xserver: Branch 'server-1.2-branch' - 2 commits

Daniel Stone daniels at kemper.freedesktop.org
Thu Oct 26 00:25:53 EEST 2006


 configure.ac            |   43 +++++++++++++++++++++++++++++++++++++++++--
 include/dix-config.h.in |    3 +++
 os/WaitFor.c            |   34 +++++++++++++++++++++++++++++++---
 os/utils.c              |   39 +++++++++++++++++++++++++++++++++++----
 4 files changed, 110 insertions(+), 9 deletions(-)

New commits:
diff-tree dfac36e56a4c1dbccb7b302738dbf60985cc12ba (from d04e2545a7238133692aa4501d24e5fdae30df08)
Author: Daniel Stone <daniel at fooishbar.org>
Date:   Wed Oct 25 23:55:43 2006 +0300

    WaitForSomething: allow time to rewind
    If time rewinds dramatically, reset all the timers to fix their expiry.
    (cherry picked from d3e57faffee63df1424a209d0418d3a712f91ae6 commit)

diff --git a/os/WaitFor.c b/os/WaitFor.c
index 0457678..896fdf1 100644
--- a/os/WaitFor.c
+++ b/os/WaitFor.c
@@ -119,11 +119,13 @@ mffs(fd_mask mask)
 struct _OsTimerRec {
     OsTimerPtr		next;
     CARD32		expires;
+    CARD32              delta;
     OsTimerCallback	callback;
     pointer		arg;
 };
 
 static void DoTimer(OsTimerPtr timer, CARD32 now, OsTimerPtr *prev);
+static void CheckAllTimers(CARD32 now);
 static OsTimerPtr timers = NULL;
 
 /*****************
@@ -200,6 +202,11 @@ WaitForSomething(int *pClientsReady)
         {
             now = GetTimeInMillis();
 	    timeout = timers->expires - now;
+            /* time has rewound.  reset the timers. */
+            if (timeout > timers->delta) {
+                CheckAllTimers(now);
+                timeout = timers->expires - now;
+            }
             if (timeout < 0)
                 timeout = 0;
 	    waittime.tv_sec = timeout / MILLI_PER_SECOND;
@@ -426,6 +433,20 @@ ANYSET(FdMask *src)
 }
 #endif
 
+/* If time has rewound, re-run every affected timer.
+ * TimerForce will change timer->next, but it will _generally_ only
+ * promote timers in the list, meaning that we should still be
+ * walking every timer. */
+static void
+CheckAllTimers(CARD32 now)
+{
+    OsTimerPtr timer;
+
+    for (timer = timers; timer; timer = timer->next) {
+        if (timer->expires - now > timer->delta)
+            TimerForce(timer);
+    }
+}
 
 static void
 DoTimer(OsTimerPtr timer, CARD32 now, OsTimerPtr *prev)
@@ -467,8 +488,13 @@ TimerSet(OsTimerPtr timer, int flags, CA
     }
     if (!millis)
 	return timer;
-    if (!(flags & TimerAbsolute))
+    if (flags & TimerAbsolute) {
+        timer->delta = millis - now;
+    }
+    else {
+        timer->delta = millis;
 	millis += now;
+    }
     timer->expires = millis;
     timer->callback = func;
     timer->arg = arg;
@@ -481,8 +507,10 @@ TimerSet(OsTimerPtr timer, int flags, CA
     }
     for (prev = &timers;
 	 *prev && (int) ((*prev)->expires - millis) <= 0;
-	 prev = &(*prev)->next)
-	;
+	 prev = &(*prev)->next) {
+        if ((*prev)->expires - now > (*prev)->delta)
+            CheckAllTimers(now);
+    }
     timer->next = *prev;
     *prev = timer;
     return timer;
diff-tree d04e2545a7238133692aa4501d24e5fdae30df08 (from d12d0839fdede9ddad219815ced89664a2c44458)
Author: Daniel Stone <daniel at fooishbar.org>
Date:   Wed Oct 25 23:57:00 2006 +0300

    GetTimeInMillis: spuport monotonic clock
    Add support for CLOCK_MONOTONIC from clock_gettime, and use that in
    GetTimeInMillis() if available, falling back to the old gettimeofday()
    implementation.
    
