| 1 | /* Run a function on the main thread |
| 2 | Copyright (C) 2019-2020 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include "defs.h" |
| 20 | #include "run-on-main-thread.h" |
| 21 | #include "ser-event.h" |
| 22 | #if CXX_STD_THREAD |
| 23 | #include <mutex> |
| 24 | #endif |
| 25 | #include "event-loop.h" |
| 26 | |
| 27 | /* The serial event used when posting runnables. */ |
| 28 | |
| 29 | static struct serial_event *runnable_event; |
| 30 | |
| 31 | /* Runnables that have been posted. */ |
| 32 | |
| 33 | static std::vector<std::function<void ()>> runnables; |
| 34 | |
| 35 | #if CXX_STD_THREAD |
| 36 | |
| 37 | /* Mutex to hold when handling RUNNABLE_EVENT or RUNNABLES. */ |
| 38 | |
| 39 | static std::mutex runnable_mutex; |
| 40 | |
| 41 | #endif |
| 42 | |
| 43 | /* Run all the queued runnables. */ |
| 44 | |
| 45 | static void |
| 46 | run_events (int error, gdb_client_data client_data) |
| 47 | { |
| 48 | std::vector<std::function<void ()>> local; |
| 49 | |
| 50 | /* Hold the lock while changing the globals, but not while running |
| 51 | the runnables. */ |
| 52 | { |
| 53 | #if CXX_STD_THREAD |
| 54 | std::lock_guard<std::mutex> lock (runnable_mutex); |
| 55 | #endif |
| 56 | |
| 57 | /* Clear the event fd. Do this before flushing the events list, |
| 58 | so that any new event post afterwards is sure to re-awaken the |
| 59 | event loop. */ |
| 60 | serial_event_clear (runnable_event); |
| 61 | |
| 62 | /* Move the vector in case running a runnable pushes a new |
| 63 | runnable. */ |
| 64 | local = std::move (runnables); |
| 65 | } |
| 66 | |
| 67 | for (auto &item : local) |
| 68 | { |
| 69 | try |
| 70 | { |
| 71 | item (); |
| 72 | } |
| 73 | catch (...) |
| 74 | { |
| 75 | /* Ignore exceptions in the callback. */ |
| 76 | } |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | /* See run-on-main-thread.h. */ |
| 81 | |
| 82 | void |
| 83 | run_on_main_thread (std::function<void ()> &&func) |
| 84 | { |
| 85 | #if CXX_STD_THREAD |
| 86 | std::lock_guard<std::mutex> lock (runnable_mutex); |
| 87 | #endif |
| 88 | runnables.emplace_back (std::move (func)); |
| 89 | serial_event_set (runnable_event); |
| 90 | } |
| 91 | |
| 92 | void |
| 93 | _initialize_run_on_main_thread () |
| 94 | { |
| 95 | runnable_event = make_serial_event (); |
| 96 | add_file_handler (serial_event_fd (runnable_event), run_events, nullptr); |
| 97 | } |