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author | Tom Tromey <tom@tromey.com> | 2019-03-08 15:51:06 -0700 |
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committer | Tom Tromey <tom@tromey.com> | 2019-09-30 20:30:39 -0600 |
commit | 0e0174f4d56e034b9ad0ff76040f862bc81b5ff0 (patch) | |
tree | 56c1f51213748383d192e1369dcf6cb6df92e875 | |
parent | 7e3ed550beaf5dba6b32586c8986c0bc79b959b6 (diff) | |
download | binutils-gdb-0e0174f4d56e034b9ad0ff76040f862bc81b5ff0.tar.gz |
Introduce run_on_main_thread
This introduces a way for a callback to be run on the main thread.
gdb/ChangeLog
2019-09-30 Tom Tromey <tom@tromey.com>
* unittests/main-thread-selftests.c: New file.
* Makefile.in (SUBDIR_UNITTESTS_SRCS): Add
main-thread-selftests.c.
* ser-event.h (run_on_main_thread): Declare.
* ser-event.c (runnable_event, runnables, runnable_mutex): New
globals.
(run_events, run_on_main_thread, _initialize_ser_event): New
functions.
-rw-r--r-- | gdb/ChangeLog | 11 | ||||
-rw-r--r-- | gdb/Makefile.in | 1 | ||||
-rw-r--r-- | gdb/ser-event.c | 78 | ||||
-rw-r--r-- | gdb/ser-event.h | 6 | ||||
-rw-r--r-- | gdb/unittests/main-thread-selftests.c | 80 |
5 files changed, 176 insertions, 0 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index d46b44df2aa..d0bd8af785c 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,16 @@ 2019-09-30 Tom Tromey <tom@tromey.com> + * unittests/main-thread-selftests.c: New file. + * Makefile.in (SUBDIR_UNITTESTS_SRCS): Add + main-thread-selftests.c. + * ser-event.h (run_on_main_thread): Declare. + * ser-event.c (runnable_event, runnables, runnable_mutex): New + globals. + (run_events, run_on_main_thread, _initialize_ser_event): New + functions. + +2019-09-30 Tom Tromey <tom@tromey.com> + * symtab.c (demangled_mutex): New global. (symbol_set_names): Use a lock_guard. diff --git a/gdb/Makefile.in b/gdb/Makefile.in index c4c858b5594..d4eca61d06e 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -426,6 +426,7 @@ 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 \ diff --git a/gdb/ser-event.c b/gdb/ser-event.c index a65a186526f..029ced7619c 100644 --- a/gdb/ser-event.c +++ b/gdb/ser-event.c @@ -20,6 +20,10 @@ #include "ser-event.h" #include "serial.h" #include "gdbsupport/filestuff.h" +#if CXX_STD_THREAD +#include <mutex> +#endif +#include "event-loop.h" /* On POSIX hosts, a serial_event is basically an abstraction for the classical self-pipe trick. @@ -217,3 +221,77 @@ serial_event_clear (struct serial_event *event) ResetEvent (state->event); #endif } + + + +/* 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; + +#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 ser-event.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); +} + +void +_initialize_ser_event () +{ + runnable_event = make_serial_event (); + add_file_handler (serial_event_fd (runnable_event), run_events, nullptr); +} diff --git a/gdb/ser-event.h b/gdb/ser-event.h index 137348557f9..61a84f9cc79 100644 --- a/gdb/ser-event.h +++ b/gdb/ser-event.h @@ -19,6 +19,8 @@ #ifndef SER_EVENT_H #define SER_EVENT_H +#include <functional> + /* This is used to be able to signal the event loop (or any other select/poll) of events, in a race-free manner. @@ -48,4 +50,8 @@ extern void serial_event_set (struct serial_event *event); call is made. */ extern void serial_event_clear (struct serial_event *event); +/* Send a runnable to the main thread. */ + +extern void run_on_main_thread (std::function<void ()> &&); + #endif diff --git a/gdb/unittests/main-thread-selftests.c b/gdb/unittests/main-thread-selftests.c new file mode 100644 index 00000000000..e5bd2d36cea --- /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 <http://www.gnu.org/licenses/>. */ + +#include "defs.h" +#include "gdbsupport/selftest.h" +#include "gdbsupport/block-signals.h" +#include "ser-event.h" +#include "event-loop.h" +#if CXX_STD_THREAD +#include <thread> +#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 ("main_thread", + selftests::main_thread_tests::run_tests); +#endif +} |