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Diffstat (limited to 'Doc/lib/libsignal.tex')
| -rw-r--r-- | Doc/lib/libsignal.tex | 54 |
1 files changed, 50 insertions, 4 deletions
diff --git a/Doc/lib/libsignal.tex b/Doc/lib/libsignal.tex index e3aa171..3029385 100644 --- a/Doc/lib/libsignal.tex +++ b/Doc/lib/libsignal.tex @@ -18,10 +18,6 @@ the handler for \constant{SIGCHLD}, which follows the underlying implementation. \item -There is no way to ``block'' signals temporarily from critical -sections (since this is not supported by all \UNIX{} flavors). - -\item Although Python signal handlers are called asynchronously as far as the Python user is concerned, they can only occur between the ``atomic'' instructions of the Python interpreter. This means that @@ -92,6 +88,16 @@ The variables defined in the \module{signal} module are: One more than the number of the highest signal number. \end{datadesc} +\begin{datadesc}{SIG_BLOCK} +\end{datadesc} +\begin{datadesc}{SIG_UNBLOCK} +\end{datadesc} +\begin{datadesc}{SIG_SETMASK} + These constants are for use as the first parameter of the + \function{sigprocmask} function described below. +\end{datadesc} + + The \module{signal} module defines the following functions: \begin{funcdesc}{alarm}{time} @@ -144,6 +150,46 @@ The \module{signal} module defines the following functions: \obindex{frame} \end{funcdesc} +The following functions are supported if your platform does. Most +modern \UNIX-alikes now do. + +\begin{funcdesc}{sigpending}{} + Return the set of pending signals, i.e. a list containing the + numbers of those signals that have been raised while blocked. + \versionadded{2.3} +\end{funcdesc} + +\begin{funcdesc}{sigprocmask}{how, sigset} + Change the list of currently blocked signals. The parameter + \var{how} should be one of \constant{SIG_BLOCK}, + \constant{SIG_UNBLOCK} or \constant{SIG_SETMASK} and \var{sigset} + should be a sequence of signal numbers. The behaviour of the call + depends on the value of \var{how}: + + \begin{tableii}{l|l}{textrm}{Value of \var{how}}{Behaviour of call} + \lineii{\constant{SIG_BLOCK}} + {The set of blocked signals is the union of the current set + and \var{sigset}.} + \lineii{\constant{SIG_UNBLOCK}} + {The signals in \var{sigset} are removed from the current + set of blocked signals. It is legal to attempt to unblock + a signal which is not blocked.} + \lineii{\constant{SIG_SETMASK}} + {The set of blocked signals is set to the \var{sigset}.} + \end{tableii} + + A list contating the numbers of the previously blocked signals is + returned. + \versionadded{2.3} +\end{funcdesc} + +\begin{funcdesc}{sigsuspend}{sigset} + Temporarily replace the signal mask with \var{sigset} (which should + be a sequnce of signal numbers) and suspend the process until a + signal is received. + \versionadded{2.3} +\end{funcdesc} + \subsection{Example} \nodename{Signal Example} |