
implementation.
noexcept
.
ssl::host_name_verification
class, which is
a drop-in replacement for ssl::rfc2818_verification
.
The ssl::rfc2818_verification
class has been marked
as deprecated. As a consequence of this change, SSL support now depends
on functions that were introduced in OpenSSL 1.0.2.
ssl::context
constructor to take ownership
of a native handle.
gcc
to use
__cplusplus
macro.
strand<>
converting constructors and assignment operators.
async_read
overloads.
ssl::context
class to propagate non-EOF errors
from the add_certificate_authority
function.
thread_pool
destructor hang that occurred when the pool had an associated I/O object.
select
reactor to recreate the "self
pipe trick" sockets on error. This addresses an issue on some versions
of Windows, where these sockets are discconected after a system sleep.
priority_scheduler
example to demonstrate calls to shutdown()
and destroy()
.
use_awaitable_t::as_default_on
function.
boost::placeholders
namespace.
async_compose
implementation due to incorrect overload selection.
async_initiate
helper function to automatically deduce its return type. This is enabled
for C++11 or later.
return_type
.
async_initiate
.
completion_signature<T>
: Checks if T
is a signature of the form R(Args...)
.
completion_handler_for<T, Signature>
: Checks if T
is usable as a completion handler with the specified signature.
completion_token_for<T, Signature>
: Checks if T
is a completion token that can be used with async_initiate and the
specified signature.
BOOST_ASIO_COMPLETION_SIGNATURE
,
BOOST_ASIO_COMPLETION_HANDLER_FOR
,
and BOOST_ASIO_COMPLETION_TOKEN_FOR
are provided. These macros expand to typename
when concepts are unsupported.
Added the nested template type rebind_executor
to all I/O object types, as a way to generically rebind them to use alternative
I/O executors. For example:
using my_socket_type = tcp::socket::rebind_executor<my_executor_type>::other;
executor_type
and member function get_executor()
. Note that the presence of executor_type
and get_executor()
should be treated as optional, and consequently
it may be preferable to access them via the associated_executor
trait and the get_associated_executor()
helper function.
Added the default_completion_token
trait, so that every I/O executor type now has an associated default completion
token type. This trait may be used in asynchronous operation declarations
as follows:
template < typename IoObject, typename CompletionToken = typename default_completion_token< typename IoObject::executor_type >::type > auto async_fyz( IoObject& io_object, CompletionToken&& token = typename default_completion_token< typename IoObject::executor_type >::type{} );
If not specialised, this trait type is void
,
meaning no default completion token type is available for the given I/O
executor.
Specialised the default_completion_token
trait for the use_awaitable
completion token, so that it may be used as shown in the following example:
auto socket = use_awaitable.as_default_on(tcp::socket(my_context)); // ... co_await socket.async_connect(my_endpoint); // Defaults to use_awaitable.
In this example, the type of the socket
object is transformed from tcp::socket
to have an I/O executor with the default completion token set to use_awaitable
. Alternatively, the socket
type may be computed directly:
using tcp_socket = use_awaitable_t<>::as_default_on_t<tcp::socket>; tcp_socket socket(my_context); // ... co_await socket.async_connect(my_endpoint); // Defaults to use_awaitable.
async_initiate
to the Windows-specific I/O objects' asynchronous operations.
Ensured that the executor type is propagated to newly accepted sockets. When synchronously or asynchronously accepting a new connection, but without specifying an executor or execution context, the accept operation will now correctly propagate the executor type from the acceptor to the socket. For example, if your acceptor type is:
basic_socket_acceptor<ip::tcp, my_executor_type>
then your accepted socket type will be:
basic_stream_socket<ip::tcp, my_executor_type>
Protocol
copy and move operations never throw.
Endpoint
default constructor and move operations never throw.
noexcept
qualifier
to protocol accessors.
noexcept
qualifier
to socket move constructors.
case
fall-through in the free function connect()
implementation.
is_*_buffer_sequence
detection traits for
user-defined sequence types.
CancelIoEx
entry point.
get_option()
member function to be const.
shutdown
function.
is_dynamic_buffer
.
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.
asio::io_context&
now accept either an Executor
or a reference to a concrete ExecutionContext
(such as asio::io_context
or asio::thread_pool
).
Note: One potential source 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);
get_io_context
and get_io_service
member functions have now been removed.
async_result
form with an initiate
static
member function.
