| 1 | /* |
| 2 | * SPDX-License-Identifier: LGPL-2.1-only |
| 3 | * |
| 4 | * Copyright (C) 2008-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | * |
| 6 | * Ring buffer backend (types). |
| 7 | */ |
| 8 | |
| 9 | #ifndef _LTTNG_RING_BUFFER_BACKEND_TYPES_H |
| 10 | #define _LTTNG_RING_BUFFER_BACKEND_TYPES_H |
| 11 | |
| 12 | #include <limits.h> |
| 13 | #include <stdint.h> |
| 14 | #include "shm_internal.h" |
| 15 | #include "vatomic.h" |
| 16 | |
| 17 | #define RB_BACKEND_PAGES_PADDING 16 |
| 18 | struct lttng_ust_lib_ring_buffer_backend_pages { |
| 19 | unsigned long mmap_offset; /* offset of the subbuffer in mmap */ |
| 20 | union v_atomic records_commit; /* current records committed count */ |
| 21 | union v_atomic records_unread; /* records to read */ |
| 22 | unsigned long data_size; /* Amount of data to read from subbuf */ |
| 23 | DECLARE_SHMP(char, p); /* Backing memory map */ |
| 24 | char padding[RB_BACKEND_PAGES_PADDING]; |
| 25 | }; |
| 26 | |
| 27 | struct lttng_ust_lib_ring_buffer_backend_subbuffer { |
| 28 | /* Identifier for subbuf backend pages. Exchanged atomically. */ |
| 29 | unsigned long id; /* backend subbuffer identifier */ |
| 30 | }; |
| 31 | |
| 32 | struct lttng_ust_lib_ring_buffer_backend_counts { |
| 33 | /* |
| 34 | * Counter specific to the sub-buffer location within the ring buffer. |
| 35 | * The actual sequence number of the packet within the entire ring |
| 36 | * buffer can be derived from the formula nr_subbuffers * seq_cnt + |
| 37 | * subbuf_idx. |
| 38 | */ |
| 39 | uint64_t seq_cnt; /* packet sequence number */ |
| 40 | }; |
| 41 | |
| 42 | /* |
| 43 | * Forward declaration of frontend-specific channel and ring_buffer. |
| 44 | */ |
| 45 | struct channel; |
| 46 | struct lttng_ust_lib_ring_buffer; |
| 47 | |
| 48 | struct lttng_ust_lib_ring_buffer_backend_pages_shmp { |
| 49 | DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_pages, shmp); |
| 50 | }; |
| 51 | |
| 52 | #define RB_BACKEND_RING_BUFFER_PADDING 64 |
| 53 | struct lttng_ust_lib_ring_buffer_backend { |
| 54 | /* Array of ring_buffer_backend_subbuffer for writer */ |
| 55 | DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_subbuffer, buf_wsb); |
| 56 | /* ring_buffer_backend_subbuffer for reader */ |
| 57 | struct lttng_ust_lib_ring_buffer_backend_subbuffer buf_rsb; |
| 58 | /* Array of lib_ring_buffer_backend_counts for the packet counter */ |
| 59 | DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_counts, buf_cnt); |
| 60 | /* |
| 61 | * Pointer array of backend pages, for whole buffer. |
| 62 | * Indexed by ring_buffer_backend_subbuffer identifier (id) index. |
| 63 | */ |
| 64 | DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_pages_shmp, array); |
| 65 | DECLARE_SHMP(char, memory_map); /* memory mapping */ |
| 66 | |
| 67 | DECLARE_SHMP(struct channel, chan); /* Associated channel */ |
| 68 | int cpu; /* This buffer's cpu. -1 if global. */ |
| 69 | union v_atomic records_read; /* Number of records read */ |
| 70 | unsigned int allocated:1; /* is buffer allocated ? */ |
| 71 | char padding[RB_BACKEND_RING_BUFFER_PADDING]; |
| 72 | }; |
| 73 | |
| 74 | struct lttng_ust_lib_ring_buffer_shmp { |
| 75 | DECLARE_SHMP(struct lttng_ust_lib_ring_buffer, shmp); /* Channel per-cpu buffers */ |
| 76 | }; |
| 77 | |
| 78 | #define RB_BACKEND_CHANNEL_PADDING 64 |
| 79 | struct channel_backend { |
| 80 | unsigned long buf_size; /* Size of the buffer */ |
| 81 | unsigned long subbuf_size; /* Sub-buffer size */ |
| 82 | unsigned int subbuf_size_order; /* Order of sub-buffer size */ |
| 83 | unsigned int num_subbuf_order; /* |
| 84 | * Order of number of sub-buffers/buffer |
| 85 | * for writer. |
| 86 | */ |
| 87 | unsigned int buf_size_order; /* Order of buffer size */ |
| 88 | unsigned int extra_reader_sb:1; /* has extra reader subbuffer ? */ |
| 89 | unsigned long num_subbuf; /* Number of sub-buffers for writer */ |
| 90 | uint64_t start_tsc; /* Channel creation TSC value */ |
| 91 | DECLARE_SHMP(void *, priv_data);/* Client-specific information */ |
| 92 | struct lttng_ust_lib_ring_buffer_config config; /* Ring buffer configuration */ |
| 93 | char name[NAME_MAX]; /* Channel name */ |
| 94 | char padding[RB_BACKEND_CHANNEL_PADDING]; |
| 95 | struct lttng_ust_lib_ring_buffer_shmp buf[]; |
| 96 | }; |
| 97 | |
| 98 | #endif /* _LTTNG_RING_BUFFER_BACKEND_TYPES_H */ |