1sigblock(3UCB) SunOS/BSD Compatibility Library Functions sigblock(3UCB)
2
3
4
6 sigblock, sigmask, sigpause, sigsetmask - block signals
7
9 /usr/ucb/cc [ flag ... ] file ...
10 #include <signal.h>
11
12 int sigblock(mask)
13 int mask;
14
15
16 int sigmask(signum)
17 int signum;
18
19
20 int sigpause(mask)
21 int mask;
22
23
24 int sigsetmask(mask)
25 int mask;
26
27
29 sigblock() adds the signals specified in mask to the set of signals
30 currently being blocked from delivery. Signals are blocked if the
31 appropriate bit in mask is a 1; the macro sigmask is provided to con‐
32 struct the mask for a given signum. sigblock() returns the previous
33 mask. The previous mask may be restored using sigsetmask().
34
35
36 sigpause() assigns mask to the set of masked signals and then waits for
37 a signal to arrive; on return the set of masked signals is restored.
38 mask is usually 0 to indicate that no signals are now to be blocked.
39 sigpause() always terminates by being interrupted, returning −1 and
40 setting errno to EINTR.
41
42
43 sigsetmask() sets the current signal mask (those signals that are
44 blocked from delivery). Signals are blocked if the corresponding bit
45 in mask is a 1; the macro sigmask is provided to construct the mask for
46 a given signum.
47
48
49 In normal usage, a signal is blocked using sigblock(). To begin a crit‐
50 ical section, variables modified on the occurrence of the signal are
51 examined to determine that there is no work to be done, and the process
52 pauses awaiting work by using sigpause() with the mask returned by sig‐
53 block().
54
55
56 It is not possible to block SIGKILL, SIGSTOP, or SIGCONT, this
57 restriction is silently imposed by the system.
58
60 sigblock() and sigsetmask() return the previous set of masked signals.
61 sigpause() returns −1 and sets errno to EINTR.
62
64 kill(2), sigaction(2), signal(3UCB), sigvec(3UCB)
65
67 Use of these interfaces should be restricted to only applications writ‐
68 ten on BSD platforms. Use of these interfaces with any of the system
69 libraries or in multi-thread applications is unsupported.
70
71
72
73SunOS 5.11 30 Oct 2007 sigblock(3UCB)