#include <config.h>
#include <stdarg.h>
#include <evutil.h>

Include dependency graph for event.h:

This graph shows which files directly or indirectly include this file:

Classes
struct	event
struct	evkeyval
struct	evbuffer
struct	event_watermark
struct	bufferevent

Macros
#define	EVLIST_TIMEOUT 0x01
#define	EVLIST_INSERTED 0x02
#define	EVLIST_SIGNAL 0x04
#define	EVLIST_ACTIVE 0x08
#define	EVLIST_INTERNAL 0x10
#define	EVLIST_INIT 0x80
#define	EVLIST_ALL (0xf000 \| 0x9f)
#define	EV_TIMEOUT 0x01
#define	EV_READ 0x02
#define	EV_WRITE 0x04
#define	EV_SIGNAL 0x08
#define	EV_PERSIST 0x10 /* Persistant event */
#define	_EVENT_DEFINED_TQENTRY
#define	TAILQ_ENTRY(type)
#define	EVENT_SIGNAL(ev) (int)(ev)->ev_fd
#define	EVENT_FD(ev) (int)(ev)->ev_fd
#define	_EVENT_LOG_DEBUG 0
#define	_EVENT_LOG_MSG 1
#define	_EVENT_LOG_WARN 2
#define	_EVENT_LOG_ERR 3
#define	evtimer_add(ev, tv) event_add(ev, tv)
#define	evtimer_set(ev, cb, arg) event_set(ev, -1, 0, cb, arg)
#define	evtimer_del(ev) event_del(ev)
#define	evtimer_pending(ev, tv) event_pending(ev, EV_TIMEOUT, tv)
#define	evtimer_initialized(ev) ((ev)->ev_flags & EVLIST_INIT)
#define	timeout_add(ev, tv) event_add(ev, tv)
#define	timeout_set(ev, cb, arg) event_set(ev, -1, 0, cb, arg)
#define	timeout_del(ev) event_del(ev)
#define	timeout_pending(ev, tv) event_pending(ev, EV_TIMEOUT, tv)
#define	timeout_initialized(ev) ((ev)->ev_flags & EVLIST_INIT)
#define	signal_add(ev, tv) event_add(ev, tv)
#define	signal_set(ev, x, cb, arg) event_set(ev, x, EV_SIGNAL\|EV_PERSIST, cb, arg)
#define	signal_del(ev) event_del(ev)
#define	signal_pending(ev, tv) event_pending(ev, EV_SIGNAL, tv)
#define	signal_initialized(ev) ((ev)->ev_flags & EVLIST_INIT)
#define	event_initialized(ev) ((ev)->ev_flags & EVLIST_INIT)
#define	EVBUFFER_READ 0x01
#define	EVBUFFER_WRITE 0x02
#define	EVBUFFER_EOF 0x10
#define	EVBUFFER_ERROR 0x20
#define	EVBUFFER_TIMEOUT 0x40
#define	EVBUFFER_LENGTH(x) (x)->off
#define	EVBUFFER_DATA(x) (x)->buffer
#define	EVBUFFER_INPUT(x) (x)->input
#define	EVBUFFER_OUTPUT(x) (x)->output

#define	EVLOOP_ONCE 0x01
#define	EVLOOP_NONBLOCK 0x02

Typedefs
typedef void(*	event_log_cb )(int severity, const char *msg)
typedef void(*	evbuffercb )(struct bufferevent , void )
typedef void(*	everrorcb )(struct bufferevent , short what, void )

