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Posted to dev@apr.apache.org by Brian Pane <bp...@pacbell.net> on 2002/03/10 06:46:10 UTC
[PATCH] Suppress locking in UNIX apr_file_read and apr_file_write
unless APR_XTHREAD is set
This involves an API semantics change, so I'm posting it
for comments before committing...
The idea here is to skip the mutex locking for buffered
file reads and writes unless the file has been created with
APR_XTHREAD. This fixes a bit of bogusness in the httpd,
where we do a huge number of mutex lock/unlock cycles when
reading the config file--which is only accessed by a single
thread.
--Brian
Index: file_io/unix/readwrite.c
===================================================================
RCS file: /home/cvs/apr/file_io/unix/readwrite.c,v
retrieving revision 1.75
diff -u -r1.75 readwrite.c
--- file_io/unix/readwrite.c 18 Feb 2002 06:08:53 -0000 1.75
+++ file_io/unix/readwrite.c 10 Mar 2002 05:33:53 -0000
@@ -118,7 +118,9 @@
apr_uint64_t size = *nbytes;
#if APR_HAS_THREADS
- apr_thread_mutex_lock(thefile->thlock);
+ if (thefile->flags & APR_XTHREAD) {
+ apr_thread_mutex_lock(thefile->thlock);
+ }
#endif
if (thefile->direction == 1) {
@@ -164,7 +166,9 @@
rv = 0;
}
#if APR_HAS_THREADS
- apr_thread_mutex_unlock(thefile->thlock);
+ if (thefile->flags & APR_XTHREAD) {
+ apr_thread_mutex_unlock(thefile->thlock);
+ }
#endif
return rv;
}
@@ -223,7 +227,9 @@
int size = *nbytes;
#if APR_HAS_THREADS
- apr_thread_mutex_lock(thefile->thlock);
+ if (thefile->flags & APR_XTHREAD) {
+ apr_thread_mutex_lock(thefile->thlock);
+ }
#endif
if ( thefile->direction == 0 ) {
@@ -251,7 +257,9 @@
}
#if APR_HAS_THREADS
- apr_thread_mutex_unlock(thefile->thlock);
+ if (thefile->flags & APR_XTHREAD) {
+ apr_thread_mutex_unlock(thefile->thlock);
+ }
#endif
return rv;
}
Re: [PATCH] Suppress locking in UNIX apr_file_read and apr_file_write unless APR_XTHREAD is set
Posted by Bill Stoddard <bi...@wstoddard.com>.
Sounds reasonable. Make sure to update the documentation and at least take a shot at
changing all the other platforms. If you break something, it will get fixed. It is more
important to get the semantics the same everywhere...
Bill
> This involves an API semantics change, so I'm posting it
> for comments before committing...
>
> The idea here is to skip the mutex locking for buffered
> file reads and writes unless the file has been created with
> APR_XTHREAD. This fixes a bit of bogusness in the httpd,
> where we do a huge number of mutex lock/unlock cycles when
> reading the config file--which is only accessed by a single
> thread.
>
> --Brian
>
>
> Index: file_io/unix/readwrite.c
> ===================================================================
> RCS file: /home/cvs/apr/file_io/unix/readwrite.c,v
> retrieving revision 1.75
> diff -u -r1.75 readwrite.c
> --- file_io/unix/readwrite.c 18 Feb 2002 06:08:53 -0000 1.75
> +++ file_io/unix/readwrite.c 10 Mar 2002 05:33:53 -0000
> @@ -118,7 +118,9 @@
> apr_uint64_t size = *nbytes;
>
> #if APR_HAS_THREADS
> - apr_thread_mutex_lock(thefile->thlock);
> + if (thefile->flags & APR_XTHREAD) {
> + apr_thread_mutex_lock(thefile->thlock);
> + }
> #endif
>
> if (thefile->direction == 1) {
> @@ -164,7 +166,9 @@
> rv = 0;
> }
> #if APR_HAS_THREADS
> - apr_thread_mutex_unlock(thefile->thlock);
> + if (thefile->flags & APR_XTHREAD) {
> + apr_thread_mutex_unlock(thefile->thlock);
> + }
> #endif
> return rv;
> }
> @@ -223,7 +227,9 @@
> int size = *nbytes;
>
> #if APR_HAS_THREADS
> - apr_thread_mutex_lock(thefile->thlock);
> + if (thefile->flags & APR_XTHREAD) {
> + apr_thread_mutex_lock(thefile->thlock);
> + }
> #endif
>
> if ( thefile->direction == 0 ) {
> @@ -251,7 +257,9 @@
> }
>
> #if APR_HAS_THREADS
> - apr_thread_mutex_unlock(thefile->thlock);
> + if (thefile->flags & APR_XTHREAD) {
> + apr_thread_mutex_unlock(thefile->thlock);
> + }
> #endif
> return rv;
> }
>
>