1*062c5bc4SJason Schmidlapp /*
2*062c5bc4SJason Schmidlapp * pthread_mutex_destroy.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 <stdio.h>
44*062c5bc4SJason Schmidlapp #include <stdlib.h>
45*062c5bc4SJason Schmidlapp #include <string.h>
46*062c5bc4SJason Schmidlapp
47*062c5bc4SJason Schmidlapp #include "pthread.h"
48*062c5bc4SJason Schmidlapp #include "implement.h"
49*062c5bc4SJason Schmidlapp
50*062c5bc4SJason Schmidlapp
51*062c5bc4SJason Schmidlapp int
pthread_mutex_destroy(pthread_mutex_t * mutex)52*062c5bc4SJason Schmidlapp pthread_mutex_destroy (pthread_mutex_t * mutex)
53*062c5bc4SJason Schmidlapp {
54*062c5bc4SJason Schmidlapp int result = 0;
55*062c5bc4SJason Schmidlapp pthread_mutex_t mx;
56*062c5bc4SJason Schmidlapp
57*062c5bc4SJason Schmidlapp /*
58*062c5bc4SJason Schmidlapp * Let the system deal with invalid pointers.
59*062c5bc4SJason Schmidlapp */
60*062c5bc4SJason Schmidlapp
61*062c5bc4SJason Schmidlapp /*
62*062c5bc4SJason Schmidlapp * Check to see if we have something to delete.
63*062c5bc4SJason Schmidlapp */
64*062c5bc4SJason Schmidlapp if (*mutex < PTHREAD_ERRORCHECK_MUTEX_INITIALIZER)
65*062c5bc4SJason Schmidlapp {
66*062c5bc4SJason Schmidlapp mx = *mutex;
67*062c5bc4SJason Schmidlapp
68*062c5bc4SJason Schmidlapp result = pthread_mutex_trylock (&mx);
69*062c5bc4SJason Schmidlapp
70*062c5bc4SJason Schmidlapp /*
71*062c5bc4SJason Schmidlapp * If trylock succeeded and the mutex is not recursively locked it
72*062c5bc4SJason Schmidlapp * can be destroyed.
73*062c5bc4SJason Schmidlapp */
74*062c5bc4SJason Schmidlapp if (result == 0)
75*062c5bc4SJason Schmidlapp {
76*062c5bc4SJason Schmidlapp if (mx->kind != PTHREAD_MUTEX_RECURSIVE || 1 == mx->recursive_count)
77*062c5bc4SJason Schmidlapp {
78*062c5bc4SJason Schmidlapp /*
79*062c5bc4SJason Schmidlapp * FIXME!!!
80*062c5bc4SJason Schmidlapp * The mutex isn't held by another thread but we could still
81*062c5bc4SJason Schmidlapp * be too late invalidating the mutex below since another thread
82*062c5bc4SJason Schmidlapp * may already have entered mutex_lock and the check for a valid
83*062c5bc4SJason Schmidlapp * *mutex != NULL.
84*062c5bc4SJason Schmidlapp *
85*062c5bc4SJason Schmidlapp * Note that this would be an unusual situation because it is not
86*062c5bc4SJason Schmidlapp * common that mutexes are destroyed while they are still in
87*062c5bc4SJason Schmidlapp * use by other threads.
88*062c5bc4SJason Schmidlapp */
89*062c5bc4SJason Schmidlapp *mutex = NULL;
90*062c5bc4SJason Schmidlapp
91*062c5bc4SJason Schmidlapp result = pthread_mutex_unlock (&mx);
92*062c5bc4SJason Schmidlapp
93*062c5bc4SJason Schmidlapp if (result == 0)
94*062c5bc4SJason Schmidlapp {
95*062c5bc4SJason Schmidlapp pte_osSemaphoreDelete(mx->handle);
96*062c5bc4SJason Schmidlapp
97*062c5bc4SJason Schmidlapp free(mx);
98*062c5bc4SJason Schmidlapp
99*062c5bc4SJason Schmidlapp }
100*062c5bc4SJason Schmidlapp else
101*062c5bc4SJason Schmidlapp {
102*062c5bc4SJason Schmidlapp /*
103*062c5bc4SJason Schmidlapp * Restore the mutex before we return the error.
104*062c5bc4SJason Schmidlapp */
105*062c5bc4SJason Schmidlapp *mutex = mx;
106*062c5bc4SJason Schmidlapp }
107*062c5bc4SJason Schmidlapp }
108*062c5bc4SJason Schmidlapp else /* mx->recursive_count > 1 */
109*062c5bc4SJason Schmidlapp {
110*062c5bc4SJason Schmidlapp /*
111*062c5bc4SJason Schmidlapp * The mutex must be recursive and already locked by us (this thread).
112*062c5bc4SJason Schmidlapp */
113*062c5bc4SJason Schmidlapp mx->recursive_count--; /* Undo effect of pthread_mutex_trylock() above */
114*062c5bc4SJason Schmidlapp result = EBUSY;
115*062c5bc4SJason Schmidlapp }
116*062c5bc4SJason Schmidlapp }
117*062c5bc4SJason Schmidlapp }
118*062c5bc4SJason Schmidlapp else
119*062c5bc4SJason Schmidlapp {
120*062c5bc4SJason Schmidlapp /*
121*062c5bc4SJason Schmidlapp * See notes in pte_mutex_check_need_init() above also.
122*062c5bc4SJason Schmidlapp */
123*062c5bc4SJason Schmidlapp
124*062c5bc4SJason Schmidlapp pte_osMutexLock (pte_mutex_test_init_lock);
125*062c5bc4SJason Schmidlapp
126*062c5bc4SJason Schmidlapp
127*062c5bc4SJason Schmidlapp /*
128*062c5bc4SJason Schmidlapp * Check again.
129*062c5bc4SJason Schmidlapp */
130*062c5bc4SJason Schmidlapp if (*mutex >= PTHREAD_ERRORCHECK_MUTEX_INITIALIZER)
131*062c5bc4SJason Schmidlapp {
132*062c5bc4SJason Schmidlapp /*
133*062c5bc4SJason Schmidlapp * This is all we need to do to destroy a statically
134*062c5bc4SJason Schmidlapp * initialised mutex that has not yet been used (initialised).
135*062c5bc4SJason Schmidlapp * If we get to here, another thread
136*062c5bc4SJason Schmidlapp * waiting to initialise this mutex will get an EINVAL.
137*062c5bc4SJason Schmidlapp */
138*062c5bc4SJason Schmidlapp *mutex = NULL;
139*062c5bc4SJason Schmidlapp }
140*062c5bc4SJason Schmidlapp else
141*062c5bc4SJason Schmidlapp {
142*062c5bc4SJason Schmidlapp /*
143*062c5bc4SJason Schmidlapp * The mutex has been initialised while we were waiting
144*062c5bc4SJason Schmidlapp * so assume it's in use.
145*062c5bc4SJason Schmidlapp */
146*062c5bc4SJason Schmidlapp result = EBUSY;
147*062c5bc4SJason Schmidlapp }
148*062c5bc4SJason Schmidlapp
149*062c5bc4SJason Schmidlapp pte_osMutexUnlock(pte_mutex_test_init_lock);
150*062c5bc4SJason Schmidlapp
151*062c5bc4SJason Schmidlapp }
152*062c5bc4SJason Schmidlapp
153*062c5bc4SJason Schmidlapp return (result);
154*062c5bc4SJason Schmidlapp }
155