diff options
Diffstat (limited to 'gdb')
| -rw-r--r-- | gdb/NEWS | 7 | ||||
| -rw-r--r-- | gdb/doc/gdb.texinfo | 4 | ||||
| -rw-r--r-- | gdb/infrun.c | 41 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.threads/schedlock-new-thread.c | 54 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.threads/schedlock-new-thread.exp | 67 |
5 files changed, 164 insertions, 9 deletions
@@ -392,6 +392,13 @@ show tui mouse-events from the current process state. GDB will show this additional information automatically, or through one of the memory-tag subcommands. +* Scheduler-locking and new threads + + When scheduler-locking is in effect, only the current thread may run + when the inferior is resumed. However, previously, new threads + created by the resumed thread would still be able to run free. Now, + they are held stopped. + * "info breakpoints" now displays enabled breakpoint locations of disabled breakpoints as in the "y-" state. For example: diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 4cbaaa6..79b7431 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -7123,7 +7123,9 @@ the following: There is no locking and any thread may run at any time. @item on -Only the current thread may run when the inferior is resumed. +Only the current thread may run when the inferior is resumed. New +threads created by the resumed thread are held stopped at their entry +point, before they execute any instruction. @item step Behaves like @code{on} when stepping, and @code{off} otherwise. diff --git a/gdb/infrun.c b/gdb/infrun.c index 409c224..943ea88 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -107,6 +107,8 @@ static bool start_step_over (void); static bool step_over_info_valid_p (void); +static bool schedlock_applies (struct thread_info *tp); + /* Asynchronous signal handler registered as event loop source for when we have pending events ready to be passed to the core. */ static struct async_event_handler *infrun_async_inferior_event_token; @@ -1961,7 +1963,13 @@ static void update_thread_events_after_step_over (thread_info *event_thread, const target_waitstatus &event_status) { - if (target_supports_set_thread_options (0)) + if (schedlock_applies (event_thread)) + { + /* If scheduler-locking applies, continue reporting + thread-created/thread-cloned events. */ + return; + } + else if (target_supports_set_thread_options (0)) { /* We can control per-thread options. Disable events for the event thread, unless the thread is gone. */ @@ -2535,9 +2543,14 @@ do_target_resume (ptid_t resume_ptid, bool step, enum gdb_signal sig) to start stopped. We need to release the displaced stepping buffer if the stepped thread exits, so we also enable thread-exit events. + + - If scheduler-locking applies, threads that the current thread + spawns should remain halted. It's not strictly necessary to + enable thread-exit events in this case, but it doesn't hurt. */ if (step_over_info_valid_p () - || displaced_step_in_progress_thread (tp)) + || displaced_step_in_progress_thread (tp) + || schedlock_applies (tp)) { gdb_thread_options options = GDB_THREAD_OPTION_CLONE | GDB_THREAD_OPTION_EXIT; @@ -2546,6 +2559,13 @@ do_target_resume (ptid_t resume_ptid, bool step, enum gdb_signal sig) else target_thread_events (true); } + else + { + if (target_supports_set_thread_options (0)) + tp->set_thread_options (0); + else if (!displaced_step_in_progress_any_thread ()) + target_thread_events (false); + } /* If we're resuming more than one thread simultaneously, then any thread other than the leader is being set to run free. Clear any @@ -6295,16 +6315,21 @@ handle_inferior_event (struct execution_control_state *ecs) parent->set_running (false); /* If resuming the child, mark it running. */ - if (ecs->ws.kind () == TARGET_WAITKIND_THREAD_CLONED - || (follow_child || (!detach_fork && (non_stop || sched_multi)))) + if ((ecs->ws.kind () == TARGET_WAITKIND_THREAD_CLONED + && !schedlock_applies (ecs->event_thread)) + || (ecs->ws.kind () != TARGET_WAITKIND_THREAD_CLONED + && (follow_child + || (!detach_fork && (non_stop || sched_multi))))) child->set_running (true); /* In non-stop mode, also resume the other branch. */ if ((ecs->ws.kind () == TARGET_WAITKIND_THREAD_CLONED - && target_is_non_stop_p ()) - || (!detach_fork && (non_stop - || (sched_multi - && target_is_non_stop_p ())))) + && target_is_non_stop_p () + && !schedlock_applies (ecs->event_thread)) + || (ecs->ws.kind () != TARGET_WAITKIND_THREAD_CLONED + && (!detach_fork && (non_stop + || (sched_multi + && target_is_non_stop_p ()))))) { if (follow_child) switch_to_thread (parent); diff --git a/gdb/testsuite/gdb.threads/schedlock-new-thread.c b/gdb/testsuite/gdb.threads/schedlock-new-thread.c new file mode 100644 index 0000000..4fe7769 --- /dev/null +++ b/gdb/testsuite/gdb.threads/schedlock-new-thread.c @@ -0,0 +1,54 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2021-2023 Free Software Foundation, Inc. + + 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 <pthread.h> +#include <assert.h> +#include <unistd.h> + +static void * +thread_func (void *arg) +{ +#if !SCHEDLOCK + while (1) + sleep (1); +#endif + + return NULL; +} + +int +main (void) +{ + pthread_t thread; + int ret; + + ret = pthread_create (&thread, NULL, thread_func, NULL); /* set break 1 here */ + assert (ret == 0); + +#if SCHEDLOCK + /* When testing with schedlock enabled, the new thread won't run, so + we can't join it, as that would hang forever. Instead, sleep for + a bit, enough that if the spawned thread is scheduled, it hits + the thread_func breakpoint before the main thread reaches the + "return 0" line below. */ + sleep (3); +#else + pthread_join (thread, NULL); +#endif + + return 0; /* set break 2 here */ +} diff --git a/gdb/testsuite/gdb.threads/schedlock-new-thread.exp b/gdb/testsuite/gdb.threads/schedlock-new-thread.exp new file mode 100644 index 0000000..ecaeea5 --- /dev/null +++ b/gdb/testsuite/gdb.threads/schedlock-new-thread.exp @@ -0,0 +1,67 @@ +# Copyright 2021-2023 Free Software Foundation, Inc. + +# 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/>. + +# Test continuing over a thread spawn with scheduler-locking on. + +standard_testfile .c + +foreach_with_prefix schedlock {off on} { + set sl [expr $schedlock == "on" ? 1 : 0] + if { [build_executable "failed to prepare" $testfile-$sl \ + $srcfile \ + [list debug pthreads additional_flags=-DSCHEDLOCK=$sl]] \ + == -1 } { + return + } +} + +proc test {non-stop schedlock} { + save_vars ::GDBFLAGS { + append ::GDBFLAGS " -ex \"set non-stop ${non-stop}\"" + set sl [expr $schedlock == "on" ? 1 : 0] + clean_restart $::binfile-$sl + } + + set linenum1 [gdb_get_line_number "set break 1 here"] + + if { ![runto $::srcfile:$linenum1] } { + return + } + + delete_breakpoints + + set linenum2 [gdb_get_line_number "set break 2 here"] + gdb_breakpoint $linenum2 + + gdb_breakpoint "thread_func" + + gdb_test_no_output "set scheduler-locking $schedlock" + + if {$schedlock} { + gdb_test "continue" \ + "return 0.*set break 2 here .*" \ + "continue does not stop in new thread" + } else { + gdb_test "continue" \ + "thread_func .*" \ + "continue stops in new thread" + } +} + +foreach_with_prefix non-stop {off on} { + foreach_with_prefix schedlock {off on} { + test ${non-stop} ${schedlock} + } +} |