From: Andrew Burgess <aburgess@redhat.com>
To: gdb-patches@sourceware.org
Cc: Andrew Burgess <aburgess@redhat.com>
Subject: [PATCH] gdb: new $_inferior_threads convenience variable
Date: Wed, 2 Nov 2022 14:34:16 +0000 [thread overview]
Message-ID: <20221102143416.3307157-1-aburgess@redhat.com> (raw)
Add a new convenience variable $_inferior_threads that contains the
number of (non-exited) threads in the current inferior. This can be
used in command scripts, or breakpoint conditions, etc to adjust the
behaviour for multi-threaded inferiors.
---
gdb/NEWS | 3 +++
gdb/doc/gdb.texinfo | 9 +++++++--
gdb/testsuite/gdb.base/default.exp | 1 +
gdb/testsuite/gdb.multi/tids.exp | 20 ++++++++++++++++++++
gdb/thread.c | 25 +++++++++++++++++++++++++
gdbsupport/iterator-range.h | 4 ++++
6 files changed, 60 insertions(+), 2 deletions(-)
diff --git a/gdb/NEWS b/gdb/NEWS
index 8b519a648f7..3642d42e55a 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -71,6 +71,9 @@
For both /r and /b GDB is now better at using whitespace in order to
align the disassembled instruction text.
+* New convenience variable $_inferior_threads contains the number of
+ non-exited threads in the current inferior.
+
* New commands
maintenance set ignore-prologue-end-flag on|off
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index ea66f4ee42d..977cabd3771 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -3642,8 +3642,10 @@
@samp{$_gthread} contain, respectively, the per-inferior thread number
and the global thread number of the current thread. You may find this
useful in writing breakpoint conditional expressions, command scripts,
-and so forth. @xref{Convenience Vars,, Convenience Variables}, for
-general information on convenience variables.
+and so forth. The convenience variable @samp{$_inferior_threads}
+contains the number of non-exited threads in the current inferior.
+@xref{Convenience Vars,, Convenience Variables}, for general
+information on convenience variables.
If @value{GDBN} detects the program is multi-threaded, it augments the
usual message about stopping at a breakpoint with the ID and name of
@@ -12655,6 +12657,9 @@
@item $_gthread
The global number of the current thread. @xref{global thread numbers}.
+@item $_inferior_threads
+The number of non-exited threads in the current inferior. @xref{Threads}.
+
@item $_gdb_major
@itemx $_gdb_minor
@vindex $_gdb_major@r{, convenience variable}
diff --git a/gdb/testsuite/gdb.base/default.exp b/gdb/testsuite/gdb.base/default.exp
index 29e76642830..cae131cc59b 100644
--- a/gdb/testsuite/gdb.base/default.exp
+++ b/gdb/testsuite/gdb.base/default.exp
@@ -584,6 +584,7 @@ set show_conv_list \
{$_thread = 0} \
{$_gthread = 0} \
{$_inferior = 1} \
+ {$_inferior_threads = 0} \
{$_exception = <error: No frame selected>} \
{$_probe_argc = <error: No frame selected>} \
{$_probe_arg0 = <error: No frame selected>} \
diff --git a/gdb/testsuite/gdb.multi/tids.exp b/gdb/testsuite/gdb.multi/tids.exp
index fb7c2a29a71..1bcba02a1c9 100644
--- a/gdb/testsuite/gdb.multi/tids.exp
+++ b/gdb/testsuite/gdb.multi/tids.exp
@@ -123,6 +123,8 @@ with_test_prefix "single inferior" {
info_threads "" "1"
gdb_test "thread" "Current thread is 1 .*"
+
+ gdb_test "print \$_inferior_threads" " = 1"
}
# "info threads" while there are multiple inferiors should show
@@ -140,8 +142,14 @@ with_test_prefix "two inferiors" {
gdb_test "inferior 2" "Switching to inferior 2 .*" "switch to inferior 2"
gdb_test "file ${binfile}" ".*" "load file in inferior 2"
+ gdb_test "print \$_inferior_threads" " = 0" \
+ "no threads before we start the second inferior"
+
runto_main
+ gdb_test "print \$_inferior_threads" " = 1" \
+ "no other threads started yet"
