new class PISemaphore

doc for PIProtectedVariable
2024-11-12 18:50:22 +03:00
parent 5b066cbc27
commit 4655d72554
5 changed files with 333 additions and 8 deletions
--- a/libs/main/thread/pisemaphore.h
+++ b/libs/main/thread/pisemaphore.h
@@ -0,0 +1,95 @@
+/*! \file pisemaphore.h
+ * \ingroup Semaphore
+ * \~\brief
+ * \~english Basic semaphore
+ * \~russian Простой семафор
+ */
+/*
+    PIP - Platform Independent Primitives
+	PISemaphore, PISemaphoreLocker
+	Ivan Pelipenko peri4ko@yandex.ru
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef PISEMAPHORE_H
+#define PISEMAPHORE_H
+
+#include "piconditionvar.h"
+
+
+class PIP_EXPORT PISemaphore {
+public:
+	NO_COPY_CLASS(PISemaphore)
+
+	//! \~english Constructs semaphore with \"initial\" available resources.
+	//! \~russian Создает семафор с \"initial\" начальными свободными ресурсами.
+	PISemaphore(int initial = 0);
+
+	//! \~english Destroy semaphore.
+	//! \~russian Деструктор семафора.
+	~PISemaphore();
+
+
+	//! \~english Acquire \"cnt\" resources. If no available resources, than blocks until they freed.
+	//! \~russian Захватывает \"cnt\" ресурсов. Если свободных ресурсов недостаточно, то блокирует до их появления.
+	void acquire(int cnt = 1);
+
+	//! \~english Try to acquire \"cnt\" resources. Returns if operation was successfull.
+	//! \~russian Пробует захватывает \"cnt\" ресурсов. Возвращает успех захвата.
+	bool tryAcquire(int cnt = 1);
+
+	//! \~english Try to acquire \"cnt\" resources for \"timeout\". Returns if operation was successfull (timeout has not expired).
+	//! \~russian Пробует захватывает \"cnt\" ресурсов в течении \"timeout\". Возвращает успех захвата (не истек ли тайм-аут).
+	bool tryAcquire(int cnt, PISystemTime timeout);
+
+	//! \~english Release \"cnt\" resources.
+	//! \~russian Освобождает \"cnt\" ресурсов.
+	void release(int cnt = 1);
+
+	//! \~english Returns available resources count.
+	//! \~russian Возвращает количество свободных ресурсов.
+	int available() const;
+
+private:
+	int count = 0;
+	mutable PIMutex mutex;
+	PIConditionVariable var;
+};
+
+
+class PIP_EXPORT PISemaphoreLocker {
+public:
+	NO_COPY_CLASS(PISemaphoreLocker);
+
+	//! \~english Constructs and acquire \"cnt\" resources on semaphore "s" if "condition" is \c true.
+	//! \~russian Создается и захватывает \"cnt\" ресурсов у семафора "s" если "condition" \c true.
+	PISemaphoreLocker(PISemaphore & s, int cnt = 1, bool condition = true): sem(s), count(cnt), cond(condition) {
+		if (cond) sem.acquire(count);
+	}
+
+	//! \~english Release "cnt" resources on semaphore if "condition" was \c true.
+	//! \~russian Освобождает "cnt" ресурсов у семафора если "condition" был \c true.
+	~PISemaphoreLocker() {
+		if (cond) sem.release(count);
+	}
+
+private:
+	PISemaphore & sem;
+	int count = 1;
+	bool cond = true;
+};
+
+
+#endif // PIMUTEX_H