List session event loglevel for the JUL domain
[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 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License, version 2 only, as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * more details.
16 *
17 * You should have received a copy of the GNU General Public License along with
18 * this program; if not, write to the Free Software Foundation, Inc., 51
19 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20 */
21
22 #include <assert.h>
23 #include <time.h>
24 #include <pthread.h>
25 #include <urcu/tls-compat.h>
26 #include <urcu/uatomic.h>
27 #include <urcu/list.h>
28 #include <lttng/health.h>
29 #include <common/macros.h>
30
31 /*
32 * These are the value added to the current state depending of the position in
33 * the thread where is either waiting on a poll() or running in the code.
34 */
35 #define HEALTH_POLL_VALUE (1UL << 0)
36 #define HEALTH_CODE_VALUE (1UL << 1)
37
38 #define HEALTH_IS_IN_POLL(x) ((x) & HEALTH_POLL_VALUE)
39
40 struct health_app;
41
42 enum health_flags {
43 HEALTH_ERROR = (1U << 0),
44 };
45
46 struct health_state {
47 /*
48 * last counter and last_time are only read and updated by the health_check
49 * thread (single updater).
50 */
51 unsigned long last;
52 struct timespec last_time;
53
54 /*
55 * current and flags are updated by multiple threads concurrently.
56 */
57 unsigned long current; /* progress counter, updated atomically */
58 enum health_flags flags; /* other flags, updated atomically */
59 int type; /* Indicates the nature of the thread. */
60 /* Node of the global TLS state list. */
61 struct cds_list_head node;
62 };
63
64 enum health_cmd {
65 HEALTH_CMD_CHECK = 0,
66 };
67
68 struct health_comm_msg {
69 uint32_t cmd; /* enum health_cmd */
70 } LTTNG_PACKED;
71
72 struct health_comm_reply {
73 uint64_t ret_code; /* bitmask of threads in bad health */
74 } LTTNG_PACKED;
75
76 /* Declare TLS health state. */
77 extern DECLARE_URCU_TLS(struct health_state, health_state);
78
79 /*
80 * Update current counter by 1 to indicate that the thread entered or left a
81 * blocking state caused by a poll(). If the counter's value is not an even
82 * number (meaning a code execution flow), an assert() is raised.
83 */
84 static inline void health_poll_entry(void)
85 {
86 /* Code MUST be in code execution state which is an even number. */
87 assert(!(uatomic_read(&URCU_TLS(health_state).current)
88 & HEALTH_POLL_VALUE));
89
90 uatomic_add(&URCU_TLS(health_state).current, HEALTH_POLL_VALUE);
91 }
92
93 /*
94 * Update current counter by 1 indicating the exit of a poll or blocking call.
95 * If the counter's value is not an odd number (a poll execution), an assert()
96 * is raised.
97 */
98 static inline void health_poll_exit(void)
99 {
100 /* Code MUST be in poll execution state which is an odd number. */
101 assert(uatomic_read(&URCU_TLS(health_state).current)
102 & HEALTH_POLL_VALUE);
103
104 uatomic_add(&URCU_TLS(health_state).current, HEALTH_POLL_VALUE);
105 }
106
107 /*
108 * Update current counter by 2 indicates progress in execution of a
109 * thread.
110 */
111 static inline void health_code_update(void)
112 {
113 uatomic_add(&URCU_TLS(health_state).current, HEALTH_CODE_VALUE);
114 }
115
116 /*
117 * Set health "error" flag.
118 */
119 static inline void health_error(void)
120 {
121 uatomic_or(&URCU_TLS(health_state).flags, HEALTH_ERROR);
122 }
123
124 struct health_app *health_app_create(int nr_types);
125 void health_app_destroy(struct health_app *ha);
126 int health_check_state(struct health_app *ha, int type);
127 void health_register(struct health_app *ha, int type);
128 void health_unregister(struct health_app *ha);
129
130 #endif /* HEALTH_INTERNAL_H */
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