Xi: store unused classes in devPrivates.

Rather than freeing/allocing classes each time the device capabilities need to
swap, store them in the devPrivates system.
When a class is unused, it is pushed into the devPrivates, and later recovered
when needed again. This saves us a lot of memory allocations/frees, admittedly
on the cost of some memory.

1 files changed, 10 insertions, 0 deletions

diff --git a/dix/devices.c b/dix/devices.c
index a78a1255d..266a66c61 100644
--- a/dix/devices.c
+++ b/dix/devices.c
@@ -89,6 +89,8 @@ SOFTWARE.
 /* The client that is allowed to change pointer-keyboard pairings. */
 static ClientPtr pairingClient = NULL;
 DevPrivateKey CoreDevicePrivateKey = &CoreDevicePrivateKey;
+/* Used to sture classes currently not in use by an MD */
+DevPrivateKey UnusedClassesPrivateKey = &UnusedClassesPrivateKey;
 
 /**
  * Create a new input device and init it to sane values. The device is added
@@ -2550,6 +2552,7 @@ AllocMasterDevice(ClientPtr client, char* name, DeviceIntPtr* ptr, DeviceIntPtr*
 {
     DeviceIntPtr pointer;
     DeviceIntPtr keyboard;
+    ClassesPtr classes;
     *ptr = *keybd = NULL;
 
     pointer = AddInputDevice(client, CorePointerProc, TRUE);
@@ -2602,6 +2605,13 @@ AllocMasterDevice(ClientPtr client, char* name, DeviceIntPtr* ptr, DeviceIntPtr*
     keyboard->u.lastSlave = NULL;
     keyboard->isMaster = TRUE;
 
+
+    /* The ClassesRec stores the device classes currently not used. */
+    classes = xcalloc(1, sizeof(ClassesRec));
+    dixSetPrivate(&pointer->devPrivates, UnusedClassesPrivateKey, classes);
+    classes = xcalloc(1, sizeof(ClassesRec));
+    dixSetPrivate(&keyboard->devPrivates, UnusedClassesPrivateKey, classes);
+
     *ptr = pointer;
     *keybd = keyboard;