[PATCH 6/7] server: Expose the thread input keystate lock through shared memory.

[Rémi Bernon]

From: Rémi Bernon

---
 server/protocol.def |  1 +
 server/queue.c      | 24 ++++++++++++++++++------
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/server/protocol.def b/server/protocol.def
index f69a3e8a846..12eef14cc67 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -936,6 +936,7 @@ typedef volatile struct
     user_handle_t        cursor;           /* handle to the cursor */
     int                  cursor_count;     /* cursor show count */
     unsigned char        keystate[256];    /* key state */
+    int                  keystate_lock;    /* keystate is locked */
 } input_shm_t;

typedef volatile union
diff --git a/server/queue.c b/server/queue.c
index c082d7acab8..7411168a2ff 100644
--- a/server/queue.c
+++ b/server/queue.c
@@ -108,7 +108,6 @@ struct thread_input
     int                    caret_state;   /* caret on/off state */
     struct list            msg_list;      /* list of hardware messages */
     unsigned char          desktop_keystate[256]; /* desktop keystate when keystate was synced */
-    int                    keystate_lock; /* keystate is locked */
     const input_shm_t     *shared;        /* thread input in session shared memory */
 };

@@ -250,7 +249,6 @@ static struct thread_input *create_thread_input( struct thread *thread )
     if ((input = alloc_object( &thread_input_ops )))
     {
         list_init( &input->msg_list );
-        input->keystate_lock = 0;
         input->shared = NULL;

if (!(input->desktop = get_thread_desktop( thread, 0 /* FIXME: access rights */ )))
@@ -279,6 +277,7 @@ static struct thread_input *create_thread_input( struct thread *thread )
             shared->cursor = 0;
             shared->cursor_count = 0;
             memset( (void *)shared->keystate, 0, sizeof(shared->keystate) );
+            shared->keystate_lock = 0;
         }
         SHARED_WRITE_END;
     }
@@ -364,7 +363,7 @@ static void sync_input_keystate( struct thread_input *input )
     struct desktop *desktop;
     int i;

-    if (!(desktop = input->desktop) || input->keystate_lock) return;
+    if (!(desktop = input->desktop) || input_shm->keystate_lock) return;
     desktop_shm = input->desktop->shared;

SHARED_WRITE_BEGIN( input_shm, input_shm_t )
@@ -381,14 +380,27 @@ static void sync_input_keystate( struct thread_input *input )
 /* locks thread input keystate to prevent synchronization */
 static void lock_input_keystate( struct thread_input *input )
 {
-    input->keystate_lock++;
+    const input_shm_t *input_shm = input->shared;
+
+    SHARED_WRITE_BEGIN( input_shm, input_shm_t )
+    {
+        shared->keystate_lock++;
+    }
+    SHARED_WRITE_END;
 }

/* unlock the thread input keystate and synchronize it again */
 static void unlock_input_keystate( struct thread_input *input )
 {
-    input->keystate_lock--;
-    if (!input->keystate_lock) sync_input_keystate( input );
+    const input_shm_t *input_shm = input->shared;
+
+    SHARED_WRITE_BEGIN( input_shm, input_shm_t )
+    {
+        shared->keystate_lock--;
+    }
+    SHARED_WRITE_END;
+
+    if (!input_shm->keystate_lock) sync_input_keystate( input );
 }

/* change the thread input data of a given thread */