Functions
struct event_base *	event_base_new (void)
struct event_base *	event_init (void)
int	event_reinit (struct event_base *base)
int	event_dispatch (void)
int	event_base_dispatch (struct event_base *)
const char *	event_base_get_method (struct event_base *)
void	event_base_free (struct event_base *)
void	event_set_log_callback (event_log_cb cb)
int	event_base_set (struct event_base , struct event )
int	event_loop (int)
int	event_base_loop (struct event_base *, int)
int	event_loopexit (const struct timeval *)
int	event_base_loopexit (struct event_base , const struct timeval )
int	event_loopbreak (void)
int	event_base_loopbreak (struct event_base *)
void	event_set (struct event , int, short, void()(int, short, void ), void )
int	event_once (int, short, void()(int, short, void ), void , const struct timeval )
int	event_base_once (struct event_base base, int fd, short events, void(callback)(int, short, void ), void arg, const struct timeval *timeout)
int	event_add (struct event ev, const struct timeval timeout)
int	event_del (struct event *)
void	event_active (struct event *, int, short)
int	event_pending (struct event ev, short event, struct timeval tv)
const char *	event_get_version (void)
const char *	event_get_method (void)
int	event_priority_init (int)
int	event_base_priority_init (struct event_base *, int)
int	event_priority_set (struct event *, int)
struct bufferevent *	bufferevent_new (int fd, evbuffercb readcb, evbuffercb writecb, everrorcb errorcb, void *cbarg)
int	bufferevent_base_set (struct event_base base, struct bufferevent bufev)
int	bufferevent_priority_set (struct bufferevent *bufev, int pri)
void	bufferevent_free (struct bufferevent *bufev)
void	bufferevent_setcb (struct bufferevent bufev, evbuffercb readcb, evbuffercb writecb, everrorcb errorcb, void cbarg)
void	bufferevent_setfd (struct bufferevent *bufev, int fd)
int	bufferevent_write (struct bufferevent bufev, const void data, size_t size)
int	bufferevent_write_buffer (struct bufferevent bufev, struct evbuffer buf)
size_t	bufferevent_read (struct bufferevent bufev, void data, size_t size)
int	bufferevent_enable (struct bufferevent *bufev, short event)
int	bufferevent_disable (struct bufferevent *bufev, short event)
void	bufferevent_settimeout (struct bufferevent *bufev, int timeout_read, int timeout_write)
void	bufferevent_setwatermark (struct bufferevent *bufev, short events, size_t lowmark, size_t highmark)
struct evbuffer *	evbuffer_new (void)
void	evbuffer_free (struct evbuffer *)
int	evbuffer_expand (struct evbuffer *, size_t)
int	evbuffer_add (struct evbuffer , const void , size_t)
int	evbuffer_remove (struct evbuffer , void , size_t)
char *	evbuffer_readline (struct evbuffer *)
int	evbuffer_add_buffer (struct evbuffer , struct evbuffer )
int	evbuffer_add_printf (struct evbuffer , const char fmt,...)
int	evbuffer_add_vprintf (struct evbuffer , const char fmt, va_list ap)
void	evbuffer_drain (struct evbuffer *, size_t)
int	evbuffer_write (struct evbuffer *, int)
int	evbuffer_read (struct evbuffer *, int, int)
u_char *	evbuffer_find (struct evbuffer , const u_char , size_t)
void	evbuffer_setcb (struct evbuffer , void()(struct evbuffer , size_t, size_t, void ), void *)
void	evtag_init (void)
void	evtag_marshal (struct evbuffer evbuf, ev_uint32_t tag, const void data, ev_uint32_t len)
void	encode_int (struct evbuffer *evbuf, ev_uint32_t number)
void	evtag_marshal_int (struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer)
void	evtag_marshal_string (struct evbuffer buf, ev_uint32_t tag, const char string)
void	evtag_marshal_timeval (struct evbuffer evbuf, ev_uint32_t tag, struct timeval tv)
int	evtag_unmarshal (struct evbuffer src, ev_uint32_t ptag, struct evbuffer *dst)
int	evtag_peek (struct evbuffer evbuf, ev_uint32_t ptag)
int	evtag_peek_length (struct evbuffer evbuf, ev_uint32_t plength)
int	evtag_payload_length (struct evbuffer evbuf, ev_uint32_t plength)
int	evtag_consume (struct evbuffer *evbuf)
int	evtag_unmarshal_int (struct evbuffer evbuf, ev_uint32_t need_tag, ev_uint32_t pinteger)
int	evtag_unmarshal_fixed (struct evbuffer src, ev_uint32_t need_tag, void data, size_t len)
int	evtag_unmarshal_string (struct evbuffer evbuf, ev_uint32_t need_tag, char *pstring)
int	evtag_unmarshal_timeval (struct evbuffer evbuf, ev_uint32_t need_tag, struct timeval ptv)

Detailed Description

A library for writing event-driven network servers

Definition in file event.h.

