bsd/man/man2/sigsuspend.2

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  34 .\"     @(#)sigsuspend.2        8.1 (Berkeley) 6/4/93
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  36 .Dd June 4, 1993
  37 .Dt SIGSUSPEND 2
  38 .Os
  39 .Sh NAME
  40 .Nm sigsuspend
  41 .Nd atomically release blocked signals and wait for interrupt
  42 .Sh SYNOPSIS
  43 .Fd #include <signal.h>
  44 .Ft int
  45 .Fn sigsuspend "const sigset_t *sigmask"
  46 .Sh DESCRIPTION
  47 .Fn Sigsuspend
  48 temporarily changes the blocked signal mask to the set to which
  49 .Fa sigmask
  50 points,
  51 and then waits for a signal to arrive;
  52 on return the previous set of masked signals is restored.
  53 The signal mask set
  54 is usually empty to indicate that all
  55 signals are to be unblocked for the duration of the call.
  56 .Pp
  57 In normal usage, a signal is blocked using
  58 .Xr sigprocmask 2
  59 to begin a critical section, variables modified on the occurrence
  60 of the signal are examined to determine that there is no work
  61 to be done, and the process pauses awaiting work by using
  62 .Fn sigsuspend
  63 with the previous mask returned by
  64 .Xr sigprocmask .
  65 .Sh RETURN VALUES
  66 The
  67 .Fn sigsuspend
  68 function
  69 always terminates by being interrupted, returning -1 with
  70 .Va errno
  71 set to
  72 .Dv EINTR .
  73 .Sh SEE ALSO
  74 .Xr sigprocmask 2 ,
  75 .Xr sigaction 2 ,
  76 .Xr sigsetops 3
  77 .Sh STANDARDS
  78 The
  79 .Nm sigsupend
  80 function call
  81 conforms to
  82 .St -p1003.1-88 .