From: Pedro Alves <pedro@palves.net>
To: gdb-patches@sourceware.org
Subject: [PATCH v2 20/29] gdbserver: Queue no-resumed event after thread exit
Date: Wed, 13 Jul 2022 23:24:24 +0100 [thread overview]
Message-ID: <20220713222433.374898-21-pedro@palves.net> (raw)
In-Reply-To: <20220713222433.374898-1-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_TO_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 54ab0a7d8f5..9858e228675 100644
--- a/gdbserver/linux-low.cc
+++ b/gdbserver/linux-low.cc
@@ -2965,7 +2965,6 @@ 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 ());
@@ -2979,23 +2978,7 @@ 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);
@@ -3006,7 +2989,7 @@ 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);
@@ -6173,6 +6156,32 @@ 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 051a7196ef7..43c35009030 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 75a23e2c692..8b3e8bf884d 100644
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -4742,7 +4742,17 @@ 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 ad32af0416e..96c0f49d2dd 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 0aa7db49c18..dd8a55cf827 100644
--- a/gdbserver/target.h
+++ b/gdbserver/target.h
@@ -323,6 +323,9 @@ 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:[~2022-07-13 22:25 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-13 22:24 [PATCH v2 00/29] Step over thread clone and " Pedro Alves
2022-07-13 22:24 ` [PATCH v2 01/29] displaced step: pass down target_waitstatus instead of gdb_signal Pedro Alves
2022-07-20 20:21 ` Simon Marchi
2022-07-13 22:24 ` [PATCH v2 02/29] linux-nat: introduce pending_status_str Pedro Alves
2022-07-20 20:38 ` Simon Marchi
2022-07-13 22:24 ` [PATCH v2 03/29] gdb/linux: Delete all other LWPs immediately on ptrace exec event Pedro Alves
2022-07-21 0:45 ` Simon Marchi
2022-07-13 22:24 ` [PATCH v2 04/29] Step over clone syscall w/ breakpoint, TARGET_WAITKIND_THREAD_CLONED Pedro Alves
2022-07-21 1:35 ` Simon Marchi
2022-10-17 18:54 ` Pedro Alves
2022-10-18 12:40 ` [PATCH] Don't explicitly set clone child ptrace options (was: Re: [PATCH v2 04/29] Step over clone syscall w/ breakpoint, TARGET_WAITKIND_THREAD_CLONED) Pedro Alves
2022-10-28 14:50 ` Simon Marchi
2022-12-12 20:13 ` [PATCH v2 04/29] Step over clone syscall w/ breakpoint, TARGET_WAITKIND_THREAD_CLONED Pedro Alves
2022-07-13 22:24 ` [PATCH v2 05/29] Support clone events in the remote protocol Pedro Alves
2022-07-21 2:25 ` Simon Marchi
2022-12-12 20:14 ` Pedro Alves
2022-07-13 22:24 ` [PATCH v2 06/29] Avoid duplicate QThreadEvents packets Pedro Alves
2022-07-21 2:30 ` Simon Marchi
2022-12-12 20:14 ` Pedro Alves
2022-07-13 22:24 ` [PATCH v2 07/29] Thread options & clone events (core + remote) Pedro Alves
2022-07-21 3:14 ` Simon Marchi
2022-10-27 19:55 ` [PATCH] enum_flags to_string (was: Re: [PATCH v2 07/29] Thread options & clone events (core + remote)) Pedro Alves
2022-10-28 10:26 ` [PATCH v2] " Pedro Alves
2022-10-28 11:08 ` [PATCH v3] " Pedro Alves
2022-10-28 15:59 ` Simon Marchi
2022-10-28 18:23 ` Pedro Alves
2022-10-31 12:47 ` Simon Marchi
2022-11-07 17:26 ` [PATCH v5] " Pedro Alves
2022-11-07 18:29 ` Simon Marchi
