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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:46:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:46:30 +0000
commitb5896ba9f6047e7031e2bdee0622d543e11a6734 (patch)
treefd7b460593a2fee1be579bec5697e6d887ea3421 /src/util/events.c
parentInitial commit. (diff)
downloadpostfix-b5896ba9f6047e7031e2bdee0622d543e11a6734.tar.xz
postfix-b5896ba9f6047e7031e2bdee0622d543e11a6734.zip
Adding upstream version 3.4.23.upstream/3.4.23upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--src/util/events.c1261
1 files changed, 1261 insertions, 0 deletions
diff --git a/src/util/events.c b/src/util/events.c
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--- /dev/null
+++ b/src/util/events.c
@@ -0,0 +1,1261 @@
+/*++
+/* NAME
+/* events 3
+/* SUMMARY
+/* event manager
+/* SYNOPSIS
+/* #include <events.h>
+/*
+/* time_t event_time()
+/*
+/* void event_loop(delay)
+/* int delay;
+/*
+/* time_t event_request_timer(callback, context, delay)
+/* void (*callback)(int event, void *context);
+/* void *context;
+/* int delay;
+/*
+/* int event_cancel_timer(callback, context)
+/* void (*callback)(int event, void *context);
+/* void *context;
+/*
+/* void event_enable_read(fd, callback, context)
+/* int fd;
+/* void (*callback)(int event, void *context);
+/* void *context;
+/*
+/* void event_enable_write(fd, callback, context)
+/* int fd;
+/* void (*callback)(int event, void *context);
+/* void *context;
+/*
+/* void event_disable_readwrite(fd)
+/* int fd;
+/*
+/* void event_drain(time_limit)
+/* int time_limit;
+/*
+/* void event_fork(void)
+/* DESCRIPTION
+/* This module delivers I/O and timer events.
+/* Multiple I/O streams and timers can be monitored simultaneously.
+/* Events are delivered via callback routines provided by the
+/* application. When requesting an event, the application can provide
+/* private context that is passed back when the callback routine is
+/* executed.
+/*
+/* event_time() returns a cached value of the current time.
+/*
+/* event_loop() monitors all I/O channels for which the application has
+/* expressed interest, and monitors the timer request queue.
+/* It notifies the application whenever events of interest happen.
+/* A negative delay value causes the function to pause until something
+/* happens; a positive delay value causes event_loop() to return when
+/* the next event happens or when the delay time in seconds is over,
+/* whatever happens first. A zero delay effectuates a poll.
+/*
+/* Note: in order to avoid race conditions, event_loop() cannot
+/* not be called recursively.
+/*
+/* event_request_timer() causes the specified callback function to
+/* be called with the specified context argument after \fIdelay\fR
+/* seconds, or as soon as possible thereafter. The delay should
+/* not be negative (the manifest EVENT_NULL_DELAY provides for
+/* convenient zero-delay notification).
+/* The event argument is equal to EVENT_TIME.
+/* Only one timer request can be active per (callback, context) pair.
+/* Calling event_request_timer() with an existing (callback, context)
+/* pair does not schedule a new event, but updates the time of event
+/* delivery. The result is the absolute time at which the timer is
+/* scheduled to go off.
+/*
+/* event_cancel_timer() cancels the specified (callback, context) request.
+/* The application is allowed to cancel non-existing requests. The result
+/* value is the amount of time left before the timer would have gone off,
+/* or -1 in case of no pending timer.
+/*
+/* event_enable_read() (event_enable_write()) enables read (write) events
+/* on the named I/O channel. It is up to the application to assemble
+/* partial reads or writes.
+/* An I/O channel cannot handle more than one request at the
+/* same time. The application is allowed to enable an event that
+/* is already enabled (same channel, same read or write operation,
+/* but perhaps a different callback or context). On systems with
+/* kernel-based event filters this is preferred usage, because
+/* each disable and enable request would cost a system call.
+/*
+/* The manifest constants EVENT_NULL_CONTEXT and EVENT_NULL_TYPE
+/* provide convenient null values.
+/*
+/* The callback routine has the following arguments:
+/* .IP fd
+/* The stream on which the event happened.
+/* .IP event
+/* An indication of the event type:
+/* .RS
+/* .IP EVENT_READ
+/* read event,
+/* .IP EVENT_WRITE
+/* write event,
+/* .IP EVENT_XCPT
+/* exception (actually, any event other than read or write).
