1*062c5bc4SJason Schmidlapp /*
2*062c5bc4SJason Schmidlapp * pthread_mutex_timedlock.c
3*062c5bc4SJason Schmidlapp *
4*062c5bc4SJason Schmidlapp * Description:
5*062c5bc4SJason Schmidlapp * This translation unit implements mutual exclusion (mutex) primitives.
6*062c5bc4SJason Schmidlapp *
7*062c5bc4SJason Schmidlapp * --------------------------------------------------------------------------
8*062c5bc4SJason Schmidlapp *
9*062c5bc4SJason Schmidlapp * Pthreads-embedded (PTE) - POSIX Threads Library for embedded systems
10*062c5bc4SJason Schmidlapp * Copyright(C) 2008 Jason Schmidlapp
11*062c5bc4SJason Schmidlapp *
12*062c5bc4SJason Schmidlapp * Contact Email: jschmidlapp@users.sourceforge.net
13*062c5bc4SJason Schmidlapp *
14*062c5bc4SJason Schmidlapp *
15*062c5bc4SJason Schmidlapp * Based upon Pthreads-win32 - POSIX Threads Library for Win32
16*062c5bc4SJason Schmidlapp * Copyright(C) 1998 John E. Bossom
17*062c5bc4SJason Schmidlapp * Copyright(C) 1999,2005 Pthreads-win32 contributors
18*062c5bc4SJason Schmidlapp *
19*062c5bc4SJason Schmidlapp * Contact Email: rpj@callisto.canberra.edu.au
20*062c5bc4SJason Schmidlapp *
21*062c5bc4SJason Schmidlapp * The original list of contributors to the Pthreads-win32 project
22*062c5bc4SJason Schmidlapp * is contained in the file CONTRIBUTORS.ptw32 included with the
23*062c5bc4SJason Schmidlapp * source code distribution. The list can also be seen at the
24*062c5bc4SJason Schmidlapp * following World Wide Web location:
25*062c5bc4SJason Schmidlapp * http://sources.redhat.com/pthreads-win32/contributors.html
26*062c5bc4SJason Schmidlapp *
27*062c5bc4SJason Schmidlapp * This library is free software; you can redistribute it and/or
28*062c5bc4SJason Schmidlapp * modify it under the terms of the GNU Lesser General Public
29*062c5bc4SJason Schmidlapp * License as published by the Free Software Foundation; either
30*062c5bc4SJason Schmidlapp * version 2 of the License, or (at your option) any later version.
31*062c5bc4SJason Schmidlapp *
32*062c5bc4SJason Schmidlapp * This library is distributed in the hope that it will be useful,
33*062c5bc4SJason Schmidlapp * but WITHOUT ANY WARRANTY; without even the implied warranty of
34*062c5bc4SJason Schmidlapp * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
35*062c5bc4SJason Schmidlapp * Lesser General Public License for more details.
36*062c5bc4SJason Schmidlapp *
37*062c5bc4SJason Schmidlapp * You should have received a copy of the GNU Lesser General Public
38*062c5bc4SJason Schmidlapp * License along with this library in the file COPYING.LIB;
39*062c5bc4SJason Schmidlapp * if not, write to the Free Software Foundation, Inc.,
40*062c5bc4SJason Schmidlapp * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
41*062c5bc4SJason Schmidlapp */
42*062c5bc4SJason Schmidlapp
43*062c5bc4SJason Schmidlapp #include <pte_osal.h>
44*062c5bc4SJason Schmidlapp
45*062c5bc4SJason Schmidlapp #include <stdio.h>
46*062c5bc4SJason Schmidlapp #include <stdlib.h>
47*062c5bc4SJason Schmidlapp
48*062c5bc4SJason Schmidlapp #include "pthread.h"
49*062c5bc4SJason Schmidlapp #include "implement.h"
50*062c5bc4SJason Schmidlapp
51*062c5bc4SJason Schmidlapp
52*062c5bc4SJason Schmidlapp static int
pte_timed_eventwait(pte_osSemaphoreHandle event,const struct timespec * abstime)53*062c5bc4SJason Schmidlapp pte_timed_eventwait (pte_osSemaphoreHandle event, const struct timespec *abstime)
54*062c5bc4SJason Schmidlapp /*
55*062c5bc4SJason Schmidlapp * ------------------------------------------------------
56*062c5bc4SJason Schmidlapp * DESCRIPTION
57*062c5bc4SJason Schmidlapp * This function waits on an event until signaled or until
58*062c5bc4SJason Schmidlapp * abstime passes.