Macro Definition Documentation

#define event_initialized ( ev ) ((ev)->ev_flags & EVLIST_INIT)

Test if an event structure has been initialized.

The event_initialized() macro can be used to check if an event has been initialized.

Parameters

ev	an event structure to be tested

Returns: 1 if the structure has been initialized, or 0 if it has not been initialized

Definition at line 653 of file event.h.

#define EVLOOP_NONBLOCK 0x02

Do not block.

Definition at line 362 of file event.h.

#define EVLOOP_ONCE 0x01

event_loop() flagsBlock at most once.

Definition at line 361 of file event.h.

#define evtimer_add	(	ev,
		tv
	)	event_add(ev, tv)

Add a timer event.

Parameters

ev	the event struct
tv	timeval struct

Definition at line 458 of file event.h.

#define evtimer_del ( ev ) event_del(ev)

Delete a timer event.

Parameters

ev	the event struct to be disabled

Definition at line 476 of file event.h.

#define evtimer_set	(	ev,
		cb,
		arg
	)	event_set(ev, -1, 0, cb, arg)

Define a timer event.

Parameters

ev	event struct to be modified
cb	callback function
arg	argument that will be passed to the callback function

Definition at line 468 of file event.h.

#define TAILQ_ENTRY ( type )

Value:

struct {                                                                \
        struct type *tqe_next;  /* next element */                      \
        struct type **tqe_prev; /* address of previous next element */  \
}

Definition at line 204 of file event.h.

#define timeout_add	(	ev,
		tv
	)	event_add(ev, tv)

Add a timeout event.

Parameters

ev	the event struct to be disabled
tv	the timeout value, in seconds

Definition at line 486 of file event.h.

#define timeout_del ( ev ) event_del(ev)

Disable a timeout event.

Parameters

ev	the timeout event to be disabled

Definition at line 504 of file event.h.

#define timeout_set	(	ev,
		cb,
		arg
	)	event_set(ev, -1, 0, cb, arg)

Define a timeout event.

Parameters

ev	the event struct to be defined
cb	the callback to be invoked when the timeout expires
arg	the argument to be passed to the callback

Definition at line 496 of file event.h.

Function Documentation

int bufferevent_base_set	(	struct event_base *	base,
		struct bufferevent *	bufev
	)

Assign a bufferevent to a specific event_base.

Parameters

base	an event_base returned by event_init()
bufev	a bufferevent struct returned by bufferevent_new()

Returns: 0 if successful, or -1 if an error occurred

See Also: bufferevent_new()

Definition at line 443 of file evbuffer.c.

int bufferevent_disable	(	struct bufferevent *	bufev,
		short	event
	)

Disable a bufferevent.

Parameters

bufev	the bufferevent to be disabled
event	any combination of EV_READ \| EV_WRITE.

Returns: 0 if successful, or -1 if an error occurred

See Also: bufferevent_enable()

Definition at line 388 of file evbuffer.c.

int bufferevent_enable	(	struct bufferevent *	bufev,
		short	event
	)

Enable a bufferevent.

Parameters

bufev	the bufferevent to be enabled
event	any combination of EV_READ \| EV_WRITE.

Returns: 0 if successful, or -1 if an error occurred

See Also: bufferevent_disable()

Definition at line 372 of file evbuffer.c.

void bufferevent_free ( struct bufferevent * bufev )

Deallocate the storage associated with a bufferevent structure.

Parameters

bufev the bufferevent structure to be freed.

Definition at line 309 of file evbuffer.c.

struct bufferevent* bufferevent_new	(	int	fd,
		evbuffercb	readcb,
		evbuffercb	writecb,
		everrorcb	errorcb,
		void *	cbarg
	)

read

Create a new bufferevent.

libevent provides an abstraction on top of the regular event callbacks. This abstraction is called a buffered event. A buffered event provides input and output buffers that get filled and drained automatically. The user of a buffered event no longer deals directly with the I/O, but instead is reading from input and writing to output buffers.

Once initialized, the bufferevent structure can be used repeatedly with bufferevent_enable() and bufferevent_disable().

