pipe_fs_i.h
上传用户:jlfgdled
上传日期:2013-04-10
资源大小:33168k
文件大小:2k
- #ifndef _LINUX_PIPE_FS_I_H
- #define _LINUX_PIPE_FS_I_H
- #define PIPEFS_MAGIC 0x50495045
- struct pipe_inode_info {
- wait_queue_head_t wait;
- char *base;
- unsigned int len;
- unsigned int start;
- unsigned int readers;
- unsigned int writers;
- unsigned int waiting_readers;
- unsigned int waiting_writers;
- unsigned int r_counter;
- unsigned int w_counter;
- };
- /* 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_BASE(inode) ((inode).i_pipe->base)
- #define PIPE_START(inode) ((inode).i_pipe->start)
- #define PIPE_LEN(inode) ((inode).i_pipe->len)
- #define PIPE_READERS(inode) ((inode).i_pipe->readers)
- #define PIPE_WRITERS(inode) ((inode).i_pipe->writers)
- #define PIPE_WAITING_READERS(inode) ((inode).i_pipe->waiting_readers)
- #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_EMPTY(inode) (PIPE_LEN(inode) == 0)
- #define PIPE_FULL(inode) (PIPE_LEN(inode) == PIPE_SIZE)
- #define PIPE_FREE(inode) (PIPE_SIZE - PIPE_LEN(inode))
- #define PIPE_END(inode) ((PIPE_START(inode) + PIPE_LEN(inode)) & (PIPE_SIZE-1))
- #define PIPE_MAX_RCHUNK(inode) (PIPE_SIZE - PIPE_START(inode))
- #define PIPE_MAX_WCHUNK(inode) (PIPE_SIZE - PIPE_END(inode))
- /* Drop the inode semaphore and wait for a pipe event, atomically */
- void pipe_wait(struct inode * inode);
- struct inode* pipe_new(struct inode* inode);
- #endif