binutils-gdb/gdb/run-on-main-thread.c
Tom Tromey 47ccd6b84b Only allow QUIT on the main thread
Pedro pointed out that gdb worker threads should not react to quits.
While I don't think that the new DWARF reader can call QUIT from a
worker thread (and I don't think the existing minsym threading code
can either), it seems safest to address this before checking in the
new code.  This patch arranges for the QUIT macro to only work on the
main thread.
2022-03-30 13:39:48 -06:00

120 lines
2.8 KiB
C

/* Run a function on the main thread
Copyright (C) 2019-2022 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "run-on-main-thread.h"
#include "ser-event.h"
#if CXX_STD_THREAD
#include <thread>
#include <mutex>
#endif
#include "gdbsupport/event-loop.h"
/* The serial event used when posting runnables. */
static struct serial_event *runnable_event;
/* Runnables that have been posted. */
static std::vector<std::function<void ()>> runnables;
#if CXX_STD_THREAD
/* Mutex to hold when handling RUNNABLE_EVENT or RUNNABLES. */
static std::mutex runnable_mutex;
/* The main thread. */
static std::thread::id main_thread;
#endif
/* Run all the queued runnables. */
static void
run_events (int error, gdb_client_data client_data)
{
std::vector<std::function<void ()>> local;
/* Hold the lock while changing the globals, but not while running
the runnables. */
{
#if CXX_STD_THREAD
std::lock_guard<std::mutex> lock (runnable_mutex);
#endif
/* Clear the event fd. Do this before flushing the events list,
so that any new event post afterwards is sure to re-awaken the
event loop. */
serial_event_clear (runnable_event);
/* Move the vector in case running a runnable pushes a new
runnable. */
local = std::move (runnables);
}
for (auto &item : local)
{
try
{
item ();
}
catch (...)
{
/* Ignore exceptions in the callback. */
}
}
}
/* See run-on-main-thread.h. */
void
run_on_main_thread (std::function<void ()> &&func)
{
#if CXX_STD_THREAD
std::lock_guard<std::mutex> lock (runnable_mutex);
#endif
runnables.emplace_back (std::move (func));
serial_event_set (runnable_event);
}
/* See run-on-main-thread.h. */
bool
is_main_thread ()
{
#if CXX_STD_THREAD
return std::this_thread::get_id () == main_thread;
#else
return true;
#endif
}
void _initialize_run_on_main_thread ();
void
_initialize_run_on_main_thread ()
{
#if CXX_STD_THREAD
main_thread = std::this_thread::get_id ();
#endif
runnable_event = make_serial_event ();
add_file_handler (serial_event_fd (runnable_event), run_events, nullptr,
"run-on-main-thread");
}