Remove SIGIO support for input [v5]

This removes all of the SIGIO handling support used for input
throughout the X server, preparing the way for using threads for input
handling instead.

Places calling OsBlockSIGIO and OsReleaseSIGIO are marked with calls
to stub functions input_lock/input_unlock so that we don't lose this
information.

xfree86 SIGIO support is reworked to use internal versions of
OsBlockSIGIO and OsReleaseSIGIO.

v2: Don't change locking order (Peter Hutterer)
v3: Comment weird && FALSE in xf86Helper.c
    Leave errno save/restore in xf86ReadInput
    Squash with stub adding patch (Peter Hutterer)
v4: Leave UseSIGIO config parameter so that
    existing config files don't break (Peter Hutterer)
v5: Split a couple of independent patch bits out
    of kinput.c (Peter Hutterer)

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>

dix/devices.c

@@ -493,14 +493,14 @@ DisableDevice(DeviceIntPtr dev, BOOL sendevent)
 
     FreeSprite(dev);
 
-    /* now that the device is disabled, we can reset the signal handler's
+    /* now that the device is disabled, we can reset the event reader's
      * last.slave */
-    OsBlockSignals();
+    input_lock();
     for (other = inputInfo.devices; other; other = other->next) {
         if (other->last.slave == dev)
             other->last.slave = NULL;
     }
-    OsReleaseSignals();
+    input_unlock();
 
     LeaveWindow(dev);
     SetFocusOut(dev);
@@ -1033,7 +1033,7 @@ CloseDownDevices(void)
 {
     DeviceIntPtr dev;
 
-    OsBlockSignals();
+    input_lock();
 
     /* Float all SDs before closing them. Note that at this point resources
      * (e.g. cursors) have been freed already, so we can't just call
@@ -1060,7 +1060,7 @@ CloseDownDevices(void)
     XkbDeleteRulesDflts();
     XkbDeleteRulesUsed();
 
-    OsReleaseSignals();
+    input_unlock();
 }
 
 /**

dix/ptrveloc.c

@@ -165,7 +165,7 @@ AccelerationDefaultCleanup(DeviceIntPtr dev)
          * AccelSchemeProc(), but that seems impossible. Schemes don't get
          * switched often anyway.
          */
-        OsBlockSignals();
+        input_lock();
         dev->valuator->accelScheme.AccelSchemeProc = NULL;
         FreeVelocityData(vel);
         free(vel);
@@ -175,7 +175,7 @@ AccelerationDefaultCleanup(DeviceIntPtr dev)
                                                 accelData);
         free(dev->valuator->accelScheme.accelData);
         dev->valuator->accelScheme.accelData = NULL;
-        OsReleaseSignals();
+        input_unlock();
     }
 }
 

dix/touch.c

@@ -79,7 +79,7 @@ TouchResizeQueue(ClientPtr client, void *closure)
 {
     int i;
 
-    OsBlockSignals();
+    input_lock();
 
     /* first two ids are reserved */
     for (i = 2; i < MAXDEVICES; i++) {
@@ -112,7 +112,7 @@ TouchResizeQueue(ClientPtr client, void *closure)
         }
 
     }
-    OsReleaseSignals();
+    input_unlock();
 
     return TRUE;
 }
@@ -1077,7 +1077,7 @@ TouchEndPhysicallyActiveTouches(DeviceIntPtr dev)
     InternalEvent *eventlist = InitEventList(GetMaximumEventsNum());
     int i;
 
-    OsBlockSignals();
+    input_lock();
     mieqProcessInputEvents();
     for (i = 0; i < dev->last.num_touches; i++) {
         DDXTouchPointInfoPtr ddxti = dev->last.touches + i;
@@ -1091,7 +1091,7 @@ TouchEndPhysicallyActiveTouches(DeviceIntPtr dev)
                 mieqProcessDeviceEvent(dev, eventlist + j, NULL);
         }
     }
-    OsReleaseSignals();
+    input_unlock();
 
     FreeEventList(eventlist, GetMaximumEventsNum());
 }