diff options
Diffstat (limited to 'Doc/lib/libsignal.tex')
| -rw-r--r-- | Doc/lib/libsignal.tex | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/Doc/lib/libsignal.tex b/Doc/lib/libsignal.tex index 13139d7..63b671f 100644 --- a/Doc/lib/libsignal.tex +++ b/Doc/lib/libsignal.tex @@ -20,7 +20,7 @@ the Python user is concerned, they can only occur between the ``atomic'' instructions of the Python interpreter. This means that signals arriving during long calculations implemented purely in C (e.g.\ regular expression matches on large bodies of text) may be -delayed for an arbitrary time. +delayed for an arbitrary amount of time. \item When a signal arrives during an I/O operation, it is possible that the @@ -48,8 +48,10 @@ threads simultaneously is:\ always perform \code{signal()} operations in the main thread of execution. Any thread can perform an \code{alarm()}, \code{getsignal()}, or \code{pause()}; only the main thread can set a new signal handler, and the main thread will be the -only one to receive signals. This means that signals can't be used as -a means of interthread communication. Use locks instead. +only one to receive signals (this is enforced by the Python signal +module, even if the underlying thread implementation supports sending +signals to individual threads). This means that signals can't be used +as a means of interthread communication. Use locks instead. \end{itemize} @@ -126,4 +128,9 @@ The signal module defines the following functions: When threads are enabled, this function can only be called from the main thread; attempting to call it from other threads will cause a \code{ValueError} exception to be raised. + + The \var{handler} is called with two arguments: the signal number + and the current stack frame (\code{None} or a frame object; see the + reference manual for a description of frame objects). +\obindex{frame} \end{funcdesc} |