The async_result
template now supports a new form:
template <typename CompletionToken, typename Signature> struct async_result { typedef /* ... */ return_type; template <typename Initiation, typename RawCompletionToken, typename... Args> static return_type initiate( Initiation&& initiation, RawCompletionToken&& token, Args&&... args); };
initiate
member
function must: (a) transform the token into a completion handler
object handler
; (b)
cause the invocation of the function object initiation
as if by calling std::forward<Initiation>(initiation)(std::move(handler), std::forward<Args>(args)...)
. Note that the invocation of
initiation
may be
deferred (e.g. lazily evaluated), in which case initiation
and args
must be
decay-copied and moved as required.
async_initiate
has also been added as a wrapper for the invocation of async_result<>::initiate
. For backward compatibility,
this function supports both the old and new async_result
forms.
async_initiate
.
handler_type
trait and single-argument form of async_result
have now been removed.
asio
namespace.
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.
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<>
.
DynamicBuffer_v2
concept which is CopyConstructible.
This change adds a new set of type requirements for dynamic buffers,
DynamicBuffer_v2
,
which supports copy construction. These new type requirements enable
dynamic buffers to be used as arguments to user-defined composed
operations, where the same dynamic buffer object is used repeatedly
for multiple underlying operations. For example:
template <typename DynamicBuffer> void echo_line(tcp::socket& sock, DynamicBuffer buf) { n = asio::read_until(sock, buf, '\n'); asio::write(sock, buf, asio::transfer_exactly(n)); }
DynamicBuffer
type requirements have been renamed to DynamicBuffer_v1
.
These requirements continue to be compatible with the Networking
TS.
is_dynamic_buffer_v1
and is_dynamic_buffer_v2
have been added to test for conformance to DynamicBuffer_v1
and DynamicBuffer_v2
respectively. The existing is_dynamic_buffer
trait has been retained and delegates to is_dynamic_buffer_v1
(unless BOOST_ASIO_NO_DYNAMIC_BUFFER_V1
is explicitly defined, in which case it delegates to is_dynamic_buffer_v2
).
dynamic_string_buffer
and dynamic_vector_buffer
classes conform to both DynamicBuffer_v1
and DynamicBuffer_v2
requirements.
BOOST_ASIO_NO_DYNAMIC_BUFFER_V1
is defined, all support for DynamicBuffer_v1
types and functions is #ifdef-ed out. Support for using basic_streambuf
with the read
, async_read
,
read_until
, async_read_until
, write
, and async_write
functions is also disabled as a consequence.
async_compose
function that simplifies the implementation of user-defined asynchronous
operations.
make_strand
function,
which creates a strand
with a deduced Executor
template argument.
local::basic_endpoint
that takes a string_view
.
ip::address
, ip::address_v4
,
ip::address_v6
, ip::basic_endpoint
,
and executor_work_guard
classes.
buffer_sequence_begin
and buffer_sequence_end
functions.
BOOST_ASIO_DISABLE_VISIBILITY
configuration #define
that allows visibility pragmas to be disabled. (Note: If symbols are hidden,
extra care must be taken to ensure that Asio types are not passed across
shared library API boundaries.)
error::message_size
)
occurs on a datagram-oriented socket.
SO_REUSEPORT
when the reuse_address
option is set.
unistd.h
when
targeting Haiku OS, to fix feature detection.
network_v[46].hpp
headers to the top-level convenience header.
pthread_cond_timedwait
.
EndpointSequence
iterator type rather
than assume the presence of a const_iterator
typedef.
buffer_sequence_begin
and buffer_sequence_end
to prevent implicit conversion. This change addresses an issue where a
call to buffer_sequence_begin
or buffer_sequence_end
could trigger an implicit conversion to const_buffer
or mutable_buffer
. Whenever
this implicit conversion occurred, the return value of buffer_sequence_begin
or buffer_sequence_end
would point to a temporary object.
eof
error
on SSL shutdown as it actually indicates success.
SSL_ERROR_SYSCALL
result without an associated
error.
<atomic>
when targeting apple/clang/libc++ with
recent Xcode versions, even for C++03. This fixes a warning about the deprecation
of OSMemoryBarrier
.
decltype
support for that compiler.
