Wrappers and utility functions for Libevent. More...

#include "orconfig.h"
#include "lib/evloop/compat_libevent.h"
#include "lib/crypt_ops/crypto_rand.h"
#include "lib/log/log.h"
#include "lib/log/util_bug.h"
#include "lib/string/compat_string.h"
#include <event2/event.h>
#include <event2/thread.h>
#include <string.h>

Data Structures
struct	periodic_timer_t

struct	mainloop_event_t

Functions
STATIC void	libevent_logging_callback (int severity, const char *msg)

void	configure_libevent_logging (void)

void	suppress_libevent_log_msg (const char *msg)

void	tor_event_free_ (struct event *ev)

static void	rescan_mainloop_cb (evutil_socket_t fd, short events, void *arg)

void	tor_libevent_initialize (tor_libevent_cfg_t *torcfg)

bool	tor_libevent_is_initialized (void)

struct event_base *	tor_libevent_get_base (void)

const char *	tor_libevent_get_method (void)

const char *	tor_libevent_get_version_str (void)

const char *	tor_libevent_get_header_version_str (void)

static void	periodic_timer_cb (evutil_socket_t fd, short what, void *arg)

periodic_timer_t *	periodic_timer_new (struct event_base base, const struct timeval tv, void(cb)(periodic_timer_t timer, void data), void data)

void	periodic_timer_launch (periodic_timer_t timer, const struct timeval tv)

void	periodic_timer_disable (periodic_timer_t *timer)

void	periodic_timer_free_ (periodic_timer_t *timer)

static void	mainloop_event_cb (evutil_socket_t fd, short what, void *arg)

static void	mainloop_event_postloop_cb (evutil_socket_t fd, short what, void *arg)

static mainloop_event_t *	mainloop_event_new_impl (int postloop, void(cb)(mainloop_event_t , void ), void userdata)

mainloop_event_t *	mainloop_event_new (void(cb)(mainloop_event_t , void ), void userdata)

mainloop_event_t *	mainloop_event_postloop_new (void(cb)(mainloop_event_t , void ), void userdata)

void	mainloop_event_activate (mainloop_event_t *event)

int	mainloop_event_schedule (mainloop_event_t event, const struct timeval tv)

void	mainloop_event_cancel (mainloop_event_t *event)

void	mainloop_event_free_ (mainloop_event_t *event)

int	tor_init_libevent_rng (void)

void	tor_libevent_free_all (void)

int	tor_libevent_run_event_loop (struct event_base *base, int once)

void	tor_libevent_exit_loop_after_delay (struct event_base base, const struct timeval delay)

void	tor_libevent_exit_loop_after_callback (struct event_base *base)

Variables
static const char *	suppress_msg = NULL

static struct event_base *	the_event_base = NULL

static struct event *	rescan_mainloop_ev = NULL

Detailed Description

Wrappers and utility functions for Libevent.

Definition in file compat_libevent.c.

Function Documentation

◆ configure_libevent_logging()

void configure_libevent_logging ( void )

Set hook to intercept log messages from libevent.

Definition at line 58 of file compat_libevent.c.

Referenced by init_libevent().

◆ libevent_logging_callback()

STATIC void libevent_logging_callback	(	int	severity,
		const char *	msg
	)

Callback function passed to event_set_log() so we can intercept log messages from libevent.

Definition at line 27 of file compat_libevent.c.

Referenced by configure_libevent_logging().

◆ mainloop_event_activate()

void mainloop_event_activate ( mainloop_event_t * event )

Schedule event to run in the main loop, immediately. If it is not scheduled, it will run anyway. If it is already scheduled to run later, it will run now instead. This function will have no effect if the event is already scheduled to run.

This function may only be called from the main thread.

Definition at line 425 of file compat_libevent.c.

Referenced by alertfn_prompt(), connection_start_reading_from_linked_conn(), control_event_logmsg_pending(), mark_cdm_cache_dirty(), and scheduler_ev_active().

◆ mainloop_event_cancel()

void mainloop_event_cancel ( mainloop_event_t * event )

Cancel event if it is currently active or pending. (Do nothing if the event is not currently active or pending.)

Definition at line 458 of file compat_libevent.c.

◆ mainloop_event_cb()

static void mainloop_event_cb	(	evutil_socket_t	fd,
		short	what,
		void *	arg
	)

static

Internal: Implements mainloop event using a libevent event.

