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 .Fo sigsuspend
  46 .Fa "const sigset_t *sigmask"
  47 .Fc
  48 .Sh DESCRIPTION
  49 .Fn sigsuspend
  50 temporarily changes the blocked signal mask to the set to which
  51 .Fa sigmask
  52 points,
  53 and then waits for a signal to arrive;
  54 on return the previous set of masked signals is restored.
  55 The signal mask set
  56 is usually empty to indicate that all
  57 signals are to be unblocked for the duration of the call.
  58 .Pp
  59 In normal usage, a signal is blocked using
  60 .Xr sigprocmask 2
  61 to begin a critical section, variables modified on the occurrence
  62 of the signal are examined to determine that there is no work
  63 to be done, and the process pauses awaiting work by using
  64 .Fn sigsuspend
  65 with the previous mask returned by
  66 .Xr sigprocmask .
  67 .Sh RETURN VALUES
  68 The
  69 .Fn sigsuspend
  70 function
  71 always terminates by being interrupted, returning -1 with
  72 .Va errno
  73 set to
  74 .Dv EINTR .
  75 .Sh SEE ALSO
  76 .Xr sigaction 2 ,
  77 .Xr sigprocmask 2 ,
  78 .Xr sigsetops 3
  79 .Sh STANDARDS
  80 The
  81 .Nm sigsuspend
  82 function call
  83 conforms to
  84 .St -p1003.1-88 .