1*062c5bc4SJason Schmidlapp /*
2*062c5bc4SJason Schmidlapp * -------------------------------------------------------------
3*062c5bc4SJason Schmidlapp *
4*062c5bc4SJason Schmidlapp * Module: sem_getvalue.c
5*062c5bc4SJason Schmidlapp *
6*062c5bc4SJason Schmidlapp * Purpose:
7*062c5bc4SJason Schmidlapp * Semaphores aren't actually part of PThreads.
8*062c5bc4SJason Schmidlapp * They are defined by the POSIX Standard:
9*062c5bc4SJason Schmidlapp *
10*062c5bc4SJason Schmidlapp * POSIX 1003.1-2001
11*062c5bc4SJason Schmidlapp *
12*062c5bc4SJason Schmidlapp * -------------------------------------------------------------
13*062c5bc4SJason Schmidlapp *
14*062c5bc4SJason Schmidlapp * --------------------------------------------------------------------------
15*062c5bc4SJason Schmidlapp *
16*062c5bc4SJason Schmidlapp * Pthreads-embedded (PTE) - POSIX Threads Library for embedded systems
17*062c5bc4SJason Schmidlapp * Copyright(C) 2008 Jason Schmidlapp
18*062c5bc4SJason Schmidlapp *
19*062c5bc4SJason Schmidlapp * Contact Email: jschmidlapp@users.sourceforge.net
20*062c5bc4SJason Schmidlapp *
21*062c5bc4SJason Schmidlapp *
22*062c5bc4SJason Schmidlapp * Based upon Pthreads-win32 - POSIX Threads Library for Win32
23*062c5bc4SJason Schmidlapp * Copyright(C) 1998 John E. Bossom
24*062c5bc4SJason Schmidlapp * Copyright(C) 1999,2005 Pthreads-win32 contributors
25*062c5bc4SJason Schmidlapp *
26*062c5bc4SJason Schmidlapp * Contact Email: rpj@callisto.canberra.edu.au
27*062c5bc4SJason Schmidlapp *
28*062c5bc4SJason Schmidlapp * The original list of contributors to the Pthreads-win32 project
29*062c5bc4SJason Schmidlapp * is contained in the file CONTRIBUTORS.ptw32 included with the
30*062c5bc4SJason Schmidlapp * source code distribution. The list can also be seen at the
31*062c5bc4SJason Schmidlapp * following World Wide Web location:
32*062c5bc4SJason Schmidlapp * http://sources.redhat.com/pthreads-win32/contributors.html
33*062c5bc4SJason Schmidlapp *
34*062c5bc4SJason Schmidlapp * This library is free software; you can redistribute it and/or
35*062c5bc4SJason Schmidlapp * modify it under the terms of the GNU Lesser General Public
36*062c5bc4SJason Schmidlapp * License as published by the Free Software Foundation; either
37*062c5bc4SJason Schmidlapp * version 2 of the License, or (at your option) any later version.
38*062c5bc4SJason Schmidlapp *
39*062c5bc4SJason Schmidlapp * This library is distributed in the hope that it will be useful,
40*062c5bc4SJason Schmidlapp * but WITHOUT ANY WARRANTY; without even the implied warranty of
41*062c5bc4SJason Schmidlapp * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
42*062c5bc4SJason Schmidlapp * Lesser General Public License for more details.
43*062c5bc4SJason Schmidlapp *
44*062c5bc4SJason Schmidlapp * You should have received a copy of the GNU Lesser General Public
45*062c5bc4SJason Schmidlapp * License along with this library in the file COPYING.LIB;
46*062c5bc4SJason Schmidlapp * if not, write to the Free Software Foundation, Inc.,
47*062c5bc4SJason Schmidlapp * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
48*062c5bc4SJason Schmidlapp */
49*062c5bc4SJason Schmidlapp
50*062c5bc4SJason Schmidlapp #include "pthread.h"
51*062c5bc4SJason Schmidlapp #include "semaphore.h"
52*062c5bc4SJason Schmidlapp #include "implement.h"
53*062c5bc4SJason Schmidlapp
54*062c5bc4SJason Schmidlapp
55*062c5bc4SJason Schmidlapp int
sem_getvalue(sem_t * sem,int * sval)56*062c5bc4SJason Schmidlapp sem_getvalue (sem_t * sem, int *sval)
57*062c5bc4SJason Schmidlapp /*
58*062c5bc4SJason Schmidlapp * ------------------------------------------------------
59*062c5bc4SJason Schmidlapp * DOCPUBLIC
60*062c5bc4SJason Schmidlapp * This function stores the current count value of the
61*062c5bc4SJason Schmidlapp * semaphore.
