1*062c5bc4SJason Schmidlapp /*
2*062c5bc4SJason Schmidlapp * -------------------------------------------------------------
3*062c5bc4SJason Schmidlapp *
4*062c5bc4SJason Schmidlapp * Module: sem_post_multiple.c
5*062c5bc4SJason Schmidlapp *
6*062c5bc4SJason Schmidlapp * Purpose:
7*062c5bc4SJason Schmidlapp * Semaphores aren't actually part of the PThreads standard.
8*062c5bc4SJason Schmidlapp * They are defined by the POSIX Standard:
9*062c5bc4SJason Schmidlapp *
10*062c5bc4SJason Schmidlapp * POSIX 1003.1b-1993 (POSIX.1b)
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 <stdio.h>
51*062c5bc4SJason Schmidlapp #include <stdlib.h>
52*062c5bc4SJason Schmidlapp
53*062c5bc4SJason Schmidlapp #include "pthread.h"
54*062c5bc4SJason Schmidlapp #include "semaphore.h"
55*062c5bc4SJason Schmidlapp #include "implement.h"
56*062c5bc4SJason Schmidlapp
57*062c5bc4SJason Schmidlapp
58*062c5bc4SJason Schmidlapp int
sem_post_multiple(sem_t * sem,int count)59*062c5bc4SJason Schmidlapp sem_post_multiple (sem_t * sem, int count)
60*062c5bc4SJason Schmidlapp /*
61*062c5bc4SJason Schmidlapp * ------------------------------------------------------
62*062c5bc4SJason Schmidlapp * DOCPUBLIC
63*062c5bc4SJason Schmidlapp * This function posts multiple wakeups to a semaphore.
64*062c5bc4SJason Schmidlapp *
65*062c5bc4SJason Schmidlapp * PARAMETERS
66*062c5bc4SJason Schmidlapp * sem
67*062c5bc4SJason Schmidlapp * pointer to an instance of sem_t
68*062c5bc4SJason Schmidlapp *
69*062c5bc4SJason Schmidlapp * count
70*062c5bc4SJason Schmidlapp * counter, must be greater than zero.
71*062c5bc4SJason Schmidlapp *
72*062c5bc4SJason Schmidlapp * DESCRIPTION
73*062c5bc4SJason Schmidlapp * This function posts multiple wakeups to a semaphore. If there
74*062c5bc4SJason Schmidlapp * are waiting threads (or processes), n <= count are awakened;
75*062c5bc4SJason Schmidlapp * the semaphore value is incremented by count - n.
76*062c5bc4SJason Schmidlapp *
77*062c5bc4SJason Schmidlapp * RESULTS
78*062c5bc4SJason Schmidlapp * 0 successfully posted semaphore,
79*062c5bc4SJason Schmidlapp * -1 failed, error in errno
80*062c5bc4SJason Schmidlapp * ERRNO
81*062c5bc4SJason Schmidlapp * EINVAL 'sem' is not a valid semaphore
82*062c5bc4SJason Schmidlapp * or count is less than or equal to zero.
83*062c5bc4SJason Schmidlapp * ERANGE semaphore count is too big
84*062c5bc4SJason Schmidlapp *
85*062c5bc4SJason Schmidlapp * ------------------------------------------------------
86*062c5bc4SJason Schmidlapp */
87*062c5bc4SJason Schmidlapp {
88*062c5bc4SJason Schmidlapp int result = 0;
89*062c5bc4SJason Schmidlapp long waiters;
90*062c5bc4SJason Schmidlapp sem_t s = *sem;
91*062c5bc4SJason Schmidlapp
92*062c5bc4SJason Schmidlapp if (s == NULL || count <= 0)
93*062c5bc4SJason Schmidlapp {
94*062c5bc4SJason Schmidlapp result = EINVAL;
95*062c5bc4SJason Schmidlapp }
96*062c5bc4SJason Schmidlapp else if ((result = pthread_mutex_lock (&s->lock)) == 0)
97*062c5bc4SJason Schmidlapp {
98*062c5bc4SJason Schmidlapp /* See sem_destroy.c
99*062c5bc4SJason Schmidlapp */
100*062c5bc4SJason Schmidlapp if (*sem == NULL)
101*062c5bc4SJason Schmidlapp {
102*062c5bc4SJason Schmidlapp (void) pthread_mutex_unlock (&s->lock);
103*062c5bc4SJason Schmidlapp result = EINVAL;
104*062c5bc4SJason Schmidlapp return -1;
105*062c5bc4SJason Schmidlapp }
106*062c5bc4SJason Schmidlapp
107*062c5bc4SJason Schmidlapp if (s->value <= (SEM_VALUE_MAX - count))
108*062c5bc4SJason Schmidlapp {
109*062c5bc4SJason Schmidlapp waiters = -s->value;
110*062c5bc4SJason Schmidlapp s->value += count;
111*062c5bc4SJason Schmidlapp if (waiters > 0)
112*062c5bc4SJason Schmidlapp {
113*062c5bc4SJason Schmidlapp
114*062c5bc4SJason Schmidlapp pte_osSemaphorePost(s->sem, (waiters<=count)?waiters:count);
115*062c5bc4SJason Schmidlapp result = 0;
116*062c5bc4SJason Schmidlapp }
117*062c5bc4SJason Schmidlapp /*
118*062c5bc4SJason Schmidlapp else
119*062c5bc4SJason Schmidlapp {
120*062c5bc4SJason Schmidlapp s->value -= count;
121*062c5bc4SJason Schmidlapp result = EINVAL;
122*062c5bc4SJason Schmidlapp }
123*062c5bc4SJason Schmidlapp */
124*062c5bc4SJason Schmidlapp }
125*062c5bc4SJason Schmidlapp else
126*062c5bc4SJason Schmidlapp {
127*062c5bc4SJason Schmidlapp result = ERANGE;
128*062c5bc4SJason Schmidlapp }
129*062c5bc4SJason Schmidlapp
130*062c5bc4SJason Schmidlapp (void) pthread_mutex_unlock (&s->lock);
131*062c5bc4SJason Schmidlapp }
132*062c5bc4SJason Schmidlapp
133*062c5bc4SJason Schmidlapp if (result != 0)
134*062c5bc4SJason Schmidlapp {
135*062c5bc4SJason Schmidlapp errno = result;
136*062c5bc4SJason Schmidlapp return -1;
137*062c5bc4SJason Schmidlapp }
138*062c5bc4SJason Schmidlapp
139*062c5bc4SJason Schmidlapp return 0;
140*062c5bc4SJason Schmidlapp
141*062c5bc4SJason Schmidlapp } /* sem_post_multiple */
142