_WIN32_WINNT
to 0x0601
(Windows 7).
dispatch
documentation
to note that it may call the supplied function object in the current thread.
post
and defer
documentation to clarify the the
distinction between them.
system_executor
was not
being correctly cleaned up on exit.
std::future
availability with libstdc++.
read_until
.
std::experimental::string_view
and std::string_view
with newer clang/libc++.
std::invoke_result
.
decltype
is available.
size()
, max_size()
or empty()
on default-constructed resolver results.
std::string_view
detection issue when using
clang-cl.
io_context::executor_type::dispatch
.
basic_socket_acceptor::get_option
.
experimental::detached
completion token.
experimental::redirect_error
completion token.
experimental::co_spawn
facility for integration with the coroutines technical specification.
asio::steady_timer
rather than asio::deadline_timer
.
asio::dynamic_buffer
rather than asio::streambuf
.
asio::io_context::run_for()
function for blocking clients.
BOOST_ASIO_NO_DEPRECATED
is defined.
BOOST_ASIO_USE_BOOST_DATE_TIME_FOR_SOCKET_IOSTREAM
to enable the old Boost.Date_Time interface in basic_socket_streambuf
and basic_socket_iostream
.
is_dynamic_buffer
trait.
async_result
incompatibility
with deprecated handler_type
.
basic_resolver_results::value_type
typedef.
SSL_OP_NO_COMPRESSION
is defined.
add_certificate_authority
to process multiple certificates in a bundle.
std::invoke_result
rather than std::result_of
.
std::string_view
for C++17 or later, and
std::experimental::string_view
for C++14. Define the preprocessor
macro BOOST_ASIO_DISABLE_STD_STRING_VIEW
to force the use of std::experimental::string_view (assuming it is available)
when compiling in C++17 mode.
DynamicBuffer
template
arguments are decayed before using in enable_if
tests.
basic_yield_context
to work with completion signatures containing reference parameters.
spawn()
correctly store decayed copies of their
function and handler arguments.
basic_socket<Protocol, SocketService>
we now have simply basic_socket<Protocol>
.
The old interface can be enabled by defining the BOOST_ASIO_ENABLE_OLD_SERVICES
macro.
io_context
basis.
ssl::stream<>
constructor argument.
g++
versions >= 4.7 to use standard
atomics, to fix a linker error when using g++
4.6 (#13121).
constexpr
and
variadic templates with recent MSVC versions.
auto_ptr
.
asio_handler_is_continuation
result in reactive async_accept
implementation.
poll.h
rather than sys/poll.h
on
some modern POSIX platforms (#12419).
__thread
keyword extension for android/clang/x86 targets.
EAGAIN
or EWOULDBLOCK
) with posix::stream_descriptor
, when using the Linux
epoll backend.
allocator_traits
to rebind allocators in C++11 or later.
ssl::context_base
enumerations to enable support
for any TLS version, and improved consistency of SSL/TLS version handling
across OpenSSL releases.
gcc
(#12302).
std::atomic_thread_fence
, when available,
to eliminate a deprecated function warning on newest macOS SDK (#12482).
getaddrinfo
in Apple's NAT64 environment.
asio::connect()
when the connect_condition
returns an end iterator (#12354).
getsockname
reports 0.0.0.0 (#12406).
SSL_COMP_free_compression_methods
to fix two memory leaks reported at shutdown, for OpenSSL versions >=
1.0.2 and < 1.1.0 (#10795).
use_future
compile
error encountered on some standard library implementations, by changing
std::allocator<void>
use to a non-void template parameter.
getaddrinfo
by default on Apple OSes, rather than emulation in terms of getipnodebyname
.
OPENSSL_NO_SSL3
feature test #define
(#11754).
SSL_CTX_clear_chain_certs
function, if available.
strncat
in the getaddrinfo
emulation
and in the SSL wrapper's password handling.
CreateEventW
rather than CreateEvent
(#11732).
ConnectEx
function are mapped to their portable equivalents (#10744).
BOOST_ASIO_DISABLE_CONNECTEX
to allow use of ConnectEx
to be explicitly disabled.
windows::object_handle
when there are pending wait operations on destruction (#10624).
EINVAL
.
ssl::stream<>
bug that may result in spurious 'short read' errors.
