zsh testcase hangs in AIX

zsh testcase hangs in AIX

[Ayappan P2]

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Hi,

We are porting zsh 5.5.1 in AIX. As part of the build, we are running
internal test suites by invoking "make check".

We are experiencing a hang issue with one of the testcase named "
A04redirect.ztst" . Below is the console output (with verbose set to 2 ).

ZTST_test: looking for new test
ZTST_test: examining line:

ZTST_test: examining line:
  fn() { local foo; read foo; print $foo; }
ZTST_getchunk: read code chunk:
  fn() { local foo; read foo; print $foo; }
  coproc fn
  print test output >&p
  read bar <&p
  print $bar
ZTST_test: examining line:
>test output
ZTST_getredir: read redir for '>':
test output
test output
ZTST_test: examining line:

Running test: '>&p' and '<&p' redirection
ZTST_test: expecting status: 0
Input: /tmp/zsh.ztst.2359968/ztst.in,
output: /tmp/zsh.ztst.2359968/ztst.out,
error: /tmp/zsh.ztst.2359968/ztst.terr
test output




It hanged at this step.

Any help would be great.

Thanks
Ayappan P

Re: zsh testcase hangs in AIX

[Bart Schaefer]

On Tue, Jul 30, 2019 at 7:47 AM Ayappan P2 <ayappap2@in.ibm.com> wrote:
>
> We are porting zsh 5.5.1 in AIX.

Why not 5.7.1, the more recent release?

> Any help would be great.

This is testing the coprocess, which uses pipe() and then dups the
resulting descriptors before forking a child process.  This means
there is a situation where you have two-way communication between the
parent and child, so if there is either insufficient buffer space [so
write() blocks] or the buffers are not flushed [so read() blocks] then
the exchange can deadlock.  The test is assuming that pipes have more
than 12 bytes of buffering but are flushed at least on a line-by-line
basis.