pipe_fs_i.h
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上传日期:2009-04-28
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文件大小:2k
- #ifndef _LINUX_PIPE_FS_I_H
- #define _LINUX_PIPE_FS_I_H
- #define PIPEFS_MAGIC 0x50495045
- #define PIPE_BUFFERS (16)
- struct pipe_buffer {
- struct page *page;
- unsigned int offset, len;
- struct pipe_buf_operations *ops;
- };
- struct pipe_buf_operations {
- int can_merge;
- void * (*map)(struct file *, struct pipe_inode_info *, struct pipe_buffer *);
- void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *);
- void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
- };
- struct pipe_inode_info {
- wait_queue_head_t wait;
- unsigned int nrbufs, curbuf;
- struct pipe_buffer bufs[PIPE_BUFFERS];
- struct page *tmp_page;
- unsigned int start;
- unsigned int readers;
- unsigned int writers;
- unsigned int waiting_writers;
- unsigned int r_counter;
- unsigned int w_counter;
- struct fasync_struct *fasync_readers;
- struct fasync_struct *fasync_writers;
- };
- /* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
- memory allocation, whereas PIPE_BUF makes atomicity guarantees. */
- #define PIPE_SIZE PAGE_SIZE
- #define PIPE_SEM(inode) (&(inode).i_sem)
- #define PIPE_WAIT(inode) (&(inode).i_pipe->wait)
- #define PIPE_READERS(inode) ((inode).i_pipe->readers)
- #define PIPE_WRITERS(inode) ((inode).i_pipe->writers)
- #define PIPE_WAITING_WRITERS(inode) ((inode).i_pipe->waiting_writers)
- #define PIPE_RCOUNTER(inode) ((inode).i_pipe->r_counter)
- #define PIPE_WCOUNTER(inode) ((inode).i_pipe->w_counter)
- #define PIPE_FASYNC_READERS(inode) (&((inode).i_pipe->fasync_readers))
- #define PIPE_FASYNC_WRITERS(inode) (&((inode).i_pipe->fasync_writers))
- /* Drop the inode semaphore and wait for a pipe event, atomically */
- void pipe_wait(struct inode * inode);
- struct inode* pipe_new(struct inode* inode);
- void free_pipe_info(struct inode* inode);
- #endif