X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fcommon%2Fpthread-lock.hpp;fp=src%2Fcommon%2Fpthread-lock.hpp;h=35fde097cadbf92ea6f6744bc236272c2120c5e7;hb=0a325f4dec3f6d553dad5d2c26ebfdc78201c363;hp=0000000000000000000000000000000000000000;hpb=332a2147fece4548eac38a0929b208230a8da31f;p=lttng-tools.git

diff --git a/src/common/pthread-lock.hpp b/src/common/pthread-lock.hpp
new file mode 100644
index 000000000..35fde097c
--- /dev/null
+++ b/src/common/pthread-lock.hpp
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#ifndef LTTNG_PTHREAD_LOCK_H
+#define LTTNG_PTHREAD_LOCK_H
+
+#include <common/exception.hpp>
+
+#include <pthread.h>
+#include <mutex>
+
+namespace lttng {
+namespace pthread {
+
+namespace details {
+/*
+ * Class wrapping pthread mutexes and satisfying the Mutex named requirements, except
+ * for the "Default Constructible" requirement. The class is not default-constructible since the
+ * intention is to ease the transition of existing C-code using pthread mutexes to idiomatic C++.
+ *
+ * New code should use std::mutex.
+ */
+class mutex {
+public:
+	mutex(pthread_mutex_t& mutex_p) : _mutex{mutex_p}
+	{
+	}
+
+	/* "Not copyable" and "not moveable" Mutex requirements. */
+	mutex(mutex const &) = delete;
+	mutex &operator=(mutex const &) = delete;
+
+	void lock()
+	{
+		if (pthread_mutex_lock(&_mutex) != 0) {
+			LTTNG_THROW_POSIX("Failed to lock mutex", errno);
+		}
+	}
+
+	bool try_lock()
+	{
+		const auto ret = pthread_mutex_trylock(&_mutex);
+
+		if (ret == 0) {
+			return true;
+		} else if (errno == EBUSY || errno == EAGAIN) {
+			return false;
+		} else {
+			LTTNG_THROW_POSIX("Failed to try to lock mutex", errno);
+		}
+	}
+
+	void unlock()
+	{
+		if (pthread_mutex_unlock(&_mutex) != 0) {
+			LTTNG_THROW_POSIX("Failed to unlock mutex", errno);
+		}
+	}
+
+private:
+	pthread_mutex_t& _mutex;
+};
+} /* namespace details */
+
+/*
+ * Provides the basic concept of std::lock_guard for posix mutexes.
+ *
+ * `lock` is held for the duration of lock_guard's lifetime.
+ */
+class lock_guard {
+public:
+	lock_guard(pthread_mutex_t& mutex) : _mutex{mutex}, _guard(_mutex)
+	{
+	}
+
+	lock_guard(const lock_guard &) = delete;
+
+private:
+	details::mutex _mutex;
+	std::lock_guard<details::mutex> _guard;
+};
+
+} /* namespace pthread */
+} /* namespace lttng */
+
+#endif /* LTTNG_PTHREAD_LOCK_H */