2 * Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 #include <sys/_types.h>
34 #include <sys/limits.h>
40 #define UMTX_UNOWNED 0x0
41 #define UMTX_CONTESTED LONG_MIN
44 uintptr_t u_owner; /* Owner of the mutex. */
47 #define USYNC_PROCESS_SHARED 0x0001 /* Process shared sync objs */
49 #define UMUTEX_UNOWNED 0x0
50 #define UMUTEX_CONTESTED 0x80000000
52 #define UMUTEX_ERROR_CHECK 0x0002 /* Error-checking mutex */
53 #define UMUTEX_PRIO_INHERIT 0x0004 /* Priority inherited mutex */
54 #define UMUTEX_PRIO_PROTECT 0x0008 /* Priority protect mutex */
56 __lwpid_t m_owner; /* Owner of the mutex */
57 uint32_t m_flags; /* Flags of the mutex */
58 uint32_t m_ceilings[2]; /* Priority protect ceiling */
59 uint32_t m_spare[4]; /* Spare space */
62 /* op code for _umtx_op */
63 #define UMTX_OP_LOCK 0
64 #define UMTX_OP_UNLOCK 1
65 #define UMTX_OP_WAIT 2
66 #define UMTX_OP_WAKE 3
67 #define UMTX_OP_MUTEX_TRYLOCK 4
68 #define UMTX_OP_MUTEX_LOCK 5
69 #define UMTX_OP_MUTEX_UNLOCK 6
70 #define UMTX_OP_SET_CEILING 7
76 * System call for userland mutex operations.
77 * Bug: assume sizeof(uintptr_t) == sizeof(long)
79 int _umtx_op(void *obj, int op, uintptr_t val, void *uaddr, void *uaddr2);
82 * Old (deprecated) userland mutex system calls.
84 int _umtx_lock(struct umtx *mtx);
85 int _umtx_unlock(struct umtx *mtx);
88 * Standard api. Try uncontested acquire/release and asks the
89 * kernel to resolve failures.
92 umtx_init(struct umtx *umtx)
94 umtx->u_owner = UMTX_UNOWNED;
97 static __inline uintptr_t
98 umtx_owner(struct umtx *umtx)
100 return (umtx->u_owner & ~LONG_MIN);
104 umtx_lock(struct umtx *umtx, uintptr_t id)
106 if (atomic_cmpset_acq_ptr(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
107 if (_umtx_lock(umtx) == -1)
113 umtx_trylock(struct umtx *umtx, uintptr_t id)
115 if (atomic_cmpset_acq_ptr(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
121 umtx_timedlock(struct umtx *umtx, uintptr_t id, const struct timespec *timeout)
123 if (atomic_cmpset_acq_ptr(&umtx->u_owner, UMTX_UNOWNED, id) == 0)
124 if (_umtx_op(umtx, UMTX_OP_LOCK, id, 0,
125 __DECONST(void *, timeout)) == -1)
131 umtx_unlock(struct umtx *umtx, uintptr_t id)
133 if (atomic_cmpset_rel_ptr(&umtx->u_owner, id, UMTX_UNOWNED) == 0)
134 if (_umtx_unlock(umtx) == -1)
140 umtx_wait(long *p, long val, const struct timespec *timeout)
142 if (_umtx_op(p, UMTX_OP_WAIT, val, 0,
143 __DECONST(void *, timeout)) == -1)
148 /* Wake threads waiting on a user address. */
150 umtx_wake(long *p, int nr_wakeup)
152 if (_umtx_op(p, UMTX_OP_WAKE, nr_wakeup, 0, 0) == -1)
161 struct umtx_q *umtxq_alloc(void);
162 void umtxq_free(struct umtx_q *);
163 int kern_umtx_wake(struct thread *td, void *uaddr, int n_wake);
164 void umtx_pi_adjust(struct thread *td, u_char oldpri);
165 void umtx_thread_init(struct thread *td);
166 void umtx_thread_fini(struct thread *td);
167 void umtx_thread_alloc(struct thread *td);
168 void umtx_thread_exit(struct thread *td);
169 #endif /* !_KERNEL */
170 #endif /* !_SYS_UMTX_H_ */