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author | Pedro Alves <pedro@palves.net> | 2021-09-29 15:53:52 +0200 |
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committer | Tom de Vries <tdevries@suse.de> | 2021-09-29 15:53:52 +0200 |
commit | 8e4e0c7a49d8b216676f31f670f235308ff2117b (patch) | |
tree | ff271554f7e5e07182cefc7bef98987232e2ade6 /lt~obsolete.m4 | |
parent | 607679092fce3bd6d73830b41630e9edd3affea3 (diff) | |
download | gdb-8e4e0c7a49d8b216676f31f670f235308ff2117b.zip gdb-8e4e0c7a49d8b216676f31f670f235308ff2117b.tar.gz gdb-8e4e0c7a49d8b216676f31f670f235308ff2117b.tar.bz2 |
Fix gdb.multi/multi-term-settings.exp race
The gdb.multi/multi-term-settings.exp testcase sometimes fails like so:
Running /home/pedro/gdb/mygit/src/gdb/testsuite/gdb.multi/multi-term-settings.exp ...
FAIL: gdb.multi/multi-term-settings.exp: inf1_how=attach: inf2_how=attach: stop with control-c (SIGINT)
It's easier to reproduce if you stress the machine at the same time, like e.g.:
$ stress -c 24
Looking at gdb.log, we see:
(gdb) attach 60422
Attaching to program: build/gdb/testsuite/outputs/gdb.multi/multi-term-settings/multi-term-settings, process 60422
[New Thread 60422.60422]
Reading symbols from /lib/x86_64-linux-gnu/libc.so.6...
Reading symbols from /usr/lib/debug//lib/x86_64-linux-gnu/libc-2.31.so...
Reading symbols from /lib64/ld-linux-x86-64.so.2...
(No debugging symbols found in /lib64/ld-linux-x86-64.so.2)
0x00007f2fc2485334 in __GI___clock_nanosleep (clock_id=<optimized out>, clock_id@entry <mailto:clock_id@entry>=0, flags=flags@entry <mailto:flags@entry>=0, req=req@entry <mailto:req@entry>=0x7ffe23126940, rem=rem@entry <mailto:rem@entry>=0x0) at ../sysdeps/unix/sysv/linux/clock_nanosleep.c:78
78 ../sysdeps/unix/sysv/linux/clock_nanosleep.c: No such file or directory.
(gdb) PASS: gdb.multi/multi-term-settings.exp: inf1_how=attach: inf2_how=attach: inf2: attach
set schedule-multiple on
(gdb) PASS: gdb.multi/multi-term-settings.exp: inf1_how=attach: inf2_how=attach: set schedule-multiple on
info inferiors
Num Description Connection Executable
1 process 60404 1 (extended-remote localhost:2349) build/gdb/testsuite/outputs/gdb.multi/multi-term-settings/multi-term-settings
* 2 process 60422 1 (extended-remote localhost:2349) build/gdb/testsuite/outputs/gdb.multi/multi-term-settings/multi-term-settings
(gdb) PASS: gdb.multi/multi-term-settings.exp: inf1_how=attach: inf2_how=attach: info inferiors
pid=60422, count=46
pid=60422, count=47
pid=60422, count=48
pid=60422, count=49
pid=60422, count=50
pid=60422, count=51
pid=60422, count=52
pid=60422, count=53
pid=60422, count=54
pid=60422, count=55
pid=60422, count=56
pid=60422, count=57
pid=60422, count=58
pid=60422, count=59
pid=60422, count=60
pid=60422, count=61
pid=60422, count=62
pid=60422, count=63
pid=60422, count=64
pid=60422, count=65
pid=60422, count=66
pid=60422, count=67
pid=60422, count=68
pid=60422, count=69
pid=60404, count=54
pid=60404, count=55
pid=60404, count=56
pid=60404, count=57
pid=60404, count=58
PASS: gdb.multi/multi-term-settings.exp: inf1_how=attach: inf2_how=attach: continue
Quit
(gdb) FAIL: gdb.multi/multi-term-settings.exp: inf1_how=attach: inf2_how=attach: stop with control-c (SIGINT)
If you look at the testcase's sources, you'll see that the intention
is to resumes the program with "continue", wait to see a few of those
"pid=..., count=..." lines, and then interrupt the program with
Ctrl-C. But somehow, that resulted in GDB printing "Quit", instead of
the Ctrl-C stopping the program with SIGINT.
Here's what is happening:
#1 - those "pid=..., count=..." lines we see above weren't actually
output by the inferior after it has been continued (see #1).
Note that "inf1_how" and "inf2_how" are "attach". What happened
is that those "pid=..., count=..." lines were output by the
inferiors _before_ they were attached to. We see them at that
point instead of earlier, because that's where the testcase
reads from the inferiors' spawn_ids.
#2 - The testcase mistakenly thinks those "pid=..., count=..." lines
happened after the continue was processed by GDB, meaning it has
waited enough, and so sends the Ctrl-C. GDB hasn't yet passed
the terminal to the inferior, so the Ctrl-C results in that
Quit.
The fix here is twofold:
#1 - flush inferior output right after attaching
#2 - consume the "Continuing" printed by "continue", indicating the
inferior has the terminal. This is the same as done throughout
the testsuite to handle this exact problem of sending Ctrl-C too
soon.
gdb/testsuite/ChangeLog:
yyyy-mm-dd Pedro Alves <pedro@palves.net <mailto:pedro@palves.net>>
* gdb.multi/multi-term-settings.exp (create_inferior): Flush
inferior output.
(coretest): Use $gdb_test_name. After issuing "continue", wait
for "Continuing".
Change-Id: Iba7671dfe1eee6b98d29cfdb05a1b9aa2f9defb9
Diffstat (limited to 'lt~obsolete.m4')
0 files changed, 0 insertions, 0 deletions