[PATCH v3 6/7] Implement "info threads -gid"

Pedro Alves
2016-01-06T13:11:46Z

This commit makes global thread IDs optionaly visible in "info
threads", with the new "-gid" switch:

(gdb) info threads -gid
Id GId Target Id Frame
1.1 1 Thread 0x7ffff7fc2740 (LWP 6022) "threads" (running)
1.2 3 Thread 0x7ffff77c0700 (LWP 6028) "threads" (running)
1.3 4 Thread 0x7ffff7fc2740 (LWP 6032) "threads" (running)
2.1 2 Thread 0x7ffff7fc1700 (LWP 6037) "threads" (running)
2.2 5 Thread 0x7ffff77c0700 (LWP 6038) "threads" (running)
* 2.3 6 Thread 0x7ffff7fc2740 (LWP 6039) "threads" (running)

(gdb) info threads
Id Target Id Frame
1.1 Thread 0x7ffff7fc2740 (LWP 6022) "threads" (running)
1.2 Thread 0x7ffff77c0700 (LWP 6028) "threads" (running)
1.3 Thread 0x7ffff7fc2740 (LWP 6032) "threads" (running)
2.1 Thread 0x7ffff7fc1700 (LWP 6037) "threads" (running)
2.2 Thread 0x7ffff77c0700 (LWP 6038) "threads" (running)
* 2.3 Thread 0x7ffff7fc2740 (LWP 6039) "threads" (running)

No regressions on x86_64 Fedora 20.

gdb/ChangeLog:
2016-01-06 Pedro Alves <palves@redhat.com>

* NEWS: Mention "info threads -gid".
* gdbthread.h (struct thread_info) <global_num>: Mention "info
threads -gid".
* thread.c (info_threads_command): Handle "-gid".
(_initialize_thread): Adjust "info threads" help string to mention
-gid.

gdb/testsuite/ChangeLog:
2016-01-06 Pedro Alves <palves@redhat.com>

* gdb.multi/tids.exp: Test "info threads -gid".

gdb/doc/ChangeLog:
2016-01-06 Pedro Alves <palves@redhat.com>

* gdb.texinfo (Threads): Document "info threads -gid".
---
gdb/NEWS | 3 +++
gdb/doc/gdb.texinfo | 19 +++++++++++++------
gdb/gdbthread.h | 4 ++--
gdb/testsuite/gdb.multi/tids.exp | 8 ++++++++
gdb/thread.c | 14 ++++++++++++--
5 files changed, 38 insertions(+), 10 deletions(-)

diff --git a/gdb/NEWS b/gdb/NEWS
index c87a73d..32e7bd3 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -34,6 +34,9 @@
[Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
(gdb)

+* You can use "info threads -gid" to display the global thread ID of
+ all threads.
+
* The new convenience variable $_inferior holds the number of the
current inferior.

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 1bf2208..8ce3b01 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -2959,6 +2959,10 @@ threads that you want to display using the thread ID list syntax
the per-inferior thread number assigned by @value{GDBN}

@item
+the global thread number assigned by @value{GDBN}, if the @samp{-gid}
+option was specified
+
+@item
the target system's thread identifier (@var{systag})

@item
@@ -2989,15 +2993,18 @@ For example,

If you're debugging multiple inferiors, @value{GDBN} displays thread
IDs using the qualified @var{inferior-num}.@var{thread-num} format.
-Otherwise, only @var{thread-num} is shown:
+Otherwise, only @var{thread-num} is shown.
+
+If you specify the @samp{-gid} option, @value{GDBN} displays a column
+indicating each thread's global thread ID:

@smallexample
(@value{GDBP}) info threads
- Id Target Id Frame
- 1.1 process 35 thread 13 main (argc=1, argv=0x7ffffff8)
- 1.2 process 35 thread 23 0x34e5 in sigpause ()
- 1.3 process 35 thread 27 0x34e5 in sigpause ()
-* 2.1 process 65 thread 1 main (argc=1, argv=0x7ffffff8)
+ Id GId Target Id Frame
+ 1.1 1 process 35 thread 13 main (argc=1, argv=0x7ffffff8)
+ 1.2 3 process 35 thread 23 0x34e5 in sigpause ()
+ 1.3 4 process 35 thread 27 0x34e5 in sigpause ()
+* 2.1 2 process 65 thread 1 main (argc=1, argv=0x7ffffff8)
@end smallexample

On Solaris, you can display more information about user threads with a
diff --git a/gdb/gdbthread.h b/gdb/gdbthread.h
index 6c23687..b8d5ac2 100644
--- a/gdb/gdbthread.h
+++ b/gdb/gdbthread.h
@@ -216,8 +216,8 @@ struct thread_info
Above, both inferiors 1 and 2 have threads numbered 1-3, but each
thread has its own unique global ID. */

- /* The thread's global GDB thread number. This is exposed to MI and
- Python/Scheme. */
+ /* The thread's global GDB thread number. This is exposed to MI,
+ Python/Scheme and visible with "info threads -gid". */
int global_num;

/* The per-inferior thread number. This is unique in the inferior
diff --git a/gdb/testsuite/gdb.multi/tids.exp b/gdb/testsuite/gdb.multi/tids.exp
index 12aca07..badb1f1 100644
--- a/gdb/testsuite/gdb.multi/tids.exp
+++ b/gdb/testsuite/gdb.multi/tids.exp
@@ -150,6 +150,14 @@ with_test_prefix "two inferiors" {
info_threads "" "1.1 1.2 2.1 2.2" \
"info threads again"

+ # Same, but show the global ID.
+ gdb_test "info threads -gid" \
+ [multi_line \
+ " 1\.1 +1 +.*" \
+ "\\* 1\.2 +4 +.* thread_function1 .* at .*$srcfile:.*" \
+ " 2\.1 +2 +.*" \
+ " 2\.2 +3 +.* thread_function1 .* at .*$srcfile:.*"]
+
# Confirm the convenience variable show the expected number.
gdb_test "p \$_thread == 2" " = 1"

diff --git a/gdb/thread.c b/gdb/thread.c
index 64002e1..24eb83e 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -1381,7 +1381,16 @@ print_thread_info (struct ui_out *uiout, char *requested_threads, int pid)
static void
info_threads_command (char *arg, int from_tty)
{
- print_thread_info_1 (current_uiout, arg, 0, -1, 0);
+ int show_global_ids = 0;
+
+ if (arg != NULL
+ && check_for_argument (&arg, "-gid", sizeof ("-gid") - 1))
+ {
+ arg = skip_spaces (arg);
+ show_global_ids = 1;
+ }
+
+ print_thread_info_1 (current_uiout, arg, 0, -1, show_global_ids);
}

/* See gdbthread.h. */
@@ -2085,7 +2094,8 @@ _initialize_thread (void)

add_info ("threads", info_threads_command,
_("Display currently known threads.\n\
-Usage: info threads [ID]...\n\
+Usage: info threads [-gid] [ID]...\n\
+-gid: Show global thread IDs.\n\
If ID is given, it is a space-separated list of IDs of threads to display.\n\
Otherwise, all threads are displayed."));

--
1.9.3