79 lines
2.3 KiB
D
79 lines
2.3 KiB
D
/** Implements a thread-safe, typed producer-consumer queue.
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Copyright: © 2017 RejectedSoftware e.K.
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Authors: Sönke Ludwig
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License: Subject to the terms of the MIT license, as written in the included LICENSE.txt file.
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*/
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module vibe.core.channel;
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// multiple producers allowed, multiple consumers allowed - Q: should this be restricted to allow higher performance? maybe configurable?
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// currently always buffered - TODO: implement blocking non-buffered mode
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// TODO: implement a multi-channel wait, e.g.
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// TaggedAlgebraic!(...) consumeAny(ch1, ch2, ch3); - requires a waitOnMultipleConditions function
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// TODO: implement close()
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// TODO: fully support non-copyable types using swap/move where appropriate
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// TODO: add unit tests
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// Q: Should this be exposed as a class, or as an RC struct?
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private final class Channel(T, size_t buffer_size = 100) {
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import vibe.core.concurrency : isWeaklyIsolated;
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static assert(isWeaklyIsolated!T, "Channel data type "~T.stringof~" is not safe to pass between threads.");
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Mutex m_mutex;
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TaskCondition m_condition;
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FixedRingBuffer!(T, buffer_size) m_items;
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this()
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shared {
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m_mutex = cast(shared)new Mutex;
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m_condition = cast(shared)new TaskCondition(cast(Mutex)m_mutex);
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}
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bool empty()
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shared {
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synchronized (m_mutex)
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return (cast(Channel)this).m_items.empty;
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}
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T consumeOne()
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shared {
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auto thisus = cast(Channel)this;
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T ret;
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bool was_full = false;
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synchronized (m_mutex) {
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while (thisus.m_items.empty)
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thisus.m_condition.wait();
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was_full = thisus.m_items.full;
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swap(thisus.m_items.front, ret);
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}
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if (was_full) thisus.m_condition.notifyAll();
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return ret.move;
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}
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void consumeAll(ref FixedRingBuffer!(T, buffer_size) dst)
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shared {
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auto thisus = cast(Channel)this;
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bool was_full = false;
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synchronized (m_mutex) {
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while (thisus.m_items.empty)
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thisus.m_condition.wait();
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was_full = thisus.m_items.full;
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swap(thisus.m_items, dst);
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}
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if (was_full) thisus.m_condition.notifyAll();
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}
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void put(T item)
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shared {
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auto thisus = cast(Channel)this;
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bool need_notify = false;
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synchronized (m_mutex) {
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while (thisus.m_items.full)
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thisus.m_condition.wait();
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need_notify = thisus.m_items.empty;
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thisus.m_items.put(item.move);
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}
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if (need_notify) thisus.m_condition.notifyAll();
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}
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}
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