cregit-Linux how code gets into the kernel

Release 4.16 lib/dec_and_lock.c

Directory: lib
// SPDX-License-Identifier: GPL-2.0
#include <linux/export.h>
#include <linux/spinlock.h>
#include <linux/atomic.h>

 * This is an implementation of the notion of "decrement a
 * reference count, and return locked if it decremented to zero".
 * NOTE NOTE NOTE! This is _not_ equivalent to
 *      if (atomic_dec_and_test(&atomic)) {
 *              spin_lock(&lock);
 *              return 1;
 *      }
 *      return 0;
 * because the spin-lock and the decrement must be
 * "atomic".

int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock) { /* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */ if (atomic_add_unless(atomic, -1, 1)) return 0; /* Otherwise do it the slow way */ spin_lock(lock); if (atomic_dec_and_test(atomic)) return 1; spin_unlock(lock); return 0; }


Linus Torvalds (pre-git)2445.28%133.33%
David S. Miller2343.40%133.33%
Nicholas Piggin611.32%133.33%


Overall Contributors

Linus Torvalds (pre-git)2942.03%112.50%
David S. Miller2333.33%112.50%
Nicholas Piggin710.14%112.50%
Linus Torvalds710.14%225.00%
Arun Sharma11.45%112.50%
Paul Gortmaker11.45%112.50%
Greg Kroah-Hartman11.45%112.50%
Directory: lib
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