Make python bindings threaded, by dropping/acquiring Python GIL where needed

1 files changed, 50 insertions, 0 deletions

diff --git a/libvirt_wrap.h b/libvirt_wrap.h
index e745215..906245a 100644
--- a/libvirt_wrap.h
+++ b/libvirt_wrap.h
@@ -48,3 +48,53 @@ PyObject * libvirt_charPtrConstWrap(const char *str);
 PyObject * libvirt_virConnectPtrWrap(virConnectPtr node);
 PyObject * libvirt_virDomainPtrWrap(virDomainPtr node);
 
+
+/* Provide simple macro statement wrappers (adapted from GLib, in turn from Perl):
+ *  LIBVIRT_STMT_START { statements; } LIBVIRT_STMT_END;
+ *  can be used as a single statement, as in
+ *  if (x) LIBVIRT_STMT_START { ... } LIBVIRT_STMT_END; else ...
+ *
+ *  When GCC is compiling C code in non-ANSI mode, it will use the
+ *  compiler __extension__ to wrap the statements wihin `({' and '})' braces.
+ *  When compiling on platforms where configure has defined
+ *  HAVE_DOWHILE_MACROS, statements will be wrapped with `do' and `while (0)'.
+ *  For any other platforms (SunOS4 is known to have this issue), wrap the
+ *  statements with `if (1)' and `else (void) 0'.
+ */
+#if !(defined (LIBVIRT_STMT_START) && defined (LIBVIRT_STMT_END))
+# if defined (__GNUC__) && !defined (__STRICT_ANSI__) && !defined (__cplusplus)
+#  define LIBVIRT_STMT_START (void) __extension__ (
+#  define LIBVIRT_STMT_END )
+# else /* !(__GNUC__ && !__STRICT_ANSI__ && !__cplusplus) */
+#  if defined (HAVE_DOWHILE_MACROS)
+#   define LIBVIRT_STMT_START do
+#   define LIBVIRT_STMT_END while (0)
+#  else /* !HAVE_DOWHILE_MACROS */
+#   define LIBVIRT_STMT_START if (1)
+#   define LIBVIRT_STMT_END else (void) 0
+#  endif /* !HAVE_DOWHILE_MACROS */
+# endif /* !(__GNUC__ && !__STRICT_ANSI__ && !__cplusplus) */
+#endif
+
+#define LIBVIRT_BEGIN_ALLOW_THREADS			\
+  LIBVIRT_STMT_START {					\
+    PyThreadState *_save = NULL;			\
+    if (PyEval_ThreadsInitialized())			\
+      _save = PyEval_SaveThread();
+
+#define LIBVIRT_END_ALLOW_THREADS                           \
+  if (PyEval_ThreadsInitialized())			    \
+    PyEval_RestoreThread(_save);			    \
+    } LIBVIRT_STMT_END
+
+#define LIBVIRT_ENSURE_THREAD_STATE			\
+  LIBVIRT_STMT_START {					\
+  PyGILState_STATE _save;				\
+    if (PyEval_ThreadsInitialized())			\
+      _save = PyGILState_Ensure();
+
+#define LIBVIRT_RELEASE_THREAD_STATE                           \
+  if (PyEval_ThreadsInitialized())			       \
+    PyGILState_Release(_save);				       \
+  } LIBVIRT_STMT_END
+