+++ /dev/null
-/*
- * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License, version 2 only, as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 51
- * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-#define _GNU_SOURCE
-#include <assert.h>
-#include <inttypes.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-
-#include <common/defaults.h>
-#include <common/error.h>
-
-#include "health.h"
-
-static const struct timespec time_delta = {
- .tv_sec = DEFAULT_HEALTH_CHECK_DELTA_S,
- .tv_nsec = DEFAULT_HEALTH_CHECK_DELTA_NS,
-};
-
-/* Define TLS health state. */
-DEFINE_URCU_TLS(struct health_state, health_state);
-
-/*
- * It ensures that TLS memory used for the node and its container structure
- * don't get reclaimed after the TLS owner thread exits until we have finished
- * using it.
- */
-static pthread_mutex_t health_mutex = PTHREAD_MUTEX_INITIALIZER;
-
-static struct health_tls_state_list health_state_list = {
- .head = CDS_LIST_HEAD_INIT(health_state_list.head),
-};
-
-/*
- * This keeps track of the error state for unregistered thread. A thread
- * reporting a health error, normally unregisters and quits. This makes the TLS
- * health state not available to the health_check_state() call so on unregister
- * we update this global error array so we can keep track of which thread was
- * on error if the TLS health state has been removed.
- */
-static enum health_flags global_error_state[HEALTH_NUM_TYPE];
-
-/*
- * Lock health state global list mutex.
- */
-static void state_lock(void)
-{
- pthread_mutex_lock(&health_mutex);
-}
-
-/*
- * Unlock health state global list mutex.
- */
-static void state_unlock(void)
-{
- pthread_mutex_unlock(&health_mutex);
-}
-
-/*
- * Set time difference in res from time_a and time_b.
- */
-static void time_diff(const struct timespec *time_a,
- const struct timespec *time_b, struct timespec *res)
-{
- if (time_a->tv_nsec - time_b->tv_nsec < 0) {
- res->tv_sec = time_a->tv_sec - time_b->tv_sec - 1;
- res->tv_nsec = 1000000000L + time_a->tv_sec - time_b->tv_sec;
- } else {
- res->tv_sec = time_a->tv_sec - time_b->tv_sec;
- res->tv_nsec = time_a->tv_nsec - time_b->tv_nsec;
- }
-}
-
-/*
- * Return true if time_a - time_b > diff, else false.
- */
-static int time_diff_gt(const struct timespec *time_a,
- const struct timespec *time_b, const struct timespec *diff)
-{
- struct timespec res;
-
- time_diff(time_a, time_b, &res);
- time_diff(&res, diff, &res);
-
- if (res.tv_sec > 0) {
- return 1;
- } else if (res.tv_sec == 0 && res.tv_nsec > 0) {
- return 1;
- }
-
- return 0;
-}
-
-/*
- * Health mutex MUST be held across use of the returned struct health_state to
- * provide existence guarantee.
- *
- * Return the health_state object or NULL if not found.
- */
-static struct health_state *find_health_state(enum health_type type)
-{
- struct health_state *state;
-
- /* Find the right health state in the global TLS list. */
- cds_list_for_each_entry(state, &health_state_list.head, node) {
- if (state->type == type) {
- return state;
- }
- }
-
- return NULL;
-}
-
-/*
- * Check health of a specific health type. Note that if a thread has not yet
- * initialize its health subsystem or has quit, it's considered in a good
- * state.
- *
- * Return 0 if health is bad or else 1.
- */
-int health_check_state(enum health_type type)
-{
- int retval = 1, ret;
- unsigned long current, last;
- struct timespec current_time;
- struct health_state *state;
-
- assert(type < HEALTH_NUM_TYPE);
-
- state_lock();
-
- state = find_health_state(type);
- if (!state) {
- /* Check the global state since the state is not visiable anymore. */
- if (global_error_state[type] & HEALTH_ERROR) {
- retval = 0;
- }
- goto not_found;
- }
-
- last = state->last;
- current = uatomic_read(&state->current);
-
- ret = clock_gettime(CLOCK_MONOTONIC, ¤t_time);
- if (ret < 0) {
- PERROR("Error reading time\n");
- /* error */
- retval = 0;
- goto end;
- }
-
- /*
- * Thread is in bad health if flag HEALTH_ERROR is set. It is also in bad
- * health if, after the delta delay has passed, its the progress counter
- * has not moved and it has NOT been waiting for a poll() call.
- */
- if (uatomic_read(&state->flags) & HEALTH_ERROR) {
- retval = 0;
- goto end;
- }
-
- /*
- * Initial condition need to update the last counter and sample time, but
- * should not check health in this initial case, because we don't know how
- * much time has passed.
- */
- if (state->last_time.tv_sec == 0 && state->last_time.tv_nsec == 0) {
- /* update last counter and last sample time */
- state->last = current;
- memcpy(&state->last_time, ¤t_time, sizeof(current_time));
- } else {
- if (time_diff_gt(¤t_time, &state->last_time, &time_delta)) {
- if (current == last && !HEALTH_IS_IN_POLL(current)) {
- /* error */
- retval = 0;
- }
- /* update last counter and last sample time */
- state->last = current;
- memcpy(&state->last_time, ¤t_time, sizeof(current_time));
- }
- }
-
-end:
- DBG("Health state current %lu, last %lu, ret %d",
- current, last, ret);
-not_found:
- state_unlock();
-
- return retval;
-}
-
-/*
- * Init health state.
- */
-void health_register(enum health_type type)
-{
- struct health_state *state;
-
- assert(type < HEALTH_NUM_TYPE);
-
- /* Init TLS state. */
- uatomic_set(&URCU_TLS(health_state).last, 0);
- uatomic_set(&URCU_TLS(health_state).last_time.tv_sec, 0);
- uatomic_set(&URCU_TLS(health_state).last_time.tv_nsec, 0);
- uatomic_set(&URCU_TLS(health_state).current, 0);
- uatomic_set(&URCU_TLS(health_state).flags, 0);
- uatomic_set(&URCU_TLS(health_state).type, type);
-
- /* Add it to the global TLS state list. */
- state_lock();
- state = find_health_state(type);
- /*
- * Duplicates are not accepted, since lookups don't handle them at the
- * moment.
- */
- assert(!state);
-
- cds_list_add(&URCU_TLS(health_state).node, &health_state_list.head);
- state_unlock();
-}
-
-/*
- * Remove node from global list.
- */
-void health_unregister(void)
-{
- state_lock();
- /*
- * On error, set the global_error_state since we are about to remove
- * the node from the global list.
- */
- if (uatomic_read(&URCU_TLS(health_state).flags) & HEALTH_ERROR) {
- uatomic_set(&global_error_state[URCU_TLS(health_state).type],
- HEALTH_ERROR);
- }
- cds_list_del(&URCU_TLS(health_state).node);
- state_unlock();
-}
projects / lttng-tools.git / blobdiff