validate canons without yatest_common

5 files changed, 379 insertions, 0 deletions

diff --git a/library/cpp/threading/blocking_queue/blocking_queue.cpp b/library/cpp/threading/blocking_queue/blocking_queue.cpp
new file mode 100644
index 0000000000..db199c80be
--- /dev/null
+++ b/library/cpp/threading/blocking_queue/blocking_queue.cpp
@@ -0,0 +1,3 @@
+#include "blocking_queue.h"
+
+// just check compilability
diff --git a/library/cpp/threading/blocking_queue/blocking_queue.h b/library/cpp/threading/blocking_queue/blocking_queue.h
new file mode 100644
index 0000000000..48d3762f68
--- /dev/null
+++ b/library/cpp/threading/blocking_queue/blocking_queue.h
@@ -0,0 +1,158 @@
+#pragma once
+
+#include <util/generic/deque.h>
+#include <util/generic/maybe.h>
+#include <util/generic/yexception.h>
+#include <util/system/condvar.h>
+#include <util/system/guard.h>
+#include <util/system/mutex.h>
+
+#include <utility>
+
+namespace NThreading {
+    ///
+    /// TBlockingQueue is a queue of elements of limited or unlimited size.
+    /// Queue provides Push and Pop operations that block if operation can't be executed
+    /// (queue is empty or maximum size is reached).
+    ///
+    /// Queue can be stopped, in that case all blocked operation will return `Nothing` / false.
+    ///
+    /// All operations are thread safe.
+    ///
+    ///
+    /// Example of usage:
+    ///     TBlockingQueue<int> queue;
+    ///
+    ///     ...
+    ///
+    ///     // thread 1
+    ///     queue.Push(42);
+    ///     queue.Push(100500);
+    ///
+    ///     ...
+    ///
+    ///     // thread 2
+    ///     while (TMaybe<int> number = queue.Pop()) {
+    ///         ProcessNumber(number.GetRef());
+    ///     }
+    template <class TElement>
+    class TBlockingQueue {
+    public:
+        ///
+        /// Creates blocking queue with given maxSize
+        /// if maxSize == 0 then queue is unlimited
+        TBlockingQueue(size_t maxSize)
+            : MaxSize(maxSize == 0 ? Max<size_t>() : maxSize)
+            , Stopped(false)
+        {
+        }
+
+        ///
+        /// Blocks until queue has some elements or queue is stopped or deadline is reached.
+        /// Returns `Nothing` if queue is stopped or deadline is reached.
+        /// Returns element otherwise.
+        TMaybe<TElement> Pop(TInstant deadline = TInstant::Max()) {
+            TGuard<TMutex> g(Lock);
+
+            const auto canPop = [this]() { return CanPop(); };
+            if (!CanPopCV.WaitD(Lock, deadline, canPop)) {
+                return Nothing();
+            }
+
+            if (Stopped && Queue.empty()) {
+                return Nothing();
+            }
+            TElement e = std::move(Queue.front());
+            Queue.pop_front();
+            CanPushCV.Signal();
+            return std::move(e);
+        }
+
+        TMaybe<TElement> Pop(TDuration duration) {
+            return Pop(TInstant::Now() + duration);
+        }
+
+        ///
+        /// Blocks until queue has space for new elements or queue is stopped or deadline is reached.
+        /// Returns false exception if queue is stopped and push failed or deadline is reached.
+        /// Pushes element to queue and returns true otherwise.
+        bool Push(const TElement& e, TInstant deadline = TInstant::Max()) {
+            return PushRef(e, deadline);
+        }
+
+        bool Push(TElement&& e, TInstant deadline = TInstant::Max()) {
+            return PushRef(std::move(e), deadline);
+        }
+
+        bool Push(const TElement& e, TDuration duration) {
+            return Push(e, TInstant::Now() + duration);
+        }
+
+        bool Push(TElement&& e, TDuration duration) {
+            return Push(std::move(e), TInstant::Now() + duration);
+        }
+
+        ///
+        /// Stops the queue, all blocked operations will be aborted.
+        void Stop() {
+            TGuard<TMutex> g(Lock);
+            Stopped = true;
+            CanPopCV.BroadCast();
+            CanPushCV.BroadCast();
+        }
+
+        ///
+        /// Checks whether queue is empty.
