GNU Octave  9.1.0
A high-level interpreted language, primarily intended for numerical computations, mostly compatible with Matlab
cxx-signal-helpers.cc
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25 
26 #if defined (HAVE_CONFIG_H)
27 # include "config.h"
28 #endif
29 
30 #include <sys/types.h>
31 #include <signal.h>
32 #include <stdlib.h>
33 #include <string.h>
34 
35 #if defined (__WIN32__) && ! defined (__CYGWIN__)
36 # include <windows.h>
37 #else
38 # include <pthread.h>
39 #endif
40 
41 #include "signal-wrappers.h"
42 
43 #if ! defined (__WIN32__) || defined (__CYGWIN__)
44 
45 // The following pattern often used in C code to initialize a static
46 // variable could possibly cause trouble in multi-threaded code:
47 //
48 // TYPE * get_var () {
49 // static bool initialized = false;
50 // static TYPE *var;
51 // if (! initialized) {
52 // var = ...;
53 // initialized = true;
54 // }
55 // return var;
56 // }
57 //
58 // Changing this code to
59 //
60 // static TYPE *var = init_var ();
61 //
62 // doesn't work in C because the static variable can't be initialized by
63 // a function call. So we have to do this job in C++. To avoid calling
64 // new, initialize sigset_t rather than a pointer to allocated storage.
65 
66 static const sigset_t
67 init_async_signals ()
68 {
69  sigset_t sigmask;
70 
71  sigemptyset (&sigmask);
72 
73  // The signals listed here should match the list of signals that
74  // we handle in the signal handler thread.
75 
76  // Interrupt signals.
77 
78 #if defined (SIGINT)
79  sigaddset (&sigmask, SIGINT);
80 #endif
81 
82 #if defined (SIGBREAK)
83  sigaddset (&sigmask, SIGBREAK);
84 #endif
85 
86  // Termination signals.
87 
88 #if defined (SIGHUP)
89  sigaddset (&sigmask, SIGHUP);
90 #endif
91 
92 #if defined (SIGQUIT)
93  sigaddset (&sigmask, SIGQUIT);
94 #endif
95 
96 #if defined (SIGTERM)
97  sigaddset (&sigmask, SIGTERM);
98 #endif
99 
100  // Alarm signals.
101 
102 #if defined (SIGALRM)
103  sigaddset (&sigmask, SIGALRM);
104 #endif
105 
106 #if defined (SIGVTALRM)
107  sigaddset (&sigmask, SIGVTALRM);
108 #endif
109 
110  // I/O signals.
111 
112 #if defined (SIGLOST)
113  sigaddset (&sigmask, SIGLOST);
114 #endif
115 
116 #if defined (SIGPIPE)
117  sigaddset (&sigmask, SIGPIPE);
118 #endif
119 
120  // Job control signals.
121 
122 #if defined (SIGCHLD)
123  sigaddset (&sigmask, SIGCHLD);
124 #endif
125 
126 #if defined (SIGCLD)
127  sigaddset (&sigmask, SIGCLD);
128 #endif
129 
130  // Resource limit signals.
131 
132 #if defined (SIGXCPU)
133  sigaddset (&sigmask, SIGXCPU);
134 #endif
135 
136 #if defined (SIGXFSZ)
137  sigaddset (&sigmask, SIGXFSZ);
138 #endif
139 
140  return sigmask;
141 }
142 
143 // Initialized once, is const so we never write to it again and it can
144 // be accessed by multiple threads without locking.
145 
146 static const sigset_t async_signals = init_async_signals ();
147 
148 #endif
149 
150 void
152 {
153 #if ! defined (__WIN32__) || defined (__CYGWIN__)
154  pthread_sigmask (SIG_BLOCK, &async_signals, 0);
155 #endif
156 }
157 
158 void
160 {
161 #if ! defined (__WIN32__) || defined (__CYGWIN__)
162  pthread_sigmask (SIG_UNBLOCK, &async_signals, 0);
163 #endif
164 }
165 
166 #if ! defined (__WIN32__) || defined (__CYGWIN__)
167 
168 static void *
169 signal_watcher (void *arg)
170 {
171  octave_sig_handler *handler = reinterpret_cast<octave_sig_handler *> (arg);
172 
174 
175  while (1)
176  {
177  int sig_caught;
178 
179  if (sigwait (&async_signals, &sig_caught))
180  {
181  // FIXME: what else should we do?
182  abort ();
183  }
184 
185  // Let handler have complete control over what to do.
186  (*handler) (sig_caught);
187  }
188 }
189 
190 #endif
191 
192 void
194 {
195 #if ! defined (__WIN32__)
196  pthread_t sighandler_thread_id;
197 
198  if (pthread_create (&sighandler_thread_id, 0, signal_watcher,
199  reinterpret_cast<void *> (handler)))
200  {
201  // FIXME: what else should we do?
202  abort ();
203  }
204 #else
206 
207  octave_unused_parameter (handler);
208 #endif
209 }
void octave_create_interrupt_watcher_thread(octave_sig_handler *handler)
void octave_unblock_async_signals()
void octave_block_async_signals()
void octave_sig_handler(int)