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 <pthread.h>
  24 #include <urcu/tls-compat.h>
  25 #include <urcu/uatomic.h>
  26 #include <urcu/list.h>
  27
  28 /*
  29  * These are the value added to the current state depending of the position in
  30  * the thread where is either waiting on a poll() or running in the code.
  31  */
  32 #define HEALTH_POLL_VALUE       (1UL << 0)
  33 #define HEALTH_CODE_VALUE       (1UL << 1)
  34
  35 #define HEALTH_IS_IN_POLL(x)    ((x) & HEALTH_POLL_VALUE)
  36
  37 enum health_flags {
  38         HEALTH_ERROR = (1U << 0),
  39 };
  40
  41 enum health_type {
  42         HEALTH_TYPE_CMD                 = 0,
  43         HEALTH_TYPE_APP_MANAGE  = 1,
  44         HEALTH_TYPE_APP_REG             = 2,
  45         HEALTH_TYPE_KERNEL              = 3,
  46         HEALTH_TYPE_CONSUMER    = 4,
  47
  48         HEALTH_NUM_TYPE,
  49 };
  50
  51 struct health_tls_state_list {
  52         struct cds_list_head head;
  53 };
  54
  55 struct health_state {
  56         /*
  57          * last counter and last_time are only read and updated by the health_check
  58          * thread (single updater).
  59          */
  60         unsigned long last;
  61         struct timespec last_time;
  62
  63         /*
  64          * current and flags are updated by multiple threads concurrently.
  65          */
  66         unsigned long current;          /* progress counter, updated atomically */
  67         enum health_flags flags;        /* other flags, updated atomically */
  68         enum health_type type;          /* Indicates the nature of the thread. */
  69         /* Node of the global TLS state list. */
  70         struct cds_list_head node;
  71 };
  72
  73 /* Declare TLS health state. */
  74 extern DECLARE_URCU_TLS(struct health_state, health_state);
  75
  76 /* Health state counters for the client command thread */
  77 extern struct health_state health_thread_cmd;
  78
  79 /* Health state counters for the application management thread */
  80 extern struct health_state health_thread_app_manage;
  81
  82 /* Health state counters for the application registration thread */
  83 extern struct health_state health_thread_app_reg;
  84
  85 /* Health state counters for the kernel thread */
  86 extern struct health_state health_thread_kernel;
  87
  88 /*
  89  * Update current counter by 1 to indicate that the thread entered or
  90  * left a blocking state caused by a poll().
  91  */
  92 static inline void health_poll_update(struct health_state *state)
  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(struct health_state *state)
 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(struct health_state *state)
 110 {
 111         uatomic_or(&URCU_TLS(health_state).flags, HEALTH_ERROR);
 112 }
 113
 114 int health_check_state(enum health_type type);
 115 void health_register(enum health_type type);
 116 void health_unregister(void);
 117
 118 #endif /* _HEALTH_H */