ERR_remove_state
.
std::addressof
with g++
(#10982).
join_group
failures as non-fatal.
std::endl
to ensure output is flushed.
yield_context
object with asynchronous operations.
yield_context
to
allow reentrant calls to the completion handler from an initiating function.
kqueue
reactor so that it works on FreeBSD
(#10606).
kqueue
reactor which resulted
in spinning when using serial ports on Mac OS (#10496).
kqueue
reactor support for read-only file descriptors
(#10367).
/dev/poll
reactor
(#10350, #10572).
WSASocketW
,
as WSASocketA
has been
deprecated (#10534).
use_future
and spawn()
are not made available when including the asio.hpp
convenience header (#10567).
asio::strand
as deprecated. Use asio::io_service::strand
instead.
kqueue
backend that was introduced
in Asio 1.10.2.
gcc
on AIX.
gcc
problem to do with anonymous enums
(#10042).
HANDLE
backend change to ignore ERROR_MORE_DATA
.
Instead, the error will be propagated as with any other (i.e. in an error_code
or thrown as a system_error
), and the number of bytes
transferred will be returned. For code that needs to handle partial messages,
the error_code
overload
should be used (#10034).
signal_set
implementation's signal number check (#9324).
SO_UPDATE_CONNECT_CONTEXT
is defined (#10016).
VerifyVersionInfo
rather than GetVersionEx
, as GetVersionEx
has been deprecated.
asio::spawn()
to work correctly with new Boost.Coroutine interface (#9442, #9928).
asio::spawn()
coroutines are correctly unwound when
cleaned up by the io_service
destructor (#9731).
io_service::wrap()
and strand::wrap()
(#9741).
ConnectEx
,
if available, for connection-oriented IP sockets.
io_service
backend for non-Windows (and non-IOCP Windows) platforms to use a single
condition variable per io_service
instance. This addresses a potential race condition when run_one()
is used from multiple threads.
boost::chrono
and std::chrono
clocks (#9662, #9778).
EV_CLEAR
handling in the kqueue backend, to address other cases where the close()
system call may hang on Mac OS X.
resolver_query_base::flags::operator~
(#9548).
select
reactor
more efficient on Windows for large numbers of sockets (#9528).
gcc
(#9550).
GetQueuedCompletionStatus
timeout workaround on recent versions of Windows.
io_service
,
strand
, buffers,
composed operations, timers, etc., should all work as normal.
cancel()
function is not supported for sockets. Asynchronous operations may
only be cancelled by closing the socket.
null_buffers
are not supported.
tcp::no_delay
and socket_base::keep_alive
options are supported.
async_connect
were not correctly propagated through to the completion handler (#8795).
io_service
.
When the bug occurs, the result of an asynchronous operation (error and
bytes tranferred) is incorrectly discarded and zero values used instead.
For TCP sockets this results in spurious end-of-file notifications (#8933).
async_wait
on a signal that is already raised (#8738).
async_write_at
operations (#8669).
HANDLE
backend to treat ERROR_MORE_DATA
as a non-fatal error when returned by GetOverlappedResult
for a synchronous read (#8722).
generic
as a keyword. Added a workaround that renames the namespace to cpp_generic
when those language extensions
are in effect.
async_result
support in Boost 1.54. In
particular, the buffered stream templates have been updated so that they
adhere to current handler patterns (#9000, #9001).
use_future
support
for Microsoft Visual Studio 2012.
std::min
in the Windows IOCP backend to avoid
a dependency on the <algorithm>
header (#8758).
SSL_CTX_clear_options
function (#9273).
handler_type
and async_result
, that
allow the customisation of the return type of an initiating function.
asio::spawn()
function, a high-level wrapper for running stackful coroutines, based on
the Boost.Coroutine library. The spawn()
function enables programs to implement
asynchronous logic in a synchronous manner. For example: size_t n
= my_socket.async_read_some(my_buffer, yield);
. For further information, see Stackful
Coroutines.
asio::use_future
special value, which provides
first-class support for returning a C++11 std::future
from an asynchronous operation's initiating function. For example: future<size_t>
= my_socket.async_read_some(my_buffer, asio::use_future);
. For further information, see Futures.
asio_handler_is_continuation
.