+/* .RE
+/* .IP context
+/* Application context given to event_enable_read() (event_enable_write()).
+/* .PP
+/* event_disable_readwrite() disables further I/O events on the specified
+/* I/O channel. The application is allowed to cancel non-existing
+/* I/O event requests.
+/*
+/* event_drain() repeatedly calls event_loop() until no more timer
+/* events or I/O events are pending or until the time limit is reached.
+/* This routine must not be called from an event_whatever() callback
+/* routine. Note: this function assumes that no new I/O events
+/* will be registered.
+/*
+/* event_fork() must be called by a child process after it is
+/* created with fork(), to re-initialize event processing.
+/* DIAGNOSTICS
+/* Panics: interface violations. Fatal errors: out of memory,
+/* system call failure. Warnings: the number of available
+/* file descriptors is much less than FD_SETSIZE.
+/* BUGS
+/* This module is based on event selection. It assumes that the
+/* event_loop() routine is called frequently. This approach is
+/* not suitable for applications with compute-bound loops that
+/* take a significant amount of time.
+/* LICENSE
+/* .ad
+/* .fi
+/* The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/* Wietse Venema
+/* IBM T.J. Watson Research
+/* P.O. Box 704
+/* Yorktown Heights, NY 10598, USA
+/*--*/
+
+/* System libraries. */
+
+#include "sys_defs.h"
+#include <sys/time.h> /* XXX: 44BSD uses bzero() */
+#include <time.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stddef.h> /* offsetof() */
+#include <string.h> /* bzero() prototype for 44BSD */
+#include <limits.h> /* INT_MAX */
+
+#ifdef USE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+
+/* Application-specific. */
+
+#include "mymalloc.h"
+#include "msg.h"
+#include "iostuff.h"
+#include "ring.h"
+#include "events.h"
+
+#if !defined(EVENTS_STYLE)
+#error "must define EVENTS_STYLE"
+#endif
+
+ /*
+ * Traditional BSD-style select(2). Works everywhere, but has a built-in
+ * upper bound on the number of file descriptors, and that limit is hard to
+ * change on Linux. Is sometimes emulated with SYSV-style poll(2) which
+ * doesn't have the file descriptor limit, but unfortunately does not help
+ * to improve the performance of servers with lots of connections.
+ */
+#define EVENT_ALLOC_INCR 10
+
+#if (EVENTS_STYLE == EVENTS_STYLE_SELECT)
+typedef fd_set EVENT_MASK;
+
+#define EVENT_MASK_BYTE_COUNT(mask) sizeof(*(mask))
+#define EVENT_MASK_ZERO(mask) FD_ZERO(mask)
+#define EVENT_MASK_SET(fd, mask) FD_SET((fd), (mask))
+#define EVENT_MASK_ISSET(fd, mask) FD_ISSET((fd), (mask))
+#define EVENT_MASK_CLR(fd, mask) FD_CLR((fd), (mask))
+#define EVENT_MASK_CMP(m1, m2) memcmp((m1), (m2), EVENT_MASK_BYTE_COUNT(m1))
+#else
+
+ /*
+ * Kernel-based event filters (kqueue, /dev/poll, epoll). We use the
+ * following file descriptor mask structure which is expanded on the fly.