59*062c5bc4SJason Schmidlapp * If abstime has passed when this routine is called then
60*062c5bc4SJason Schmidlapp * it returns a result to indicate this.
61*062c5bc4SJason Schmidlapp *
62*062c5bc4SJason Schmidlapp * If 'abstime' is a NULL pointer then this function will
63*062c5bc4SJason Schmidlapp * block until it can successfully decrease the value or
64*062c5bc4SJason Schmidlapp * until interrupted by a signal.
65*062c5bc4SJason Schmidlapp *
66*062c5bc4SJason Schmidlapp * This routine is not a cancelation point.
67*062c5bc4SJason Schmidlapp *
68*062c5bc4SJason Schmidlapp * RESULTS
69*062c5bc4SJason Schmidlapp * 0 successfully signaled,
70*062c5bc4SJason Schmidlapp * ETIMEDOUT abstime passed
71*062c5bc4SJason Schmidlapp * EINVAL 'event' is not a valid event,
72*062c5bc4SJason Schmidlapp *
73*062c5bc4SJason Schmidlapp * ------------------------------------------------------
74*062c5bc4SJason Schmidlapp */
75*062c5bc4SJason Schmidlapp {
76*062c5bc4SJason Schmidlapp
77*062c5bc4SJason Schmidlapp unsigned int milliseconds;
78*062c5bc4SJason Schmidlapp pte_osResult status;
79*062c5bc4SJason Schmidlapp int retval;
80*062c5bc4SJason Schmidlapp
81*062c5bc4SJason Schmidlapp if (abstime == NULL)
82*062c5bc4SJason Schmidlapp {
83*062c5bc4SJason Schmidlapp status = pte_osSemaphorePend(event, NULL);
84*062c5bc4SJason Schmidlapp }
85*062c5bc4SJason Schmidlapp else
86*062c5bc4SJason Schmidlapp {
87*062c5bc4SJason Schmidlapp /*
88*062c5bc4SJason Schmidlapp * Calculate timeout as milliseconds from current system time.
89*062c5bc4SJason Schmidlapp */
90*062c5bc4SJason Schmidlapp milliseconds = pte_relmillisecs (abstime);
91*062c5bc4SJason Schmidlapp
92*062c5bc4SJason Schmidlapp status = pte_osSemaphorePend(event, &milliseconds);
93*062c5bc4SJason Schmidlapp }
94*062c5bc4SJason Schmidlapp
95*062c5bc4SJason Schmidlapp
96*062c5bc4SJason Schmidlapp if (status == PTE_OS_TIMEOUT)
97*062c5bc4SJason Schmidlapp {
98*062c5bc4SJason Schmidlapp retval = ETIMEDOUT;
99*062c5bc4SJason Schmidlapp }
100*062c5bc4SJason Schmidlapp else
101*062c5bc4SJason Schmidlapp {
102*062c5bc4SJason Schmidlapp retval = 0;
103*062c5bc4SJason Schmidlapp }
104*062c5bc4SJason Schmidlapp
105*062c5bc4SJason Schmidlapp return retval;
106*062c5bc4SJason Schmidlapp
107*062c5bc4SJason Schmidlapp } /* pte_timed_semwait */
108*062c5bc4SJason Schmidlapp
109*062c5bc4SJason Schmidlapp
110*062c5bc4SJason Schmidlapp int
pthread_mutex_timedlock(pthread_mutex_t * mutex,const struct timespec * abstime)111*062c5bc4SJason Schmidlapp pthread_mutex_timedlock (pthread_mutex_t * mutex,
112*062c5bc4SJason Schmidlapp const struct timespec *abstime)
113*062c5bc4SJason Schmidlapp {
114*062c5bc4SJason Schmidlapp int result;
115*062c5bc4SJason Schmidlapp pthread_mutex_t mx;
116*062c5bc4SJason Schmidlapp
117*062c5bc4SJason Schmidlapp /*
118*062c5bc4SJason Schmidlapp * Let the system deal with invalid pointers.
119*062c5bc4SJason Schmidlapp */
120*062c5bc4SJason Schmidlapp
121*062c5bc4SJason Schmidlapp /*
122*062c5bc4SJason Schmidlapp * We do a quick check to see if we need to do more work
123*062c5bc4SJason Schmidlapp * to initialise a static mutex. We check
124*062c5bc4SJason Schmidlapp * again inside the guarded section of pte_mutex_check_need_init()
125*062c5bc4SJason Schmidlapp * to avoid race conditions.
