rt_sem_init.2

rtlinux(realtime linix)3.0,在kernel2.2.18上编译运行

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.TH RT_SEM_INIT 2 "21 July 1997" "rt_ipc" "rt_ipc"
.SH NAME
rt_sem_init \- create a semaphore
.SH SYNOPSIS
.nf
.B #define MODULE
.B #include <linux/module.h> 
.B #include <linux/kernel.h> 
.B #include <linux/version.h> 
.B #include <linux/errno.h> 
.B #include "rt_ipc.h"
.fi
.sp
.BI "int rt_sem_init(rt_sem_t *" sem ", RT_SEMTYPE " type ", int " init_val ");
.SH DESCRIPTION
.B rt_sem_init
is called to initialize a real-time semaphore.  A semaphore can be used for
communication and synchronization among real-time tasks.  Communication
between Linux processes and real-time tasks is done using the standard
Real-Time Linux RT-FIFO facilities.
.PP
.I sem
must point to a statically allocated structure.
.I type
is RT_SEM_BINARY or RT_SEM_COUNTING.
.I init_val
is the initial value of the semaphore (usually 0).
.SH "RETURN VALUE"
On success, 0 is returned.  On failure, a negative value is returned
as described below.
.SH ERRORS
.IP \fB-EINVAL\fP
.I init_val
is negative (or 
.I type
is RT_SEM_BINARY, and 
.I init_val
is greater than one.
.SH "BUGS"
Priority inheritance is not currently supported.
.SH "AUTHOR"
Jerry Epplin <[e-mail]>
.SH "SEE ALSO"
.BR rt_task_ipc_delete (2), 
.BR rt_task_ipc_init (2), 
.BR rt_sem_destroy (2), 
.BR rt_sem_post (2), 
.BR rt_sem_trywait (2), 
.BR rt_sem_wait (2)