Definition at line 330 of file compat_libevent.c.

◆ mainloop_event_free_()

void mainloop_event_free_ ( mainloop_event_t * event )

Cancel event and release all storage associated with it.

Definition at line 467 of file compat_libevent.c.

◆ mainloop_event_new()

mainloop_event_t* mainloop_event_new	(	void()(mainloop_event_t , void *)	cb,
		void *	userdata
	)

Create and return a new mainloop_event_t to run the function cb.

When run, the callback function will be passed the mainloop_event_t and userdata as its arguments. The userdata pointer must remain valid for as long as the mainloop_event_t event exists: it is your responsibility to free it.

The event is not scheduled by default: Use mainloop_event_activate() or mainloop_event_schedule() to make it run.

Definition at line 396 of file compat_libevent.c.

Referenced by mainloop_schedule_shutdown(), and reenable_blocked_connection_init().

◆ mainloop_event_new_impl()

static mainloop_event_t* mainloop_event_new_impl	(	int	postloop,
		void()(mainloop_event_t , void *)	cb,
		void *	userdata
	)

static

Helper for mainloop_event_new() and mainloop_event_postloop_new().

Definition at line 367 of file compat_libevent.c.

Referenced by mainloop_event_new(), and mainloop_event_postloop_new().

◆ mainloop_event_postloop_cb()

static void mainloop_event_postloop_cb	(	evutil_socket_t	fd,
		short	what,
		void *	arg
	)

static

As mainloop_event_cb, but implements a post-loop event.

Definition at line 342 of file compat_libevent.c.

◆ mainloop_event_postloop_new()

mainloop_event_t* mainloop_event_postloop_new	(	void()(mainloop_event_t , void *)	cb,
		void *	userdata
	)

As mainloop_event_new(), but create a post-loop event.

A post-loop event behaves like any ordinary event, but any events that it activates cannot run until Libevent has checked for other events at least once.

Definition at line 410 of file compat_libevent.c.

Referenced by do_signewnym(), hibernate_schedule_wakeup_event(), initialize_mainloop_events(), and tor_mainloop_connect_pubsub_events().

◆ mainloop_event_schedule()

int mainloop_event_schedule	(	mainloop_event_t *	event,
		const struct timeval *	tv
	)

Schedule event to run in the main loop, after a delay of tv.

If the event is scheduled for a different time, cancel it and run after this delay instead. If the event is currently pending to run now, has no effect.

Do not call this function with tv == NULL – use mainloop_event_activate() instead.

This function may only be called from the main thread.

Definition at line 443 of file compat_libevent.c.

Referenced by do_signewnym(), hibernate_schedule_wakeup_event(), mainloop_schedule_shutdown(), and periodic_event_set_interval().

◆ periodic_timer_cb()

static void periodic_timer_cb	(	evutil_socket_t	fd,
		short	what,
		void *	arg
	)

static

Libevent callback to implement a periodic event.

Definition at line 237 of file compat_libevent.c.

◆ periodic_timer_disable()

void periodic_timer_disable ( periodic_timer_t * timer )

Disable the provided timer, but do not free it.

You can reenable the same timer later with periodic_timer_launch.

If the timer is already disabled, this function does nothing.

Definition at line 293 of file compat_libevent.c.

◆ periodic_timer_free_()

void periodic_timer_free_ ( periodic_timer_t * timer )

Stop and free a periodic timer

Definition at line 301 of file compat_libevent.c.

◆ periodic_timer_launch()

void periodic_timer_launch	(	periodic_timer_t *	timer,
		const struct timeval *	tv
	)

Launch the timer timer to run at tv from now, and every tv thereafter.

If the timer is already enabled, this function does nothing.

Definition at line 277 of file compat_libevent.c.

◆ periodic_timer_new()

periodic_timer_t* periodic_timer_new	(	struct event_base *	base,
		const struct timeval *	tv,
		void()(periodic_timer_t timer, void *data)	cb,
		void *	data
	)

Create and schedule a new timer that will run every tv in the event loop of base. When the timer fires, it will run the timer in cb with the user-supplied data in data.

Definition at line 249 of file compat_libevent.c.

◆ suppress_libevent_log_msg()

void suppress_libevent_log_msg ( const char * msg )

Ignore any libevent log message that contains msg.

Definition at line 65 of file compat_libevent.c.

Referenced by init_libevent().

