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