Asynchronous operations may represent a continuation of the asynchronous
control flow associated with the current executing handler. The asio_handler_is_continuation
hook can
be customised to return true
if this is the case, and Asio's implementation can use this knowledge to
optimise scheduling of the new handler. To cover common cases, Asio customises
the hook for strands, spawn()
and composed asynchronous operations.
generic::datagram_protocol
,
generic::raw_protocol
, generic::seq_packet_protocol
and generic::stream_protocol
, which 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. For further information, see Support
for Other Protocols.
ip::tcp::socket
can be converted into a generic::stream_protocol::socket
via move construction. For further information, see Support
for Other Protocols.
basic_socket_acceptor<>
's accept()
and async_accept()
functions to allow a new connection to
be accepted directly into a socket of a more generic type. For example,
an ip::tcp::acceptor
can be used to accept into a
generic::stream_protocol::socket
object. For further information,
see Support
for Other Protocols.
ssl::stream<>
class's handshake()
and async_handshake()
functions have been added. These
accept a ConstBufferSequence
to be used as initial input to the ssl engine for the handshake procedure.
ssl::context
objects.
set_verify_depth()
function to the ssl::context
and ssl::stream<>
classes.
add_certificate_authority()
, use_certificate()
, use_certificate_chain()
, use_private_key()
, use_rsa_private_key()
and use_tmp_dh()
, have been added to the ssl::context
class.
ssl::context
to automatically disable
SSL compression by default. To enable, use the new ssl::context::clear_options()
function, as in my_context.clear_options(ssl::context::no_compression)
.
signal_set
implementation.
#warning
directive #7939.
epoll
implementation.
error_code
with an invalid
(i.e. NULL
) error_category
#8613.
basic_waitable_timer
's
underlying implementation so that it can handle any time_point
value without overflowing the intermediate duration objects.
run()
and poll()
on the same io_service
object #8354.
ssl::rfc2818_verification
class.
boost/asio/detail/winsock_init.hpp
for details.
basic_socket::get_option
's
documentation (#7562).
long
rather
than int
for SSL_CTX options,
to match OpenSSL (#7209).
_snwprintf
to address a compile error due to the changed swprintf
signature in recent versions of MinGW (#7373).
io_service
threads due
to running out of work (#7552).
noexcept
qualifier
for error categories (#7797).
accept
as non-fatal (#7488).
ip::tcp::iostream
and C++11 (#7162).
#include <cctype>
, needed for some versions of MinGW.
gcc
's atomic builtins on ARM CPUs, when
available (#7140).
io_service
has been destroyed.
epoll_create1()
function but always fail with ENOSYS
(#7012).
buffered_write_stream
(#6310).
epoll_reactor
backend to do lazy registration for EPOLLOUT
events.
epoll_reactor
handling of out-of-band data, which was broken by an incomplete fix in
the last release.
OPENSSL_NO_ENGINE
feature test #define
(#6432).
windows::object_handle
so that it works with Windows
compilers that support C++11 move semantics (such as g++
).
g++
4.7 when compiling in C++11 mode
(#6620).
signal_set
handlers were not being delivered when the io_service
was constructed with a concurrency_hint
of 1 (#6657).
basic_waitable_timer
based around the C++11 clock type requirements. It may be used with the
clocks from the C++11 <chrono>
library facility or, if those are not available, Boost.Chrono. The typedefs
high_resolution_timer
,
steady_timer
and system_timer
may be used to create timer
objects for the standard clock types.
windows::object_handle
class for performing waits
on Windows kernel objects. Thanks go to Boris Schaeling for contributing
substantially to the development of this feature.
connect()
can return EAGAIN in certain circumstances. Remapped this to another error
so that it doesn't look like a non-blocking operation (#6048).
buffered_write_stream
(#6310).
io_service
is repeatedly run without
anything to do (#6321).
concurrency_hint
is 1) to eliminate a lock/unlock pair.
epoll_reactor
speculative operations to be performed without holding the lock.
epoll_reactor
's
I/O operation immediately before the corresponding handler is called.
This also improves scalability across CPUs when multiple threads
are running the io_service
.
boost::array
or std::array
) of exactly two buffers.
async_read_until
(#5688).
signal()
function from the global namespace (#5722).
deadline_timer
implementation so that it does not read the clock unless the timer heap
is non-empty.
null_buffers
operations so that they obey the user's non-blocking setting (#5756).
fd_set
at runtime when using Windows.
epoll_reactor
initialisation (#6006).
BOOST_ASIO_STRAND_IMPLEMENTATIONS
to
the desired number.
BOOST_ASIO_ENABLE_SEQUENTIAL_STRAND_ALLOCATION
flag which switches the allocation of strand implementations to use a round-robin
approach rather than hashing.
strand.post()
is used.