+ */
+typedef struct {
+ char *data; /* bit mask */
+ size_t data_len; /* data byte count */
+} EVENT_MASK;
+
+ /* Bits per byte, byte in vector, bit offset in byte, bytes per set. */
+#define EVENT_MASK_NBBY (8)
+#define EVENT_MASK_FD_BYTE(fd, mask) \
+ (((unsigned char *) (mask)->data)[(fd) / EVENT_MASK_NBBY])
+#define EVENT_MASK_FD_BIT(fd) (1 << ((fd) % EVENT_MASK_NBBY))
+#define EVENT_MASK_BYTES_NEEDED(len) \
+ (((len) + (EVENT_MASK_NBBY -1)) / EVENT_MASK_NBBY)
+#define EVENT_MASK_BYTE_COUNT(mask) ((mask)->data_len)
+
+ /* Memory management. */
+#define EVENT_MASK_ALLOC(mask, bit_len) do { \
+ size_t _byte_len = EVENT_MASK_BYTES_NEEDED(bit_len); \
+ (mask)->data = mymalloc(_byte_len); \
+ memset((mask)->data, 0, _byte_len); \
+ (mask)->data_len = _byte_len; \
+ } while (0)
+#define EVENT_MASK_REALLOC(mask, bit_len) do { \
+ size_t _byte_len = EVENT_MASK_BYTES_NEEDED(bit_len); \
+ size_t _old_len = (mask)->data_len; \
+ (mask)->data = myrealloc((mask)->data, _byte_len); \
+ if (_byte_len > _old_len) \
+ memset((mask)->data + _old_len, 0, _byte_len - _old_len); \
+ (mask)->data_len = _byte_len; \
+ } while (0)
+#define EVENT_MASK_FREE(mask) myfree((mask)->data)
+
+ /* Set operations, modeled after FD_ZERO/SET/ISSET/CLR. */
+#define EVENT_MASK_ZERO(mask) \
+ memset((mask)->data, 0, (mask)->data_len)
+#define EVENT_MASK_SET(fd, mask) \
+ (EVENT_MASK_FD_BYTE((fd), (mask)) |= EVENT_MASK_FD_BIT(fd))
+#define EVENT_MASK_ISSET(fd, mask) \
+ (EVENT_MASK_FD_BYTE((fd), (mask)) & EVENT_MASK_FD_BIT(fd))
+#define EVENT_MASK_CLR(fd, mask) \
+ (EVENT_MASK_FD_BYTE((fd), (mask)) &= ~EVENT_MASK_FD_BIT(fd))
+#define EVENT_MASK_CMP(m1, m2) \
+ memcmp((m1)->data, (m2)->data, EVENT_MASK_BYTE_COUNT(m1))
+#endif
+
+ /*
+ * I/O events.
+ */
+typedef struct EVENT_FDTABLE EVENT_FDTABLE;
+
+struct EVENT_FDTABLE {
+ EVENT_NOTIFY_RDWR_FN callback;
+ char *context;
+};
+static EVENT_MASK event_rmask; /* enabled read events */
+static EVENT_MASK event_wmask; /* enabled write events */
+static EVENT_MASK event_xmask; /* for bad news mostly */
+static int event_fdlimit; /* per-process open file limit */
+static EVENT_FDTABLE *event_fdtable; /* one slot per file descriptor */
+static int event_fdslots; /* number of file descriptor slots */
+static int event_max_fd = -1; /* highest fd number seen */
+
+ /*
+ * FreeBSD kqueue supports no system call to find out what descriptors are
+ * registered in the kernel-based filter. To implement our own sanity checks
+ * we maintain our own descriptor bitmask.
+ *
+ * FreeBSD kqueue does support application context pointers. Unfortunately,
+ * changing that information would cost a system call, and some of the
+ * competitors don't support application context. To keep the implementation
+ * simple we maintain our own table with call-back information.
+ *
+ * FreeBSD kqueue silently unregisters a descriptor from its filter when the
+ * descriptor is closed, so our information could get out of sync with the
+ * kernel. But that will never happen, because we have to meticulously
+ * unregister a file descriptor before it is closed, to avoid errors on
+ * systems that are built with EVENTS_STYLE == EVENTS_STYLE_SELECT.
+ */
+#if (EVENTS_STYLE == EVENTS_STYLE_KQUEUE)
+#include <sys/event.h>
+
+ /*
+ * Some early FreeBSD implementations don't have the EV_SET macro.
+ */
+#ifndef EV_SET
+#define EV_SET(kp, id, fi, fl, ffl, da, ud) do { \
+ (kp)->ident = (id); \
+ (kp)->filter = (fi); \
+ (kp)->flags = (fl); \
+ (kp)->fflags = (ffl); \
+ (kp)->data = (da); \
+ (kp)->udata = (ud); \
+ } while(0)
+#endif
+
+ /*
+ * Macros to initialize the kernel-based filter; see event_init().
+ */
+static int event_kq; /* handle to event filter */
+
+#define EVENT_REG_INIT_HANDLE(er, n) do { \
+ er = event_kq = kqueue(); \
+ } while (0)
+#define EVENT_REG_INIT_TEXT "kqueue"
+
+#define EVENT_REG_FORK_HANDLE(er, n) do { \
+ (void) close(event_kq); \
+ EVENT_REG_INIT_HANDLE(er, (n)); \
+ } while (0)
+
+ /*
+ * Macros to update the kernel-based filter; see event_enable_read(),
+ * event_enable_write() and event_disable_readwrite().
