Lines Matching full:signal
34 to a process. Signal delivery resembles the occurrence of a hardware
35 interrupt: the signal is blocked from further occurrence,
38 the \fIhandler\fP to which a signal is delivered, or specify that
39 the signal is to be \fIblocked\fP or \fIignored\fP. A process may
52 to a process is implementation specific. Signal routines execute
53 with the signal that caused their invocation \fIblocked\fP, but other
57 Signal types
63 The set of signals is defined in the file \fI<signal.h>\fP.
77 SIGINT for the normal interrupt signal; SIGQUIT for the more
78 powerful \fIquit\fP signal, that normally causes a core image
82 signal which a process cannot catch or ignore.
88 A process can request notification via a SIGIO signal
91 A process may request to receive a SIGURG signal when an
94 A process may be \fIstopped\fP by a signal sent to it or the members
95 of its process group. The SIGSTOP signal is a powerful stop
96 signal, because it cannot be caught. Other stop signals
99 A SIGCONT signal is sent to a process when it is
101 Processes may receive notification with a SIGCHLD signal when
108 Signal handlers
110 A process has a handler associated with each signal.
111 The handler controls the way the signal is delivered.
114 #include <signal.h>
126 assigns interrupt handler address \fIsv_handler\fP to signal \fIsigno\fP.
128 specifies either an interrupt routine for the signal, that the
129 signal is to be ignored,
131 if the signal occurs.
136 signal mask to be used when the handler is invoked; it implicitly includes
137 the signal which invoked the handler.
138 Signal masks include one bit for each signal;
139 the mask for a signal \fIsigno\fP is provided by the macro
140 \fIsigmask\fP(\fIsigno\fP), from \fI<signal.h>\fP.
142 restarted if the signal handler returns and
144 stack or a special signal stack (see below). If \fIosv\fP
145 is non-zero, the previous signal vector is returned.
147 When a signal condition arises for a process, the signal
149 If the signal is not currently \fIblocked\fP by the process
150 then it will be delivered. The process of signal delivery
151 adds the signal to be delivered and those signals
152 specified in the associated signal
155 and places the process in the context of the signal
156 handling routine. The call is arranged so that if the signal
157 handling routine exits normally the signal mask will be restored
160 it must arrange to restore the signal mask itself.
168 The signal handling routine \fIsv_handler\fP is called by a C call
174 The \fIsigno\fP gives the number of the signal that occurred, and
178 context before the signal.
182 A process can send a signal to another process or group of processes
191 Unless the process sending the signal is privileged,
192 it must have the same effective user id as the process receiving the signal.
216 and then to pause waiting for a signal and restoring the mask, by using:
222 Signal stacks
238 process is currently on the signal stack,
241 When a signal is to be delivered, the system checks whether
242 the process is on a signal stack. If not, then the process is switched
243 to the signal stack for delivery, with the return from the signal
246 If the process wishes to take a non-local exit from the signal routine,
247 or run code from the signal stack that uses a different stack,
248 a \fIsigstack\fP call should be used to reset the signal stack.