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| author | Dominique Quatravaux <dominique.quatravaux@epfl.ch> | 2022-02-16 09:15:39 -0500 |
|---|---|---|
| committer | Simon Marchi <simon.marchi@polymtl.ca> | 2022-02-19 11:02:22 -0500 |
| commit | 9cca177baec32a1ed1422a87a1f57cda2d2eb21a (patch) | |
| tree | 4f2970d77dfe9d7d7668d2179a4e70067b7d2f9e | |
| parent | 9c192281e2c34efcd6991ae3cf7361c2c3e17a8d (diff) | |
| download | gdb-9cca177baec32a1ed1422a87a1f57cda2d2eb21a.zip gdb-9cca177baec32a1ed1422a87a1f57cda2d2eb21a.tar.gz gdb-9cca177baec32a1ed1422a87a1f57cda2d2eb21a.tar.bz2 | |
gdb/darwin: remove not-so-harmless spurious call to `wait4`
As seen in https://sourceware.org/bugzilla/show_bug.cgi?id=24069 this
code will typically wait4() a second time on the same process that was
already wait4()'d a few lines above. While this used to be
harmless/idempotent (when we assumed that the process already exited),
this now causes a deadlock in the WIFSTOPPED case.
The early (~2019) history of bug #24069 cautiously suggests to use
WNOHANG instead of outright deleting the call. However, tests on the
current version of Darwin (Big Sur) demonstrate that gdb runs just fine
without a redundant call to wait4(), as would be expected.
Notwithstanding the debatable value of conserving bug compatibility with
an OS release that is more than a decade old, there is scant evidence of
what that double-wait4() was supposed to achieve in the first place - A
cursory investigation with `git blame` pinpoints commits bb00b29d7802
and a80b95ba67e2 from the 2008-2009 era, but fails to answer the
"why" question conclusively.
Co-Authored-By: Philippe Blain <levraiphilippeblain@gmail.com>
Change-Id: Id4e4415d66d6ff6b3552b60d761693f17015e4a0
| -rw-r--r-- | gdb/darwin-nat.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/gdb/darwin-nat.c b/gdb/darwin-nat.c index d96ce1a..8b0ecfd 100644 --- a/gdb/darwin-nat.c +++ b/gdb/darwin-nat.c @@ -1113,9 +1113,6 @@ darwin_nat_target::decode_message (mach_msg_header_t *hdr, inferior_debug (4, _("darwin_wait: pid=%d exit, status=0x%x\n"), res_pid, wstatus); - /* Looks necessary on Leopard and harmless... */ - wait4 (inf->pid, &wstatus, 0, NULL); - return ptid_t (inf->pid); } else |