src/bin/lttng-sessiond/health.h

   1 /*
   2  * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #ifndef _HEALTH_H
  19 #define _HEALTH_H
  20
  21 #include <assert.h>
  22 #include <time.h>
  23 #include <urcu/uatomic.h>
  24
  25 /*
  26  * These are the value added to the current state depending of the position in
  27  * the thread where is either waiting on a poll() or running in the code.
  28  */
  29 #define HEALTH_POLL_VALUE       (1UL << 0)
  30 #define HEALTH_CODE_VALUE       (1UL << 1)
  31
  32 #define HEALTH_IS_IN_POLL(x)    ((x) & HEALTH_POLL_VALUE)
  33
  34 enum health_flags {
  35         HEALTH_EXIT =  (1U << 0),
  36         HEALTH_ERROR = (1U << 1),
  37 };
  38
  39 struct health_state {
  40         /*
  41          * last counter and last_time are only read and updated by the health_check
  42          * thread (single updater).
  43          */
  44         unsigned long last;
  45         struct timespec last_time;
  46
  47         /*
  48          * current and flags are updated by multiple threads concurrently.
  49          */
  50         unsigned long current;          /* progress counter, updated atomically */
  51         enum health_flags flags;        /* other flags, updated atomically */
  52 };
  53
  54 /* Health state counters for the client command thread */
  55 extern struct health_state health_thread_cmd;
  56
  57 /* Health state counters for the application management thread */
  58 extern struct health_state health_thread_app_manage;
  59
  60 /* Health state counters for the application registration thread */
  61 extern struct health_state health_thread_app_reg;
  62
  63 /* Health state counters for the kernel thread */
  64 extern struct health_state health_thread_kernel;
  65
  66 /*
  67  * Update current counter by 1 to indicate that the thread entered or
  68  * left a blocking state caused by a poll().
  69  */
  70 static inline void health_poll_update(struct health_state *state)
  71 {
  72         assert(state);
  73         uatomic_add(&state->current, HEALTH_POLL_VALUE);
  74 }
  75
  76 /*
  77  * Update current counter by 2 indicates progress in execution of a
  78  * thread.
  79  */
  80 static inline void health_code_update(struct health_state *state)
  81 {
  82         assert(state);
  83         uatomic_add(&state->current, HEALTH_CODE_VALUE);
  84 }
  85
  86 /*
  87  * Set health "exit" flag.
  88  */
  89 static inline void health_exit(struct health_state *state)
  90 {
  91         assert(state);
  92         uatomic_or(&state->flags, HEALTH_EXIT);
  93 }
  94
  95 /*
  96  * Set health "error" flag.
  97  */
  98 static inline void health_error(struct health_state *state)
  99 {
 100         assert(state);
 101         uatomic_or(&state->flags, HEALTH_ERROR);
 102 }
 103
 104 /*
 105  * Init health state.
 106  */
 107 static inline void health_init(struct health_state *state)
 108 {
 109         assert(state);
 110         state->last = 0;
 111         state->last_time.tv_sec = 0;
 112         state->last_time.tv_nsec = 0;
 113         uatomic_set(&state->current, 0);
 114         uatomic_set(&state->flags, 0);
 115 }
 116
 117 int health_check_state(struct health_state *state);
 118
 119 #endif /* _HEALTH_H */