summaryrefslogtreecommitdiffstats
path: root/cpukit/posix/src/sigtimedwait.c
blob: 77dbe533ca698e27b8415825074c369c4186a18b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
/**
 *  @file
 *
 *  @brief Wait for Queued Signals
 *  @ingroup POSIXAPI
 */

/*
 *  COPYRIGHT (c) 1989-2008.
 *  On-Line Applications Research Corporation (OAR).
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.org/license/LICENSE.
 */

#if HAVE_CONFIG_H
#include "config.h"
#endif

#include <pthread.h>
#include <signal.h>
#include <errno.h>

#include <rtems/posix/pthreadimpl.h>
#include <rtems/posix/psignalimpl.h>
#include <rtems/score/threadqimpl.h>
#include <rtems/seterr.h>
#include <rtems/score/isr.h>

static int _POSIX_signals_Get_lowest(
  sigset_t   set
)
{
  int signo;

  for ( signo = SIGRTMIN ; signo <= SIGRTMAX ; signo++ ) {
    if ( set & signo_to_mask( signo ) ) {
      goto found_it;
    }
  }

  /*
   *  We assume SIGHUP == 1 and is the first non-real-time signal.
   */

  #if (SIGHUP != 1)
    #error "Assumption that SIGHUP==1 violated!!"
  #endif
  for ( signo = SIGHUP ; signo <= __SIGLASTNOTRT ; signo++ ) {
    if ( set & signo_to_mask( signo ) ) {
      goto found_it;
    }
  }

  /*
   *  This is structured this way to eliminate the need to have
   *  a return 0.  This routine will NOT be called unless a signal
   *  is pending in the set passed in.
   */
found_it:
  return signo;
}

/**
 *  3.3.8 Synchronously Accept a Signal, P1003.1b-1993, p. 76
 */
int sigtimedwait(
  const sigset_t         *__restrict set,
  siginfo_t              *__restrict info,
  const struct timespec  *__restrict timeout
)
{
  Thread_Control    *executing;
  POSIX_API_Control *api;
  Watchdog_Interval  interval;
  siginfo_t          signal_information;
  siginfo_t         *the_info;
  int                signo;
  ISR_lock_Context   lock_context;

  /*
   *  Error check parameters before disabling interrupts.
   */
  if ( !set )
    rtems_set_errno_and_return_minus_one( EINVAL );

  /*  NOTE: This is very specifically a RELATIVE not ABSOLUTE time
   *        in the Open Group specification.
   */

  interval = 0;
  if ( timeout ) {

    if ( !_Timespec_Is_valid( timeout ) )
      rtems_set_errno_and_return_minus_one( EINVAL );

    interval = _Timespec_To_ticks( timeout );

    if ( !interval )
      rtems_set_errno_and_return_minus_one( EINVAL );
  }

  /*
   *  Initialize local variables.
   */

  the_info = ( info ) ? info : &signal_information;

  executing = _Thread_Get_executing();
  api = executing->API_Extensions[ THREAD_API_POSIX ];

  /*
   *  What if they are already pending?
   */

  /* API signals pending? */

  _POSIX_signals_Acquire( &lock_context );
  if ( *set & api->signals_pending ) {
    /* XXX real info later */
    the_info->si_signo = _POSIX_signals_Get_lowest( api->signals_pending );
    _POSIX_signals_Clear_signals(
      api,
      the_info->si_signo,
      the_info,
      false,
      false,
      false
    );
    _POSIX_signals_Release( &lock_context );

    the_info->si_code = SI_USER;
    the_info->si_value.sival_int = 0;
    return the_info->si_signo;
  }

  /* Process pending signals? */

  if ( *set & _POSIX_signals_Pending ) {
    signo = _POSIX_signals_Get_lowest( _POSIX_signals_Pending );
    _POSIX_signals_Clear_signals( api, signo, the_info, true, false, false );
    _POSIX_signals_Release( &lock_context );

    the_info->si_signo = signo;
    the_info->si_code = SI_USER;
    the_info->si_value.sival_int = 0;
    return signo;
  }

  the_info->si_signo = -1;

  executing->Wait.return_code     = EINTR;
  executing->Wait.option          = *set;
  executing->Wait.return_argument = the_info;
  _Thread_queue_Enqueue_critical(
    &_POSIX_signals_Wait_queue.Queue,
    POSIX_SIGNALS_TQ_OPERATIONS,
    executing,
    STATES_WAITING_FOR_SIGNAL | STATES_INTERRUPTIBLE_BY_SIGNAL,
    interval,
    EAGAIN,
    &lock_context
  );

  /*
   * When the thread is set free by a signal, it is need to eliminate
   * the signal.
   */

  _POSIX_signals_Clear_signals(
    api,
    the_info->si_signo,
    the_info,
    false,
    false,
    true
  );

  /* Set errno only if return code is not EINTR or
   * if EINTR was caused by a signal being caught, which
   * was not in our set.
   */

  if ( (executing->Wait.return_code != EINTR)
       || !(*set & signo_to_mask( the_info->si_signo )) ) {
    errno = executing->Wait.return_code;
    return -1;
  }

  return the_info->si_signo;
}