After a respectable lunch at Boudin's, Ryan and I think we have the general
answers
to child handles.
The apr_foo_open/create calls need an APR_INHERIT flag bit to mark resources as
inheritable. This offers two advantages;
1. the app doesn't need to worry about fork/exec cleanups v.s. inherit bits
for
createprocess() based Win32 (and other non-forks.)
2. mainline code is more readable, as the user no longer registers their own
cleanup_for_exec handlers to simply close handles.
The patch, for apr_file_open, follows. Rbb is working on a similar for
Sockets, and
calls that generate 'handles' will need to be reviewed as well...
I obviously have the much larger job of applying the APR_INHERIT flag
judiciously
throughout the entire server and removing child cleanups where appropriate ...
Bill
Index: file_io/unix/open.c
===================================================================
RCS file: /home/cvs/apr/file_io/unix/open.c,v
retrieving revision 1.77
diff -u -r1.77 open.c
--- file_io/unix/open.c 2001/06/27 19:40:34 1.77
+++ file_io/unix/open.c 2001/07/13 20:41:08
@@ -167,7 +167,8 @@
(*new)->dataRead = 0;
(*new)->direction = 0;
apr_pool_cleanup_register((*new)->cntxt, (void *)(*new),
apr_unix_file_cleanup,
- apr_pool_cleanup_null);
+ (flag & APR_INHERIT) ? apr_pool_cleanup_null
+ : apr_unix_file_cleanup);
return APR_SUCCESS;
}
Index: file_io/win32/open.c
===================================================================
RCS file: /home/cvs/apr/file_io/win32/open.c,v
retrieving revision 1.77
diff -u -r1.77 open.c
--- file_io/win32/open.c 2001/06/27 19:40:41 1.77
+++ file_io/win32/open.c 2001/07/13 20:41:10
@@ -173,6 +173,7 @@
apr_int32_t flag, apr_fileperms_t perm,
apr_pool_t *cont)
{
+ SECURITY_ATTRIBUTES sa, *psa = NULL;
/* XXX: The default FILE_FLAG_SEQUENTIAL_SCAN is _wrong_ for
* sdbm and any other random files! We _must_ rethink
* this approach.
@@ -236,6 +237,12 @@
*/
attributes |= FILE_FLAG_OVERLAPPED;
}
+ if (flag & APR_INHERIT) {
+ sa.nLength = sizeof(sa);
+ sa.bInheritHandle = TRUE;
+ sa.lpSecurityDescriptor = NULL;
+ psa = &sa;
+ }
#if APR_HAS_UNICODE_FS
if (os_level >= APR_WIN_NT) {
@@ -244,12 +251,12 @@
/ sizeof(apr_wchar_t), fname))
return rv;
handle = CreateFileW(wfname, oflags, sharemode,
- NULL, createflags, attributes, 0);
+ psa, createflags, attributes, 0);
}
else
#endif
handle = CreateFileA(fname, oflags, sharemode,
- NULL, createflags, attributes, 0);
+ psa, createflags, attributes, 0);
if (handle == INVALID_HANDLE_VALUE) {
return apr_get_os_error();
Index: include/apr_file_io.h
===================================================================
RCS file: /home/cvs/apr/include/apr_file_io.h,v
retrieving revision 1.103
diff -u -r1.103 apr_file_io.h
--- include/apr_file_io.h 2001/06/27 19:40:46 1.103
+++ include/apr_file_io.h 2001/07/13 20:41:13
@@ -89,6 +89,10 @@
#define APR_SHARELOCK 1024 /* Platform dependent support for higher
level locked read/write access to support
writes across process/machines */
+#define APR_INHERIT 4096 /* Create the file inheritable by the child
+ process. fork()ed implementations
+ automatically register a child cleanup
+ in the _absence_ of this flag. */
/* flags for apr_file_seek */
#define APR_SET SEEK_SET
@@ -141,6 +145,10 @@
* APR_SHARELOCK Platform dependent support for higher
* level locked read/write access to support
* writes across process/machines
+ * APR_INHERIT Create the file inheritable by the child
+ * processes. fork()ed implementations
+ * automatically register a child cleanup
+ * in the _absence_ of this flag.
* </PRE>
* @param perm Access permissions for file.
* @param cont The pool to use.
