[PATCH v2 0/1] MR8802: win32u: Avoid calling server in NtUserGetKeyState() when input keystate is in sync.

[Paul Gofman (＠gofman)]

--
  v2: win32u: Avoid calling server in NtUserGetKeyState() when input keystate is in sync.
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/8802

[PATCH v2 1/1] win32u: Avoid calling server in NtUserGetKeyState() when input keystate is in sync.

[Paul Gofman]

From: Paul Gofman <pgofman(a)codeweavers.com>

---
 dlls/win32u/input.c | 13 ++++++++++++-
 server/protocol.def |  2 ++
 server/queue.c      |  6 ++++++
 server/winstation.c |  1 +
 4 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/dlls/win32u/input.c b/dlls/win32u/input.c
index c7ba334f1c0..c718bd1cbbc 100644
--- a/dlls/win32u/input.c
+++ b/dlls/win32u/input.c
@@ -1019,16 +1019,27 @@ SHORT WINAPI NtUserGetKeyState( INT vkey )
 {
     struct object_lock lock = OBJECT_LOCK_INIT;
     const input_shm_t *input_shm;
+    UINT64 keystate_serial = 0;
     BOOL ret = FALSE;
     SHORT retval = 0;
     NTSTATUS status;
 
     while ((status = get_shared_input( GetCurrentThreadId(), &lock, &input_shm )) == STATUS_PENDING)
     {
-        ret = !!input_shm->keystate_lock; /* needs a request for sync_input_keystate */
+        ret = !!input_shm->keystate_lock; /* needs a request for sync_input_keystate if desktop keystate differs. */
+        keystate_serial = input_shm->keystate_serial;
         retval = (signed char)(input_shm->keystate[vkey & 0xff] & 0x81);
     }
 
+    if (!ret)
+    {
+        struct object_lock lock = OBJECT_LOCK_INIT;
+        const desktop_shm_t *desktop_shm;
+
+        while ((status = get_shared_desktop( &lock, &desktop_shm )) == STATUS_PENDING)
+            ret = keystate_serial == desktop_shm->keystate_serial;
+    }
+
     if (!ret) SERVER_START_REQ( get_key_state )
     {
         req->key = vkey;
diff --git a/server/protocol.def b/server/protocol.def
index ecc20a8e2d0..1112d09f3d6 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -985,6 +985,7 @@ typedef volatile struct
     struct shared_cursor cursor;           /* global cursor information */
     unsigned char        keystate[256];    /* asynchronous key state */
     unsigned __int64     monitor_serial;   /* winstation monitor update counter */
+    unsigned __int64     keystate_serial;  /* keystate update counter */
 } desktop_shm_t;
 
 typedef volatile struct
@@ -1010,6 +1011,7 @@ typedef volatile struct
     int                  cursor_count;     /* cursor show count */
     unsigned char        keystate[256];    /* key state */
     int                  keystate_lock;    /* keystate is locked */
+    unsigned __int64     keystate_serial;  /* keystate update counter at last sync */
 } input_shm_t;
 
 typedef volatile struct
diff --git a/server/queue.c b/server/queue.c
index f42d8f57446..c3d80ed7f2d 100644
--- a/server/queue.c
+++ b/server/queue.c
@@ -283,6 +283,7 @@ static struct thread_input *create_thread_input( struct thread *thread )
             shared->cursor_count = 0;
             memset( (void *)shared->keystate, 0, sizeof(shared->keystate) );
             shared->keystate_lock = 0;
+            shared->keystate_serial = 1;
         }
         SHARED_WRITE_END;
     }
@@ -379,6 +380,7 @@ static void sync_input_keystate( struct thread_input *input )
             if (input->desktop_keystate[i] == desktop_shm->keystate[i]) continue;
             shared->keystate[i] = input->desktop_keystate[i] = desktop_shm->keystate[i];
         }
+        shared->keystate_serial = desktop_shm->keystate_serial;
     }
     SHARED_WRITE_END;
 }
@@ -1525,6 +1527,7 @@ int attach_thread_input( struct thread *thread_from, struct thread *thread_to )
         SHARED_WRITE_BEGIN( input_shm, input_shm_t )
         {
             memset( (void *)shared->keystate, 0, sizeof(shared->keystate) );
+            shared->keystate_serial = 1;
         }
         SHARED_WRITE_END;
     }
@@ -1790,6 +1793,7 @@ static void update_desktop_key_state( struct desktop *desktop, unsigned int msg,
     SHARED_WRITE_BEGIN( desktop->shared, desktop_shm_t )
     {
         update_key_state( shared->keystate, msg, wparam, 1 );
+        ++shared->keystate_serial;
     }
     SHARED_WRITE_END;
 }
@@ -3801,6 +3805,7 @@ DECL_HANDLER(get_key_state)
         {
             reply->state = shared->keystate[req->key & 0xff];
             shared->keystate[req->key & 0xff] &= ~0x40;
+            ++shared->keystate_serial;
         }
         SHARED_WRITE_END;
         release_object( desktop );
@@ -3838,6 +3843,7 @@ DECL_HANDLER(set_key_state)
         SHARED_WRITE_BEGIN( desktop->shared, desktop_shm_t )
         {
             memcpy( (void *)shared->keystate, get_req_data(), size );
+            ++shared->keystate_serial;
         }
         SHARED_WRITE_END;
         release_object( desktop );
diff --git a/server/winstation.c b/server/winstation.c
index bb5596f9a03..bfcd4a53613 100644
--- a/server/winstation.c
+++ b/server/winstation.c
@@ -325,6 +325,7 @@ static struct desktop *create_desktop( const struct unicode_str *name, unsigned
                 shared->cursor.clip.right = 0;
                 shared->cursor.clip.bottom = 0;
                 memset( (void *)shared->keystate, 0, sizeof(shared->keystate) );
+                shared->keystate_serial = 1;
                 shared->monitor_serial = winstation->monitor_serial;
             }
             SHARED_WRITE_END;
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/8802

[Paul Gofman (＠gofman)]

v2:
 - don't introduce 'input_state' variable (assume shared memory read never fails);
 - rename `desktop_keystate_serial` to `keystate_serial`;
 - initialize input keystate serial to 1.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/8802#note_113522

[PATCH v2 0/1] MR8802: win32u: Avoid calling server in NtUserGetKeyState() when input keystate is in sync. - approved

[Rémi Bernon]

This merge request was approved by Rémi Bernon.
-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/8802