+        bool Empty() const {
+            TGuard<TMutex> g(Lock);
+            return Queue.empty();
+        }
+
+        ///
+        /// Returns size of the queue.
+        size_t Size() const {
+            TGuard<TMutex> g(Lock);
+            return Queue.size();
+        }
+
+        ///
+        /// Checks whether queue is stopped.
+        bool IsStopped() const {
+            TGuard<TMutex> g(Lock);
+            return Stopped;
+        }
+
+    private:
+        bool CanPush() const {
+            return Queue.size() < MaxSize || Stopped;
+        }
+
+        bool CanPop() const {
+            return !Queue.empty() || Stopped;
+        }
+
+        template <typename Ref>
+        bool PushRef(Ref e, TInstant deadline) {
+            TGuard<TMutex> g(Lock);
+            const auto canPush = [this]() { return CanPush(); };
+            if (!CanPushCV.WaitD(Lock, deadline, canPush)) {
+                return false;
+            }
+            if (Stopped) {
+                return false;
+            }
+            Queue.push_back(std::forward<TElement>(e));
+            CanPopCV.Signal();
+            return true;
+        }
+
+    private:
+        TMutex Lock;
+        TCondVar CanPopCV;
+        TCondVar CanPushCV;
+        TDeque<TElement> Queue;
+        size_t MaxSize;
+        bool Stopped;
+    };
+
+}
diff --git a/library/cpp/threading/cancellation/README.md b/library/cpp/threading/cancellation/README.md
new file mode 100644
index 0000000000..98e0e9b299
--- /dev/null
+++ b/library/cpp/threading/cancellation/README.md
@@ -0,0 +1,112 @@
+The Cancellation library
+========================
+
+Intro
+-----
+
+This small library provides primitives for implementation of a cooperative cancellation of long running or asynchronous operations.
+The design has been copied from the well-known CancellationTokenSource/CancellationToken classes of the .NET Framework
+
+To use the library include `cancellation_token.h`.
+
+Examples
+--------
+
+1. Simple check for cancellation
+
+    ```c++
+    void LongRunningOperation(TCancellationToken token) {
+        ...
+        if (token.IsCancellationRequested()) {
+            return;
+        }
+        ...
+    }
+
+    TCancellationTokenSource source;
+    TThread thread([token = source.Token()]() { LongRunningOperation(std::move(token)); });
+    thread.Start();
+    ...
+    source.Cancel();
+    thread.Join();
+    ```
+
+2. Exit via an exception
+
+    ```c++
+    void LongRunningOperation(TCancellationToken token) {
+        try {
+            for (;;) {
+                ...
+                token.ThrowIfCancellationRequested();
+                ...
+            }
+        } catch (TOperationCancelledException const&) {
+            return;
+        } catch (...) {
+            Y_FAIL("Never should be there")
+        }
+    }
+
+    TCancellationTokenSource source;
+    TThread thread([token = source.Token()]() { LongRunningOperation(std::move(token)); });
+    thread.Start();
+    ...
+    source.Cancel();
+    thread.Join();
+    ```
+
+3. Periodic poll with cancellation
+
+    ```c++
+    void LongRunningOperation(TCancellationToken token) {
+        while (!token.Wait(PollInterval)) {
+            ...
+        }
+    }
+
+    TCancellationTokenSource source;
+    TThread thread([token = source.Token()]() { LongRunningOperation(std::move(token)); });
+    thread.Start();
+    ...
+    source.Cancel();
+    thread.Join();
+    ```
+
+4. Waiting on the future
+
+    ```c++
+    TFuture<void> InnerOperation();
+    TFuture<void> OuterOperation(TCancellationToken token) {
+        return WaitAny(FirstOperation(), token.Future())
+                    .Apply([token = std::move(token)](auto&&) {
+                        token.ThrowIfCancellationRequested();
+                    });
+    }
+
+    TCancellationTokenSource source;
+    auto future = OuterOperation();
+    ...
+    source.Cancel()
+    ...
+    try {
+        auto value = future.ExtractValueSync();
+    } catch (TOperationCancelledException const&) {
+        // cancelled
+    }
+    ```
+
+5. Using default token when no cancellation needed
+
+    ```c++
+    void LongRunningOperation(TCancellationToken token) {
+        ...
