From c0b0a9bce9237b0abe150c1a7b54939affecc751 Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Mon, 5 Mar 2012 14:12:52 +1000
Subject: dix: add dtrace probes to input API

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

Note that GetPointerEvents and friends may also be triggered 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("Event: device %d type %d detail %d flags %#x %s\n",
              deviceid, type, detail, flags, str);
  }

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Acked-by: Jeremy Huddleston <jeremyhu@apple.com>
---
 dix/Xserver.d | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'dix/Xserver.d')

diff --git a/dix/Xserver.d b/dix/Xserver.d
index 2ad337351..248d48e24 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, nvalues, mask, values */
+	probe input__event(int, int, uint32_t, uint32_t, int8_t, uint8_t*, double*);
 };
 
 #pragma D attributes Unstable/Unstable/Common provider Xserver provider
-- 
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