62*062c5bc4SJason Schmidlapp * RESULTS
63*062c5bc4SJason Schmidlapp *
64*062c5bc4SJason Schmidlapp * Return value
65*062c5bc4SJason Schmidlapp *
66*062c5bc4SJason Schmidlapp * 0 sval has been set.
67*062c5bc4SJason Schmidlapp * -1 failed, error in errno
68*062c5bc4SJason Schmidlapp *
69*062c5bc4SJason Schmidlapp * in global errno
70*062c5bc4SJason Schmidlapp *
71*062c5bc4SJason Schmidlapp * EINVAL 'sem' is not a valid semaphore,
72*062c5bc4SJason Schmidlapp * ENOSYS this function is not supported,
73*062c5bc4SJason Schmidlapp *
74*062c5bc4SJason Schmidlapp *
75*062c5bc4SJason Schmidlapp * PARAMETERS
76*062c5bc4SJason Schmidlapp *
77*062c5bc4SJason Schmidlapp * sem pointer to an instance of sem_t
78*062c5bc4SJason Schmidlapp *
79*062c5bc4SJason Schmidlapp * sval pointer to int.
80*062c5bc4SJason Schmidlapp *
81*062c5bc4SJason Schmidlapp * DESCRIPTION
82*062c5bc4SJason Schmidlapp * This function stores the current count value of the semaphore
83*062c5bc4SJason Schmidlapp * pointed to by sem in the int pointed to by sval.
84*062c5bc4SJason Schmidlapp */
85*062c5bc4SJason Schmidlapp {
86*062c5bc4SJason Schmidlapp if (sem == NULL || *sem == NULL || sval == NULL)
87*062c5bc4SJason Schmidlapp {
88*062c5bc4SJason Schmidlapp errno = EINVAL;
89*062c5bc4SJason Schmidlapp return -1;
90*062c5bc4SJason Schmidlapp }
91*062c5bc4SJason Schmidlapp else
92*062c5bc4SJason Schmidlapp {
93*062c5bc4SJason Schmidlapp long value;
94*062c5bc4SJason Schmidlapp register sem_t s = *sem;
95*062c5bc4SJason Schmidlapp int result = 0;
96*062c5bc4SJason Schmidlapp
97*062c5bc4SJason Schmidlapp if ((result = pthread_mutex_lock(&s->lock)) == 0)
98*062c5bc4SJason Schmidlapp {
99*062c5bc4SJason Schmidlapp /* See sem_destroy.c
100*062c5bc4SJason Schmidlapp */
101*062c5bc4SJason Schmidlapp if (*sem == NULL)
102*062c5bc4SJason Schmidlapp {
103*062c5bc4SJason Schmidlapp (void) pthread_mutex_unlock (&s->lock);
104*062c5bc4SJason Schmidlapp errno = EINVAL;
105*062c5bc4SJason Schmidlapp return -1;
106*062c5bc4SJason Schmidlapp }
107*062c5bc4SJason Schmidlapp
108*062c5bc4SJason Schmidlapp value = s->value;
109*062c5bc4SJason Schmidlapp (void) pthread_mutex_unlock(&s->lock);
110*062c5bc4SJason Schmidlapp *sval = value;
111*062c5bc4SJason Schmidlapp }
112*062c5bc4SJason Schmidlapp
113*062c5bc4SJason Schmidlapp return result;
114*062c5bc4SJason Schmidlapp }
115*062c5bc4SJason Schmidlapp
116*062c5bc4SJason Schmidlapp } /* sem_getvalue */
117