126*062c5bc4SJason Schmidlapp */
127*062c5bc4SJason Schmidlapp if (*mutex >= PTHREAD_ERRORCHECK_MUTEX_INITIALIZER)
128*062c5bc4SJason Schmidlapp {
129*062c5bc4SJason Schmidlapp if ((result = pte_mutex_check_need_init (mutex)) != 0)
130*062c5bc4SJason Schmidlapp {
131*062c5bc4SJason Schmidlapp return (result);
132*062c5bc4SJason Schmidlapp }
133*062c5bc4SJason Schmidlapp }
134*062c5bc4SJason Schmidlapp
135*062c5bc4SJason Schmidlapp mx = *mutex;
136*062c5bc4SJason Schmidlapp
137*062c5bc4SJason Schmidlapp if (mx->kind == PTHREAD_MUTEX_NORMAL)
138*062c5bc4SJason Schmidlapp {
139*062c5bc4SJason Schmidlapp if (PTE_ATOMIC_EXCHANGE(&mx->lock_idx,1) != 0)
140*062c5bc4SJason Schmidlapp {
141*062c5bc4SJason Schmidlapp while (PTE_ATOMIC_EXCHANGE(&mx->lock_idx,-1) != 0)
142*062c5bc4SJason Schmidlapp {
143*062c5bc4SJason Schmidlapp if (0 != (result = pte_timed_eventwait (mx->handle, abstime)))
144*062c5bc4SJason Schmidlapp {
145*062c5bc4SJason Schmidlapp return result;
146*062c5bc4SJason Schmidlapp }
147*062c5bc4SJason Schmidlapp }
148*062c5bc4SJason Schmidlapp }
149*062c5bc4SJason Schmidlapp }
150*062c5bc4SJason Schmidlapp else
151*062c5bc4SJason Schmidlapp {
152*062c5bc4SJason Schmidlapp pthread_t self = pthread_self();
153*062c5bc4SJason Schmidlapp
154*062c5bc4SJason Schmidlapp if (PTE_ATOMIC_COMPARE_EXCHANGE(&mx->lock_idx,1,0) == 0)
155*062c5bc4SJason Schmidlapp {
156*062c5bc4SJason Schmidlapp mx->recursive_count = 1;
157*062c5bc4SJason Schmidlapp mx->ownerThread = self;
158*062c5bc4SJason Schmidlapp }
159*062c5bc4SJason Schmidlapp else
160*062c5bc4SJason Schmidlapp {
161*062c5bc4SJason Schmidlapp if (pthread_equal (mx->ownerThread, self))
162*062c5bc4SJason Schmidlapp {
163*062c5bc4SJason Schmidlapp if (mx->kind == PTHREAD_MUTEX_RECURSIVE)
164*062c5bc4SJason Schmidlapp {
165*062c5bc4SJason Schmidlapp mx->recursive_count++;
166*062c5bc4SJason Schmidlapp }
167*062c5bc4SJason Schmidlapp else
168*062c5bc4SJason Schmidlapp {
169*062c5bc4SJason Schmidlapp return EDEADLK;
170*062c5bc4SJason Schmidlapp }
171*062c5bc4SJason Schmidlapp }
172*062c5bc4SJason Schmidlapp else
173*062c5bc4SJason Schmidlapp {
174*062c5bc4SJason Schmidlapp while (PTE_ATOMIC_EXCHANGE(&mx->lock_idx,-1) != 0)
175*062c5bc4SJason Schmidlapp {
176*062c5bc4SJason Schmidlapp if (0 != (result = pte_timed_eventwait (mx->handle, abstime)))
177*062c5bc4SJason Schmidlapp {
178*062c5bc4SJason Schmidlapp return result;
179*062c5bc4SJason Schmidlapp }
180*062c5bc4SJason Schmidlapp }
181*062c5bc4SJason Schmidlapp
182*062c5bc4SJason Schmidlapp mx->recursive_count = 1;
183*062c5bc4SJason Schmidlapp mx->ownerThread = self;
184*062c5bc4SJason Schmidlapp }
185*062c5bc4SJason Schmidlapp }
186*062c5bc4SJason Schmidlapp }
187*062c5bc4SJason Schmidlapp
188*062c5bc4SJason Schmidlapp return 0;
189*062c5bc4SJason Schmidlapp }
190