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1 | #ifndef _LINUX_RING_BUFFER_FRONTEND_TYPES_H |
2 | #define _LINUX_RING_BUFFER_FRONTEND_TYPES_H | |
3 | ||
4 | /* | |
5 | * linux/ringbuffer/frontend_types.h | |
6 | * | |
7 | * (C) Copyright 2005-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
8 | * | |
9 | * Ring Buffer Library Synchronization Header (types). | |
10 | * | |
11 | * Author: | |
12 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
13 | * | |
14 | * See ring_buffer_frontend.c for more information on wait-free algorithms. | |
15 | * | |
16 | * Dual LGPL v2.1/GPL v2 license. | |
17 | */ | |
18 | ||
a6352fd4 MD |
19 | #include <string.h> |
20 | ||
14641deb MD |
21 | #include <urcu/list.h> |
22 | #include <urcu/uatomic.h> | |
14641deb MD |
23 | |
24 | #include "ust/core.h" | |
25 | ||
1dbfff0c | 26 | #include <ust/usterr-signal-safe.h> |
8d8a24c8 | 27 | #include <ust/ringbuffer-config.h> |
4931a13e | 28 | #include "backend_types.h" |
a6352fd4 | 29 | #include "shm.h" |
852c2936 MD |
30 | |
31 | /* | |
32 | * A switch is done during tracing or as a final flush after tracing (so it | |
33 | * won't write in the new sub-buffer). | |
34 | */ | |
35 | enum switch_mode { SWITCH_ACTIVE, SWITCH_FLUSH }; | |
36 | ||
852c2936 MD |
37 | /* channel: collection of per-cpu ring buffers. */ |
38 | struct channel { | |
14641deb | 39 | int record_disabled; |
852c2936 MD |
40 | unsigned long commit_count_mask; /* |
41 | * Commit count mask, removing | |
42 | * the MSBs corresponding to | |
43 | * bits used to represent the | |
44 | * subbuffer index. | |
45 | */ | |
46 | ||
47 | struct channel_backend backend; /* Associated backend */ | |
48 | ||
49 | unsigned long switch_timer_interval; /* Buffer flush (jiffies) */ | |
50 | unsigned long read_timer_interval; /* Reader wakeup (jiffies) */ | |
14641deb | 51 | //wait_queue_head_t read_wait; /* reader wait queue */ |
852c2936 | 52 | int finalized; /* Has channel been finalized */ |
a6352fd4 MD |
53 | DECLARE_SHMP(struct shm_header, shm_header); |
54 | } ____cacheline_aligned; | |
852c2936 MD |
55 | |
56 | /* Per-subbuffer commit counters used on the hot path */ | |
57 | struct commit_counters_hot { | |
58 | union v_atomic cc; /* Commit counter */ | |
59 | union v_atomic seq; /* Consecutive commits */ | |
a6352fd4 | 60 | } ____cacheline_aligned; |
852c2936 MD |
61 | |
62 | /* Per-subbuffer commit counters used only on cold paths */ | |
63 | struct commit_counters_cold { | |
64 | union v_atomic cc_sb; /* Incremented _once_ at sb switch */ | |
a6352fd4 | 65 | } ____cacheline_aligned; |
852c2936 | 66 | |
852c2936 MD |
67 | /* ring buffer state */ |
68 | struct lib_ring_buffer { | |
69 | /* First 32 bytes cache-hot cacheline */ | |
70 | union v_atomic offset; /* Current offset in the buffer */ | |
a6352fd4 | 71 | DECLARE_SHMP(struct commit_counters_hot, commit_hot); |
852c2936 | 72 | /* Commit count per sub-buffer */ |
14641deb | 73 | long consumed; /* |
852c2936 MD |
74 | * Current offset in the buffer |
75 | * standard atomic access (shared) | |
76 | */ | |
14641deb | 77 | int record_disabled; |
852c2936 MD |
78 | /* End of first 32 bytes cacheline */ |
79 | union v_atomic last_tsc; /* | |
80 | * Last timestamp written in the buffer. | |
81 | */ | |
82 | ||
83 | struct lib_ring_buffer_backend backend; /* Associated backend */ | |
84 | ||
a6352fd4 | 85 | DECLARE_SHMP(struct commit_counters_cold, commit_cold); |
852c2936 | 86 | /* Commit count per sub-buffer */ |
14641deb | 87 | long active_readers; /* |
852c2936 MD |
88 | * Active readers count |
89 | * standard atomic access (shared) | |
90 | */ | |
91 | /* Dropped records */ | |
92 | union v_atomic records_lost_full; /* Buffer full */ | |
93 | union v_atomic records_lost_wrap; /* Nested wrap-around */ | |
94 | union v_atomic records_lost_big; /* Events too big */ | |
95 | union v_atomic records_count; /* Number of records written */ | |
96 | union v_atomic records_overrun; /* Number of overwritten records */ | |
14641deb | 97 | //wait_queue_head_t read_wait; /* reader buffer-level wait queue */ |
852c2936 | 98 | int finalized; /* buffer has been finalized */ |
14641deb MD |
99 | //struct timer_list switch_timer; /* timer for periodical switch */ |
100 | //struct timer_list read_timer; /* timer for read poll */ | |
852c2936 MD |
101 | unsigned long get_subbuf_consumed; /* Read-side consumed */ |
102 | unsigned long prod_snapshot; /* Producer count snapshot */ | |
103 | unsigned long cons_snapshot; /* Consumer count snapshot */ | |
104 | int get_subbuf:1; /* Sub-buffer being held by reader */ | |
105 | int switch_timer_enabled:1; /* Protected by ring_buffer_nohz_lock */ | |
106 | int read_timer_enabled:1; /* Protected by ring_buffer_nohz_lock */ | |
a6352fd4 | 107 | } ____cacheline_aligned; |
852c2936 MD |
108 | |
109 | static inline | |
110 | void *channel_get_private(struct channel *chan) | |
111 | { | |
112 | return chan->backend.priv; | |
113 | } | |
114 | ||
115 | /* | |
116 | * Issue warnings and disable channels upon internal error. | |
117 | * Can receive struct lib_ring_buffer or struct lib_ring_buffer_backend | |
118 | * parameters. | |
119 | */ | |
120 | #define CHAN_WARN_ON(c, cond) \ | |
121 | ({ \ | |
122 | struct channel *__chan; \ | |
123 | int _____ret = unlikely(cond); \ | |
124 | if (_____ret) { \ | |
125 | if (__same_type(*(c), struct channel_backend)) \ | |
14641deb | 126 | __chan = caa_container_of((void *) (c), \ |
852c2936 MD |
127 | struct channel, \ |
128 | backend); \ | |
129 | else if (__same_type(*(c), struct channel)) \ | |
130 | __chan = (void *) (c); \ | |
131 | else \ | |
132 | BUG_ON(1); \ | |
14641deb | 133 | uatomic_inc(&__chan->record_disabled); \ |
852c2936 MD |
134 | WARN_ON(1); \ |
135 | } \ | |
136 | _____ret; \ | |
137 | }) | |
138 | ||
139 | #endif /* _LINUX_RING_BUFFER_FRONTEND_TYPES_H */ |