diff options
| author | Ken Brown <kbrown@cornell.edu> | 2020-08-03 16:35:00 +0300 |
|---|---|---|
| committer | Ken Brown <kbrown@cornell.edu> | 2020-08-04 15:15:19 +0300 |
| commit | 251624a3529c3d0d3d9cdb5fbaf4c3e9b079c894 (patch) | |
| tree | 70f727776719541a32eb7a40b2f20af4c0a027e1 | |
| parent | 289af73a896b110580e237ecfdf044dcdc2f5066 (diff) | |
Cygwin: FIFO: don't read from pipes that are closing
Don't try to read from fifo_client_handlers that are in the fc_closing
state. Experiments have shown that this always yields
STATUS_PIPE_BROKEN, so it just wastes a Windows system call.
Re-order the values in enum fifo_client_connect_state to reflect the
new status of fc_closing.
| -rw-r--r-- | winsup/cygwin/fhandler.h | 9 | ||||
| -rw-r--r-- | winsup/cygwin/fhandler_fifo.cc | 6 | ||||
| -rw-r--r-- | winsup/cygwin/select.cc | 2 |
3 files changed, 5 insertions, 12 deletions
diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h index f64eabda4..40e201b0f 100644 --- a/winsup/cygwin/fhandler.h +++ b/winsup/cygwin/fhandler.h @@ -1276,20 +1276,13 @@ public: #define CYGWIN_FIFO_PIPE_NAME_LEN 47 -/* We view the fc_closing state as borderline between open and closed - for a writer at the other end of a fifo_client_handler. - - We still attempt to read from the writer when the handler is in - this state, and we don't declare a reader to be at EOF if there's a - handler in this state. But the existence of a handler in this - state is not sufficient to unblock a reader trying to open. */ enum fifo_client_connect_state { fc_unknown, fc_error, fc_disconnected, - fc_listening, fc_closing, + fc_listening, fc_connected, fc_input_avail, }; diff --git a/winsup/cygwin/fhandler_fifo.cc b/winsup/cygwin/fhandler_fifo.cc index c816c692a..1e1140f53 100644 --- a/winsup/cygwin/fhandler_fifo.cc +++ b/winsup/cygwin/fhandler_fifo.cc @@ -365,7 +365,7 @@ fhandler_fifo::cleanup_handlers () while (i < nhandlers) { - if (fc_handler[i].get_state () < fc_closing) + if (fc_handler[i].get_state () < fc_connected) delete_client_handler (i); else i++; @@ -1280,7 +1280,7 @@ fhandler_fifo::raw_read (void *in_ptr, size_t& len) for (j = 0; j < nhandlers; j++) if (fc_handler[j].last_read) break; - if (j < nhandlers && fc_handler[j].get_state () >= fc_closing) + if (j < nhandlers && fc_handler[j].get_state () >= fc_connected) { NTSTATUS status; IO_STATUS_BLOCK io; @@ -1315,7 +1315,7 @@ fhandler_fifo::raw_read (void *in_ptr, size_t& len) /* Second pass. */ for (int i = 0; i < nhandlers; i++) - if (fc_handler[i].get_state () >= fc_closing) + if (fc_handler[i].get_state () >= fc_connected) { NTSTATUS status; IO_STATUS_BLOCK io; diff --git a/winsup/cygwin/select.cc b/winsup/cygwin/select.cc index 0c94f6c45..9ee305f64 100644 --- a/winsup/cygwin/select.cc +++ b/winsup/cygwin/select.cc @@ -878,7 +878,7 @@ peek_fifo (select_record *s, bool from_select) { fifo_client_handler &fc = fh->get_fc_handler (i); fc.query_and_set_state (); - if (fc.get_state () >= fc_closing) + if (fc.get_state () >= fc_connected) { nconnected++; if (fc.get_state () == fc_input_avail) |