    This is _slightly_ faster on some 64-bit architectures, and _slightly_
    slower on others (though barely measurable).
    (cherry picked from d285833290316cb5dd1e7f1e52c96be3e9cf21cd commit)

diff --git a/configure.ac b/configure.ac
index 7945a27..25570f2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -515,7 +515,7 @@ XEXT_LIB='$(top_builddir)/Xext/libXext.l
 XEXTXORG_LIB='$(top_builddir)/Xext/libXextbuiltin.la'
 
 dnl Core modules for most extensions, et al.
-REQUIRED_MODULES="randrproto renderproto [fixesproto >= 4.0] damageproto xcmiscproto xextproto xproto xtrans xf86miscproto xf86vidmodeproto xf86bigfontproto [scrnsaverproto >= 1.1] bigreqsproto resourceproto fontsproto inputproto xf86dgaproto [kbproto >= 1.0.3]"
+REQUIRED_MODULES="randrproto renderproto [fixesproto >= 4.0] damageproto xcmiscproto xextproto [xproto >= 7.0.9] xtrans xf86miscproto xf86vidmodeproto xf86bigfontproto [scrnsaverproto >= 1.1] bigreqsproto resourceproto fontsproto inputproto xf86dgaproto [kbproto >= 1.0.3]"
 REQUIRED_LIBS="xfont xau fontenc"
 
 AM_CONDITIONAL(XV, [test "x$XV" = xyes])
@@ -873,9 +873,46 @@ PKG_CHECK_MODULES([XSERVERLIBS], [$REQUI
 
 XSERVER_CFLAGS="${XSERVERCFLAGS_CFLAGS}"
 XSERVER_LIBS="${XSERVERLIBS_LIBS} ${SYS_LIBS} -lm"
-AC_SUBST([XSERVER_LIBS])
 AC_SUBST([SYS_LIBS])
 
+AC_CHECK_FUNCS([clock_gettime], [have_clock_gettime=yes],
+               [AC_CHECK_LIB([rt], [clock_gettime], [have_clock_gettime=-lrt],
+                             [have_clock_gettime=no])])
+
+AC_MSG_CHECKING([for a useful monotonic clock ...])
+
+if ! test "x$have_clock_gettime" = xno; then
+    if ! test "x$have_clock_gettime" = xyes; then
+        LIBS="$have_clock_gettime"
+    else
+        LIBS=""
+    fi
+
+    AC_RUN_IFELSE([
+#define _POSIX_C_SOURCE 199309L
+#include <time.h>
+
+int main(int argc, char *argv[]) {
+    struct timespec tp;
+
+    if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0)
+        return 0;
+    else
+        return 1;
+}
+    ], [MONOTONIC_CLOCK=yes], [MONOTONIC_CLOCK=no],
+       [MONOTONIC_CLOCK="cross compiling"])
+else
+    MONOTONIC_CLOCK=no
+fi
+
+AC_MSG_RESULT([$MONOTONIC_CLOCK])
+
+if test "x$MONOTONIC_CLOCK" = xyes; then
+    AC_DEFINE(MONOTONIC_CLOCK, 1, [Have monotonic clock from clock_gettime()])
+    XSERVER_LIBS="$XSERVER_LIBS $LIBS"
+fi
+
 dnl Imake defines SVR4 on SVR4 systems, and many files check for it, so
 dnl we need to replicate that here until those can all be fixed
 AC_MSG_CHECKING([if SVR4 needs to be defined])
@@ -890,6 +927,8 @@ AC_MSG_RESULT([yes])], AC_MSG_RESULT([no
 XSERVER_CFLAGS="$XSERVER_CFLAGS $CORE_INCS $XEXT_INC $COMPOSITE_INC $DAMAGE_INC $FIXES_INC $XI_INC $MI_INC $MIEXT_SHADOW_INC $MIEXT_LAYER_INC $MIEXT_DAMAGE_INC $RENDER_INC $RANDR_INC $FB_INC"
 AC_DEFINE_UNQUOTED(X_BYTE_ORDER,[$ENDIAN],[Endian order])
 
