Author: artagnon
Date: Mon Oct 4 15:26:44 2010
New Revision: 1004286
URL: http://svn.apache.org/viewvc?rev=1004286&view=rev
Log:
Merge r985477 from subversion/branches/performance
* subversion/libsvn_subr/io.c
(get_default_file_perms): Store the permissions of the created
temporary file in a static variable and re-use it in subsequent
calls instead of checking persmissions everytime. This has
performance benefits.
Review by: artagnon
Approved by: julianfoad
Modified:
subversion/trunk/ (props changed)
subversion/trunk/subversion/libsvn_subr/io.c
Propchange: subversion/trunk/
------------------------------------------------------------------------------
--- svn:mergeinfo (original)
+++ svn:mergeinfo Mon Oct 4 15:26:44 2010
@@ -23,7 +23,7 @@
/subversion/branches/log-g-performance:870941-871032
/subversion/branches/merge-skips-obstructions:874525-874615
/subversion/branches/nfc-nfd-aware-client:870276,870376
-/subversion/branches/performance:983764,983766,984927,985014,985037,985046,985669,987893,995507,995603,1001413
+/subversion/branches/performance:983764,983766,984927,985014,985037,985046,985477,985669,987893,995507,995603,1001413
/subversion/branches/ra_serf-digest-authn:875693-876404
/subversion/branches/reintegrate-improvements:873853-874164
/subversion/branches/subtree-mergeinfo:876734-878766
Modified: subversion/trunk/subversion/libsvn_subr/io.c
URL:
http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_subr/io.c?rev=1004286&r1=1004285&r2=1004286&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_subr/io.c (original)
+++ subversion/trunk/subversion/libsvn_subr/io.c Mon Oct 4 15:26:44 2010
@@ -1268,30 +1268,46 @@ reown_file(const char *path,
static svn_error_t *
get_default_file_perms(apr_fileperms_t *perms, apr_pool_t *scratch_pool)
{
- apr_finfo_t finfo;
- apr_file_t *fd;
+ /* the default permissions as read from the temp folder */
+ static apr_fileperms_t default_perms = 0;
+
+ /* Technically, this "racy": Multiple threads may use enter here and
+ try to figure out the default permisission concurrently. That's fine
+ since they will end up with the same results. Even more technical,
+ apr_fileperms_t is an atomic type on 32+ bit machines.
+ */
+ if (default_perms == 0)
+ {
+ apr_finfo_t finfo;
+ apr_file_t *fd;
- /* Get the perms for a newly created file to find out what bits
- should be set.
+ /* Get the perms for a newly created file to find out what bits
+ should be set.
- NOTE: normally del_on_close can be problematic because APR might
- delete the file if we spawned any child processes. In this case,
- the lifetime of this file handle is about 3 lines of code, so
- we can safely use del_on_close here.
-
- NOTE: not so fast, shorty. if some other thread forks off a child,
- then the APR cleanups run, and the file will disappear. sigh.
-
- Using svn_io_open_uniquely_named() here because other tempfile
- creation functions tweak the permission bits of files they create.
- */
- SVN_ERR(svn_io_open_uniquely_named(&fd, NULL, NULL, "svn-tempfile", ".tmp",
- svn_io_file_del_on_pool_cleanup,
- scratch_pool, scratch_pool));
- SVN_ERR(svn_io_file_info_get(&finfo, APR_FINFO_PROT, fd, scratch_pool));
- SVN_ERR(svn_io_file_close(fd, scratch_pool));
+ Normally del_on_close can be problematic because APR might
+ delete the file if we spawned any child processes. In this
+ case, the lifetime of this file handle is about 3 lines of
+ code, so we can safely use del_on_close here.
+
+ Not so fast! If some other thread forks off a child, then the
+ APR cleanups run, and the file will disappear. So use
+ del_on_pool_cleanup instead.
+
+ Using svn_io_open_uniquely_named() here because other tempfile
+ creation functions tweak the permission bits of files they create.
+ */
+ SVN_ERR(svn_io_open_uniquely_named(&fd, NULL, NULL, "svn-tempfile",
".tmp",
+ svn_io_file_del_on_pool_cleanup,
+ scratch_pool, scratch_pool));
+ SVN_ERR(svn_io_file_info_get(&finfo, APR_FINFO_PROT, fd, scratch_pool));
+ SVN_ERR(svn_io_file_close(fd, scratch_pool));
+
+ *perms = finfo.protection;
+ default_perms = finfo.protection;
+ }
+ else
+ *perms = default_perms;
- *perms = finfo.protection;
return SVN_NO_ERROR;
}