+ */
+#define EVENT_REG_FD_OP(er, fh, ev, op) do { \
+ struct kevent dummy; \
+ EV_SET(&dummy, (fh), (ev), (op), 0, 0, 0); \
+ (er) = kevent(event_kq, &dummy, 1, 0, 0, 0); \
+ } while (0)
+
+#define EVENT_REG_ADD_OP(e, f, ev) EVENT_REG_FD_OP((e), (f), (ev), EV_ADD)
+#define EVENT_REG_ADD_READ(e, f) EVENT_REG_ADD_OP((e), (f), EVFILT_READ)
+#define EVENT_REG_ADD_WRITE(e, f) EVENT_REG_ADD_OP((e), (f), EVFILT_WRITE)
+#define EVENT_REG_ADD_TEXT "kevent EV_ADD"
+
+#define EVENT_REG_DEL_OP(e, f, ev) EVENT_REG_FD_OP((e), (f), (ev), EV_DELETE)
+#define EVENT_REG_DEL_READ(e, f) EVENT_REG_DEL_OP((e), (f), EVFILT_READ)
+#define EVENT_REG_DEL_WRITE(e, f) EVENT_REG_DEL_OP((e), (f), EVFILT_WRITE)
+#define EVENT_REG_DEL_TEXT "kevent EV_DELETE"
+
+ /*
+ * Macros to retrieve event buffers from the kernel; see event_loop().
+ */
+typedef struct kevent EVENT_BUFFER;
+
+#define EVENT_BUFFER_READ(event_count, event_buf, buflen, delay) do { \
+ struct timespec ts; \
+ struct timespec *tsp; \
+ if ((delay) < 0) { \
+ tsp = 0; \
+ } else { \
+ tsp = &ts; \
+ ts.tv_nsec = 0; \
+ ts.tv_sec = (delay); \
+ } \
+ (event_count) = kevent(event_kq, (struct kevent *) 0, 0, (event_buf), \
+ (buflen), (tsp)); \
+ } while (0)
+#define EVENT_BUFFER_READ_TEXT "kevent"
+
+ /*
+ * Macros to process event buffers from the kernel; see event_loop().
+ */
+#define EVENT_GET_FD(bp) ((bp)->ident)
+#define EVENT_GET_TYPE(bp) ((bp)->filter)
+#define EVENT_TEST_READ(bp) (EVENT_GET_TYPE(bp) == EVFILT_READ)
+#define EVENT_TEST_WRITE(bp) (EVENT_GET_TYPE(bp) == EVFILT_WRITE)
+
+#endif
+
+ /*
+ * Solaris /dev/poll does not support application context, so we have to
+ * maintain our own. This has the benefit of avoiding an expensive system
+ * call just to change a call-back function or argument.
+ *
+ * Solaris /dev/poll does have a way to query if a specific descriptor is
+ * registered. However, we maintain a descriptor mask anyway because a) it
+ * avoids having to make an expensive system call to find out if something
+ * is registered, b) some EVENTS_STYLE_MUMBLE implementations need a
+ * descriptor bitmask anyway and c) we use the bitmask already to implement
+ * sanity checks.
+ */
+#if (EVENTS_STYLE == EVENTS_STYLE_DEVPOLL)
+#include <sys/devpoll.h>
+#include <fcntl.h>
+
+ /*
+ * Macros to initialize the kernel-based filter; see event_init().
+ */
+static int event_pollfd; /* handle to file descriptor set */
+
+#define EVENT_REG_INIT_HANDLE(er, n) do { \
+ er = event_pollfd = open("/dev/poll", O_RDWR); \
+ if (event_pollfd >= 0) close_on_exec(event_pollfd, CLOSE_ON_EXEC); \
+ } while (0)
+#define EVENT_REG_INIT_TEXT "open /dev/poll"
+
+#define EVENT_REG_FORK_HANDLE(er, n) do { \
+ (void) close(event_pollfd); \
+ EVENT_REG_INIT_HANDLE(er, (n)); \
+ } while (0)
+
+ /*
+ * Macros to update the kernel-based filter; see event_enable_read(),
+ * event_enable_write() and event_disable_readwrite().
