gdb: give names to event loop file handlers

Assign names to event loop file handlers.  They will be used in debug
messages when file handlers are invoked.

In GDB, each UI used to get its own unique number, until commit
cbe256847e19 ("Remove ui::num").  Re-introduce this field, and use it to
make a unique name for the handler.

I'm not too sure what goes on in ser-base.c, all I know is that it's
what is used when debugging remotely.  I've just named the main handler
"serial".  It would be good to have unique names there too.  For instance
when debugging with two different remote connections, we'd ideally want
the handlers to have unique names.  I didn't do it in this patch though.

gdb/ChangeLog:

	* async-event.c (initialize_async_signal_handlers): Pass name to
	add_file_handler
	* event-top.c (ui_register_input_event_handler): Likewise.
	* linux-nat.c (linux_nat_target::async): Likewise.
	* run-on-main-thread.c (_initialize_run_on_main_thread):
	Likewise
	* ser-base.c (reschedule): Likewise.
	(ser_base_async): Likewise.
	* tui/tui-io.c: Likewise.
	* top.h (struct ui) <num>: New field.
	* top.c (highest_ui_num): New variable.
	(ui::ui): Initialize num.

gdbserver/ChangeLog:

	* linux-low.cc (linux_process_target::async): Pass name to
	add_file_handler.
	* remote-utils.cc (handle_accept_event): Likewise.
	(remote_open): Likewise.

gdbsupport/ChangeLog:

	* event-loop.h (add_file_handler): Add "name" parameter.
	* event-loop.cc (struct file_handler) <name>: New field.
	(create_file_handler): Add "name" parameter, assign it to file
	handler.
	(add_file_handler): Add "name" parameter.

Change-Id: I9f1545f73888ebb6778eb653a618ca44d105f92c

3 files changed, 15 insertions, 5 deletions

diff --git a/gdbserver/ChangeLog b/gdbserver/ChangeLog
index d667a20..9ed90ba 100644
--- a/gdbserver/ChangeLog
+++ b/gdbserver/ChangeLog
@@ -1,3 +1,10 @@
+2020-10-02  Simon Marchi  <simon.marchi@polymtl.ca>
+
+	* linux-low.cc (linux_process_target::async): Pass name to
+	add_file_handler.
+	* remote-utils.cc (handle_accept_event): Likewise.
+	(remote_open): Likewise.
+
 2020-10-01  Kamil Rytarowski  <n54@gmx.com>
 
 	* netbsd-i386-low.cc: Add.
diff --git a/gdbserver/linux-low.cc b/gdbserver/linux-low.cc
index 70d5521..1ae72a2 100644
--- a/gdbserver/linux-low.cc
+++ b/gdbserver/linux-low.cc
@@ -6092,7 +6092,8 @@ linux_process_target::async (bool enable)
 
 	  /* Register the event loop handler.  */
 	  add_file_handler (linux_event_pipe[0],
-			    handle_target_event, NULL);
+			    handle_target_event, NULL,
+			    "linux-low");
 
 	  /* Always trigger a linux_wait.  */
 	  async_file_mark ();
diff --git a/gdbserver/remote-utils.cc b/gdbserver/remote-utils.cc
index c26668d..5a6ceb1 100644
--- a/gdbserver/remote-utils.cc
+++ b/gdbserver/remote-utils.cc
@@ -194,7 +194,7 @@ handle_accept_event (int err, gdb_client_data client_data)
   enable_async_notification (remote_desc);
 
   /* Register the event loop handler.  */
-  add_file_handler (remote_desc, handle_serial_event, NULL);
+  add_file_handler (remote_desc, handle_serial_event, NULL, "remote-net");
 
   /* We have a new GDB connection now.  If we were disconnected
      tracing, there's a window where the target could report a stop
@@ -331,7 +331,7 @@ remote_open (const char *name)
       enable_async_notification (remote_desc);
 
       /* Register the event loop handler.  */
-      add_file_handler (remote_desc, handle_serial_event, NULL);
+      add_file_handler (remote_desc, handle_serial_event, NULL, "remote-stdio");
     }
 #ifndef USE_WIN32API
   else if (port_str == NULL)
@@ -372,7 +372,8 @@ remote_open (const char *name)
       enable_async_notification (remote_desc);
 
       /* Register the event loop handler.  */
-      add_file_handler (remote_desc, handle_serial_event, NULL);
+      add_file_handler (remote_desc, handle_serial_event, NULL,
+			"remote-device");
     }
 #endif /* USE_WIN32API */
   else
@@ -398,7 +399,8 @@ remote_open (const char *name)
       fflush (stderr);
 
       /* Register the event loop handler.  */
-      add_file_handler (listen_desc, handle_accept_event, NULL);
+      add_file_handler (listen_desc, handle_accept_event, NULL,
+			"remote-listen");
     }
 }