From 6e41f2cf18217dd5f4086852b61bb6f0146c1e0b Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Fri, 5 Nov 2010 22:24:46 +0000 Subject: [refcnt] Check reference validity on each use of ref_get() and ref_put() Check that the reference count is valid (i.e. non-negative) on each call to ref_get() and ref_put(), using an assert() at the point of use. Signed-off-by: Michael Brown --- src/include/ipxe/refcnt.h | 38 +++++++++++++++++++++++++++++++++++--- 1 file changed, 35 insertions(+), 3 deletions(-) (limited to 'src/include') diff --git a/src/include/ipxe/refcnt.h b/src/include/ipxe/refcnt.h index 49fce5044..0e8b8658c 100644 --- a/src/include/ipxe/refcnt.h +++ b/src/include/ipxe/refcnt.h @@ -9,6 +9,9 @@ FILE_LICENCE ( GPL2_OR_LATER ); +#include +#include + /** * A reference counter * @@ -26,7 +29,7 @@ struct refcnt { * When this count is decremented below zero, the free() * method will be called. */ - int refcnt; + int count; /** Free containing object * * This method is called when the reference count is @@ -75,8 +78,37 @@ ref_init ( struct refcnt *refcnt, .free = free_fn, \ } -extern struct refcnt * ref_get ( struct refcnt *refcnt ); -extern void ref_put ( struct refcnt *refcnt ); +extern void ref_increment ( struct refcnt *refcnt ); +extern void ref_decrement ( struct refcnt *refcnt ); + +/** + * Get additional reference to object + * + * @v refcnt Reference counter, or NULL + * @ret refcnt Reference counter + * + * If @c refcnt is NULL, no action is taken. + */ +#define ref_get( refcnt ) ( { \ + if ( refcnt ) \ + assert ( (refcnt)->count >= 0 ); \ + ref_increment ( refcnt ); \ + (refcnt); } ) + +/** + * Drop reference to object + * + * @v refcnt Reference counter, or NULL + * @ret refcnt Reference counter + * + * If @c refcnt is NULL, no action is taken. + */ +#define ref_put( refcnt ) do { \ + if ( refcnt ) \ + assert ( (refcnt)->count >= 0 ); \ + ref_decrement ( refcnt ); \ + } while ( 0 ) + extern void ref_no_free ( struct refcnt *refcnt ); #endif /* _IPXE_REFCNT_H */ -- cgit v1.2.3-55-g7522