From: Pedro Alves <pedro@palves.net>
To: gdb-patches@sourceware.org
Subject: [PATCH 22/31] gdbserver: Queue no-resumed event after thread exit
Date: Mon, 12 Dec 2022 20:30:52 +0000 [thread overview]
Message-ID: <20221212203101.1034916-23-pedro@palves.net> (raw)
In-Reply-To: <20221212203101.1034916-1-pedro@palves.net>
Normally, if the last thread resumed thread on the target exits, the
server sends a no-resumed event to GDB. If however, GDB enables the
GDB_THREAD_OPTION_EXIT option on a thread, and, that thread exits, the
server sends a thread exit event for that thread instead.
In all-stop RSP mode, since events can only be forwarded to GDB one at
a time, and the whole target stops whenever an event is reported, GDB
resumes the target again after getting a THREAD_EXITED event, and then
the server finally reports back a no-resumed event if/when
appropriate.
For non-stop RSP though, events are asynchronous, and if the server
sends a thread-exit event for the last resumed thread, the no-resumed
event is never sent. This patch makes sure that in non-stop mode, the
server queues a no-resumed event after the thread-exit event if it was
the last resumed thread that exited.
Without this, we'd see failures in step-over-thread-exit testcases
added later in the series, like so:
continue
Continuing.
- No unwaited-for children left.
- (gdb) PASS: gdb.threads/step-over-thread-exit.exp: displaced-stepping=off: non-stop=on: target-non-stop=on: schedlock=off: ns_stop_all=1: continue stops when thread exits
+ FAIL: gdb.threads/step-over-thread-exit.exp: displaced-stepping=off: non-stop=on: target-non-stop=on: schedlock=off: ns_stop_all=1: continue stops when thread exits (timeout)
(and other similar ones)
Change-Id: I927d78b30f88236dbd5634b051a716f72420e7c7
---
gdbserver/linux-low.cc | 47 +++++++++++++++++++++++++-----------------
gdbserver/linux-low.h | 2 ++
gdbserver/server.cc | 12 ++++++++++-
gdbserver/target.cc | 6 ++++++
gdbserver/target.h | 6 ++++++
5 files changed, 53 insertions(+), 20 deletions(-)
diff --git a/gdbserver/linux-low.cc b/gdbserver/linux-low.cc
index ebc3bf34127..bf6dc1d995a 100644
--- a/gdbserver/linux-low.cc
+++ b/gdbserver/linux-low.cc
@@ -2963,7 +2963,6 @@ linux_process_target::wait_1 (ptid_t ptid, target_waitstatus *ourstatus,
int report_to_gdb;
int trace_event;
int in_step_range;
- int any_resumed;
threads_debug_printf ("[%s]", target_pid_to_str (ptid).c_str ());
@@ -2977,23 +2976,7 @@ linux_process_target::wait_1 (ptid_t ptid, target_waitstatus *ourstatus,
in_step_range = 0;
ourstatus->set_ignore ();
- auto status_pending_p_any = [&] (thread_info *thread)
- {
- return status_pending_p_callback (thread, minus_one_ptid);
- };
-
- auto not_stopped = [&] (thread_info *thread)
- {
- return not_stopped_callback (thread, minus_one_ptid);
- };
-
- /* Find a resumed LWP, if any. */
- if (find_thread (status_pending_p_any) != NULL)
- any_resumed = 1;
- else if (find_thread (not_stopped) != NULL)
- any_resumed = 1;
- else
- any_resumed = 0;
+ bool was_any_resumed = any_resumed ();
if (step_over_bkpt == null_ptid)
pid = wait_for_event (ptid, &w, options);
@@ -3004,7 +2987,7 @@ linux_process_target::wait_1 (ptid_t ptid, target_waitstatus *ourstatus,
pid = wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
}
- if (pid == 0 || (pid == -1 && !any_resumed))
+ if (pid == 0 || (pid == -1 && !was_any_resumed))
{
gdb_assert (target_options & TARGET_WNOHANG);
@@ -6166,6 +6149,32 @@ linux_process_target::thread_stopped (thread_info *thread)
return get_thread_lwp (thread)->stopped;
}
+bool
+linux_process_target::any_resumed ()
+{
+ bool any_resumed;
+
+ auto status_pending_p_any = [&] (thread_info *thread)
+ {
+ return status_pending_p_callback (thread, minus_one_ptid);
+ };
+
+ auto not_stopped = [&] (thread_info *thread)
+ {
+ return not_stopped_callback (thread, minus_one_ptid);
+ };
+
+ /* Find a resumed LWP, if any. */
+ if (find_thread (status_pending_p_any) != NULL)
+ any_resumed = 1;
+ else if (find_thread (not_stopped) != NULL)
+ any_resumed = 1;
+ else
+ any_resumed = 0;
+
+ return any_resumed;
+}
+
/* This exposes stop-all-threads functionality to other modules. */
void
diff --git a/gdbserver/linux-low.h b/gdbserver/linux-low.h
index 1c1754d2b59..33a14e15173 100644
--- a/gdbserver/linux-low.h
+++ b/gdbserver/linux-low.h
@@ -259,6 +259,8 @@ class linux_process_target : public process_stratum_target
bool thread_stopped (thread_info *thread) override;
+ bool any_resumed () override;
+
void pause_all (bool freeze) override;
void unpause_all (bool unfreeze) override;
diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index 5099db1ee31..77b4b57466d 100644
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -4740,7 +4740,17 @@ handle_target_event (int err, gdb_client_data client_data)
}
}
else
- push_stop_notification (cs.last_ptid, cs.last_status);
+ {
+ push_stop_notification (cs.last_ptid, cs.last_status);
+
+ if (cs.last_status.kind () == TARGET_WAITKIND_THREAD_EXITED
+ && !target_any_resumed ())
+ {
+ target_waitstatus ws;
+ ws.set_no_resumed ();
+ push_stop_notification (null_ptid, ws);
+ }
+ }
}
/* Be sure to not change the selected thread behind GDB's back.
