Move to kernel style SPDX license identifiers
[lttng-tools.git] / include / lttng / health-internal.h
1 #ifndef HEALTH_INTERNAL_H
2 #define HEALTH_INTERNAL_H
3
4 /*
5 * Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
6 * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7 *
8 * SPDX-License-Identifier: GPL-2.0-only
9 *
10 */
11
12 #include <assert.h>
13 #include <common/compat/time.h>
14 #include <pthread.h>
15 #include <urcu/tls-compat.h>
16 #include <urcu/uatomic.h>
17 #include <urcu/list.h>
18 #include <lttng/health.h>
19 #include <common/macros.h>
20
21 /*
22 * These are the value added to the current state depending of the position in
23 * the thread where is either waiting on a poll() or running in the code.
24 */
25 #define HEALTH_POLL_VALUE (1UL << 0)
26 #define HEALTH_CODE_VALUE (1UL << 1)
27
28 #define HEALTH_IS_IN_POLL(x) ((x) & HEALTH_POLL_VALUE)
29
30 struct health_app;
31
32 enum health_flags {
33 HEALTH_ERROR = (1U << 0),
34 };
35
36 struct health_state {
37 /*
38 * last counter and last_time are only read and updated by the health_check
39 * thread (single updater).
40 */
41 unsigned long last;
42 struct timespec last_time;
43
44 /*
45 * current and flags are updated by multiple threads concurrently.
46 */
47 unsigned long current; /* progress counter, updated atomically */
48 enum health_flags flags; /* other flags, updated atomically */
49 int type; /* Indicates the nature of the thread. */
50 /* Node of the global TLS state list. */
51 struct cds_list_head node;
52 };
53
54 enum health_cmd {
55 HEALTH_CMD_CHECK = 0,
56 };
57
58 struct health_comm_msg {
59 uint32_t cmd; /* enum health_cmd */
60 } LTTNG_PACKED;
61
62 struct health_comm_reply {
63 uint64_t ret_code; /* bitmask of threads in bad health */
64 } LTTNG_PACKED;
65
66 /* Declare TLS health state. */
67 extern DECLARE_URCU_TLS(struct health_state, health_state);
68
69 /*
70 * Update current counter by 1 to indicate that the thread entered or left a
71 * blocking state caused by a poll(). If the counter's value is not an even
72 * number (meaning a code execution flow), an assert() is raised.
73 */
74 static inline void health_poll_entry(void)
75 {
76 /* Code MUST be in code execution state which is an even number. */
77 assert(!(uatomic_read(&URCU_TLS(health_state).current)
78 & HEALTH_POLL_VALUE));
79
80 uatomic_add(&URCU_TLS(health_state).current, HEALTH_POLL_VALUE);
81 }
82
83 /*
84 * Update current counter by 1 indicating the exit of a poll or blocking call.
85 * If the counter's value is not an odd number (a poll execution), an assert()
86 * is raised.
87 */
88 static inline void health_poll_exit(void)
89 {
90 /* Code MUST be in poll execution state which is an odd number. */
91 assert(uatomic_read(&URCU_TLS(health_state).current)
92 & HEALTH_POLL_VALUE);
93
94 uatomic_add(&URCU_TLS(health_state).current, HEALTH_POLL_VALUE);
95 }
96
97 /*
98 * Update current counter by 2 indicates progress in execution of a
99 * thread.
100 */
101 static inline void health_code_update(void)
102 {
103 uatomic_add(&URCU_TLS(health_state).current, HEALTH_CODE_VALUE);
104 }
105
106 /*
107 * Set health "error" flag.
108 */
109 static inline void health_error(void)
110 {
111 uatomic_or(&URCU_TLS(health_state).flags, HEALTH_ERROR);
112 }
113
114 struct health_app *health_app_create(int nr_types);
115 void health_app_destroy(struct health_app *ha);
116 int health_check_state(struct health_app *ha, int type);
117 void health_register(struct health_app *ha, int type);
118 void health_unregister(struct health_app *ha);
119
120 #endif /* HEALTH_INTERNAL_H */
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