When a FIFO is opened, syscalls.cc:open always calls fstat on the
newly-created fhandler_fifo. This results from a call to
device_access_denied.
To speed-up this fstat call, and therefore the open(2) call, use
PC_KEEP_HANDLE when the fhandler is created. The resulting
conv_handle is retained until after the fstat call if the fhandler is
a FIFO; otherwise, it is closed immediately.
---
winsup/cygwin/syscalls.cc | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index 32a155a1c..460fe6801 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -1487,8 +1487,15 @@ open (const char *unix_path, int flags, ...)
opt |= PC_CTTY;
}
+ /* If we're opening a FIFO, we will call device_access_denied
+ below. This leads to a call to fstat, which can use the
+ path_conv handle. */
+ opt |= PC_KEEP_HANDLE;
if (!(fh = build_fh_name (unix_path, opt, stat_suffixes)))
__leave; /* errno already set */
+ opt &= ~PC_KEEP_HANDLE;
+ if (!fh->isfifo ())
+ fh->pc.close_conv_handle ();
if ((flags & O_NOFOLLOW) && fh->issymlink () && !(flags & O_PATH))
{
set_errno (ELOOP);
@@ -1555,9 +1562,18 @@ open (const char *unix_path, int flags, ...)
delete fh;
fh = fh_file;
}
- else if ((fh->is_fs_special () && fh->device_access_denied (flags))
- || !fh->open_with_arch (flags, mode & 07777))
- __leave; /* errno already set */
+ else
+ {
+ if (fh->is_fs_special ())
+ {
+ if (fh->device_access_denied (flags))
+ __leave; /* errno already set */
+ else if (fh->isfifo ())
+ fh->pc.close_conv_handle ();
+ }
+ if (!fh->open_with_arch (flags, mode & 07777))
+ __leave; /* errno already set */
+ }
/* Move O_TMPFILEs to the bin to avoid blocking the parent dir. */
if ((flags & O_TMPFILE) && !fh->pc.isremote ())
try_to_bin (fh->pc, fh->get_handle (), DELETE,
--
2.30.0
