[lttng-tools.git] / include / lttng / health-internal.h

#ifndef HEALTH_INTERNAL_H
#define HEALTH_INTERNAL_H

/*
 * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
 * Copyright (C) 2013 - Mathieu Desnoyers <mathieu.desnoyers@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.
 */

#include <assert.h>
#include <time.h>
#include <pthread.h>
#include <urcu/tls-compat.h>
#include <urcu/uatomic.h>
#include <urcu/list.h>
#include <lttng/health.h>
#include <common/macros.h>

/*
 * These are the value added to the current state depending of the position in
 * the thread where is either waiting on a poll() or running in the code.
 */
#define HEALTH_POLL_VALUE 	(1UL << 0)
#define HEALTH_CODE_VALUE	(1UL << 1)

#define HEALTH_IS_IN_POLL(x)	((x) & HEALTH_POLL_VALUE)

struct health_app;

enum health_flags {
	HEALTH_ERROR			 = (1U << 0),
};

struct health_state {
	/*
	 * last counter and last_time are only read and updated by the health_check
	 * thread (single updater).
	 */
	unsigned long last;
	struct timespec last_time;

	/*
	 * current and flags are updated by multiple threads concurrently.
	 */
	unsigned long current;		/* progress counter, updated atomically */
	enum health_flags flags;	/* other flags, updated atomically */
	int type;			/* Indicates the nature of the thread. */
	/* Node of the global TLS state list. */
	struct cds_list_head node;
};

enum health_cmd {
	HEALTH_CMD_CHECK		= 0,
};

struct health_comm_msg {
	uint32_t cmd;		/* enum health_cmd */
} LTTNG_PACKED;

struct health_comm_reply {
	uint64_t ret_code;	/* bitmask of threads in bad health */
} LTTNG_PACKED;

/* Declare TLS health state. */
extern DECLARE_URCU_TLS(struct health_state, health_state);

/*
 * Update current counter by 1 to indicate that the thread entered or left a
 * blocking state caused by a poll(). If the counter's value is not an even
 * number (meaning a code execution flow), an assert() is raised.
 */
static inline void health_poll_entry(void)
{
	/* Code MUST be in code execution state which is an even number. */
	assert(!(uatomic_read(&URCU_TLS(health_state).current)
				& HEALTH_POLL_VALUE));

	uatomic_add(&URCU_TLS(health_state).current, HEALTH_POLL_VALUE);
}

/*
 * Update current counter by 1 indicating the exit of a poll or blocking call.
 * If the counter's value is not an odd number (a poll execution), an assert()
 * is raised.
 */
static inline void health_poll_exit(void)
{
	/* Code MUST be in poll execution state which is an odd number. */
	assert(uatomic_read(&URCU_TLS(health_state).current)
				& HEALTH_POLL_VALUE);

	uatomic_add(&URCU_TLS(health_state).current, HEALTH_POLL_VALUE);
}

/*
 * Update current counter by 2 indicates progress in execution of a
 * thread.
 */
static inline void health_code_update(void)
{
	uatomic_add(&URCU_TLS(health_state).current, HEALTH_CODE_VALUE);
}

/*
 * Set health "error" flag.
 */
static inline void health_error(void)
{
	uatomic_or(&URCU_TLS(health_state).flags, HEALTH_ERROR);
}

struct health_app *health_app_create(int nr_types);
void health_app_destroy(struct health_app *ha);
int health_check_state(struct health_app *ha, int type);
void health_register(struct health_app *ha, int type);
void health_unregister(struct health_app *ha);

#endif /* HEALTH_INTERNAL_H */
Commit	Line	Data
	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 */