commit 858927c9d650697e8bd74697b8815c17cc93402d
Author: Oswald Buddenhagen <ossi@kde.org>
Date:   Sun May 15 12:19:32 2011 +0200

    use monotonic clock if available
    
    this avoids that clock jumps (e.g., ntp syncs) cause timeouts.
    fixes bug 269522

diff --git a/kdm/backend/CMakeLists.txt b/kdm/backend/CMakeLists.txt
index 0fbf35e..e94a3b9 100644
--- a/kdm/backend/CMakeLists.txt
+++ b/kdm/backend/CMakeLists.txt
@@ -68,6 +68,9 @@ if(UTIL_LIBRARIES)
 	target_link_libraries( kdm ${UTIL_LIBRARIES} )
 endif(UTIL_LIBRARIES)
 target_link_libraries( kdm ${POSIX4_LIBRARIES} )
+if(QT_RT_LIBRARY)
+	target_link_libraries( kdm ${QT_RT_LIBRARY} )
+endif(QT_RT_LIBRARY)
 
 if(KDE4_ENABLE_FINAL)
         macro_add_file_dependencies(${CMAKE_CURRENT_BINARY_DIR}/kdm_final_cpp.cpp ${confci})
diff --git a/kdm/backend/dm.c b/kdm/backend/dm.c
index 13d75fb..1120bd8 100644
--- a/kdm/backend/dm.c
+++ b/kdm/backend/dm.c
@@ -1163,7 +1163,7 @@ mainLoop(void)
     fd_set reads;
 
     debug("mainLoop\n");
-    time(&now);
+    updateNow();
     while (
 #ifdef XDMCP
            anyListenSockets() ||
@@ -1213,7 +1213,7 @@ mainLoop(void)
         reads = wellKnownSocketsMask;
         nready = select(wellKnownSocketsMax + 1, &reads, 0, 0, tvp);
         debug("select returns %d\n", nready);
-        time(&now);
+        updateNow();
 #ifdef NEED_ENTROPY
         addTimerEntropy();
 #endif
diff --git a/kdm/backend/dm.h b/kdm/backend/dm.h
index 5895b5f..af8ce54 100644
--- a/kdm/backend/dm.h
+++ b/kdm/backend/dm.h
@@ -403,6 +403,17 @@ void cancelShutdown(void);
 int TTYtoVT(const char *tty);
 int activateVT(int vt);
 
+#ifdef _POSIX_MONOTONIC_CLOCK
+# define updateNow() \
+    do { \
+        struct timespec ts; \
+        clock_gettime(CLOCK_MONOTONIC, &ts); \
+        now = ts.tv_sec; \
+    } while (0)
+#else
+# define updateNow() time(&now)
+#endif
+
 /* in ctrl.c */
 void openCtrl(struct display *d);
 void closeCtrl(struct display *d);
diff --git a/kdm/backend/session.c b/kdm/backend/session.c
index 0cd82cf..7fbdfca 100644
--- a/kdm/backend/session.c
+++ b/kdm/backend/session.c
@@ -416,7 +416,8 @@ openGreeter()
     gSet(&grttalk);
     if (grtproc.pid > 0)
         return;
-    if (time(0) < lastStart + 10) /* XXX should use some readiness indicator instead */
+    updateNow();
+    if (now < lastStart + 10) /* XXX should use some readiness indicator instead */
         sessionExit(EX_UNMANAGE_DPY);
     ASPrintf(&name, "greeter for display %s", td->name);
     debug("starting %s\n", name);
@@ -446,7 +447,8 @@ openGreeter()
         sessionExit(EX_UNMANAGE_DPY);
     }
     debug("%s ready\n", name);
-    time(&lastStart);
+    updateNow();
+    lastStart = now;
 }
 
 int
@@ -577,7 +579,7 @@ manageSession(void)
         /* NOTREACHED */
 #endif
 
-    tdiff = time(0) - td->hstent->lastExit - td->openDelay;
+    tdiff = now - td->hstent->lastExit - td->openDelay;
     if (autoLogon(tdiff)) {
         if (!verify(conv_auto, False))
             goto gcont;