diff options
Diffstat (limited to 'lib/kref.c')
-rw-r--r-- | lib/kref.c | 97 |
1 files changed, 0 insertions, 97 deletions
diff --git a/lib/kref.c b/lib/kref.c deleted file mode 100644 index 3efb882..0000000 --- a/lib/kref.c +++ /dev/null @@ -1,97 +0,0 @@ -/* - * kref.c - library routines for handling generic reference counted objects - * - * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> - * Copyright (C) 2004 IBM Corp. - * - * based on lib/kobject.c which was: - * Copyright (C) 2002-2003 Patrick Mochel <mochel@osdl.org> - * - * This file is released under the GPLv2. - * - */ - -#include <linux/kref.h> -#include <linux/module.h> -#include <linux/slab.h> - -/** - * kref_init - initialize object. - * @kref: object in question. - */ -void kref_init(struct kref *kref) -{ - atomic_set(&kref->refcount, 1); - smp_mb(); -} - -/** - * kref_get - increment refcount for object. - * @kref: object. - */ -void kref_get(struct kref *kref) -{ - WARN_ON(!atomic_read(&kref->refcount)); - atomic_inc(&kref->refcount); - smp_mb__after_atomic_inc(); -} - -/** - * kref_put - decrement refcount for object. - * @kref: object. - * @release: pointer to the function that will clean up the object when the - * last reference to the object is released. - * This pointer is required, and it is not acceptable to pass kfree - * in as this function. - * - * Decrement the refcount, and if 0, call release(). - * Return 1 if the object was removed, otherwise return 0. Beware, if this - * function returns 0, you still can not count on the kref from remaining in - * memory. Only use the return value if you want to see if the kref is now - * gone, not present. - */ -int kref_put(struct kref *kref, void (*release)(struct kref *kref)) -{ - WARN_ON(release == NULL); - WARN_ON(release == (void (*)(struct kref *))kfree); - - if (atomic_dec_and_test(&kref->refcount)) { - release(kref); - return 1; - } - return 0; -} - - -/** - * kref_sub - subtract a number of refcounts for object. - * @kref: object. - * @count: Number of recounts to subtract. - * @release: pointer to the function that will clean up the object when the - * last reference to the object is released. - * This pointer is required, and it is not acceptable to pass kfree - * in as this function. - * - * Subtract @count from the refcount, and if 0, call release(). - * Return 1 if the object was removed, otherwise return 0. Beware, if this - * function returns 0, you still can not count on the kref from remaining in - * memory. Only use the return value if you want to see if the kref is now - * gone, not present. - */ -int kref_sub(struct kref *kref, unsigned int count, - void (*release)(struct kref *kref)) -{ - WARN_ON(release == NULL); - WARN_ON(release == (void (*)(struct kref *))kfree); - - if (atomic_sub_and_test((int) count, &kref->refcount)) { - release(kref); - return 1; - } - return 0; -} - -EXPORT_SYMBOL(kref_init); -EXPORT_SYMBOL(kref_get); -EXPORT_SYMBOL(kref_put); -EXPORT_SYMBOL(kref_sub); |