[PATCH] dix: add dtrace probes to input API

Peter Hutterer peter.hutterer at who-t.net
Wed Mar 7 21:47:45 PST 2012


For driver debugging, it is helpful to know whether the driver has actually
submitted an event to the server. dtrace hook can help here.

Note that GetPointerEvents and friends may also be triggerd by the server
for other emulated devices, some care must be taken when analysing the
results.

Additional difficulty: proximity events have a run-time assigned type, so
this may make automatic detection a tad harder. If in doubt, go for any
event > 64 since the only two that can have that value are ProximityIn and
ProximityOut.

An example systemtap script is below:

  # Compile+run with
  #       stap -g xorg.stp /usr/bin/Xorg
  #

  function print_valuators:string(nvaluators:long, mask_in:long, valuators_in:long) %{
          int i;
          unsigned char *mask = (unsigned char*)THIS->mask_in;
          double *valuators = (double*)THIS->valuators_in;
          char str[128] = {0};
          char *s = str;

  #define BitIsSet(ptr, bit) (((unsigned char*)(ptr))[(bit)>>3] & (1 << ((bit) & 7)))

          s += sprintf(s, "nval: %d ::", (int)THIS->nvaluators);
          for (i = 0; i < THIS->nvaluators; i++)
          {
                  s += sprintf(s, "	%d: ", i);
                  if (BitIsSet(mask, i))
                      s += sprintf(s, "%d", (int)valuators[i]);
          }

          sprintf(THIS->__retvalue, "%s", str);
  %}

  probe process(@1).mark("input_event")
  {
      deviceid = $arg1
      type = $arg2
      detail = $arg3
      flags = $arg4
      nvaluators = $arg5

      str = print_valuators(nvaluators, $arg6, $arg7)
      printf("T: device %d type %d detail %d flags %#x %s\n",
              deviceid, type, detail, flags, str);
  }

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
I'd have preferred an xf86Post*Event integration, but this way other DDXs
get use of it too. Plus, the patch is _a lot_ smaller.

 dix/Xserver-dtrace.h.in |    7 ++++++-
 dix/Xserver.d           |    2 ++
 dix/getevents.c         |   40 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 1 deletions(-)

diff --git a/dix/Xserver-dtrace.h.in b/dix/Xserver-dtrace.h.in
index daf3faf..3060190 100644
--- a/dix/Xserver-dtrace.h.in
+++ b/dix/Xserver-dtrace.h.in
@@ -54,7 +54,8 @@ extern "C" {
 	__dtrace_Xserver___resource__free(arg0, arg1, arg2, arg3)
 #define	XSERVER_SEND_EVENT(arg0, arg1, arg2) \
 	__dtrace_Xserver___send__event(arg0, arg1, arg2)
-
+#define	XSERVER_INPUT_EVENT(arg0, arg1, arg2, arg3, arg4, arg5, arg6) \
+	__dtrace_Xserver___input__event(arg0, arg1, arg2, arg3, arg4, arg5, arg6)
 
 extern void __dtrace_Xserver___client__auth(int, string, pid_t, zoneid_t);
 extern void __dtrace_Xserver___client__connect(int, int);
@@ -64,6 +65,8 @@ extern void __dtrace_Xserver___request__start(string, uint8_t, uint16_t, int, vo
 extern void __dtrace_Xserver___resource__alloc(uint32_t, uint32_t, void *, string);
 extern void __dtrace_Xserver___resource__free(uint32_t, uint32_t, void *, string);
 extern void __dtrace_Xserver___send__event(int, uint8_t, void *);
+extern void __dtrace_Xserver___input__event(int, uint16_t, uint32_t, uint32_t, int8_t, void *, void *);
+
 
 #else
 
@@ -75,6 +78,7 @@ extern void __dtrace_Xserver___send__event(int, uint8_t, void *);
 #define	XSERVER_RESOURCE_ALLOC(arg0, arg1, arg2, arg3)
 #define	XSERVER_RESOURCE_FREE(arg0, arg1, arg2, arg3)
 #define	XSERVER_SEND_EVENT(arg0, arg1, arg2)
+#define	XSERVER_INPUT_EVENT(arg0, arg1, arg2, arg3, arg4, arg5, arg6)
 
