vhost-user-test: fix g_cond_wait_until compat implementation

This fixes compilation with glib versions up to 2.30, such
as the one in CentOS 6.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

include/glib-compat.h

@@ -149,6 +149,32 @@ static inline void (g_cond_signal)(CompatGCond *cond)
 }
 #undef g_cond_signal
 
+static inline gboolean (g_cond_timed_wait)(CompatGCond *cond,
+                                           CompatGMutex *mutex,
+                                           GTimeVal *time)
+{
+    g_assert(mutex->once.status != G_ONCE_STATUS_PROGRESS);
+    g_once(&cond->once, do_g_cond_new, NULL);
+    return g_cond_timed_wait((GCond *) cond->once.retval,
+                             (GMutex *) mutex->once.retval, time);
+}
+#undef g_cond_timed_wait
+
+/* This is not a macro, because it didn't exist until 2.32.  */
+static inline gboolean g_cond_wait_until(CompatGCond *cond, CompatGMutex *mutex,
+                                         gint64 end_time)
+{
+    GTimeVal time;
+
+    /* Convert from monotonic to CLOCK_REALTIME.  */
+    end_time -= g_get_monotonic_time();
+    g_get_current_time(&time);
+    end_time += time.tv_sec * G_TIME_SPAN_SECOND + time.tv_usec;
+
+    time.tv_sec = end_time / G_TIME_SPAN_SECOND;
+    time.tv_usec = end_time % G_TIME_SPAN_SECOND;
+    return g_cond_timed_wait(cond, mutex, &time);
+}
 
 /* before 2.31 there was no g_thread_new() */
 static inline GThread *g_thread_new(const char *name,

tests/vhost-user-test.c

@@ -127,25 +127,12 @@ typedef struct TestServer {
     int fds_num;
     int fds[VHOST_MEMORY_MAX_NREGIONS];
     VhostUserMemory memory;
-    GMutex data_mutex;
-    GCond data_cond;
+    CompatGMutex data_mutex;
+    CompatGCond data_cond;
     int log_fd;
     uint64_t rings;
 } TestServer;
 
-#if !GLIB_CHECK_VERSION(2, 32, 0)
-static gboolean g_cond_wait_until(CompatGCond cond, CompatGMutex mutex,
-                                  gint64 end_time)
-{
-    gboolean ret = FALSE;
-    end_time -= g_get_monotonic_time();
-    GTimeVal time = { end_time / G_TIME_SPAN_SECOND,
-                      end_time % G_TIME_SPAN_SECOND };
-    ret = g_cond_timed_wait(cond, mutex, &time);
-    return ret;
-}
-#endif
-
 static const char *tmpfs;
 static const char *root;