From: Eli Zaretskii <eliz@gnu.org>
Date: Sun, 14 Oct 2012 08:03:16 +0000 (+0200)
Subject: Merge from trunk.
X-Git-Tag: emacs-24.3.90~173^2~7^2~665
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=dd8c2f5adeba029790a007ec829e18442a4ade36;p=emacs.git

Merge from trunk.
---

dd8c2f5adeba029790a007ec829e18442a4ade36
diff --cc src/w32inevt.c
index 7d60c06d78d,899a6fb89bf..a5868be612c
--- a/src/w32inevt.c
+++ b/src/w32inevt.c
@@@ -576,74 -576,38 +576,106 @@@ maybe_generate_resize_event (void
  		     0, 0, 0);
  }
  
 +static int
 +handle_file_notifications (struct input_event *hold_quit)
 +{
 +  BYTE *p = file_notifications;
 +  FILE_NOTIFY_INFORMATION *fni = (PFILE_NOTIFY_INFORMATION)p;
 +  const DWORD min_size
 +    = offsetof (FILE_NOTIFY_INFORMATION, FileName) + sizeof(wchar_t);
 +  struct input_event inev;
 +  int nevents = 0;
 +
 +  /* We cannot process notification before Emacs is fully initialized,
 +     since we need the UTF-16LE coding-system to be set up.  */
 +  if (!initialized)
 +    {
 +      notification_buffer_in_use = 0;
 +      return nevents;
 +    }
 +
 +  enter_crit ();
 +  if (notification_buffer_in_use)
 +    {
 +      DWORD info_size = notifications_size;
 +      Lisp_Object cs = intern ("utf-16le");
 +      Lisp_Object obj = get_watch_object (make_number (notifications_desc));
 +
 +      /* notifications_size could be zero when the buffer of
 +	 notifications overflowed on the OS level, or when the
 +	 directory being watched was itself deleted.  Do nothing in
 +	 that case.  */
 +      if (info_size
 +	  && !NILP (obj) && CONSP (obj))
 +	{
 +	  Lisp_Object callback = XCDR (obj);
 +
 +	  EVENT_INIT (inev);
 +
 +	  while (info_size >= min_size)
 +	    {
 +	      Lisp_Object utf_16_fn
 +		= make_unibyte_string ((char *)fni->FileName,
 +				       fni->FileNameLength);
 +	      /* Note: mule-conf is preloaded, so utf-16le must
 +		 already be defined at this point.  */
 +	      Lisp_Object fname
 +		= code_convert_string_norecord (utf_16_fn, cs, 0);
 +	      Lisp_Object action = lispy_file_action (fni->Action);
 +
 +	      inev.kind = FILE_NOTIFY_EVENT;
 +	      inev.code = (ptrdiff_t)notifications_desc;
 +	      inev.timestamp = GetTickCount ();
 +	      inev.modifiers = 0;
 +	      inev.frame_or_window = callback;
 +	      inev.arg = Fcons (action, fname);
 +	      kbd_buffer_store_event_hold (&inev, hold_quit);
 +
 +	      if (!fni->NextEntryOffset)
 +		break;
 +	      p += fni->NextEntryOffset;
 +	      fni = (PFILE_NOTIFY_INFORMATION)p;
 +	      info_size -= fni->NextEntryOffset;
 +	    }
 +	}
 +      notification_buffer_in_use = 0;
 +    }
 +  leave_crit ();
 +  return nevents;
 +}
 +
+ /* Here's an overview of how Emacs input works in non-GUI sessions on
+    MS-Windows.  (For description of the GUI input, see the commentary
+    before w32_msg_pump in w32fns.c.)
+ 
+    When Emacs is idle, it loops inside wait_reading_process_output,
+    calling pselect periodically to check whether any input is
+    available.  On Windows, pselect is redirected to sys_select, which
+    uses MsgWaitForMultipleObjects to wait for input, either from the
+    keyboard or from any of the Emacs subprocesses.  In addition,
+    MsgWaitForMultipleObjects wakes up when some Windows message is
+    posted to the input queue of the Emacs's main thread (which is the
+    thread in which sys_select runs).
+ 
+    When the Emacs's console window has focus, Windows sends input
+    events that originate from the keyboard or the mouse; these events
+    wake up MsgWaitForMultipleObjects, which reports that input is
+    available.  Emacs then calls w32_console_read_socket, below, to
+    read the input.  w32_console_read_socket uses
+    GetNumberOfConsoleInputEvents and ReadConsoleInput to peek at and
+    read the console input events.
+ 
+    One type of non-keyboard input event that gets reported as input
+    available is due to the Emacs's console window receiving focus.
+    When that happens, Emacs gets the FOCUS_EVENT event and sys_select
+    reports some input; however, w32_console_read_socket ignores such
+    events when called to read them.
+ 
+    Note that any other Windows message sent to the main thread will
+    also wake up MsgWaitForMultipleObjects.  These messages get
+    immediately dispatched to their destinations by calling
+    drain_message_queue.  */
+ 
  int
  w32_console_read_socket (struct terminal *terminal,
                           struct input_event *hold_quit)