[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>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#include <assert.h>
#include <common/compat/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	* SPDX-License-Identifier: GPL-2.0-only
	9	*
	10	*/
	11
	12	#include <assert.h>
	13	#include <common/compat/time.h>
	14	#include <pthread.h>
	15	#include <urcu/tls-compat.h>
	16	#include <urcu/uatomic.h>
	17	#include <urcu/list.h>
	18	#include <lttng/health.h>
	19	#include <common/macros.h>
	20
	21	/*
	22	* These are the value added to the current state depending of the position in
	23	* the thread where is either waiting on a poll() or running in the code.
	24	*/
	25	#define HEALTH_POLL_VALUE (1UL << 0)
	26	#define HEALTH_CODE_VALUE (1UL << 1)
	27
	28	#define HEALTH_IS_IN_POLL(x) ((x) & HEALTH_POLL_VALUE)
	29
	30	struct health_app;
	31
	32	enum health_flags {
	33	HEALTH_ERROR = (1U << 0),
	34	};
	35
	36	struct health_state {
	37	/*
	38	* last counter and last_time are only read and updated by the health_check
	39	* thread (single updater).
	40	*/
	41	unsigned long last;
	42	struct timespec last_time;
	43
	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	int type; /* Indicates the nature of the thread. */
	50	/* Node of the global TLS state list. */
	51	struct cds_list_head node;
	52	};
	53
	54	enum health_cmd {
	55	HEALTH_CMD_CHECK = 0,
	56	};
	57
	58	struct health_comm_msg {
	59	uint32_t cmd; /* enum health_cmd */
	60	} LTTNG_PACKED;
	61
	62	struct health_comm_reply {
	63	uint64_t ret_code; /* bitmask of threads in bad health */
	64	} LTTNG_PACKED;
	65
	66	/* Declare TLS health state. */
	67	extern DECLARE_URCU_TLS(struct health_state, health_state);
	68
	69	/*
	70	* Update current counter by 1 to indicate that the thread entered or left a
	71	* blocking state caused by a poll(). If the counter's value is not an even
	72	* number (meaning a code execution flow), an assert() is raised.
	73	*/
	74	static inline void health_poll_entry(void)
	75	{
	76	/* Code MUST be in code execution state which is an even number. */
	77	assert(!(uatomic_read(&URCU_TLS(health_state).current)
	78	& HEALTH_POLL_VALUE));
	79
	80	uatomic_add(&URCU_TLS(health_state).current, HEALTH_POLL_VALUE);
	81	}
	82
	83	/*
	84	* Update current counter by 1 indicating the exit of a poll or blocking call.
	85	* If the counter's value is not an odd number (a poll execution), an assert()
	86	* is raised.
	87	*/
	88	static inline void health_poll_exit(void)
	89	{
	90	/* Code MUST be in poll execution state which is an odd number. */
	91	assert(uatomic_read(&URCU_TLS(health_state).current)
	92	& HEALTH_POLL_VALUE);
	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(void)
	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(void)
	110	{
	111	uatomic_or(&URCU_TLS(health_state).flags, HEALTH_ERROR);
	112	}
	113
	114	struct health_app *health_app_create(int nr_types);
	115	void health_app_destroy(struct health_app *ha);
	116	int health_check_state(struct health_app *ha, int type);
	117	void health_register(struct health_app *ha, int type);
	118	void health_unregister(struct health_app *ha);
	119
	120	#endif /* HEALTH_INTERNAL_H */