◆ tor_libevent_exit_loop_after_callback()

void tor_libevent_exit_loop_after_callback ( struct event_base * base )

Tell the event loop to exit after running whichever callback is currently active.

Definition at line 531 of file compat_libevent.c.

◆ tor_libevent_exit_loop_after_delay()

void tor_libevent_exit_loop_after_delay	(	struct event_base *	base,
		const struct timeval *	delay
	)

Tell the event loop to exit after delay. If delay is NULL, instead exit after we're done running the currently active events.

Definition at line 522 of file compat_libevent.c.

◆ tor_libevent_free_all()

void tor_libevent_free_all ( void )

Un-initialize libevent in preparation for an exit

Definition at line 496 of file compat_libevent.c.

◆ tor_libevent_get_base()

struct event_base* tor_libevent_get_base ( void )

Return the current Libevent event base that we're set up to use.

Definition at line 196 of file compat_libevent.c.

Referenced by configure_nameservers(), dns_reset(), mainloop_event_new_impl(), and threadpool_register_reply_event().

◆ tor_libevent_get_header_version_str()

const char* tor_libevent_get_header_version_str ( void )

Return a string representation of the version of Libevent that was used at compilation time.

Definition at line 220 of file compat_libevent.c.

Referenced by print_library_versions().

◆ tor_libevent_get_method()

const char* tor_libevent_get_method ( void )

Return the name of the Libevent backend we're using.

Definition at line 204 of file compat_libevent.c.

◆ tor_libevent_get_version_str()

const char* tor_libevent_get_version_str ( void )

Return a string representation of the version of the currently running version of Libevent.

Definition at line 212 of file compat_libevent.c.

Referenced by options_init_from_torrc(), and print_library_versions().

◆ tor_libevent_initialize()

void tor_libevent_initialize ( tor_libevent_cfg_t * torcfg )

Initialize the Libevent library and set up the event base.

Definition at line 133 of file compat_libevent.c.

Referenced by init_libevent().

◆ tor_libevent_is_initialized()

bool tor_libevent_is_initialized ( void )

Return true iff the libevent module has been successfully initialized, and not subsequently shut down.

Definition at line 189 of file compat_libevent.c.

Referenced by tor_shutdown_event_loop_and_exit().

◆ tor_libevent_run_event_loop()

int tor_libevent_run_event_loop	(	struct event_base *	base,
		int	once
	)

Run the event loop for the provided event_base, handling events until something stops it. If once is set, then just poll-and-run once, then exit. Return 0 on success, -1 if an error occurred, or 1 if we exited because no events were pending or active.

This isn't reentrant or multithreaded.

Definition at line 513 of file compat_libevent.c.

Variable Documentation

◆ suppress_msg

const char* suppress_msg = NULL

static

A string which, if it appears in a libevent log, should be ignored.

Definition at line 23 of file compat_libevent.c.

Referenced by libevent_logging_callback(), and suppress_libevent_log_msg().

◆ the_event_base

struct event_base* the_event_base = NULL

static

Global event base for use by the main thread.

Definition at line 80 of file compat_libevent.c.

Referenced by tor_libevent_get_base(), tor_libevent_get_method(), tor_libevent_initialize(), and tor_libevent_is_initialized().

Data Structures

Functions

Variables

Detailed Description

Function Documentation

◆ configure_libevent_logging()

◆ libevent_logging_callback()

◆ mainloop_event_activate()

◆ mainloop_event_cancel()

◆ mainloop_event_cb()

◆ mainloop_event_free_()

◆ mainloop_event_new()

◆ mainloop_event_new_impl()

◆ mainloop_event_postloop_cb()

◆ mainloop_event_postloop_new()

◆ mainloop_event_schedule()

◆ periodic_timer_cb()

◆ periodic_timer_disable()

◆ periodic_timer_free_()

◆ periodic_timer_launch()

◆ periodic_timer_new()

◆ suppress_libevent_log_msg()

◆ tor_libevent_exit_loop_after_callback()

◆ tor_libevent_exit_loop_after_delay()

◆ tor_libevent_free_all()

◆ tor_libevent_get_base()

◆ tor_libevent_get_header_version_str()

◆ tor_libevent_get_method()

◆ tor_libevent_get_version_str()

◆ tor_libevent_initialize()

◆ tor_libevent_is_initialized()

◆ tor_libevent_run_event_loop()

Variable Documentation

◆ suppress_msg

◆ the_event_base