This is the mail archive of the cygwin mailing list for the Cygwin project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: cygwin-1.5.16-1: FIFOs broken

Christopher Faylor wrote:
On Sat, Apr 30, 2005 at 08:38:17PM -0400, Jerry D. Hedden wrote:

I have a client-server application written in Perl that reads and writes using FIFOs. It works fine under cygwin-1.5.15-1, but fails under cygwin-1.5.16-1 because it cannot read from the FIFO.

To test this, open two shells.  In one shell, type:
cd /tmp
mkfifo FIFO
cat <FIFO

In the other shell, you can send text to the first shell using:
cd /tmp

After you're done, just ^C in the first window.

Under 1.5.15, the above works fine.

Under 1.5.16, no text goes through the FIFO. Further, the echo command hangs, and will not terminate with ^C. A 'ps' shows an 'O' for this stuck shell. You have to do a kill -9 on the shell to terminate it.

As I mentioned in another enjoyable thread last week, fifos are only just barely working in cygwin. They are still a work in progress.

However, that said, the above WJFFM.  In fact, it works more like linux
in 1.5.16 than it does on 1.5.15, i.e., the cat command exits after
printing "YOUR TEXT HERE" whereas it continues to block in 1.5.15.

I tried the 4/30 snapshot of cygwin1.dll. It exhibited the behavior you mentioned with the 'cat' exiting after it reads text. However, this is a bad thing. It means that the FIFO is being set EOF after there is no more data. I tried my client-server app with the snapshot cygwin1.dll, and it failed because of this.

It seems to me that the behavior of FIFOs under 1.5.15 was correct, and that under both 1.5.16 and the snapshot, FIFOs are now broken.

Unsubscribe info:
Problem reports:

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]