302 lines
8.0 KiB
C
302 lines
8.0 KiB
C
/*
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* Copyright 2008-2011, Ingo Weinhold, ingo_weinhold@gmx.de.
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* Copyright 2002-2009, Axel Dörfler, axeld@pinc-software.de.
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* Distributed under the terms of the MIT License.
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*
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* Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
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* Distributed under the terms of the NewOS License.
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*/
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#ifndef _KERNEL_LOCK_H
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#define _KERNEL_LOCK_H
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#include <OS.h>
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#include <arch/atomic.h>
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#include <debug.h>
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struct mutex_waiter;
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typedef struct mutex {
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const char* name;
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struct mutex_waiter* waiters;
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spinlock lock;
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#if KDEBUG
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thread_id holder;
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#else
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int32 count;
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#endif
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uint8 flags;
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} mutex;
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#define MUTEX_FLAG_CLONE_NAME 0x1
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typedef struct recursive_lock {
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mutex lock;
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#if !KDEBUG
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thread_id holder;
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#else
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int32 _unused;
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#endif
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int recursion;
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} recursive_lock;
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struct rw_lock_waiter;
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typedef struct rw_lock {
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const char* name;
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struct rw_lock_waiter* waiters;
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spinlock lock;
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thread_id holder;
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int32 count;
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int32 owner_count;
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int16 active_readers;
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// Only > 0 while a writer is waiting: number
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// of active readers when the first waiting
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// writer started waiting.
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int16 pending_readers;
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// Number of readers that have already
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// incremented "count", but have not yet started
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// to wait at the time the last writer unlocked.
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uint32 flags;
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} rw_lock;
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#define RW_LOCK_WRITER_COUNT_BASE 0x10000
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#define RW_LOCK_FLAG_CLONE_NAME 0x1
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#if KDEBUG
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# define KDEBUG_RW_LOCK_DEBUG 0
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// Define to 1 if you want to use ASSERT_READ_LOCKED_RW_LOCK().
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# define ASSERT_LOCKED_RECURSIVE(r) \
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{ ASSERT(find_thread(NULL) == (r)->lock.holder); }
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# define ASSERT_LOCKED_MUTEX(m) { ASSERT(find_thread(NULL) == (m)->holder); }
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# define ASSERT_WRITE_LOCKED_RW_LOCK(l) \
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{ ASSERT(find_thread(NULL) == (l)->holder); }
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# if KDEBUG_RW_LOCK_DEBUG
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extern bool _rw_lock_is_read_locked(rw_lock* lock);
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# define ASSERT_READ_LOCKED_RW_LOCK(l) \
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{ ASSERT_PRINT(_rw_lock_is_read_locked(l), "rwlock %p", l); }
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# define ASSERT_UNLOCKED_RW_LOCK(l) \
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{ ASSERT_PRINT(!_rw_lock_is_read_locked(l), "rwlock %p", l); }
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# else
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# define ASSERT_READ_LOCKED_RW_LOCK(l) do {} while (false)
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# define ASSERT_UNLOCKED_RW_LOCK(l) do {} while (false)
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# endif
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#else
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# define ASSERT_LOCKED_RECURSIVE(r) do {} while (false)
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# define ASSERT_LOCKED_MUTEX(m) do {} while (false)
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# define ASSERT_WRITE_LOCKED_RW_LOCK(m) do {} while (false)
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# define ASSERT_READ_LOCKED_RW_LOCK(l) do {} while (false)
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# define ASSERT_UNLOCKED_RW_LOCK(l) do {} while (false)
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#endif
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// static initializers
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#if KDEBUG
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# define MUTEX_INITIALIZER(name) \
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{ name, NULL, B_SPINLOCK_INITIALIZER, -1, 0 }
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# define RECURSIVE_LOCK_INITIALIZER(name) { MUTEX_INITIALIZER(name), 0 }
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#else
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# define MUTEX_INITIALIZER(name) \
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{ name, NULL, B_SPINLOCK_INITIALIZER, 0, 0 }
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# define RECURSIVE_LOCK_INITIALIZER(name) { MUTEX_INITIALIZER(name), -1, 0 }
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#endif
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#define RW_LOCK_INITIALIZER(name) \
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{ name, NULL, B_SPINLOCK_INITIALIZER, -1, 0, 0, 0, 0, 0 }
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#if KDEBUG
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# define RECURSIVE_LOCK_HOLDER(recursiveLock) ((recursiveLock)->lock.holder)
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#else
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# define RECURSIVE_LOCK_HOLDER(recursiveLock) ((recursiveLock)->holder)
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#endif
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#ifdef __cplusplus
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extern "C" {
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#endif
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extern void recursive_lock_init(recursive_lock *lock, const char *name);
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// name is *not* cloned nor freed in recursive_lock_destroy()
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extern void recursive_lock_init_etc(recursive_lock *lock, const char *name,
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uint32 flags);
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extern void recursive_lock_destroy(recursive_lock *lock);
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extern status_t recursive_lock_lock(recursive_lock *lock);
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extern status_t recursive_lock_trylock(recursive_lock *lock);
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extern void recursive_lock_unlock(recursive_lock *lock);
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extern status_t recursive_lock_switch_lock(recursive_lock* from,
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recursive_lock* to);
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// Unlocks "from" and locks "to" such that unlocking and starting to wait
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// for the lock is atomic. I.e. if "from" guards the object "to" belongs
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// to, the operation is safe as long as "from" is held while destroying
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// "to".