When read enabled the bufferevent will try to read from the file descriptor and call the read callback. The write callback is executed whenever the output buffer is drained below the write low watermark, which is 0 by default.

If multiple bases are in use, bufferevent_base_set() must be called before enabling the bufferevent for the first time.

Parameters

fd	the file descriptor from which data is read and written to. This file descriptor is not allowed to be a pipe(2).
readcb	callback to invoke when there is data to be read, or NULL if no callback is desired
writecb	callback to invoke when the file descriptor is ready for writing, or NULL if no callback is desired
errorcb	callback to invoke when there is an error on the file descriptor
cbarg	an argument that will be supplied to each of the callbacks (readcb, writecb, and errorcb)

Returns: a pointer to a newly allocated bufferevent struct, or NULL if an error occurred

See Also: bufferevent_base_set(), bufferevent_free()

Definition at line 234 of file evbuffer.c.

int bufferevent_priority_set	(	struct bufferevent *	bufev,
		int	pri
	)

Assign a priority to a bufferevent.

Parameters

bufev	a bufferevent struct
pri	the priority to be assigned

Returns: 0 if successful, or -1 if an error occurred

Definition at line 296 of file evbuffer.c.

size_t bufferevent_read	(	struct bufferevent *	bufev,
		void *	data,
		size_t	size
	)

Read data from a bufferevent buffer.

The bufferevent_read() function is used to read data from the input buffer.

Parameters

bufev	the bufferevent to be read from
data	pointer to a buffer that will store the data
size	the size of the data buffer, in bytes

Returns: the amount of data read, in bytes.

Definition at line 355 of file evbuffer.c.

void bufferevent_setcb	(	struct bufferevent *	bufev,
		evbuffercb	readcb,
		evbuffercb	writecb,
		everrorcb	errorcb,
		void *	cbarg
	)

Changes the callbacks for a bufferevent.

Parameters

bufev	the bufferevent object for which to change callbacks
readcb	callback to invoke when there is data to be read, or NULL if no callback is desired
writecb	callback to invoke when the file descriptor is ready for writing, or NULL if no callback is desired
errorcb	callback to invoke when there is an error on the file descriptor
cbarg	an argument that will be supplied to each of the callbacks (readcb, writecb, and errorcb)

See Also: bufferevent_new()

Definition at line 269 of file evbuffer.c.

void bufferevent_setfd	(	struct bufferevent *	bufev,
		int	fd
	)

Changes the file descriptor on which the bufferevent operates.

Parameters

bufev	the bufferevent object for which to change the file descriptor
fd	the file descriptor to operate on

Definition at line 280 of file evbuffer.c.

void bufferevent_settimeout	(	struct bufferevent *	bufev,
		int	timeout_read,
		int	timeout_write
	)

Set the read and write timeout for a buffered event.

Parameters

bufev	the bufferevent to be modified
timeout_read	the read timeout
timeout_write	the write timeout

Definition at line 408 of file evbuffer.c.

void bufferevent_setwatermark	(	struct bufferevent *	bufev,
		short	events,
		size_t	lowmark,
		size_t	highmark
	)

Sets the watermarks for read and write events.

On input, a bufferevent does not invoke the user read callback unless there is at least low watermark data in the buffer. If the read buffer is beyond the high watermark, the buffevent stops reading from the network.

On output, the user write callback is invoked whenever the buffered data falls below the low watermark.

Parameters

bufev	the bufferevent to be modified
events	EV_READ, EV_WRITE or both
lowmark	the lower watermark to set
highmark	the high watermark to set

Definition at line 424 of file evbuffer.c.

int bufferevent_write	(	struct bufferevent *	bufev,
		const void *	data,
		size_t	size
	)

Write data to a bufferevent buffer.

The bufferevent_write() function can be used to write data to the file descriptor. The data is appended to the output buffer and written to the descriptor automatically as it becomes available for writing.

Parameters

bufev	the bufferevent to be written to
data	a pointer to the data to be written
size	the length of the data, in bytes

Returns: 0 if successful, or -1 if an error occurred

See Also: bufferevent_write_buffer()

Definition at line 326 of file evbuffer.c.

int bufferevent_write_buffer	(	struct bufferevent *	bufev,
		struct evbuffer *	buf
	)

Write data from an evbuffer to a bufferevent buffer. The evbuffer is being drained as a result.

