Remove all timed-wait APIs

[Akatsukis]

Drops all timed-wait APIs from boost.fiber. Affected interfaces:

• boost::this_fiber::sleep_for / sleep_until
• condition_variable::wait_for / wait_until (both _any and the mutex-bound variants)
• future::wait_for / wait_until, shared_future::wait_for / wait_until
• buffered_channel::push_wait_for / push_wait_until / pop_wait_for / pop_wait_until
• context::wait_until, context::sleep_link / sleep_unlink / sleep_is_linked, plus the sleep_hook_, sleep_waker_, tp_ members
• scheduler::wait_until, scheduler::sleep2ready_, sleep_queue_
• wait_queue::suspend_and_wait_until

algorithm::suspend_until(time_point) is renamed to algorithm::suspend() since the time_point has no meaning without a sleep queue. round_robin::suspend uses condition_variable::wait(lk, pred) instead of the timed variant.

Intended for fiber pools where all synchronization is via untimed waits + cross-thread wakeups; the sleep-queue scan in every dispatch iteration is gone.

[Copilot]

Pull request overview

This PR removes all timed-wait functionality from Boost.Fiber’s public APIs and internal scheduler machinery, eliminating the sleep-queue and associated deadline scanning to better support fiber pools that rely exclusively on untimed waits plus explicit wakeups.

Changes:

• Removed timed-wait APIs across this_fiber, condition_variable(_any), future/shared_future, and buffered_channel.
• Deleted scheduler sleep-queue support (sleep_queue_, sleep2ready_(), context::{tp_,sleep_*}) and switched the dispatcher to untimed algorithm::suspend().
• Renamed the scheduling-algorithm hook from suspend_until(time_point) to suspend() and updated round_robin accordingly.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/waker.cpp	Removes timed suspension helper from wait_queue.
src/scheduler.cpp	Deletes sleep-queue logic and switches idle waiting to untimed suspend.
src/context.cpp	Removes timed-wait forwarding APIs and sleep-link helpers.
src/algo/round_robin.cpp	Replaces timed suspend implementation with untimed suspend().
include/boost/fiber/waker.hpp	Removes timed-wait declaration from wait_queue.
include/boost/fiber/scheduler.hpp	Removes sleep-queue types/members and timed wait_until APIs.
include/boost/fiber/operations.hpp	Removes this_fiber::sleep_for/sleep_until APIs.
include/boost/fiber/future/future.hpp	Removes future/shared_future timed wait APIs.
include/boost/fiber/future/detail/shared_state.hpp	Removes shared-state timed wait helpers.
include/boost/fiber/context.hpp	Removes sleep-hook members and timed-wait declarations.
include/boost/fiber/condition_variable.hpp	Removes condition_variable(_any) timed wait APIs.
include/boost/fiber/buffered_channel.hpp	Removes timed push/pop channel operations.
include/boost/fiber/algo/round_robin.hpp	Updates algorithm interface override to suspend().
include/boost/fiber/algo/algorithm.hpp	Replaces suspend_until() with suspend() in the base interface.

Comments suppressed due to low confidence (2)

include/boost/fiber/operations.hpp:52

• This header removes boost::this_fiber::sleep_for() / sleep_until(), but the repo still calls these APIs in both examples and tests (e.g. examples/wait_stuff.cpp, test/test_fiber_*.cpp, test/test_future_*.cpp, test/test_mutex_*.cpp). As-is, those targets will no longer compile. Update the examples/tests to use the remaining untimed primitives (e.g. condition variables + explicit wakeups, barriers/latches, or yields) or remove/disable the affected tests if they are no longer meaningful without timed waits.

inline
fibers::fiber::id get_id() noexcept {
    return fibers::context::active()->get_id();
}

inline
void yield() noexcept {
    fibers::context::active()->yield();
}

template< typename PROPS >
PROPS & properties() {
    fibers::fiber_properties * props = fibers::context::active()->get_properties();
    if ( BOOST_LIKELY( nullptr == props) ) {
        // props could be nullptr if the thread's main fiber has not yet
        // yielded (not yet passed through algorithm_with_properties::
        // awakened()). Address that by yielding right now.
        yield();
        // Try again to obtain the fiber_properties subclass instance ptr.
        // Walk through the whole chain again because who knows WHAT might
        // have happened while we were yielding!
        props = fibers::context::active()->get_properties();
        // Could still be hosed if the running manager isn't a subclass of
        // algorithm_with_properties.
        BOOST_ASSERT_MSG( props, "this_fiber::properties not set");
    }
    return dynamic_cast< PROPS & >( * props );
}

include/boost/fiber/buffered_channel.hpp:188

• The timed buffered_channel operations (push_wait_for/push_wait_until/pop_wait_for/pop_wait_until) are removed, but the tests still call them (e.g. test/test_buffered_channel_*.cpp). This will break test builds. Update those tests to cover the remaining APIs (push, try_push, pop, try_pop, close semantics) or delete the timeout-specific test cases since the timeout feature is being removed.

        waiting_consumers_.notify_one();
        return channel_op_status::success;
    }

    channel_op_status push( value_type const& value) {
        context * active_ctx = context::active();
        for (;;) {
            detail::spinlock_lock lk{ splk_ };
            if ( BOOST_UNLIKELY( is_closed_() ) ) {
                return channel_op_status::closed;
            }
            if ( is_full_() ) {
                waiting_producers_.suspend_and_wait( lk, active_ctx);
            } else {
                slots_[pidx_] = value;
                pidx_ = (pidx_ + 1) % capacity_;
                waiting_consumers_.notify_one();
                return channel_op_status::success;
            }
        }
    }

    channel_op_status push( value_type && value) {
        context * active_ctx = context::active();
        for (;;) {
            detail::spinlock_lock lk{ splk_ };
            if ( BOOST_UNLIKELY( is_closed_() ) ) {
                return channel_op_status::closed;
            }
            if ( is_full_() ) {
                waiting_producers_.suspend_and_wait( lk, active_ctx);
            } else {
                slots_[pidx_] = std::move( value);
                pidx_ = (pidx_ + 1) % capacity_;

                waiting_consumers_.notify_one();
                return channel_op_status::success;
            }
        }
    }

    channel_op_status try_pop( value_type & value) {
        detail::spinlock_lock lk{ splk_ };
        if ( is_empty_() ) {
            return is_closed_()
                ? channel_op_status::closed
                : channel_op_status::empty;
        }
        value = std::move( slots_[cidx_]);
        cidx_ = (cidx_ + 1) % capacity_;
        waiting_producers_.notify_one();
        return channel_op_status::success;
    }

    channel_op_status pop( value_type & value) {
        context * active_ctx = context::active();
        for (;;) {
            detail::spinlock_lock lk{ splk_ };
            if ( is_empty_() ) {
                if ( BOOST_UNLIKELY( is_closed_() ) ) {
                    return channel_op_status::closed;
                }
                waiting_consumers_.suspend_and_wait( lk, active_ctx);
            } else {
                value = std::move( slots_[cidx_]);
                cidx_ = (cidx_ + 1) % capacity_;
                waiting_producers_.notify_one();
                return channel_op_status::success;
            }
        }
    }

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[Copilot]

Pull request overview

Copilot reviewed 32 out of 32 changed files in this pull request and generated no new comments.