[vcs][library][ydb] move TAsyncSemaphore from ydb/library to library/cpp/threading

Потребовалось для

1 files changed, 55 insertions, 0 deletions

diff --git a/library/cpp/threading/future/async_semaphore.h b/library/cpp/threading/future/async_semaphore.h
new file mode 100644
index 00000000000..fa4cabad3cd
--- /dev/null
+++ b/library/cpp/threading/future/async_semaphore.h
@@ -0,0 +1,55 @@
+#pragma once
+
+#include <library/cpp/threading/future/future.h>
+
+#include <util/system/spinlock.h>
+#include <util/generic/ptr.h>
+
+#include <list>
+#include <functional>
+
+namespace NThreading {
+
+class TAsyncSemaphore: public TThrRefBase {
+public:
+    using TPtr = TIntrusivePtr<TAsyncSemaphore>;
+
+    class TAutoRelease {
+    public:
+        TAutoRelease(TAsyncSemaphore::TPtr sem)
+            : Sem(std::move(sem))
+        {
+        }
+        TAutoRelease(TAutoRelease&& other)
+            : Sem(std::move(other.Sem))
+        {
+        }
+        ~TAutoRelease();
+
+        std::function<void (const TFuture<void>&)> DeferRelease();
+
+    private:
+        TAsyncSemaphore::TPtr Sem;
+    };
+
+    static TPtr Make(size_t count);
+
+    TFuture<TPtr> AcquireAsync();
+    void Release();
+    void Cancel();
+
+    TAutoRelease MakeAutoRelease() {
+        return {this};
+    }
+
+private:
+    TAsyncSemaphore(size_t count);
+
+private:
+    size_t Count_;
+    bool Cancelled_ = false;
+    TAdaptiveLock Lock_;
+    std::list<TPromise<TPtr>> Promises_;
+};
+
+} // namespace NThreading