Parameters

bufev	the bufferevent to be written to
buf	the evbuffer to be written

Returns: 0 if successful, or -1 if an error occurred

See Also: bufferevent_write()

Definition at line 343 of file evbuffer.c.

void encode_int	(	struct evbuffer *	evbuf,
		ev_uint32_t	number
	)

Encode an integer and store it in an evbuffer.

We encode integer's by nibbles; the first nibble contains the number of significant nibbles - 1; this allows us to encode up to 64-bit integers. This function is byte-order independent.

Parameters

evbuf	evbuffer to store the encoded number
number	a 32-bit integer

Definition at line 91 of file event_tagging.c.

Here is the call graph for this function:

Here is the caller graph for this function:

int evbuffer_add	(	struct evbuffer *	,
		const void *	,
		size_t
	)

Append data to the end of an evbuffer.

Parameters

buf	the event buffer to be appended to
data	pointer to the beginning of the data buffer
datlen	the number of bytes to be copied from the data buffer

Definition at line 301 of file buffer.c.

int evbuffer_add_buffer	(	struct evbuffer *	,
		struct evbuffer *
	)

Move data from one evbuffer into another evbuffer.

This is a destructive add. The data from one buffer moves into the other buffer. The destination buffer is expanded as needed.

Parameters

outbuf	the output buffer
inbuf	the input buffer

Returns: 0 if successful, or -1 if an error occurred

Definition at line 100 of file buffer.c.

int evbuffer_add_printf	(	struct evbuffer *	,
		const char *	fmt,
			...
	)

Append a formatted string to the end of an evbuffer.

Parameters

buf	the evbuffer that will be appended to
fmt	a format string
...	arguments that will be passed to printf(3)

Returns: The number of bytes added if successful, or -1 if an error occurred.

Definition at line 178 of file buffer.c.

int evbuffer_add_vprintf	(	struct evbuffer *	,
		const char *	fmt,
		va_list	ap
	)

Append a va_list formatted string to the end of an evbuffer.

Parameters

buf	the evbuffer that will be appended to
fmt	a format string
ap	a varargs va_list argument array that will be passed to vprintf(3)

Returns: The number of bytes added if successful, or -1 if an error occurred.

Definition at line 137 of file buffer.c.

void evbuffer_drain	(	struct evbuffer *	,
		size_t
	)

Remove a specified number of bytes data from the beginning of an evbuffer.

Parameters

buf	the evbuffer to be drained
len	the number of bytes to drain from the beginning of the buffer

Definition at line 321 of file buffer.c.

int evbuffer_expand	(	struct evbuffer *	,
		size_t
	)

Expands the available space in an event buffer.

Expands the available space in the event buffer to at least datlen

Parameters

buf	the event buffer to be expanded
datlen	the new minimum length requirement

Returns: 0 if successful, or -1 if an error occurred

Definition at line 265 of file buffer.c.

u_char* evbuffer_find	(	struct evbuffer *	,
		const u_char *	,
		size_t
	)

Find a string within an evbuffer.

Parameters

buffer	the evbuffer to be searched
what	the string to be searched for
len	the length of the search string

Returns: a pointer to the beginning of the search string, or NULL if the search failed.

Definition at line 428 of file buffer.c.

void evbuffer_free ( struct evbuffer * )

Deallocate storage for an evbuffer.

Parameters

pointer to the evbuffer to be freed

Definition at line 79 of file buffer.c.

struct evbuffer* evbuffer_new ( void )

read

Allocate storage for a new evbuffer.

Returns: a pointer to a newly allocated evbuffer struct, or NULL if an error occurred

Definition at line 69 of file buffer.c.

int evbuffer_read	(	struct evbuffer *	,
		int	,
		int
	)

Read from a file descriptor and store the result in an evbuffer.

Parameters

buf	the evbuffer to store the result
fd	the file descriptor to read from
howmuch	the number of bytes to be read

Returns: the number of bytes read, or -1 if an error occurred

See Also: evbuffer_write()

Definition at line 351 of file buffer.c.

char* evbuffer_readline ( struct evbuffer * )

Read a single line from an event buffer.

