http://www.ousob.com --- Legacy Redefined OuSob - File: /wwwroot/clipx/usr/include/linux/kfifo.h

/* * A simple kernel FIFO implementation. * * Copyright (C) 2004 Stelian Pop <stelian@popies.net> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */ #ifndef _LINUX_KFIFO_H #define _LINUX_KFIFO_H #ifdef __KERNEL__ #include <linux/kernel.h> #include <linux/spinlock.h> struct kfifo { unsigned char *buffer; /* the buffer holding the data */ unsigned int size; /* the size of the allocated buffer */ unsigned int in; /* data is added at offset (in % size) */ unsigned int out; /* data is extracted from off. (out % size) */ spinlock_t *lock; /* protects concurrent modifications */ }; extern struct kfifo *kfifo_init(unsigned char *buffer, unsigned int size, gfp_t gfp_mask, spinlock_t *lock); extern struct kfifo *kfifo_alloc(unsigned int size, gfp_t gfp_mask, spinlock_t *lock); extern void kfifo_free(struct kfifo *fifo); extern unsigned int __kfifo_put(struct kfifo *fifo, unsigned char *buffer, unsigned int len); extern unsigned int __kfifo_get(struct kfifo *fifo, unsigned char *buffer, unsigned int len); /** * __kfifo_reset - removes the entire FIFO contents, no locking version * @fifo: the fifo to be emptied. */ static inline void __kfifo_reset(struct kfifo *fifo) { fifo->in = fifo->out = 0; } /** * kfifo_reset - removes the entire FIFO contents * @fifo: the fifo to be emptied. */ static inline void kfifo_reset(struct kfifo *fifo) { unsigned long flags; spin_lock_irqsave(fifo->lock, flags); __kfifo_reset(fifo); spin_unlock_irqrestore(fifo->lock, flags); } /** * kfifo_put - puts some data into the FIFO * @fifo: the fifo to be used. * @buffer: the data to be added. * @len: the length of the data to be added. * * This function copies at most 'len' bytes from the 'buffer' into * the FIFO depending on the free space, and returns the number of * bytes copied. */ static inline unsigned int kfifo_put(struct kfifo *fifo, unsigned char *buffer, unsigned int len) { unsigned long flags; unsigned int ret; spin_lock_irqsave(fifo->lock, flags); ret = __kfifo_put(fifo, buffer, len); spin_unlock_irqrestore(fifo->lock, flags); return ret; } /** * kfifo_get - gets some data from the FIFO * @fifo: the fifo to be used. * @buffer: where the data must be copied. * @len: the size of the destination buffer. * * This function copies at most 'len' bytes from the FIFO into the * 'buffer' and returns the number of copied bytes. */ static inline unsigned int kfifo_get(struct kfifo *fifo, unsigned char *buffer, unsigned int len) { unsigned long flags; unsigned int ret; spin_lock_irqsave(fifo->lock, flags); ret = __kfifo_get(fifo, buffer, len); /* * optimization: if the FIFO is empty, set the indices to 0 * so we don't wrap the next time */ if (fifo->in == fifo->out) fifo->in = fifo->out = 0; spin_unlock_irqrestore(fifo->lock, flags); return ret; } /** * __kfifo_len - returns the number of bytes available in the FIFO, no locking version * @fifo: the fifo to be used. */ static inline unsigned int __kfifo_len(struct kfifo *fifo) { return fifo->in - fifo->out; } /** * kfifo_len - returns the number of bytes available in the FIFO * @fifo: the fifo to be used. */ static inline unsigned int kfifo_len(struct kfifo *fifo) { unsigned long flags; unsigned int ret; spin_lock_irqsave(fifo->lock, flags); ret = __kfifo_len(fifo); spin_unlock_irqrestore(fifo->lock, flags); return ret; } #else #warning "don't include kernel headers in userspace" #endif /* __KERNEL__ */ #endif