+        if (token.IsCancellationRequested()) {
+            return;
+        }
+        ...
+    }
+
+    // We do not want to cancel the operation. So, there is no need to create a cancellation token source
+    LongRunningOperation(TCancellationToken::Default);
+    ```
diff --git a/library/cpp/threading/cancellation/cancellation_token.cpp b/library/cpp/threading/cancellation/cancellation_token.cpp
new file mode 100644
index 0000000000..1a0a19f690
--- /dev/null
+++ b/library/cpp/threading/cancellation/cancellation_token.cpp
@@ -0,0 +1 @@
+#include "cancellation_token.h"
diff --git a/library/cpp/threading/cancellation/cancellation_token.h b/library/cpp/threading/cancellation/cancellation_token.h
new file mode 100644
index 0000000000..337e2cfda0
--- /dev/null
+++ b/library/cpp/threading/cancellation/cancellation_token.h
@@ -0,0 +1,105 @@
+#pragma once
+
+#include "operation_cancelled_exception.h"
+
+#include <library/cpp/threading/future/future.h>
+
+#include <util/generic/ptr.h>
+#include <util/generic/singleton.h>
+
+namespace NThreading {
+
+class TCancellationTokenSource;
+
+//! A cancellation token could be passed to an async or long running operation to perform a cooperative operation cancel
+class TCancellationToken {
+private:
+    TFuture<void> Future_;
+
+public:
+    TCancellationToken() = delete;
+    TCancellationToken(const TCancellationToken&) noexcept = default;
+    TCancellationToken(TCancellationToken&&) noexcept = default;
+    TCancellationToken& operator = (const TCancellationToken&) noexcept = default;
+    TCancellationToken& operator = (TCancellationToken&&) noexcept = default;
+
+    //! Shows whether a cancellation has been requested
+    bool IsCancellationRequested() const {
+        return Future_.HasValue();
+    }
+
+    //! Throws the TOperationCancelledException if a cancellation has been requested
+    void ThrowIfCancellationRequested() const {
+        if (IsCancellationRequested()) {
+            ythrow TOperationCancelledException();
+        }
+    }
+
+    //! Waits for a cancellation
+    bool Wait(TDuration duration) const {
+        return Future_.Wait(duration);
+    }
+
+    bool Wait(TInstant deadline) const {
+        return Future_.Wait(deadline);
+    }
+
+    void Wait() const {
+        return Future_.Wait();
+    }
+
+    //! Returns a future that could be used for waiting for a cancellation
+    TFuture<void> const& Future() const noexcept {
+        return Future_;
+    }
+
+    //! The default cancellation token that cannot be cancelled
+    static TCancellationToken const& Default() {
+        return *SingletonWithPriority<TCancellationToken, 0>(NewPromise());
+    }
+
+private:
+    TCancellationToken(TFuture<void> future)
+        : Future_(std::move(future))
+    {
+    }
+
+private:
+    friend class TCancellationTokenSource;
+
+    Y_DECLARE_SINGLETON_FRIEND();
+};
+
+//! A cancellation token source produces cancellation tokens to be passed to cancellable operations
+class TCancellationTokenSource {
+private:
+    TPromise<void> Promise;
+
+public:
+    TCancellationTokenSource()
+        : Promise(NewPromise())
+    {
+    }
+
+    TCancellationTokenSource(TCancellationTokenSource const&) = delete;
+    TCancellationTokenSource(TCancellationTokenSource&&) = delete;
+    TCancellationTokenSource& operator=(TCancellationTokenSource const&) = delete;
+    TCancellationTokenSource& operator=(TCancellationTokenSource&&) = delete;
+
+    //! Shows whether a cancellation has been requested
+    bool IsCancellationRequested() const noexcept {
+        return Promise.HasValue();
+    }
+
+    //! Produces a cancellation token
+    TCancellationToken Token() const {
+        return TCancellationToken(Promise.GetFuture());
+    }
+
+    //! Propagates a cancel request to all produced tokens
+    void Cancel() noexcept {
+        Promise.TrySetValue();
+    }
+};
+
+}