diff --git a/gdbserver/target.cc b/gdbserver/target.cc
index 4584e9b3a8e..833e32a4830 100644
--- a/gdbserver/target.cc
+++ b/gdbserver/target.cc
@@ -612,6 +612,12 @@ process_stratum_target::thread_stopped (thread_info *thread)
gdb_assert_not_reached ("target op thread_stopped not supported");
}
+bool
+process_stratum_target::any_resumed ()
+{
+ return true;
+}
+
bool
process_stratum_target::supports_get_tib_address ()
{
diff --git a/gdbserver/target.h b/gdbserver/target.h
index e2e818b130b..c3345fc67e8 100644
--- a/gdbserver/target.h
+++ b/gdbserver/target.h
@@ -320,6 +320,9 @@ class process_stratum_target
/* Return true if THREAD is known to be stopped now. */
virtual bool thread_stopped (thread_info *thread);
+ /* Return true if any thread is known to be resumed. */
+ virtual bool any_resumed ();
+
/* Return true if the get_tib_address op is supported. */
virtual bool supports_get_tib_address ();
@@ -683,6 +686,9 @@ target_read_btrace_conf (struct btrace_target_info *tinfo,
#define target_supports_software_single_step() \
the_target->supports_software_single_step ()
+#define target_any_resumed() \
+ the_target->any_resumed ()
+
ptid_t mywait (ptid_t ptid, struct target_waitstatus *ourstatus,
target_wait_flags options, int connected_wait);
--
2.36.0
next prev parent reply other threads:[~2022-12-12 20:31 UTC|newest]
Thread overview: 100+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-12 20:30 [PATCH 00/31] Step over thread clone and " Pedro Alves
2022-12-12 20:30 ` [PATCH 01/31] displaced step: pass down target_waitstatus instead of gdb_signal Pedro Alves
2023-02-03 10:44 ` Andrew Burgess
2023-03-10 17:15 ` Pedro Alves
2023-03-16 16:07 ` Andrew Burgess
2023-03-22 21:29 ` Andrew Burgess
2023-03-23 15:15 ` Pedro Alves
2023-03-27 12:40 ` Andrew Burgess
2023-03-27 16:21 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 02/31] linux-nat: introduce pending_status_str Pedro Alves
2023-02-03 12:00 ` Andrew Burgess
2023-03-10 17:15 ` Pedro Alves
2023-03-16 16:19 ` Andrew Burgess
2023-03-27 18:05 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 03/31] gdb/linux: Delete all other LWPs immediately on ptrace exec event Pedro Alves
2023-03-21 14:50 ` Andrew Burgess
2023-04-04 13:57 ` Pedro Alves
2023-04-14 19:29 ` Pedro Alves
2023-05-26 15:04 ` Andrew Burgess
2023-11-13 14:04 ` Pedro Alves
2023-05-26 14:45 ` Andrew Burgess
2022-12-12 20:30 ` [PATCH 04/31] Step over clone syscall w/ breakpoint, TARGET_WAITKIND_THREAD_CLONED Pedro Alves
2023-02-04 15:38 ` Andrew Burgess
2023-03-10 17:16 ` Pedro Alves
2023-03-21 16:06 ` Andrew Burgess
2023-11-13 14:05 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 05/31] Support clone events in the remote protocol Pedro Alves
2023-03-22 15:46 ` Andrew Burgess
2023-11-13 14:05 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 06/31] Avoid duplicate QThreadEvents packets Pedro Alves
2023-05-26 15:53 ` Andrew Burgess
2022-12-12 20:30 ` [PATCH 07/31] enum_flags to_string Pedro Alves
2023-01-30 20:07 ` Simon Marchi
2022-12-12 20:30 ` [PATCH 08/31] Thread options & clone events (core + remote) Pedro Alves
2023-01-31 12:25 ` Lancelot SIX
2023-03-10 19:16 ` Pedro Alves
2023-06-06 13:29 ` Andrew Burgess
2023-11-13 14:07 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 09/31] Thread options & clone events (native Linux) Pedro Alves
2023-06-06 13:43 ` Andrew Burgess
2022-12-12 20:30 ` [PATCH 10/31] Thread options & clone events (Linux GDBserver) Pedro Alves
2023-06-06 14:12 ` Andrew Burgess
