Do not execute two or more setxkbmap commands in parallel.

chrome/browser/chromeos/input_method/xkeyboard.cc

Index: chrome/browser/chromeos/input_method/xkeyboard.cc
diff --git a/chrome/browser/chromeos/input_method/xkeyboard.cc b/chrome/browser/chromeos/input_method/xkeyboard.cc
index aaf1444d63d38f12a75c544d7a8dd85af96ab3cb..263721922e9415ea502109ad45361c746bc96b6f 100644
--- a/chrome/browser/chromeos/input_method/xkeyboard.cc
+++ b/chrome/browser/chromeos/input_method/xkeyboard.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/chromeos/input_method/xkeyboard.h"
 
+#include <queue>
 #include <utility>
 
 #include <X11/XKBlib.h>
@@ -253,7 +254,10 @@ class XKeyboard {
     LOG(WARNING) << (force ? "Reapply" : "Set")
                  << " layout: " << layouts_to_set;
 
-    ExecuteSetLayoutCommand(layouts_to_set);
+    execute_queue_.push(layouts_to_set);

[Daniel Kurtz, 2011/06/07 03:19:38]

Is layouts_to_set a collection or a single layout?
If just one, please rename to layout_to_set.

[Yusuke Sato, 2011/06/07 04:54:58]

Done.

+    if (execute_queue_.size() == 1) {

[satorux1, 2011/06/07 03:19:27]

Checking the size here looks a bit tricky. Maybe better to do this in
ExecuteSetLayoutCommand()?

[Yusuke Sato, 2011/06/07 04:54:58]

Modifed both this function and the callback. PTAL.

On 2011/06/07 03:19:27, satorux1 wrote:

+      ExecuteSetLayoutCommand(layouts_to_set);
+    }
     return true;
   }
 
@@ -267,6 +271,7 @@ class XKeyboard {
     argv.push_back(kSetxkbmapCommand);
     argv.push_back("-layout");
     argv.push_back(layouts_to_set);
+    argv.push_back("-synch");
     const bool result = base::LaunchApp(argv,
                                         fds_to_remap,  // No remapping.
                                         false,  // Don't wait.
@@ -282,16 +287,24 @@ class XKeyboard {
     g_child_watch_add(pid,
                       reinterpret_cast<GChildWatchFunc>(OnSetLayoutFinish),
                       this);
+    VLOG(1) << "ExecuteSetLayoutCommand: " << layouts_to_set << ": pid=" << pid;
   }
 
   static void OnSetLayoutFinish(GPid pid, gint status, XKeyboard* self) {
-    DLOG(INFO) << "OnSetLayoutFinish: pid=" << pid;
+    VLOG(1) << "OnSetLayoutFinish: pid=" << pid;
+    DCHECK(!self->execute_queue_.empty());
+    self->execute_queue_.pop();
+    if (!self->execute_queue_.empty()) {
+      self->ExecuteSetLayoutCommand(self->execute_queue_.front());
+    }
   }
 
   // The XKB layout name which we set last time like "us" and "us(dvorak)".
   std::string current_layout_name_;
   // The mapping of modifier keys we set last time.
   ModifierMap current_modifier_map_;
+  // A queue for executing setxkbmap one by one.
+  std::queue<std::string> execute_queue_;
 
   DISALLOW_COPY_AND_ASSIGN(XKeyboard);
 };