From 73ec3d093c2af2db3636551db9d590d7ac703d91 Mon Sep 17 00:00:00 2001
From: Mihail Konev <k.mvc@ya.ru>
Date: Tue, 20 Sep 2016 18:43:15 +0000
Subject: [PATCH xserver] Add processed-all-input-dev-removes barrier

Signed-off-by: Mihail Konev <k.mvc@ya.ru>
---
 hw/xfree86/common/xf86Events.c |  1 +
 include/input.h                |  2 ++
 os/inputthread.c               | 20 ++++++++++++++++++++
 3 files changed, 23 insertions(+)

diff --git a/hw/xfree86/common/xf86Events.c b/hw/xfree86/common/xf86Events.c
index 9a8f432a0556..92b1ec5c00cb 100644
--- a/hw/xfree86/common/xf86Events.c
+++ b/hw/xfree86/common/xf86Events.c
@@ -438,6 +438,7 @@ xf86VTLeave(void)
     }
     for (pInfo = xf86InputDevs; pInfo; pInfo = pInfo->next)
         xf86DisableInputDeviceForVTSwitch(pInfo);
+    input_wait_for_processing_all_removes();
 
     input_lock();
     for (i = 0; i < xf86NumScreens; i++)
diff --git a/include/input.h b/include/input.h
index e0f6b9b01d97..3635b8ab4e97 100644
--- a/include/input.h
+++ b/include/input.h
@@ -719,6 +719,8 @@ extern _X_EXPORT void input_lock(void);
 extern _X_EXPORT void input_unlock(void);
 extern _X_EXPORT void input_force_unlock(void);
 
+extern _X_EXPORT void input_wait_for_processing_all_removes(void);
+
 extern void InputThreadPreInit(void);
 extern void InputThreadInit(void);
 extern void InputThreadFini(void);
diff --git a/os/inputthread.c b/os/inputthread.c
index 6aa0a9ce6fb5..7c8d51b7c868 100644
--- a/os/inputthread.c
+++ b/os/inputthread.c
@@ -90,6 +90,17 @@ static pthread_mutex_t input_mutex;
 static Bool input_mutex_initialized;
 #endif
 
+static Bool waiting_for_processing_all_removes = FALSE;
+static int unprocessed_removes_count = 0;
+static pthread_barrier_t all_removes_processed_barrier;
+
+void
+input_wait_for_processing_all_removes(void)
+{
+    waiting_for_processing_all_removes = TRUE;
+    pthread_barrier_wait(&all_removes_processed_barrier);
+}
+
 void
 input_lock(void)
 {
@@ -267,6 +278,7 @@ InputThreadUnregisterDev(int fd)
 
     dev->state = device_state_removed;
     inputThreadInfo->changed = TRUE;
+    unprocessed_removes_count++;
 
     input_unlock();
 
@@ -348,12 +360,18 @@ InputThreadDoWork(void *arg)
                     ospoll_remove(inputThreadInfo->fds, dev->fd);
                     xorg_list_del(&dev->node);
                     free(dev);
+                    unprocessed_removes_count--;
                     break;
                 }
             }
             input_unlock();
         }
 
+        if (waiting_for_processing_all_removes && !unprocessed_removes_count) {
+            waiting_for_processing_all_removes = FALSE;
+            pthread_barrier_wait(&all_removes_processed_barrier);
+        }
+
         if (ospoll_wait(inputThreadInfo->fds, -1) < 0) {
             if (errno == EINVAL)
                 FatalError("input-thread: %s (%s)", __func__, strerror(errno));
@@ -400,6 +418,8 @@ InputThreadPreInit(void)
     if (!inputThreadInfo)
         FatalError("input-thread: could not allocate memory");
 
+    pthread_barrier_init(&all_removes_processed_barrier, NULL, 2);
+
     inputThreadInfo->thread = 0;
     xorg_list_init(&inputThreadInfo->devs);
     inputThreadInfo->fds = ospoll_create();
-- 
2.9.2