2023-11-13 14:07 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 11/31] gdbserver: Hide and don't detach pending clone children Pedro Alves
2023-06-07 16:10 ` Andrew Burgess
2023-11-13 14:08 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 12/31] Remove gdb/19675 kfails (displaced stepping + clone) Pedro Alves
2023-06-07 17:08 ` Andrew Burgess
2022-12-12 20:30 ` [PATCH 13/31] Add test for stepping over clone syscall Pedro Alves
2023-06-07 17:42 ` Andrew Burgess
2023-11-13 14:09 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 14/31] all-stop/synchronous RSP support thread-exit events Pedro Alves
2023-06-07 17:52 ` Andrew Burgess
2023-11-13 14:11 ` Pedro Alves
2023-12-15 18:15 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 15/31] gdbserver/linux-low.cc: Ignore event_ptid if TARGET_WAITKIND_IGNORE Pedro Alves
2022-12-12 20:30 ` [PATCH 16/31] Move deleting thread on TARGET_WAITKIND_THREAD_EXITED to core Pedro Alves
2023-06-08 12:27 ` Andrew Burgess
2022-12-12 20:30 ` [PATCH 17/31] Introduce GDB_THREAD_OPTION_EXIT thread option, fix step-over-thread-exit Pedro Alves
2023-06-08 13:17 ` Andrew Burgess
2022-12-12 20:30 ` [PATCH 18/31] Implement GDB_THREAD_OPTION_EXIT support for Linux GDBserver Pedro Alves
2023-06-08 14:14 ` Andrew Burgess
2022-12-12 20:30 ` [PATCH 19/31] Implement GDB_THREAD_OPTION_EXIT support for native Linux Pedro Alves
2023-06-08 14:17 ` Andrew Burgess
2022-12-12 20:30 ` [PATCH 20/31] gdb: clear step over information on thread exit (PR gdb/27338) Pedro Alves
2023-06-08 15:29 ` Andrew Burgess
2022-12-12 20:30 ` [PATCH 21/31] stop_all_threads: (re-)enable async before waiting for stops Pedro Alves
2023-06-08 15:49 ` Andrew Burgess
2023-11-13 14:12 ` Pedro Alves
2022-12-12 20:30 ` Pedro Alves [this message]
2023-06-08 18:16 ` [PATCH 22/31] gdbserver: Queue no-resumed event after thread exit Andrew Burgess
2023-11-13 14:12 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 23/31] Don't resume new threads if scheduler-locking is in effect Pedro Alves
2023-06-08 18:24 ` Andrew Burgess
2023-11-13 14:12 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 24/31] Report thread exit event for leader if reporting thread exit events Pedro Alves
2023-06-09 13:11 ` Andrew Burgess
2022-12-12 20:30 ` [PATCH 25/31] Ignore failure to read PC when resuming Pedro Alves
2023-06-10 10:33 ` Andrew Burgess
2023-11-13 14:13 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 26/31] gdb/testsuite/lib/my-syscalls.S: Refactor new SYSCALL macro Pedro Alves
2023-06-10 10:33 ` Andrew Burgess
2022-12-12 20:30 ` [PATCH 27/31] Testcases for stepping over thread exit syscall (PR gdb/27338) Pedro Alves
2023-06-12 9:53 ` Andrew Burgess
2022-12-12 20:30 ` [PATCH 28/31] Document remote clone events, and QThreadOptions packet Pedro Alves
2023-06-05 15:53 ` Andrew Burgess
2023-11-13 14:13 ` Pedro Alves
2023-06-12 12:06 ` Andrew Burgess
2023-11-13 14:15 ` Pedro Alves
2022-12-12 20:30 ` [PATCH 29/31] inferior::clear_thread_list always silent Pedro Alves
2023-06-12 12:20 ` Andrew Burgess
2022-12-12 20:31 ` [PATCH 30/31] Centralize "[Thread ...exited]" notifications Pedro Alves
2023-02-04 16:05 ` Andrew Burgess
2023-03-10 17:21 ` Pedro Alves
2023-02-16 15:40 ` Andrew Burgess
2023-06-12 12:23 ` Andrew Burgess
2022-12-12 20:31 ` [PATCH 31/31] Cancel execution command on thread exit, when stepping, nexting, etc Pedro Alves
2023-06-12 13:12 ` Andrew Burgess
2023-01-24 19:47 ` [PATCH v3 00/31] Step over thread clone and thread exit Pedro Alves
2023-11-13 14:24 ` [PATCH " Pedro Alves
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