[PATCH] add shortcut around syscalls when file not found in win32_stat #15169
Comments
From @bulk88Created by @bulk88See attached patch. before C:\p523\src>timeit -f t.dat perl -e" -e 'nofile' for 0..100000" Version Number: Windows NT 6.1 (Build 7601) C:\p523\src> after C:\p523\src>timeit -f t.dat perl -e" -e 'nofile' for 0..100000" Version Number: Windows NT 6.1 (Build 7601) Perl Info |
From @bulk880001-add-shortcut-around-syscalls-when-file-not-found-in-.patchFrom 216a69b1f9c8f0133f186b8a7c04d1d24ee8df15 Mon Sep 17 00:00:00 2001
From: Daniel Dragan <bulk88@hotmail.com>
Date: Wed, 10 Feb 2016 15:47:44 -0500
Subject: [PATCH] add shortcut around syscalls when file not found in
win32_stat
win32_stat on success makes ~7 system calls, some from perl, some from CRT,
but on failure, typically file not found, the perl syscalls fails, then the
CRT stat runs, and fails too, so 5 mostly failing system calls are done
for file not found. If the perl syscall says file not found, the
file wont magically come into existence in the next 10-1000 us for the
CRT's syscalls, so skip calling the CRT and the additional syscalls
if the perl didn't find the file. This patch reduces the number of syscalls
from 5 to 1 for file not found for a win32 perl stat. Benchmark and
profiling info is attached to RT ticket for this patch. Note CreateFile on
a dir fails with ERROR_ACCESS_DENIED so in some cases, a failed CreateFile
is still a successful CRT stat() which does things differently so dirs can
be opened.
---
pod/perldelta.pod | 5 +++++
win32/win32.c | 8 ++++++++
2 files changed, 13 insertions(+)
diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index 0a7d4b0..d95df70 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -102,6 +102,11 @@ This empty function call now takes about a third less time to execute:
sub f{} f();
+=item *
+
+On Win32, C<stat>ing or C<-X>ing a path, if the file or directory does not exist
+is now 3.5x faster on a SSD (or any drive) than before.
+
=back
=head1 Modules and Pragmata
diff --git a/win32/win32.c b/win32/win32.c
index b410f66..651b97b 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -1514,6 +1514,14 @@ win32_stat(const char *path, Stat_t *sbuf)
nlink = bhi.nNumberOfLinks;
CloseHandle(handle);
}
+ else {
+ DWORD err = GetLastError();
+ /* very common case, skip CRT stat and its also failing syscalls */
+ if(err == ERROR_FILE_NOT_FOUND) {
+ errno = ENOENT;
+ return -1;
+ }
+ }
}
/* path will be mapped correctly above */
--
1.9.5.msysgit.1
|
From @bulk88"Time of Day","Process Name","PID","Path","Operation","Result","Detail" |
From @bulk88"Time of Day","Process Name","PID","Path","Operation","Result","Detail" |
|
The RT System itself - Status changed from 'new' to 'open' |
|
@tonycoz - Status changed from 'open' to 'pending release' |
From @khwilliamsonThank you for submitting this report. You have helped make Perl better. Perl 5.24.0 may be downloaded via https://metacpan.org/release/RJBS/perl-5.24.0 |
|
@khwilliamson - Status changed from 'pending release' to 'resolved' |
Migrated from rt.perl.org#127508 (status was 'resolved')
Searchable as RT127508$
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