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 <stdint.h>
  22 #include <urcu/uatomic.h>
  23
  24 /*
  25  * These are the value added to the current state depending of the position in
  26  * the thread where is either waiting on a poll() or running in the code.
  27  */
  28 #define HEALTH_POLL_VALUE       (1UL << 0)
  29 #define HEALTH_CODE_VALUE       (1UL << 1)
  30
  31 #define HEALTH_IS_IN_POLL(x)    ((x) & HEALTH_POLL_VALUE)
  32
  33 enum health_flags {
  34         HEALTH_EXIT = (1U << 0),
  35         HEALTH_ERROR = (1U << 1),
  36 };
  37
  38 struct health_state {
  39         /*
  40          * last counter is only read and updated by the health_check
  41          * thread (single updater).
  42          */
  43         unsigned long last;
  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 };
  50
  51 /* Health state counters for the client command thread */
  52 extern struct health_state health_thread_cmd;
  53
  54 /* Health state counters for the application management thread */
  55 extern struct health_state health_thread_app_manage;
  56
  57 /* Health state counters for the application registration thread */
  58 extern struct health_state health_thread_app_reg;
  59
  60 /* Health state counters for the kernel thread */
  61 extern struct health_state health_thread_kernel;
  62
  63 /*
  64  * Update current counter by 1 to indicate that the thread entered or
  65  * left a blocking state caused by a poll().
  66  */
  67 static inline void health_poll_update(struct health_state *state)
  68 {
  69         assert(state);
  70         uatomic_add(&state->current, HEALTH_POLL_VALUE);
  71 }
  72
  73 /*
  74  * Update current counter by 2 indicates progress in execution of a
  75  * thread.
  76  */
  77 static inline void health_code_update(struct health_state *state)
  78 {
  79         assert(state);
  80         uatomic_add(&state->current, HEALTH_CODE_VALUE);
  81 }
  82
  83 /*
  84  * Set health "exit" flag.
  85  */
  86 static inline void health_exit(struct health_state *state)
  87 {
  88         assert(state);
  89         uatomic_or(&state->flags, HEALTH_EXIT);
  90 }
  91
  92 /*
  93  * Set health "error" flag.
  94  */
  95 static inline void health_error(struct health_state *state)
  96 {
  97         assert(state);
  98         uatomic_or(&state->flags, HEALTH_ERROR);
  99 }
 100
 101 /*
 102  * Init health state.
 103  */
 104 static inline void health_init(struct health_state *state)
 105 {
 106         assert(state);
 107         uatomic_set(&state->last, 0);
 108         uatomic_set(&state->current, 0);
 109         uatomic_set(&state->flags, 0);
 110 }
 111
 112 int health_check_state(struct health_state *state);
 113
 114 #endif /* _HEALTH_H */