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
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/***********************************************************************/
/* */
/* Caml Special Light */
/* */
/* Xavier Leroy and Damien Doligez, INRIA Rocquencourt */
/* */
/* Copyright 1995 Institut National de Recherche en Informatique et */
/* Automatique. Distributed only by permission. */
/* */
/***********************************************************************/
/* $Id$ */
#include <signal.h>
#include "alloc.h"
#include "config.h"
#include "fail.h"
#include "memory.h"
#include "misc.h"
#include "mlvalues.h"
#include "roots.h"
#include "signals.h"
Volatile int async_signal_mode = 0;
Volatile int pending_signal = 0;
Volatile int something_to_do = 0;
Volatile int force_major_slice = 0;
value signal_handlers = 0;
void (*enter_blocking_section_hook)() = NULL;
void (*leave_blocking_section_hook)() = NULL;
static void execute_signal(signal_number)
int signal_number;
{
Assert (!async_signal_mode);
callback(Field(signal_handlers, signal_number), Val_int(signal_number));
}
void handle_signal(signal_number)
int signal_number;
{
#ifndef POSIX_SIGNALS
#ifndef BSD_SIGNALS
signal(signal_number, handle_signal);
#endif
#endif
if (async_signal_mode){
leave_blocking_section ();
execute_signal(signal_number);
enter_blocking_section ();
}else{
pending_signal = signal_number;
something_to_do = 1;
}
}
void urge_major_slice ()
{
force_major_slice = 1;
something_to_do = 1;
}
void enter_blocking_section()
{
int temp;
while (1){
Assert (!async_signal_mode);
/* If a signal arrives between the next two instructions,
it will be lost. */
temp = pending_signal; pending_signal = 0;
if (temp) execute_signal(temp);
async_signal_mode = 1;
if (!pending_signal) break;
async_signal_mode = 0;
}
if (enter_blocking_section_hook != NULL) enter_blocking_section_hook();
}
/* This function may be called from outside a blocking section. */
void leave_blocking_section()
{
if (leave_blocking_section_hook != NULL) leave_blocking_section_hook();
async_signal_mode = 0;
}
#ifndef SIGABRT
#define SIGABRT -1
#endif
#ifndef SIGALRM
#define SIGALRM -1
#endif
#ifndef SIGFPE
#define SIGFPE -1
#endif
#ifndef SIGHUP
#define SIGHUP -1
#endif
#ifndef SIGILL
#define SIGILL -1
#endif
#ifndef SIGINT
#define SIGINT -1
#endif
#ifndef SIGKILL
#define SIGKILL -1
#endif
#ifndef SIGPIPE
#define SIGPIPE -1
#endif
#ifndef SIGQUIT
#define SIGQUIT -1
#endif
#ifndef SIGSEGV
#define SIGSEGV -1
#endif
#ifndef SIGTERM
#define SIGTERM -1
#endif
#ifndef SIGUSR1
#define SIGUSR1 -1
#endif
#ifndef SIGUSR2
#define SIGUSR2 -1
#endif
#ifndef SIGCHLD
#define SIGCHLD -1
#endif
#ifndef SIGCONT
#define SIGCONT -1
#endif
#ifndef SIGSTOP
#define SIGSTOP -1
#endif
#ifndef SIGTSTP
#define SIGTSTP -1
#endif
#ifndef SIGTTIN
#define SIGTTIN -1
#endif
#ifndef SIGTTOU
#define SIGTTOU -1
#endif
#ifndef SIGVTALRM
#define SIGVTALRM -1
#endif
#ifndef SIGPROF
#define SIGPROF -1
#endif
int posix_signals[] = {
SIGABRT, SIGALRM, SIGFPE, SIGHUP, SIGILL, SIGINT, SIGKILL, SIGPIPE,
SIGQUIT, SIGSEGV, SIGTERM, SIGUSR1, SIGUSR2, SIGCHLD, SIGCONT,
SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGVTALRM, SIGPROF
};
#ifndef NSIG
#define NSIG 32
#endif
value install_signal_handler(signal_number, action) /* ML */
value signal_number, action;
{
int sig;
void (*act)();
#ifdef POSIX_SIGNALS
struct sigaction sigact;
#endif
sig = Int_val(signal_number);
if (sig < 0) sig = posix_signals[-sig-1];
if (sig < 0 || sig >= NSIG)
invalid_argument("Sys.signal: unavailable signal");
switch(action) {
case Val_int(0): /* Signal_default */
act = SIG_DFL;
break;
case Val_int(1): /* Signal_ignore */
act = SIG_IGN;
break;
default: /* Signal_handle */
if (signal_handlers == 0) {
int i;
Push_roots(r, 1);
r[0] = action;
signal_handlers = alloc_tuple(NSIG);
action = r[0];
Pop_roots();
for (i = 0; i < NSIG; i++) Field(signal_handlers, i) = Val_int(0);
register_global_root(&signal_handlers);
}
modify(&Field(signal_handlers, sig), Field(action, 0));
act = handle_signal;
break;
}
#ifdef POSIX_SIGNALS
sigact.sa_handler = act;
sigemptyset(&sigact.sa_mask);
sigact.sa_flags = 0;
sigaction(sig, &sigact, NULL);
#else
signal(sig, act);
#endif
return Val_unit;
}
|
