This patch adds macros for doing thread-local global variables. It is
implemented using POSIX threads, and if those aren't available then
the variables just turn into real global variables.
Rich.
--
Richard Jones, Emerging Technologies, Red Hat http://et.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines. Boot with a
live CD or over the network (PXE) and turn machines into Xen guests.
http://et.redhat.com/~rjones/virt-p2v
Index: src/threads.h
===================================================================
RCS file: src/threads.h
diff -N src/threads.h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ src/threads.h 30 Jul 2008 16:06:48 -0000
@@ -0,0 +1,67 @@
+/*
+ * Wrappers around POSIX thread functions.
+ *
+ * Copyright (C) 2008 Red Hat, Inc.
+ *
+ * See COPYING.LIB for the License of this software
+ *
+ * Author: Richard W.M. Jones <rjones@xxxxxxxxxx>
+ */
+
+#ifndef __VIR_THREADS_H__
+#define __VIR_THREADS_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef HAVE_PTHREAD_H
+
+/* These macros and functions are used to make thread-local
+ * global variables (ie. the variable is global but different
+ * values can be stored in it in each thread). The variables
+ * always have type 'void *'.
+ *
+ * THREAD_LOCAL(name)
+ * defines a thread-local variable called 'name'.
+ * THREAD_LOCAL_INIT(name)
+ * must be called before using the variable (you may call this
+ * macro as many times as you like). The value of the variable
+ * is still undefined until you call THREAD_LOCAL_SET.
+ * THREAD_LOCAL_SET(name,value)
+ * sets the value of the variable to 'value'.
+ * THREAD_LOCAL_GET(name)
+ * returns the value of the variable.
+ *
+ * If the system doesn't have POSIX threads, then this just turns
+ * into an ordinary global variable.
+ */
+#define THREAD_LOCAL(name) \
+ static pthread_once_t _##name##_once = PTHREAD_ONCE_INIT; \
+ static pthread_key_t _##name##_key; \
+ static void _initialize_##name (void) \
+ { \
+ (void) pthread_key_create (&_##name##_key, NULL); \
+ }
+
+#define THREAD_LOCAL_INIT(name) \
+ (void) pthread_once (&_##name##_once, _initialize_##name)
+
+#define THREAD_LOCAL_SET(name,value) \
+ pthread_setspecific (_##name##_key, (value))
+
+#define THREAD_LOCAL_GET(name) pthread_getspecific (_##name##_key)
+
+#else /* !HAVE_PTHREAD_H */
+
+#define THREAD_LOCAL(name) static void *name;
+#define THREAD_LOCAL_INIT(name)
+#define THREAD_LOCAL_SET(name,value) name = (value)
+#define THREAD_LOCAL_GET(name) name
+
+#endif /* !HAVE_PTHREAD_H */
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* ! __VIR_THREADS_H__ */
Index: src/internal.h
===================================================================
RCS file: /data/cvs/libvirt/src/internal.h,v
retrieving revision 1.75
diff -u -r1.75 internal.h
--- src/internal.h 26 Jun 2008 09:37:51 -0000 1.75
+++ src/internal.h 30 Jul 2008 16:06:48 -0000
@@ -12,6 +12,9 @@
#include <sys/syslimits.h>
#endif
+/* Functions which need POSIX threads. There are more
+ * thread functions available in threads.h include file.
+ */
#ifdef HAVE_PTHREAD_H
#include <pthread.h>
#define PTHREAD_MUTEX_T(v) pthread_mutex_t v
Index: src/Makefile.am
===================================================================
RCS file: /data/cvs/libvirt/src/Makefile.am,v
retrieving revision 1.86
diff -u -r1.86 Makefile.am
--- src/Makefile.am 11 Jul 2008 16:23:36 -0000 1.86
+++ src/Makefile.am 30 Jul 2008 16:06:48 -0000
@@ -42,6 +42,7 @@
domain_conf.c domain_conf.h \
capabilities.c capabilities.h \
xml.c xml.h \
+ threads.h \
event.c event.h \
xen_unified.c xen_unified.h \
xen_internal.c xen_internal.h \
--
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