Add locking for (nearly complete) thread safety to QEMU driver

ChangeLog

@@ -1,3 +1,8 @@
+Thu Dec  4 21:05:41 GMT 2008 Daniel P. Berrange <berrange@redhat.com>
+
+	* src/qemu_conf.h: Add a driver lock variable
+	* src/qemu_driver.c: Add locking for thread safety
+
 Thu Dec  4 21:01:41 GMT 2008 Daniel P. Berrange <berrange@redhat.com>
 
 	* src/qemu_driver.c: Merge all return paths from driver APIs

src/qemu_conf.h

@@ -51,6 +51,8 @@ enum qemud_cmd_flags {
 
 /* Main driver state */
 struct qemud_driver {
+    PTHREAD_MUTEX_T(lock);
+
     unsigned int qemuVersion;
     int nextvmid;