From 9411c49ecc09df989ecddb05e1756e0a9da0d1c8 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Fri, 8 Mar 2019 15:51:06 -0700 Subject: [PATCH] Introduce run_on_main_thread This introduces a way for a callback to be run on the main thread. gdb/ChangeLog 2019-11-26 Tom Tromey * run-on-main-thread.c: New file. * run-on-main-thread.h: New file. * unittests/main-thread-selftests.c: New file. * Makefile.in (SUBDIR_UNITTESTS_SRCS): Add main-thread-selftests.c. (HFILES_NO_SRCDIR): Add run-on-main-thread.h. (COMMON_SFILES): Add run-on-main-thread.c. Change-Id: I16ef82f0564e9f8a524bdc64cb31df79a988ad9f --- gdb/ChangeLog | 10 +++ gdb/Makefile.in | 3 + gdb/run-on-main-thread.c | 97 +++++++++++++++++++++++++++ gdb/run-on-main-thread.h | 28 ++++++++ gdb/unittests/main-thread-selftests.c | 80 ++++++++++++++++++++++ 5 files changed, 218 insertions(+) create mode 100644 gdb/run-on-main-thread.c create mode 100644 gdb/run-on-main-thread.h create mode 100644 gdb/unittests/main-thread-selftests.c diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 7535016bcc..80a3ea0a2a 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2019-11-26 Tom Tromey + + * run-on-main-thread.c: New file. + * run-on-main-thread.h: New file. + * unittests/main-thread-selftests.c: New file. + * Makefile.in (SUBDIR_UNITTESTS_SRCS): Add + main-thread-selftests.c. + (HFILES_NO_SRCDIR): Add run-on-main-thread.h. + (COMMON_SFILES): Add run-on-main-thread.c. + 2019-11-26 Tom Tromey * main.c (setup_alternate_signal_stack): Remove. diff --git a/gdb/Makefile.in b/gdb/Makefile.in index 8d248ae780..c487b10af8 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -433,6 +433,7 @@ SUBDIR_UNITTESTS_SRCS = \ unittests/optional-selftests.c \ unittests/parse-connection-spec-selftests.c \ unittests/ptid-selftests.c \ + unittests/main-thread-selftests.c \ unittests/mkdir-recursive-selftests.c \ unittests/rsp-low-selftests.c \ unittests/scoped_fd-selftests.c \ @@ -1116,6 +1117,7 @@ COMMON_SFILES = \ remote-fileio.c \ remote-notif.c \ reverse.c \ + run-on-main-thread.c \ rust-lang.c \ sentinel-frame.c \ ser-event.c \ @@ -1378,6 +1380,7 @@ HFILES_NO_SRCDIR = \ riscv-tdep.h \ rs6000-aix-tdep.h \ rs6000-tdep.h \ + run-on-main-thread.h \ s390-linux-tdep.h \ s390-tdep.h \ score-tdep.h \ diff --git a/gdb/run-on-main-thread.c b/gdb/run-on-main-thread.c new file mode 100644 index 0000000000..86824b5af4 --- /dev/null +++ b/gdb/run-on-main-thread.c @@ -0,0 +1,97 @@ +/* Run a function on the main thread + Copyright (C) 2019 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 . */ + +#include "defs.h" +#include "run-on-main-thread.h" +#include "ser-event.h" +#if CXX_STD_THREAD +#include +#endif +#include "event-loop.h" + +/* The serial event used when posting runnables. */ + +static struct serial_event *runnable_event; + +/* Runnables that have been posted. */ + +static std::vector> runnables; + +#if CXX_STD_THREAD + +/* Mutex to hold when handling RUNNABLE_EVENT or RUNNABLES. */ + +static std::mutex runnable_mutex; + +#endif + +/* Run all the queued runnables. */ + +static void +run_events (int error, gdb_client_data client_data) +{ + std::vector> local; + + /* Hold the lock while changing the globals, but not while running + the runnables. */ + { +#if CXX_STD_THREAD + std::lock_guard 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 &&func) +{ +#if CXX_STD_THREAD + std::lock_guard lock (runnable_mutex); +#endif + runnables.emplace_back (std::move (func)); + serial_event_set (runnable_event); +} + +void +_initialize_run_on_main_thread () +{ + runnable_event = make_serial_event (); + add_file_handler (serial_event_fd (runnable_event), run_events, nullptr); +} diff --git a/gdb/run-on-main-thread.h b/gdb/run-on-main-thread.h new file mode 100644 index 0000000000..fd1a2c4253 --- /dev/null +++ b/gdb/run-on-main-thread.h @@ -0,0 +1,28 @@ +/* Run a function on the main thread + Copyright (C) 2019 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 . */ + +#ifndef GDB_RUN_ON_MAIN_THREAD_H +#define GDB_RUN_ON_MAIN_THREAD_H + +#include + +/* Send a runnable to the main thread. */ + +extern void run_on_main_thread (std::function &&); + +#endif /* GDB_RUN_ON_MAIN_THREAD_H */ diff --git a/gdb/unittests/main-thread-selftests.c b/gdb/unittests/main-thread-selftests.c new file mode 100644 index 0000000000..2324e98442 --- /dev/null +++ b/gdb/unittests/main-thread-selftests.c @@ -0,0 +1,80 @@ +/* Self tests for run_on_main_thread + + Copyright (C) 2019 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 . */ + +#include "defs.h" +#include "gdbsupport/selftest.h" +#include "gdbsupport/block-signals.h" +#include "run-on-main-thread.h" +#include "event-loop.h" +#if CXX_STD_THREAD +#include +#endif + +namespace selftests { +namespace main_thread_tests { + +#if CXX_STD_THREAD + +static bool done; + +static void +set_done () +{ + run_on_main_thread ([] () + { + done = true; + }); +} + +static void +run_tests () +{ + std::thread thread; + + done = false; + + { + gdb::block_signals blocker; + + thread = std::thread (set_done); + } + + while (!done && gdb_do_one_event () >= 0) + ; + + /* Actually the test will just hang, but we want to test + something. */ + SELF_CHECK (done); + + thread.join (); +} + +#endif + +} +} + +void +_initialize_main_thread_selftests () +{ +#if CXX_STD_THREAD + selftests::register_test ("run_on_main_thread", + selftests::main_thread_tests::run_tests); +#endif +} -- 2.34.1