projects / lttng-ust.git / blame
| Commit | Line | Data |
|---|---|---|
| 852c2936 MD |
1 | #ifndef _LINUX_RING_BUFFER_VFS_H |
| 2 | #define _LINUX_RING_BUFFER_VFS_H | |
| 3 | ||
| 4 | /* | |
| 5 | * linux/ringbuffer/vfs.h | |
| 6 | * | |
| 7 | * (C) Copyright 2005-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
| 8 | * | |
| 9 | * Wait-free ring buffer VFS file operations. | |
| 10 | * | |
| 11 | * Author: | |
| 12 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
| 13 | * | |
| 14 | * Dual LGPL v2.1/GPL v2 license. | |
| 15 | */ | |
| 16 | ||
| 852c2936 MD |
17 | /* VFS API */ |
| 18 | ||
| 19 | extern const struct file_operations lib_ring_buffer_file_operations; | |
| 20 | ||
| 21 | /* | |
| 22 | * Internal file operations. | |
| 23 | */ | |
| 24 | ||
| 25 | int lib_ring_buffer_open(struct inode *inode, struct file *file); | |
| 26 | int lib_ring_buffer_release(struct inode *inode, struct file *file); | |
| 27 | unsigned int lib_ring_buffer_poll(struct file *filp, poll_table *wait); | |
| 28 | ssize_t lib_ring_buffer_splice_read(struct file *in, loff_t *ppos, | |
| 29 | struct pipe_inode_info *pipe, size_t len, | |
| 30 | unsigned int flags); | |
| 31 | int lib_ring_buffer_mmap(struct file *filp, struct vm_area_struct *vma); | |
| 32 | ||
| 33 | /* Ring Buffer ioctl() and ioctl numbers */ | |
| 34 | long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd, unsigned long arg); | |
| 35 | #ifdef CONFIG_COMPAT | |
| 36 | long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd, | |
| 37 | unsigned long arg); | |
| 38 | #endif | |
| 39 | ||
| 40 | /* | |
| 41 | * Use RING_BUFFER_GET_NEXT_SUBBUF / RING_BUFFER_PUT_NEXT_SUBBUF to read and | |
| 42 | * consume sub-buffers sequentially. | |
| 43 | * | |
| 44 | * Reading sub-buffers without consuming them can be performed with: | |
| 45 | * | |
| 46 | * RING_BUFFER_SNAPSHOT | |
| 47 | * RING_BUFFER_SNAPSHOT_GET_CONSUMED | |
| 48 | * RING_BUFFER_SNAPSHOT_GET_PRODUCED | |
| 49 | * | |
| 50 | * to get the offset range to consume, and then by passing each sub-buffer | |
| 51 | * offset to RING_BUFFER_GET_SUBBUF, read the sub-buffer, and then release it | |
| 52 | * with RING_BUFFER_PUT_SUBBUF. | |
| 53 | * | |
| 54 | * Note that the "snapshot" API can be used to read the sub-buffer in reverse | |
| 55 | * order, which is useful for flight recorder snapshots. | |
| 56 | */ | |
| 57 | ||
| 58 | /* Get a snapshot of the current ring buffer producer and consumer positions */ | |
| 59 | #define RING_BUFFER_SNAPSHOT _IO(0xF6, 0x00) | |
| 60 | /* Get the consumer position (iteration start) */ | |
| 61 | #define RING_BUFFER_SNAPSHOT_GET_CONSUMED _IOR(0xF6, 0x01, unsigned long) | |
| 62 | /* Get the producer position (iteration end) */ | |
| 63 | #define RING_BUFFER_SNAPSHOT_GET_PRODUCED _IOR(0xF6, 0x02, unsigned long) | |
| 64 | /* Get exclusive read access to the specified sub-buffer position */ | |
| 65 | #define RING_BUFFER_GET_SUBBUF _IOW(0xF6, 0x03, unsigned long) | |
| 66 | /* Release exclusive sub-buffer access */ | |
| 67 | #define RING_BUFFER_PUT_SUBBUF _IO(0xF6, 0x04) | |
| 68 | ||
| 69 | /* Get exclusive read access to the next sub-buffer that can be read. */ | |
| 70 | #define RING_BUFFER_GET_NEXT_SUBBUF _IO(0xF6, 0x05) | |
| 71 | /* Release exclusive sub-buffer access, move consumer forward. */ | |
| 72 | #define RING_BUFFER_PUT_NEXT_SUBBUF _IO(0xF6, 0x06) | |
| 73 | /* returns the size of the current sub-buffer, without padding (for mmap). */ | |
| 74 | #define RING_BUFFER_GET_SUBBUF_SIZE _IOR(0xF6, 0x07, unsigned long) | |
| 75 | /* returns the size of the current sub-buffer, with padding (for splice). */ | |
| 76 | #define RING_BUFFER_GET_PADDED_SUBBUF_SIZE _IOR(0xF6, 0x08, unsigned long) | |
| 77 | /* returns the maximum size for sub-buffers. */ | |
| 78 | #define RING_BUFFER_GET_MAX_SUBBUF_SIZE _IOR(0xF6, 0x09, unsigned long) | |
| 79 | /* returns the length to mmap. */ | |
| 80 | #define RING_BUFFER_GET_MMAP_LEN _IOR(0xF6, 0x0A, unsigned long) | |
| 81 | /* returns the offset of the subbuffer belonging to the mmap reader. */ | |
| 82 | #define RING_BUFFER_GET_MMAP_READ_OFFSET _IOR(0xF6, 0x0B, unsigned long) | |
| 529b552a MD |
83 | /* flush the current sub-buffer */ |
| 84 | #define RING_BUFFER_FLUSH _IO(0xF6, 0x0C) | |
| 852c2936 MD |
85 | |
| 86 | #endif /* _LINUX_RING_BUFFER_VFS_H */ |