Initial commit

include/l4/lib/mutex.h

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+/*
+ * The elementary concurrency constructs.
+ *
+ * Copyright (C) 2007 Bahadir Balban
+ */
+
+#ifndef __LIB_MUTEX_H__
+#define __LIB_MUTEX_H__
+
+#include <l4/lib/string.h>
+#include <l4/lib/spinlock.h>
+#include <l4/lib/list.h>
+#include <l4/lib/printk.h>
+#include <l4/lib/wait.h>
+#include INC_ARCH(mutex.h)
+
+/* A mutex is a binary semaphore that can sleep. */
+struct mutex {
+	int sleepers;			/* Number of sleepers */
+	struct spinlock slock;		/* Locks sleeper queue */
+	unsigned int lock;		/* The mutex lock itself */
+	struct waitqueue wq;		/* Sleeper queue head */
+};
+
+static inline void mutex_init(struct mutex *mutex)
+{
+	memset(mutex, 0, sizeof(struct mutex));
+	INIT_LIST_HEAD(&mutex->wq.task_list);
+}
+
+void mutex_lock(struct mutex *mutex);
+void mutex_unlock(struct mutex *mutex);
+
+/* NOTE: Since spinlocks guard mutex acquiring & sleeping, no locks needed */
+static inline int mutex_inc(unsigned int *cnt)
+{
+	return ++*cnt;
+}
+
+static inline int mutex_dec(unsigned int *cnt)
+{
+	return --*cnt;
+}
+
+#endif /* __LIB_MUTEX_H__ */