Reads a line terminated by either '
', '
' or '' or '
'. The returned buffer needs to be freed by the caller.

Parameters

buffer the evbuffer to read from

Returns: pointer to a single line, or NULL if an error occurred

Definition at line 211 of file buffer.c.

int evbuffer_remove	(	struct evbuffer *	,
		void *	,
		size_t
	)

Read data from an event buffer and drain the bytes read.

Parameters

buf	the event buffer to be read from
data	the destination buffer to store the result
datlen	the maximum size of the destination buffer

Returns: the number of bytes read

Definition at line 193 of file buffer.c.

void evbuffer_setcb	(	struct evbuffer *	,
		void()(struct evbuffer , size_t, size_t, void *)	,
		void *
	)

Set a callback to invoke when the evbuffer is modified.

Parameters

buffer	the evbuffer to be monitored
cb	the callback function to invoke when the evbuffer is modified
cbarg	an argument to be provided to the callback function

Definition at line 445 of file buffer.c.

int evbuffer_write	(	struct evbuffer *	,
		int
	)

Write the contents of an evbuffer to a file descriptor.

The evbuffer will be drained after the bytes have been successfully written.

Parameters

buffer	the evbuffer to be written and drained
fd	the file descriptor to be written to

Returns: the number of bytes written, or -1 if an error occurred

See Also: evbuffer_read()

Definition at line 409 of file buffer.c.

int event_add	(	struct event *	ev,
		const struct timeval *	timeout
	)

Add an event to the set of monitored events.

The function event_add() schedules the execution of the ev event when the event specified in event_set() occurs or in at least the time specified in the tv. If tv is NULL, no timeout occurs and the function will only be called if a matching event occurs on the file descriptor. The event in the ev argument must be already initialized by event_set() and may not be used in calls to event_set() until it has timed out or been removed with event_del(). If the event in the ev argument already has a scheduled timeout, the old timeout will be replaced by the new one.

Parameters

ev	an event struct initialized via event_set()
timeout	the maximum amount of time to wait for the event, or NULL to wait forever

Returns: 0 if successful, or -1 if an error occurred

See Also: event_del(), event_set()

Definition at line 719 of file event.c.

int event_base_dispatch ( struct event_base * )

Threadsafe event dispatching loop.

Parameters

eb	the event_base structure returned by event_init()

See Also: event_init(), event_dispatch()

Definition at line 410 of file event.c.

void event_base_free ( struct event_base * )

Deallocate all memory associated with an event_base, and free the base.

Note that this function will not close any fds or free any memory passed to event_set as the argument to callback.

Parameters

eb	an event_base to be freed

Definition at line 214 of file event.c.

const char* event_base_get_method ( struct event_base * )

Get the kernel event notification mechanism used by libevent.

Parameters

eb	the event_base structure returned by event_base_new()

Returns: a string identifying the kernel event mechanism (kqueue, epoll, etc.)

Definition at line 416 of file event.c.

int event_base_loop	(	struct event_base *	,
		int
	)

Handle events (threadsafe version).

This is a more flexible version of event_base_dispatch().

Parameters

eb	the event_base structure returned by event_init()
flags	any combination of EVLOOP_ONCE \| EVLOOP_NONBLOCK

Returns: 0 if successful, -1 if an error occurred, or 1 if no events were registered.

See Also: event_loopexit(), event_base_loop()

Definition at line 472 of file event.c.

int event_base_loopbreak ( struct event_base * )

Abort the active event_base_loop() immediately.

event_base_loop() will abort the loop after the next event is completed; event_base_loopbreak() is typically invoked from this event's callback. This behavior is analogous to the "break;" statement.

Subsequent invocations of event_loop() will proceed normally.

Parameters

eb	the event_base structure returned by event_init()

Returns: 0 if successful, or -1 if an error occurred

See Also: event_base_loopexit

Definition at line 452 of file event.c.

int event_base_loopexit	(	struct event_base *	,
		const struct timeval *
	)

Exit the event loop after the specified time (threadsafe variant).

The next event_base_loop() iteration after the given timer expires will complete normally (handling all queued events) then exit without blocking for events again.

Subsequent invocations of event_base_loop() will proceed normally.