+AC_SUBST([XSERVER_LIBS])
+
 dnl ---------------------------------------------------------------------------
 dnl DDX section.
 dnl ---------------------------------------------------------------------------
diff --git a/include/dix-config.h.in b/include/dix-config.h.in
index 65c42e6..35700e4 100644
--- a/include/dix-config.h.in
+++ b/include/dix-config.h.in
@@ -445,4 +445,7 @@
 /* Define to 1 if modules should avoid the libcwrapper */
 #undef NO_LIBCWRAPPER
 
+/* Have a monotonic clock from clock_gettime() */
+#undef MONOTONIC_CLOCK
+
 #endif /* _DIX_CONFIG_H_ */
diff --git a/os/utils.c b/os/utils.c
index 31ae26a..379291c 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -53,6 +53,19 @@ OR PERFORMANCE OF THIS SOFTWARE.
 #include <dix-config.h>
 #endif
 
+/* The world's most shocking hack, to ensure we get clock_gettime() and
+ * CLOCK_MONOTONIC. */
+#ifdef _POSIX_C_SOURCE
+#define _SAVED_POSIX_C_SOURCE _POSIX_C_SOURCE
+#undef _POSIX_C_SOURCE
+#endif
+#define _POSIX_C_SOURCE 199309L
+#include <time.h>
+#undef _POSIX_C_SOURCE
+#ifdef _SAVED_POSIX_C_SOURCE
+#define _POSIX_C_SOURCE _SAVED_POSIX_C_SOURCE
+#endif
+
 #ifdef __CYGWIN__
 #include <stdlib.h>
 #include <signal.h>
@@ -92,7 +105,6 @@ OR PERFORMANCE OF THIS SOFTWARE.
 #if !defined(SYSV) && !defined(WIN32) && !defined(Lynx) && !defined(QNX4)
 #include <sys/resource.h>
 #endif
-#include <time.h>
 #include <sys/stat.h>
 #include <ctype.h>    /* for isspace */
 #include <stdarg.h>
@@ -256,6 +268,8 @@ int auditTrailLevel = 1;
 
 _X_EXPORT Bool Must_have_memory = FALSE;
 
+static int monotonic_usable = -1;
+
 #ifdef AIXV3
 int SyncOn  = 0;
 extern int SelectWaitTime;
@@ -535,10 +549,27 @@ GiveUp(int sig)
 _X_EXPORT CARD32
 GetTimeInMillis(void)
 {
-    struct timeval  tp;
+    struct timeval tv;
+#ifdef MONOTONIC_CLOCK
+    struct timespec tp;
+    int spare = 0;
+
+    if (_X_UNLIKELY(monotonic_usable == -1)) {
+        if (clock_gettime(0, &tp) == 0 &&
+            clock_getcpuclockid(0, &spare) == 0)
+            monotonic_usable = 1;
+        else
+            monotonic_usable = 0;
+    }
+
+    if (_X_LIKELY(monotonic_usable == 1)) {
+        if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0)
+            return (tp.tv_sec * 1000) + (tp.tv_nsec / 1000000);
+    }
+#endif
 
-    X_GETTIMEOFDAY(&tp);
-    return(tp.tv_sec * 1000) + (tp.tv_usec / 1000);
+    X_GETTIMEOFDAY(&tv);
+    return(tv.tv_sec * 1000) + (tv.tv_usec / 1000);
 }
 
 _X_EXPORT void



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