Hi Ken, On Jul 16 12:19, Ken Brown via Cygwin-patches wrote: > There were several flaws in my previous attempt to add support for > explicitly opening a FIFO multiple times for reading. (By > "explicitly" I mean by calling open rather than by calling > fork/exec/dup.) See > > https://sourceware.org/pipermail/cygwin/2020-July/245456.html > > for one indication of problems > > The most important flaw was that I tried to use an indirect, > unreliable method for determining whether there are writers open. > This is fixed in the second patch of this series by adding a member > '_nwriters' to struct fifo_shmem_t, which counts the number of open > writers. > > We now have to give writers access to the shared memory as well as > readers, so that they can increment _nwriters in open/fork/exec/dup > and decrement it in close. > > The other patches contain miscellaneous fixes/improvements. > > Ken Brown (12): > Cygwin: FIFO: fix problems finding new owner > Cygwin: FIFO: keep a writer count in shared memory > Cygwin: fhandler_fifo::hit_eof: improve reliability > Cygwin: FIFO: reduce I/O interleaving > Cygwin: FIFO: improve taking ownership in fifo_reader_thread > Cygwin: FIFO: fix indentation > Cygwin: FIFO: make certain errors non-fatal > Cygwin: FIFO: add missing lock > Cygwin: fhandler_fifo::take_ownership: don't set event unnecessarily > Cygwin: FIFO: allow take_ownership to be interrupted > Cygwin: FIFO: clean up > Cygwin: FIFO: update commentary > > winsup/cygwin/fhandler.h | 55 +-- > winsup/cygwin/fhandler_fifo.cc | 725 ++++++++++++++++++--------------- > winsup/cygwin/select.cc | 14 +- > 3 files changed, 433 insertions(+), 361 deletions(-)
LGTM, please push. Thanks, Corinna -- Corinna Vinschen Cygwin Maintainer