Parameters

eb	the event_base structure returned by event_init()
tv	the amount of time after which the loop should terminate.

Returns: 0 if successful, or -1 if an error occurred

See Also: event_loopexit()

Definition at line 438 of file event.c.

struct event_base* event_base_new ( void )

read

Initialize the event API.

Use event_base_new() to initialize a new event base, but does not set the current_base global. If using only event_base_new(), each event added must have an event base set with event_base_set()

See Also: event_base_set(), event_base_free(), event_init()

Definition at line 174 of file event.c.

int event_base_once	(	struct event_base *	base,
		int	fd,
		short	events,
		void()(int, short, void )	callback,
		void *	arg,
		const struct timeval *	timeout
	)

Schedule a one-time event (threadsafe variant)

The function event_base_once() is similar to event_set(). However, it schedules a callback to be called exactly once and does not require the caller to prepare an event structure.

Parameters

base	an event_base returned by event_init()
fd	a file descriptor to monitor
events	event(s) to monitor; can be any of EV_TIMEOUT \| EV_READ \| EV_WRITE
callback	callback function to be invoked when the event occurs
arg	an argument to be passed to the callback function
timeout	the maximum amount of time to wait for the event, or NULL to wait forever

Returns: 0 if successful, or -1 if an error occurred

See Also: event_once()

Definition at line 588 of file event.c.

int event_base_priority_init	(	struct event_base *	,
		int
	)

Set the number of different event priorities (threadsafe variant).

See the description of event_priority_init() for more information.

Parameters

eb	the event_base structure returned by event_init()
npriorities	the maximum number of priorities

Returns: 0 if successful, or -1 if an error occurred

See Also: event_priority_init(), event_priority_set()

Definition at line 320 of file event.c.

int event_base_set	(	struct event_base *	,
		struct event *
	)

Associate a different event base with an event.

Parameters

eb	the event base
ev	the event

Definition at line 657 of file event.c.

int event_del ( struct event * )

Remove an event from the set of monitored events.

The function event_del() will cancel the event in the argument ev. If the event has already executed or has never been added the call will have no effect.

Parameters

ev	an event struct to be removed from the working set

Returns: 0 if successful, or -1 if an error occurred

See Also: event_add()

Definition at line 797 of file event.c.

int event_dispatch ( void )

Loop to process events.

In order to process events, an application needs to call event_dispatch(). This function only returns on error, and should replace the event core of the application program.

See Also: event_base_dispatch()

Definition at line 404 of file event.c.

const char* event_get_method ( void )

Get the kernel event notification mechanism used by libevent.

Returns: a string identifying the kernel event mechanism (kqueue, epoll, etc.)

Definition at line 1022 of file event.c.

const char* event_get_version ( void )

Get the libevent version number.

Returns: a string containing the version number of libevent

Definition at line 1011 of file event.c.

struct event_base* event_init ( void )

read

Initialize the event API.

The event API needs to be initialized with event_init() before it can be used. Sets the current_base global representing the default base for events that have no base associated with them.

See Also: event_base_set(), event_base_new()

Definition at line 163 of file event.c.

int event_loop ( int )

Handle events.

This is a more flexible version of event_dispatch().

Parameters

flags any combination of EVLOOP_ONCE | EVLOOP_NONBLOCK

Returns: 0 if successful, -1 if an error occurred, or 1 if no events were registered.

See Also: event_loopexit(), event_base_loop()

Definition at line 466 of file event.c.

int event_loopbreak ( void )

Abort the active event_loop() immediately.

event_loop() will abort the loop after the next event is completed; event_loopbreak() is typically invoked from this event's callback. This behavior is analogous to the "break;" statement.

Subsequent invocations of event_loop() will proceed normally.

Returns: 0 if successful, or -1 if an error occurred

See Also: event_base_loopbreak(), event_loopexit()

Definition at line 446 of file event.c.

int event_loopexit ( const struct timeval * )

Exit the event loop after the specified time.

The next event_loop() iteration after the given timer expires will complete normally (handling all queued events) then exit without blocking for events again.

Subsequent invocations of event_loop() will proceed normally.

Parameters

tv	the amount of time after which the loop should terminate.

