49 lines
1.7 KiB
C
49 lines
1.7 KiB
C
#ifndef _LINUX_PIPE_FS_I_H
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#define _LINUX_PIPE_FS_I_H
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#define PIPEFS_MAGIC 0x50495045
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struct pipe_inode_info {
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wait_queue_head_t wait;
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char *base;
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unsigned int len;
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unsigned int start;
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unsigned int readers;
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unsigned int writers;
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unsigned int waiting_writers;
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unsigned int r_counter;
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unsigned int w_counter;
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struct fasync_struct *fasync_readers;
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struct fasync_struct *fasync_writers;
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};
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/* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
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memory allocation, whereas PIPE_BUF makes atomicity guarantees. */
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#define PIPE_SIZE PAGE_SIZE
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#define PIPE_SEM(inode) (&(inode).i_sem)
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#define PIPE_WAIT(inode) (&(inode).i_pipe->wait)
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#define PIPE_BASE(inode) ((inode).i_pipe->base)
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#define PIPE_START(inode) ((inode).i_pipe->start)
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#define PIPE_LEN(inode) ((inode).i_pipe->len)
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#define PIPE_READERS(inode) ((inode).i_pipe->readers)
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#define PIPE_WRITERS(inode) ((inode).i_pipe->writers)
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#define PIPE_WAITING_WRITERS(inode) ((inode).i_pipe->waiting_writers)
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#define PIPE_RCOUNTER(inode) ((inode).i_pipe->r_counter)
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#define PIPE_WCOUNTER(inode) ((inode).i_pipe->w_counter)
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#define PIPE_FASYNC_READERS(inode) (&((inode).i_pipe->fasync_readers))
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#define PIPE_FASYNC_WRITERS(inode) (&((inode).i_pipe->fasync_writers))
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#define PIPE_EMPTY(inode) (PIPE_LEN(inode) == 0)
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#define PIPE_FULL(inode) (PIPE_LEN(inode) == PIPE_SIZE)
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#define PIPE_FREE(inode) (PIPE_SIZE - PIPE_LEN(inode))
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#define PIPE_END(inode) ((PIPE_START(inode) + PIPE_LEN(inode)) & (PIPE_SIZE-1))
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#define PIPE_MAX_RCHUNK(inode) (PIPE_SIZE - PIPE_START(inode))
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#define PIPE_MAX_WCHUNK(inode) (PIPE_SIZE - PIPE_END(inode))
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/* Drop the inode semaphore and wait for a pipe event, atomically */
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void pipe_wait(struct inode * inode);
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struct inode* pipe_new(struct inode* inode);
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#endif
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