diff options
| -rw-r--r-- | lib/libthr/thread/thr_private.h | 5 | ||||
| -rw-r--r-- | lib/libthr/thread/thr_spinlock.c | 86 | ||||
| -rw-r--r-- | share/man/man3/Makefile | 5 | ||||
| -rw-r--r-- | share/man/man3/pthread_spin_init.3 | 141 | ||||
| -rw-r--r-- | share/man/man3/pthread_spin_lock.3 | 141 |
5 files changed, 378 insertions, 0 deletions
diff --git a/lib/libthr/thread/thr_private.h b/lib/libthr/thread/thr_private.h index c2bea3f..bbf5abd 100644 --- a/lib/libthr/thread/thr_private.h +++ b/lib/libthr/thread/thr_private.h @@ -211,6 +211,11 @@ struct pthread_mutex { spinlock_t lock; }; +struct pthread_spinlock { + void *s_owner; + unsigned int s_magic; +}; + /* * Flags for mutexes. */ diff --git a/lib/libthr/thread/thr_spinlock.c b/lib/libthr/thread/thr_spinlock.c index 322d2e7..60e9522 100644 --- a/lib/libthr/thread/thr_spinlock.c +++ b/lib/libthr/thread/thr_spinlock.c @@ -1,4 +1,5 @@ /* + * Copyright (c) 2004 Michael Telahun Makonnen <mtm@FreeBSD.Org> * Copyright (c) 1997 John Birrell <jb@cimlogic.com.au>. * All rights reserved. * @@ -33,6 +34,9 @@ * */ +#include <sys/types.h> +#include <machine/atomic.h> + #include <stdlib.h> #include <stdio.h> #include <string.h> @@ -44,6 +48,88 @@ #include "thr_private.h" +#define THR_SPIN_MAGIC 0xdadadada +#define THR_SPIN_UNOWNED (void *)0 +#define MAGIC_TEST_RETURN_ON_FAIL(l) \ + do { \ + if ((l) == NULL || (l)->s_magic != THR_SPIN_MAGIC) \ + return (EINVAL); \ + } while(0) + +__weak_reference(_pthread_spin_destroy, pthread_spin_destroy); +__weak_reference(_pthread_spin_init, pthread_spin_init); +__weak_reference(_pthread_spin_lock, pthread_spin_lock); +__weak_reference(_pthread_spin_trylock, pthread_spin_trylock); +__weak_reference(_pthread_spin_unlock, pthread_spin_unlock); + +int +_pthread_spin_destroy(pthread_spinlock_t *lock) +{ + MAGIC_TEST_RETURN_ON_FAIL((*lock)); + if ((*lock)->s_owner == THR_SPIN_UNOWNED) { + (*lock)->s_magic = 0; + free((*lock)); + *lock = NULL; + return (0); + } + return (EBUSY); +} + +int +_pthread_spin_init(pthread_spinlock_t *lock, int pshared) +{ + struct pthread_spinlock *s; + + if (*lock != NULL) { + if ((*lock)->s_magic == THR_SPIN_MAGIC) + return (EBUSY); + } + s = (struct pthread_spinlock *)malloc(sizeof(struct pthread_spinlock)); + if (s == NULL) + return (ENOMEM); + s->s_magic = THR_SPIN_MAGIC; + s->s_owner = THR_SPIN_UNOWNED; + *lock = s; + return (0); +} + +/* + * If the caller sets nonblocking to 1, this function will return + * immediately without acquiring the lock it is owned by another thread. + * If set to 0, it will keep spinning until it acquires the lock. + */ +int +_pthread_spin_lock(pthread_spinlock_t *lock) +{ + MAGIC_TEST_RETURN_ON_FAIL(*lock); + if ((*lock)->s_owner == curthread) + return (EDEADLK); + while (atomic_cmpset_acq_ptr(&(*lock)->s_owner, THR_SPIN_UNOWNED, + (void *)curthread) != 1) + ; /* SPIN */ + return (0); +} + +int +_pthread_spin_trylock(pthread_spinlock_t *lock) +{ + MAGIC_TEST_RETURN_ON_FAIL(*lock); + if (atomic_cmpset_acq_ptr(&(*lock)->s_owner, THR_SPIN_UNOWNED, + (void *)curthread) == 1) + return (0); + return (EBUSY); +} + +int +_pthread_spin_unlock(pthread_spinlock_t *lock) +{ + MAGIC_TEST_RETURN_ON_FAIL(*lock); + if (atomic_cmpset_rel_ptr(&(*lock)->s_owner, (void *)curthread, + THR_SPIN_UNOWNED) == 1) + return (0); + return (EPERM); +} + void _spinunlock(spinlock_t *lck) { diff --git a/share/man/man3/Makefile b/share/man/man3/Makefile index 8f9b1e5..8e5df1b 100644 --- a/share/man/man3/Makefile +++ b/share/man/man3/Makefile @@ -189,6 +189,8 @@ PTHREAD_MAN= pthread.3 \ pthread_set_name_np.3 \ pthread_setspecific.3 \ pthread_sigmask.3 \ + pthread_spin_init.3 \ + pthread_spin_lock.3 \ pthread_suspend_all_np.3 \ pthread_suspend_np.3 \ pthread_switch_add_np.3 \ @@ -231,6 +233,9 @@ PTHREAD_MLINKS+=pthread_rwlock_rdlock.3 pthread_rwlock_tryrdlock.3 PTHREAD_MLINKS+=pthread_rwlock_wrlock.3 pthread_rwlock_trywrlock.3 PTHREAD_MLINKS+=pthread_schedparam.3 pthread_getschedparam.3 \ pthread_schedparam.3 pthread_setschedparam.3 +PTHREAD_MLINKS+=pthread_spin_init.3 pthread_spin_destroy.3 \ + pthread_spin_lock.3 pthread_spin_trylock.3 \ + pthread_spin_lock.3 pthread_spin_unlock.3 PTHREAD_MLINKS+=pthread_switch_add_np.3 pthread_switch_delete_np.3 PTHREAD_MLINKS+=pthread_testcancel.3 pthread_setcancelstate.3 \ pthread_testcancel.3 pthread_setcanceltype.3 diff --git a/share/man/man3/pthread_spin_init.3 b/share/man/man3/pthread_spin_init.3 new file mode 100644 index 0000000..87bce85 --- /dev/null +++ b/share/man/man3/pthread_spin_init.3 @@ -0,0 +1,141 @@ +.\" Copyright (c) 2004 Michael Telahun Makonnen +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.\" Note: The date here should be updated whenever a non-trivial +.\" change is made to the manual page. +.Dd January 22, 2004 +.Dt PTHREAD_SPIN_INIT 3 PTHREAD_SPIN_DESTROY 3 +.Os +.Sh NAME +.Nm pthread_spin_init pthread_spin_destroy +.Nd "initialize or destroy a spin lock" +.Sh LIBRARY +.Lb libpthread +.Lb libthr +.Sh SYNOPSIS +.In pthread.h +.Ft int +.Fn pthread_spin_init "pthread_spinlock_t *lock" "int pshared" +.Ft int +.Fn pthread_spin_destroy "pthread_spinlock_t *lock" +.Sh DESCRIPTION +The +.Fn pthread_spin_init +function will initialize +.Fa lock +to an unlocked state and +allocate any resources necessary to begin using it. +If +.Fa pshared +is set to +.Dv PTHREAD_PROCESS_SHARED +any thread, +whether belonging to the process in which the spinlock was created or not, +that has access to the memory area where +.Fa lock +resides can use +.Fa lock . +If it is set to +.Dv PTHREAD_PROCESS_PRIVATE +it can only be used by threads within the same process. +.Pp +The +.Fn pthread_spin_destroy +function will destroy +.Fa lock +and release any resources that may have been allocated on its behalf. +.Pp +.Sh DIAGNOSTICS +If successful, +both +.Fn pthread_spin_init +and +.Fn pthread_spin_destroy +will return zero. +Otherwise an error number will be returned to indicate the error. +.Pp +Neither of these functions will return EINTR. +.Pp +.Sh ERRORS +The +.Fn pthread_spin_init +and +.Fn pthread_spin_destroy +functions will fail if: +.Bl -tag -width Er +.It Bq Er EBUSY +An attempt to initialize or destroy +.Fa lock +while it is in use. +.It Bq Er EINVAL +The value specified by +.Fa lock +is invalid. +.El +.Pp +The +.Fn pthread_spin_init +function will fail if: +.Bl -tag -width Er +.It Bq Er EAGAIN +Insufficient resources, +other than memory, +to initialize +.Fa lock . +.It Bq Er ENOMEM +Insufficient memory to initialize +.Fa lock . +.El +.Sh SEE ALSO +.Xr pthread_spin_lock 3 , +.Xr pthread_spin_unlock 3 +.Sh HISTORY +The +.Fn pthread_spin_init +and +.Fn pthread_spin_destroy +functions first appeared in +.Lb libpthread +in +.Fx 5.2 , +and in +.Lb libthr +in +.Fx 5.3 . +.Sh BUGS +The implementation of +.Fn pthread_spin_init +does not fully conform to +.St -p1003.2 +because the +.Fa pshared +argument is ignored in +.Lb libthr , +and in +.Lb libpthread +if any value other than +.Dv PTHREAD_PROCESSES_PRIVATE +is specified it returns EINVAL. diff --git a/share/man/man3/pthread_spin_lock.3 b/share/man/man3/pthread_spin_lock.3 new file mode 100644 index 0000000..0dc4490 --- /dev/null +++ b/share/man/man3/pthread_spin_lock.3 @@ -0,0 +1,141 @@ +.\" Copyright (c) 2004 Michael Telahun Makonnen +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.\" Note: The date here should be updated whenever a non-trivial +.\" change is made to the manual page. +.Dd January 22, 2004 +.Dt PTHREAD_SPIN_LOCK 3 PTHREAD_SPIN_TRYLOCK 3 PTHREAD_SPIN_UNLOCK 3 +.Os +.Sh NAME +.Nm pthread_spin_lock pthread_spin_trylock pthread_spin_unlock +.Nd "lock or unlock a spin lock" +.Sh LIBRARY +.Lb libpthread +.Lb libthr +.Sh SYNOPSIS +.In pthread.h +.Ft int +.Fn pthread_spin_lock "pthread_spinlock_t *lock" +.Ft int +.Fn pthread_spin_trylock "pthread_spinlock_t *lock" +.Ft int +.Fn pthread_spin_unlock "pthread_spinlock_t *lock" +.Sh DESCRIPTION +The +.Fn pthread_spin_lock +function will acquire +.Fa lock +if it is not currently owned by another thread. +If the lock cannot be acquired immediately it will +spin attempting to acquire the lock (it will not sleep) until +it becomes available. +.Pp +The +.Fn pthread_spin_trylock +function is the same as +.Fn pthread_spin_lock +except that if it cannot acquire +.Fa lock +immediately it will return with an error. +.Pp +The +.Fn pthread_spin_unlock +function will release +.Fa lock , +which must have been previously locked by a call to +.Fn pthread_spin_lock +or +.Fn pthread_spin_trylock . +.Sh DIAGNOSTICS +If successful all these functions will return zero. +Otherwise an error number will be returned to indicate the error. +.Pp +None of these functions will return EINTR. +.Pp +.Sh ERRORS +The +.Fn pthread_spin_lock , +.Fn pthread_spin_trylock +and +.Fn pthread_spin_unlock +functions will fail if: +.Bl -tag -width Er +.It Bq Er EINVAL +The value specified by +.Fa lock +is invalid or is not initialized. +.El +.Pp +The +.Fn pthread_spin_lock +function may fail if: +.Bl -tag -width Er +.It Bq Er EDEADLK +The calling thread already owns the lock. +.El +.Pp +The +.Fn pthread_spin_trylock +function will fail if: +.Bl -tag -width Er +.It Bq Er EBUSY +Another thread currently holds +.Fa lock . +.El +.Pp +The +.Fn pthread_spin_unlock +function may fail if: +.Bl -tag -width Er +.It Bq Er EPERM +The calling thread does not own +.Fa lock . +.El +.Sh SEE ALSO +.Xr pthread_spin_init 3 , +.Xr pthread_spin_destroy 3 +.Sh HISTORY +The +.Fn pthread_spin_lock , +.Fn pthread_spin_trylock +and +.Fn pthread_spin_unlock +functions first appeared in +.Lb libpthread +in +.Fx 5.2 , +and in +.Lb libthr +in +.Fx 5.3 . +.Sh BUGS +The implementation of +.Fn pthread_spin_lock , +.Fn pthread_spin_trylock +and +.Fn pthread_spin_unlock +is expected to conform to +.St -p1003.2 . |
