From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id 453813858CDA; Fri, 12 Jan 2024 20:02:03 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 453813858CDA
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1705089723;
	bh=qX6RiODkuk9qKQJJq00b1wj0GgIUzxWt+YtB8+0FjZ0=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=CdjO6t9lZLNcjFR7I+OcRhEiPWN5FPk06RHrs+vrZXDN35WNqrlV1/u2/FCNaOFBE
	 7yWIdWpkL3WzHD/E7gSWlNSgEpxD2fkkkF3i7GyI1ny41q4j0B6hHSAcBR8NCRTxxl
	 2hRqoTfuoLmCYU4Om6kZZElQP9eYsJNAsSnD66FY=
From: "sgk at troutmask dot apl.washington.edu" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libfortran/113313] execute_command_line hangs at run time
Date: Fri, 12 Jan 2024 20:02:02 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: libfortran
X-Bugzilla-Version: 13.1.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: sgk at troutmask dot apl.washington.edu
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P4
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-113313-4-3RAfeltEtg@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-113313-4@http.gcc.gnu.org/bugzilla/>
References: <bug-113313-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D113313

--- Comment #7 from Steve Kargl <sgk at troutmask dot apl.washington.edu> -=
--
On Thu, Jan 11, 2024 at 07:03:05AM +0000, john.harper at vuw dot ac.nz wrot=
e:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D113313
>=20
> --- Comment #2 from john.harper at vuw dot ac.nz ---
> Thank you! You may wish to know that in my Ubuntu system the program=20
> runs properly if the function iam is used in an assignment statement not =
a=20
> print statement.

Interesting.  One of the first things that the internal
implementation does is=20

  /* Flush all I/O units before executing the command.  */
  flush_all_units();

libgfortran is supposedly thread-safe and looking into
flush_all_units() shows some unlocking and testing for
locks.  With 'print *, iam('john')', there may be lock
contention.=