Returns: 0 if successful, or -1 if an error occurred

See Also: event_loop(), event_base_loop(), event_base_loopexit()

Definition at line 431 of file event.c.

int event_once	(	int	,
		short	,
		void()(int, short, void )	,
		void *	,
		const struct timeval *
	)

Schedule a one-time event to occur.

The function event_once() is similar to event_set(). However, it schedules a callback to be called exactly once and does not require the caller to prepare an event structure.

Parameters

fd	a file descriptor to monitor
events	event(s) to monitor; can be any of EV_TIMEOUT \| EV_READ \| EV_WRITE
callback	callback function to be invoked when the event occurs
arg	an argument to be passed to the callback function
timeout	the maximum amount of time to wait for the event, or NULL to wait forever

Returns: 0 if successful, or -1 if an error occurred

See Also: event_set()

Definition at line 580 of file event.c.

int event_pending	(	struct event *	ev,
		short	event,
		struct timeval *	tv
	)

Checks if a specific event is pending or scheduled.

Parameters

ev	an event struct previously passed to event_add()
event	the requested event type; any of EV_TIMEOUT\|EV_READ\| EV_WRITE\|EV_SIGNAL
tv	an alternate timeout (FIXME - is this true?)

Returns: 1 if the event is pending, or 0 if the event has not occurred

Definition at line 692 of file event.c.

int event_priority_init ( int )

Set the number of different event priorities.

By default libevent schedules all active events with the same priority. However, some time it is desirable to process some events with a higher priority than others. For that reason, libevent supports strict priority queues. Active events with a lower priority are always processed before events with a higher priority.

The number of different priorities can be set initially with the event_priority_init() function. This function should be called before the first call to event_dispatch(). The event_priority_set() function can be used to assign a priority to an event. By default, libevent assigns the middle priority to all events unless their priority is explicitly set.

Parameters

npriorities the maximum number of priorities

Returns: 0 if successful, or -1 if an error occurred

See Also: event_base_priority_init(), event_priority_set()

Definition at line 314 of file event.c.

int event_priority_set	(	struct event *	,
		int
	)

Assign a priority to an event.

Parameters

ev	an event struct
priority	the new priority to be assigned

Returns: 0 if successful, or -1 if an error occurred

See Also: event_priority_init()

Definition at line 675 of file event.c.

int event_reinit ( struct event_base * base )

Reinitialized the event base after a fork

Some event mechanisms do not survive across fork. The event base needs to be reinitialized with the event_reinit() function.

Parameters

base	the event base that needs to be re-initialized

Returns: 0 if successful, or -1 if some events could not be re-added.

See Also: event_base_new(), event_init()

Definition at line 275 of file event.c.

void event_set	(	struct event *	,
		int	,
		short	,
		void()(int, short, void )	,
		void *
	)

Prepare an event structure to be added.

The function event_set() prepares the event structure ev to be used in future calls to event_add() and event_del(). The event will be prepared to call the function specified by the fn argument with an int argument indicating the file descriptor, a short argument indicating the type of event, and a void * argument given in the arg argument. The fd indicates the file descriptor that should be monitored for events. The events can be either EV_READ, EV_WRITE, or both. Indicating that an application can read or write from the file descriptor respectively without blocking.

The function fn will be called with the file descriptor that triggered the event and the type of event which will be either EV_TIMEOUT, EV_SIGNAL, EV_READ, or EV_WRITE. The additional flag EV_PERSIST makes an event_add() persistent until event_del() has been called.

Parameters

ev	an event struct to be modified
fd	the file descriptor to be monitored
event	desired events to monitor; can be EV_READ and/or EV_WRITE
fn	callback function to be invoked when the event occurs
arg	an argument to be passed to the callback function

See Also: event_add(), event_del(), event_once()

Definition at line 634 of file event.c.

void event_set_log_callback ( event_log_cb cb )

Redirect libevent's log messages.

Parameters

cb	a function taking two arguments: an integer severity between _EVENT_LOG_DEBUG and _EVENT_LOG_ERR, and a string. If cb is NULL, then the default log is used.

Definition at line 156 of file log.c.

Here is the call graph for this function:

Here is the caller graph for this function:

Classes

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

Function Documentation