2022-11-08 14:56 ` Pedro Alves
2022-12-12 20:15 ` [PATCH v2 07/29] Thread options & clone events (core + remote) Pedro Alves
2022-07-13 22:24 ` [PATCH v2 08/29] Thread options & clone events (native Linux) Pedro Alves
2022-07-21 12:38 ` Simon Marchi
2022-12-12 20:16 ` Pedro Alves
2022-07-13 22:24 ` [PATCH v2 09/29] Thread options & clone events (Linux GDBserver) Pedro Alves
2022-07-21 13:11 ` Simon Marchi
2022-12-12 20:16 ` Pedro Alves
2022-07-13 22:24 ` [PATCH v2 10/29] gdbserver: Hide and don't detach pending clone children Pedro Alves
2022-07-13 22:24 ` [PATCH v2 11/29] Remove gdb/19675 kfails (displaced stepping + clone) Pedro Alves
2022-07-13 22:24 ` [PATCH v2 12/29] Add test for stepping over clone syscall Pedro Alves
2022-07-13 22:24 ` [PATCH v2 13/29] all-stop/synchronous RSP support thread-exit events Pedro Alves
2022-07-13 22:24 ` [PATCH v2 14/29] gdbserver/linux-low.cc: Ignore event_ptid if TARGET_WAITKIND_IGNORE Pedro Alves
2022-07-13 22:24 ` [PATCH v2 15/29] Introduce GDB_TO_EXIT thread option, fix step-over-thread-exit Pedro Alves
2022-07-13 22:24 ` [PATCH v2 16/29] Implement GDB_TO_EXIT support for Linux GDBserver Pedro Alves
2022-07-13 22:24 ` [PATCH v2 17/29] Implement GDB_TO_EXIT support for native Linux Pedro Alves
2022-07-21 15:26 ` Simon Marchi
2022-12-12 20:17 ` Pedro Alves
2022-07-13 22:24 ` [PATCH v2 18/29] gdb: clear step over information on thread exit (PR gdb/27338) Pedro Alves
2022-07-21 18:12 ` Simon Marchi
2022-12-12 20:18 ` Pedro Alves
2022-07-13 22:24 ` [PATCH v2 19/29] stop_all_threads: (re-)enable async before waiting for stops Pedro Alves
2022-07-21 18:21 ` Simon Marchi
2022-12-12 20:18 ` Pedro Alves
2022-07-13 22:24 ` Pedro Alves [this message]
2022-07-13 22:24 ` [PATCH v2 21/29] Don't resume new threads if scheduler-locking is in effect Pedro Alves
2022-07-14 5:28 ` Eli Zaretskii
2022-07-21 18:49 ` Simon Marchi
2022-12-12 20:19 ` Pedro Alves
2022-07-13 22:24 ` [PATCH v2 22/29] Report thread exit event for leader if reporting thread exit events Pedro Alves
2022-07-13 22:24 ` [PATCH v2 23/29] Ignore failure to read PC when resuming Pedro Alves
2022-07-13 22:24 ` [PATCH v2 24/29] gdb/testsuite/lib/my-syscalls.S: Refactor new SYSCALL macro Pedro Alves
2022-07-13 22:24 ` [PATCH v2 25/29] Testcases for stepping over thread exit syscall (PR gdb/27338) Pedro Alves
2022-07-13 22:24 ` [PATCH v2 26/29] Document remote clone events, and QThreadOptions packet Pedro Alves
2022-07-14 5:27 ` Eli Zaretskii
2022-07-13 22:24 ` [PATCH v2 27/29] inferior::clear_thread_list always silent Pedro Alves
2022-07-13 22:24 ` [PATCH v2 28/29] Centralize "[Thread ...exited]" notifications Pedro Alves
2022-07-13 22:24 ` [PATCH v2 29/29] Cancel execution command on thread exit, when stepping, nexting, etc Pedro Alves
2022-07-21 19:28 ` [PATCH v2 00/29] Step over thread clone and thread exit Simon Marchi
2022-10-03 13:46 ` Tom de Vries
2022-10-03 18:37 ` Tom de Vries
2022-12-12 20:20 ` Pedro Alves
2022-12-12 20:19 ` Pedro Alves
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220713222433.374898-21-pedro@palves.net \
--to=pedro@palves.net \
--cc=gdb-patches@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).