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Update to use the new \csimplemacro macro
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freddrake committed Apr 9, 2002
1 parent 79bf99c commit 375e302
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Showing 2 changed files with 24 additions and 22 deletions.
36 changes: 19 additions & 17 deletions Doc/api/init.tex
Original file line number Diff line number Diff line change
Expand Up @@ -391,12 +391,13 @@ \section{Thread State and the Global Interpreter Lock
Py_END_ALLOW_THREADS
\end{verbatim}

The \code{Py_BEGIN_ALLOW_THREADS}\ttindex{Py_BEGIN_ALLOW_THREADS} macro
opens a new block and declares a hidden local variable; the
\code{Py_END_ALLOW_THREADS}\ttindex{Py_END_ALLOW_THREADS} macro closes
the block. Another advantage of using these two macros is that when
Python is compiled without thread support, they are defined empty,
thus saving the thread state and lock manipulations.
The
\csimplemacro{Py_BEGIN_ALLOW_THREADS}\ttindex{Py_BEGIN_ALLOW_THREADS}
macro opens a new block and declares a hidden local variable; the
\csimplemacro{Py_END_ALLOW_THREADS}\ttindex{Py_END_ALLOW_THREADS}
macro closes the block. Another advantage of using these two macros
is that when Python is compiled without thread support, they are
defined empty, thus saving the thread state and lock manipulations.

When thread support is enabled, the block above expands to the
following code:
Expand Down Expand Up @@ -574,30 +575,31 @@ \section{Thread State and the Global Interpreter Lock
This macro expands to
\samp{\{ PyThreadState *_save; _save = PyEval_SaveThread();}.
Note that it contains an opening brace; it must be matched with a
following \code{Py_END_ALLOW_THREADS} macro. See above for further
discussion of this macro. It is a no-op when thread support is
disabled at compile time.
following \csimplemacro{Py_END_ALLOW_THREADS} macro. See above for
further discussion of this macro. It is a no-op when thread support
is disabled at compile time.
\end{csimplemacrodesc}

\begin{csimplemacrodesc}{Py_END_ALLOW_THREADS}
This macro expands to \samp{PyEval_RestoreThread(_save); \}}.
Note that it contains a closing brace; it must be matched with an
earlier \code{Py_BEGIN_ALLOW_THREADS} macro. See above for further
discussion of this macro. It is a no-op when thread support is
disabled at compile time.
earlier \csimplemacro{Py_BEGIN_ALLOW_THREADS} macro. See above for
further discussion of this macro. It is a no-op when thread support
is disabled at compile time.
\end{csimplemacrodesc}

\begin{csimplemacrodesc}{Py_BLOCK_THREADS}
This macro expands to \samp{PyEval_RestoreThread(_save);}: it is
equivalent to \code{Py_END_ALLOW_THREADS} without the closing brace.
It is a no-op when thread support is disabled at compile time.
equivalent to \csimplemacro{Py_END_ALLOW_THREADS} without the
closing brace. It is a no-op when thread support is disabled at
compile time.
\end{csimplemacrodesc}

\begin{csimplemacrodesc}{Py_UNBLOCK_THREADS}
This macro expands to \samp{_save = PyEval_SaveThread();}: it is
equivalent to \code{Py_BEGIN_ALLOW_THREADS} without the opening
brace and variable declaration. It is a no-op when thread support
is disabled at compile time.
equivalent to \csimplemacro{Py_BEGIN_ALLOW_THREADS} without the
opening brace and variable declaration. It is a no-op when thread
support is disabled at compile time.
\end{csimplemacrodesc}

All of the following functions are only available when thread support
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10 changes: 5 additions & 5 deletions Doc/ext/extending.tex
Original file line number Diff line number Diff line change
Expand Up @@ -1068,11 +1068,11 @@ \subsection{Thin Ice
interpreter can't get in each other's way, because there is a global
lock protecting Python's entire object space. However, it is possible
to temporarily release this lock using the macro
\code{Py_BEGIN_ALLOW_THREADS}, and to re-acquire it using
\code{Py_END_ALLOW_THREADS}. This is common around blocking I/O
calls, to let other threads use the processor while waiting for the I/O to
complete. Obviously, the following function has the same problem as
the previous one:
\csimplemacro{Py_BEGIN_ALLOW_THREADS}, and to re-acquire it using
\csimplemacro{Py_END_ALLOW_THREADS}. This is common around blocking
I/O calls, to let other threads use the processor while waiting for
the I/O to complete. Obviously, the following function has the same
problem as the previous one:

\begin{verbatim}
bug(PyObject *list) {
Expand Down

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