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 be
registered with multiple signal_set
objects, however the signal number must be used only with Asio. Addresses
#2879.
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).
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.
error()
member function to socket iostreams, for retrieving the error code from
the most recent system call.
basic_deadline_timer::cancel_one()
function. This function lets you cancel
a single waiting handler on a timer. Handlers are cancelled in FIFO order.
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.
connect()
and async_connect()
. These operations try each endpoint in
a list until the socket is successfully connected, and are useful for creating
TCP clients that work with both IPv4 and IPv6.
buffer_size()
function so that it works for buffer
sequences in addition to individual buffers.
buffer_copy()
function that can be used to copy the
raw bytes between individual buffers and buffer sequences.
read()
, read_at()
, write()
and write_at()
that do not require a completion condition.
g++
4.5 or later, and MSVC 10), static_assert
is also used to generate an
informative error message. This checking may be disabled by defining BOOST_ASIO_DISABLE_HANDLER_TYPE_REQUIREMENTS
.
BOOST_ASIO_ENABLE_OLD_SSL
.
Addresses #3702,
#3958.
boost/asio/ssl/impl/src.hpp
in one source file in your program.
is_loopback()
,
is_unspecified()
and is_multicast()
functions consistently available across the ip::address
,
ip::address_v4
and ip::address_v6
classes (#3939).
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.
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.
io_control()
member function for socket acceptors (#3297).
release()
member function to posix descriptors. This function releases ownership
of the underlying native descriptor to the caller. Addresses #3900.
SOCK_SEQPACKET
).
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()
).
native_type
typedefs in favour of native_handle_type
, and the native()
member functions in favour of native_handle()
.
fork()
system call. Programs that use fork()
must call io_service.notify_fork()
at the appropriate times. Two new examples have been added showing how
to use this feature. Addresses #3238,
#4162.
close()
system call. In particular, assume that
most operating systems won't have close()
fail with EWOULDBLOCK
,
but if it does then set the blocking mode and restart the call. If any
other error occurs, assume the descriptor is closed. Addresses #3307.
asio::buffer()
overloads for std::array
, when available.
array
, shared_ptr
,
weak_ptr
and atomic
when they are available, rather
than the Boost equivalents.
what()
messages.
shutdown_service()
member functions to be private.
ip::basic_endpoint<>
objects (such as ip::tcp::endpoint
and ip::udp::endpoint
).
assign()
may have been dup()
-ed,
and so require explicit deregistration from the reactor (#4971).
io_service()
. The get_io_service()
member functions should be used instead.
resolver_query
and resolver_iterator
from
the ip::tcp
, ip::udp
and ip::icmp
classes.
buffers_iterator<>
and ip::basic_resolver_iterator
classes so that the value_type typedefs are non-const byte types.
-Wshadow
compiler option
(#3905).
FIONBIO
constant to int, to suppress a compiler warning on some platforms (#5128).
tick_count_timer
example by making
the duration type signed. Previously, a wait on an already-passed deadline
would not return for a very long time (#5418).
EV_ONESHOT
seems to cause
problems on some versions of Mac OS X, with the io_service
destructor getting stuck inside the close()
system call. Changed the kqueue backend
to use EV_CLEAR
instead
(#5021).
g++
due
to the use of anonymous enums (#4883).
EWOULDBLOCK
are
not correctly re-registered with kqueue.
asio::streambuf
to ensure that its internal
pointers are updated correctly after the data has been modified using
std::streambuf
member functions.
ip::address_v4::broadcast()
is used on 64-bit platforms.
deadline_timer
may never fire if the io_service
is running in a background thread (#4568).
has_service<>
from compiling (#4638).
close()
/closesocket()
failures are correctly propagated (#4573).
InitializeCriticalSectionAndSpinCount
(#4574).
pselect()
on HP-UX, if it is available (#4578).
deadline_timer
objects with expiry times set more than 5 minutes in the future may never
expire (#4745).
resolver
backend
on BSD platforms so that an empty service name resolves to port number
0
, as per the documentation
(#4690).
const_buffers_1
(#4746).
Protocol
and
id
to avoid clashing with
Objective-C++ keywords (#4191).
vector
reallocation
performance issue that can occur when there are many active deadline_timer
objects (#4780).
io_control()
implementation on 64-bit Mac OS X and
BSD platforms (#4782).
accept()
are incorrectly treated as successes
(#4859).