 #endif
 
@@ -86,6 +90,7 @@ extern void __dtrace_Xserver___send__event(int, uint8_t, void *);
 #define	XSERVER_RESOURCE_ALLOC_ENABLED() (1)
 #define	XSERVER_RESOURCE_FREE_ENABLED() (1)
 #define	XSERVER_SEND_EVENT_ENABLED() (1)
+#define	XSERVER_INPUT_EVENT_ENABLED() (1)
 
 #ifdef	__cplusplus
 }
diff --git a/dix/Xserver.d b/dix/Xserver.d
index 2ad3373..8debd28 100644
--- a/dix/Xserver.d
+++ b/dix/Xserver.d
@@ -48,6 +48,8 @@ provider Xserver {
 	probe resource__free(uint32_t, uint32_t, void *, string);
 	/* client id, event type, event* */
 	probe send__event(int, uint8_t, void *);
+	/* deviceid, type, button/keycode/touchid, flags, lastbit, (double*)mask, (double*)values */
+	probe input__event(int, int, uint32_t, uint32_t, int8_t, void*, void *);
 };
 
 #pragma D attributes Unstable/Unstable/Common provider Xserver provider
diff --git a/dix/getevents.c b/dix/getevents.c
index 306d0ff..3c27aef 100644
--- a/dix/getevents.c
+++ b/dix/getevents.c
@@ -68,6 +68,10 @@
 #include "extnsionst.h"
 #include "listdev.h" /* for sizing up DeviceClassesChangedEvent */
 
+#if XSERVER_DTRACE
+#include <Xserver-dtrace.h>
+#endif
+
 /* Number of motion history events to store. */
 #define MOTION_HISTORY_SIZE 256
 
@@ -1022,6 +1026,15 @@ GetKeyboardEvents(InternalEvent *events, DeviceIntPtr pDev, int type,
     RawDeviceEvent *raw;
     ValuatorMask mask;
 
+#if XSERVER_DTRACE
+    if (XSERVER_INPUT_EVENT_ENABLED()) {
+        XSERVER_INPUT_EVENT(pDev->id, type, key_code, 0,
+                            mask_in ? mask_in->last_bit + 1 : 0,
+                            mask_in ? mask_in->mask : NULL,
+                            mask_in ? mask_in->valuators : NULL);
+    }
+#endif
+
     /* refuse events from disabled devices */
     if (!pDev->enabled)
         return 0;
@@ -1503,6 +1516,15 @@ GetPointerEvents(InternalEvent *events, DeviceIntPtr pDev, int type,
     int i;
     int realtype = type;
 
+#if XSERVER_DTRACE
+    if (XSERVER_INPUT_EVENT_ENABLED()) {
+        XSERVER_INPUT_EVENT(pDev->id, type, buttons, flags,
+                            mask_in ? mask_in->last_bit + 1 : 0,
+                            mask_in ? mask_in->mask : NULL,
+                            mask_in ? mask_in->valuators : NULL);
+    }
+#endif
+
     /* refuse events from disabled devices */
     if (!pDev->enabled)
         return 0;
@@ -1630,6 +1652,15 @@ GetProximityEvents(InternalEvent *events, DeviceIntPtr pDev, int type, const Val
     DeviceEvent *event;
     ValuatorMask mask;
 
+#if XSERVER_DTRACE
+    if (XSERVER_INPUT_EVENT_ENABLED()) {
+        XSERVER_INPUT_EVENT(pDev->id, type, 0, 0,
+                            mask_in ? mask_in->last_bit + 1 : 0,
+                            mask_in ? mask_in->mask : NULL,
+                            mask_in ? mask_in->valuators : NULL);
+    }
+#endif
+
     /* refuse events from disabled devices */
     if (!pDev->enabled)
         return 0;
@@ -1753,6 +1784,15 @@ GetTouchEvents(InternalEvent *events, DeviceIntPtr dev, uint32_t ddx_touchid,
     Bool emulate_pointer = FALSE;
     int client_id = 0;
 
+#if XSERVER_DTRACE
+    if (XSERVER_INPUT_EVENT_ENABLED()) {
+        XSERVER_INPUT_EVENT(dev->id, type, ddx_touchid, flags,
+                            mask_in ? mask_in->last_bit + 1 : 0,
+                            mask_in ? mask_in->mask : NULL,
+                            mask_in ? mask_in->valuators : NULL);
+    }
+#endif
+
     if (!dev->enabled || !t || !v)
         return 0;
 
-- 
1.7.7.6



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