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extern status_t recursive_lock_switch_from_mutex(mutex* from,
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recursive_lock* to);
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// Like recursive_lock_switch_lock(), just for switching from a mutex.
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extern status_t recursive_lock_switch_from_read_lock(rw_lock* from,
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recursive_lock* to);
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// Like recursive_lock_switch_lock(), just for switching from a read-locked
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// rw_lock.
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extern int32 recursive_lock_get_recursion(recursive_lock *lock);
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extern void rw_lock_init(rw_lock* lock, const char* name);
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// name is *not* cloned nor freed in rw_lock_destroy()
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extern void rw_lock_init_etc(rw_lock* lock, const char* name, uint32 flags);
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extern void rw_lock_destroy(rw_lock* lock);
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extern status_t rw_lock_write_lock(rw_lock* lock);
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extern void mutex_init(mutex* lock, const char* name);
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// name is *not* cloned nor freed in mutex_destroy()
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extern void mutex_init_etc(mutex* lock, const char* name, uint32 flags);
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extern void mutex_destroy(mutex* lock);
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extern void mutex_transfer_lock(mutex* lock, thread_id thread);
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extern status_t mutex_switch_lock(mutex* from, mutex* to);
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// Unlocks "from" and locks "to" such that unlocking and starting to wait
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// for the lock is atomic. I.e. if "from" guards the object "to" belongs
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// to, the operation is safe as long as "from" is held while destroying
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// "to".
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extern status_t mutex_switch_from_read_lock(rw_lock* from, mutex* to);
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// Like mutex_switch_lock(), just for switching from a read-locked rw_lock.
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// implementation private:
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extern status_t _rw_lock_read_lock(rw_lock* lock);
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extern status_t _rw_lock_read_lock_with_timeout(rw_lock* lock,
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uint32 timeoutFlags, bigtime_t timeout);
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extern void _rw_lock_read_unlock(rw_lock* lock);
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extern void _rw_lock_write_unlock(rw_lock* lock);
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extern status_t _mutex_lock(mutex* lock, void* locker);
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extern void _mutex_unlock(mutex* lock);
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extern status_t _mutex_trylock(mutex* lock);
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extern status_t _mutex_lock_with_timeout(mutex* lock, uint32 timeoutFlags,
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bigtime_t timeout);
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static inline status_t
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rw_lock_read_lock(rw_lock* lock)
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{
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#if KDEBUG_RW_LOCK_DEBUG
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return _rw_lock_read_lock(lock);
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#else
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int32 oldCount = atomic_add(&lock->count, 1);
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if (oldCount >= RW_LOCK_WRITER_COUNT_BASE)
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return _rw_lock_read_lock(lock);
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return B_OK;
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#endif
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}
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static inline status_t
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rw_lock_read_lock_with_timeout(rw_lock* lock, uint32 timeoutFlags,
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bigtime_t timeout)
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{
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#if KDEBUG_RW_LOCK_DEBUG
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return _rw_lock_read_lock_with_timeout(lock, timeoutFlags, timeout);
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#else
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int32 oldCount = atomic_add(&lock->count, 1);
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if (oldCount >= RW_LOCK_WRITER_COUNT_BASE)
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return _rw_lock_read_lock_with_timeout(lock, timeoutFlags, timeout);
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return B_OK;
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#endif
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}
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static inline void
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rw_lock_read_unlock(rw_lock* lock)
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{
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#if KDEBUG_RW_LOCK_DEBUG
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_rw_lock_read_unlock(lock);
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#else
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int32 oldCount = atomic_add(&lock->count, -1);
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if (oldCount >= RW_LOCK_WRITER_COUNT_BASE)
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_rw_lock_read_unlock(lock);
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#endif
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}
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static inline void
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rw_lock_write_unlock(rw_lock* lock)
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{
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_rw_lock_write_unlock(lock);
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}
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static inline status_t
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mutex_lock(mutex* lock)
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{
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#if KDEBUG
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return _mutex_lock(lock, NULL);
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#else
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if (atomic_add(&lock->count, -1) < 0)
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return _mutex_lock(lock, NULL);
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return B_OK;
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#endif
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}
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static inline status_t
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mutex_trylock(mutex* lock)
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{
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#if KDEBUG
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return _mutex_trylock(lock);
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#else
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if (atomic_test_and_set(&lock->count, -1, 0) != 0)
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return B_WOULD_BLOCK;
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return B_OK;
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#endif
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}
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static inline status_t
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mutex_lock_with_timeout(mutex* lock, uint32 timeoutFlags, bigtime_t timeout)
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{
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#if KDEBUG
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return _mutex_lock_with_timeout(lock, timeoutFlags, timeout);
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#else
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if (atomic_add(&lock->count, -1) < 0)
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return _mutex_lock_with_timeout(lock, timeoutFlags, timeout);
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return B_OK;
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#endif
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}
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static inline void
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mutex_unlock(mutex* lock)
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{
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#if !KDEBUG
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if (atomic_add(&lock->count, 1) < -1)
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#endif
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_mutex_unlock(lock);
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}
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static inline void
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recursive_lock_transfer_lock(recursive_lock* lock, thread_id thread)
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{
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if (lock->recursion != 1)
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panic("invalid recursion level for lock transfer!");
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#if KDEBUG
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mutex_transfer_lock(&lock->lock, thread);
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#else
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lock->holder = thread;
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#endif
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}
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extern void lock_debug_init();
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#ifdef __cplusplus
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}
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#endif
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#endif /* _KERNEL_LOCK_H */
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