<boost/asio/impl/src.cpp>
in favour of <boost/asio/impl/src.hpp>
(#4560).
#include
s, e.g. if the
program uses boost::array
but does not explicitly include
<boost/array.hpp>
.)
deadline_timer
implementation to improve performance.
asio::streambuf
with async_read()
and async_read_until()
.
These read operations now use the existing capacity of the streambuf
when reading, rather than limiting
the read to 512 bytes.
#include
<boost/asio/impl/src.cpp>
to one source file in a program, then
build the program with BOOST_ASIO_SEPARATE_COMPILATION
defined in the project/compiler settings. Alternatively, BOOST_ASIO_DYN_LINK
may be defined to
build a separately-compiled Asio as part of a shared library.
BOOST_ASIO_DISABLE_FENCED_BLOCK
to permit the disabling of memory fences around completion handlers, even
if thread support is enabled.
const
types.
null_buffers
variant of async_send_to
(#4170).
unsigned char
is used with isdigit
in
getaddrinfo
emulation (#4201).
operator+
overload in buffers_iterator
(#4382).
null_buffers
operations on Windows.
timerfd
for dispatching timers on Linux, when available.
ip::resolver_query_base::flags
as per the TR2 proposal. This type prevents implicit conversion from int
to flags
,
allowing the compiler to catch cases where users incorrectly pass a numeric
port number as the service name.
#define NOMINMAX
for all Windows compilers. Users can define BOOST_ASIO_NO_NOMINMAX
to suppress this definition (#3901).
error::eof
result to the completion handler
(#4023).
io_control()
member functions to always call ioctl
on the underlying descriptor when
modifying blocking mode (#3307).
InternetProtocol::resolver_query
and InternetProtocol::resolver_iterator
,
as neither typedef is part of the documented InternetProtocol
requirements. The corresponding typedefs in the ip::tcp
,
ip::udp
and ip::icmp
classes have been deprecated.
select()
.
BOOST_ASIO_DISABLE_THREADS
macro that allows Asio's threading support to be independently disabled.
boost::addressof
to get the address of handler objects, rather than applying operator&
directly (#2977).
OVERLAPPED
structure
to be valid until both the initiating function call has returned and the
completion packet has been delivered.
boost_
prefix to
the extern "C"
thread entry point function (#3809).
getaddrinfo
emulation,
only check the socket type (SOCK_STREAM
or SOCK_DGRAM
) if a service
name has been specified. This should allow the emulation to work with raw
sockets.
buffered*_stream<>
templates to treat 0-byte reads and writes as no-ops, to comply with the
documented type requirements for SyncReadStream
,
AsyncReadStream
, SyncWriteStream
and AsyncWriteStream
.
throw
keyword to boost::throw_exception()
to allow Asio to be used when exception support is disabled. Note that
the SSL wrappers still require exception support (#2754).
/dev/poll
backend.
_GLIBCXX_DEBUG
is defined (#3098).
BOOST_ASIO_HASH_MAP_BUCKETS
may be used
to tweak the sizes used for the bucket arrays. (N.B. this feature introduced
a bug which was fixed in Asio 1.4.3 / Boost 1.40.)
io_control()
so that it adheres to the documented
type requirements for IoControlCommand (#2820).
ReadFile
call fails with ERROR_MORE_DATA
. This enables a hack
where a windows::stream_handle
can be used with a message-oriented
named pipe (#2936).
BOOST_ASIO_DISABLE_SERIAL_PORT
is defined (#2917).
windows::overlapped_ptr::complete()
are correctly passed to the completion
handler (#2614).
size_t
CompletionCondition(error_code ec, size_t total)
,
where the return value indicates the maximum number of bytes to be transferred
on the next read or write operation. (The old CompletionCondition signature
is still supported for backwards compatibility).
HANDLE
s
such as named pipes (requires HANDLE
s
that work with I/O completion ports).
HANDLE
s
such as files (requires HANDLE
s
that work with I/O completion ports).
null_buffers
type.
read_until()
and async_read_until()
overloads that take a user-defined function object for locating message
boundaries.
BOOST_ASIO_ENABLE_TWO_LOCK_QUEUE
) that
may provide better io_service
scalability across many processors.
First release of Asio as part of Boost.