+
# Now that we've added another inferior, thread IDs now show the
# inferior number.
info_threads "" "1.1 2.1" \
@@ -153,8 +161,14 @@ with_test_prefix "two inferiors" {
gdb_breakpoint "thread_function1"
gdb_continue_to_breakpoint "once"
+ gdb_test "print \$_inferior_threads" " = 2" \
+ "second thread started in inferior 2"
gdb_test "inferior 1" "Switching to inferior 1 .*"
+ gdb_test "print \$_inferior_threads" " = 1" \
+ "still only one thread in inferior 1"
gdb_continue_to_breakpoint "twice"
+ gdb_test "print \$_inferior_threads" " = 2" \
+ "second thread started in inferior 1"
info_threads "" "1.1 1.2 2.1 2.2" \
"info threads again"
@@ -187,9 +201,15 @@ with_test_prefix "two inferiors" {
gdb_test "inferior 2" "Switching to inferior 2 .*"
gdb_continue_to_breakpoint "once"
+ gdb_test "print \$_inferior_threads" " = 3" \
+ "third thread started in inferior 2"
gdb_test "inferior 1" "Switching to inferior 1 .*"
+ gdb_test "print \$_inferior_threads" " = 2" \
+ "still only two threads in inferior 1"
gdb_continue_to_breakpoint "twice"
+ gdb_test "print \$_inferior_threads" " = 3" \
+ "third thread started in inferior 1"
}
thr_apply_info_thr "1" \
diff --git a/gdb/thread.c b/gdb/thread.c
index 349fc01dd48..f8942f1c5e4 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -2123,6 +2123,21 @@ global_thread_id_make_value (struct gdbarch *gdbarch, struct internalvar *var,
return thread_num_make_value_helper (gdbarch, 1);
}
+/* Return a new value for the number of threads in the current inferior.
+ If there are no threads in the current inferior return a value of 0. */
+
+static struct value *
+inferior_threads_make_value (struct gdbarch *gdbarch, struct internalvar *var,
+ void *ignore)
+{
+ int int_val = 0;
+
+ if (inferior_ptid != null_ptid)
+ int_val = current_inferior ()->non_exited_threads ().size ();
+
+ return value_from_longest (builtin_type (gdbarch)->builtin_int, int_val);
+}
+
/* Commands with a prefix of `thread'. */
struct cmd_list_element *thread_cmd_list = NULL;
@@ -2142,6 +2157,14 @@ static const struct internalvar_funcs gthread_funcs =
NULL,
};
+/* Implementation of `_inferior_threads` convenience variable. */
+
+static const struct internalvar_funcs inferior_threads_funcs =
+{
+ inferior_threads_make_value,
+ NULL,
+};
+
void _initialize_thread ();
void
_initialize_thread ()
@@ -2258,4 +2281,6 @@ When on messages about thread creation and deletion are printed."),
create_internalvar_type_lazy ("_thread", &thread_funcs, NULL);
create_internalvar_type_lazy ("_gthread", >hread_funcs, NULL);
+ create_internalvar_type_lazy ("_inferior_threads",
+ &inferior_threads_funcs, NULL);
}
diff --git a/gdbsupport/iterator-range.h b/gdbsupport/iterator-range.h
index d35b03a3392..c99bdc8de07 100644
--- a/gdbsupport/iterator-range.h
+++ b/gdbsupport/iterator-range.h
@@ -53,6 +53,10 @@ struct iterator_range
IteratorType end () const
{ return m_end; }
+ /* The number of items in this iterator_range. */
+ std::size_t size () const
+ { return std::distance (m_begin, m_end); }
+
private:
IteratorType m_begin, m_end;
};
--
2.25.4
next reply other threads:[~2022-11-02 14:34 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-02 14:34 Andrew Burgess [this message]
2022-11-02 14:56 ` Simon Marchi
2022-11-02 15:07 ` Luis Machado
2022-11-03 14:42 ` [PATCHv2] gdb: new $_inferior_thread_count " Andrew Burgess
2022-11-03 14:48 ` Eli Zaretskii
2022-11-03 15:03 ` Luis Machado
2022-11-17 14:51 ` Andrew Burgess
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