+ */
+#define EVENT_REG_FD_OP(er, fh, ev) do { \
+ struct pollfd dummy; \
+ dummy.fd = (fh); \
+ dummy.events = (ev); \
+ (er) = write(event_pollfd, (void *) &dummy, \
+ sizeof(dummy)) != sizeof(dummy) ? -1 : 0; \
+ } while (0)
+
+#define EVENT_REG_ADD_READ(e, f) EVENT_REG_FD_OP((e), (f), POLLIN)
+#define EVENT_REG_ADD_WRITE(e, f) EVENT_REG_FD_OP((e), (f), POLLOUT)
+#define EVENT_REG_ADD_TEXT "write /dev/poll"
+
+#define EVENT_REG_DEL_BOTH(e, f) EVENT_REG_FD_OP((e), (f), POLLREMOVE)
+#define EVENT_REG_DEL_TEXT "write /dev/poll"
+
+ /*
+ * Macros to retrieve event buffers from the kernel; see event_loop().
+ */
+typedef struct pollfd EVENT_BUFFER;
+
+#define EVENT_BUFFER_READ(event_count, event_buf, buflen, delay) do { \
+ struct dvpoll dvpoll; \
+ dvpoll.dp_fds = (event_buf); \
+ dvpoll.dp_nfds = (buflen); \
+ dvpoll.dp_timeout = (delay) < 0 ? -1 : (delay) * 1000; \
+ (event_count) = ioctl(event_pollfd, DP_POLL, &dvpoll); \
+ } while (0)
+#define EVENT_BUFFER_READ_TEXT "ioctl DP_POLL"
+
+ /*
+ * Macros to process event buffers from the kernel; see event_loop().
+ */
+#define EVENT_GET_FD(bp) ((bp)->fd)
+#define EVENT_GET_TYPE(bp) ((bp)->revents)
+#define EVENT_TEST_READ(bp) (EVENT_GET_TYPE(bp) & POLLIN)
+#define EVENT_TEST_WRITE(bp) (EVENT_GET_TYPE(bp) & POLLOUT)
+
+#endif
+
+ /*
+ * Linux epoll supports no system call to find out what descriptors are
+ * registered in the kernel-based filter. To implement our own sanity checks
+ * we maintain our own descriptor bitmask.
+ *
+ * Linux epoll does support application context pointers. Unfortunately,
+ * changing that information would cost a system call, and some of the
+ * competitors don't support application context. To keep the implementation
+ * simple we maintain our own table with call-back information.
+ *
+ * Linux epoll silently unregisters a descriptor from its filter when the
+ * descriptor is closed, so our information could get out of sync with the
+ * kernel. But that will never happen, because we have to meticulously
+ * unregister a file descriptor before it is closed, to avoid errors on
+ * systems that are built with EVENTS_STYLE == EVENTS_STYLE_SELECT.
+ */
+#if (EVENTS_STYLE == EVENTS_STYLE_EPOLL)
+#include <sys/epoll.h>
+
+ /*
+ * Macros to initialize the kernel-based filter; see event_init().
+ */
+static int event_epollfd; /* epoll handle */
+
+#define EVENT_REG_INIT_HANDLE(er, n) do { \
+ er = event_epollfd = epoll_create(n); \
+ if (event_epollfd >= 0) close_on_exec(event_epollfd, CLOSE_ON_EXEC); \
+ } while (0)
+#define EVENT_REG_INIT_TEXT "epoll_create"
+
+#define EVENT_REG_FORK_HANDLE(er, n) do { \
+ (void) close(event_epollfd); \
+ EVENT_REG_INIT_HANDLE(er, (n)); \
+ } while (0)
+
+ /*
+ * Macros to update the kernel-based filter; see event_enable_read(),
+ * event_enable_write() and event_disable_readwrite().
+ */
+#define EVENT_REG_FD_OP(er, fh, ev, op) do { \
+ struct epoll_event dummy; \
+ dummy.events = (ev); \
+ dummy.data.fd = (fh); \
+ (er) = epoll_ctl(event_epollfd, (op), (fh), &dummy); \
+ } while (0)
+
+#define EVENT_REG_ADD_OP(e, f, ev) EVENT_REG_FD_OP((e), (f), (ev), EPOLL_CTL_ADD)
+#define EVENT_REG_ADD_READ(e, f) EVENT_REG_ADD_OP((e), (f), EPOLLIN)
+#define EVENT_REG_ADD_WRITE(e, f) EVENT_REG_ADD_OP((e), (f), EPOLLOUT)
+#define EVENT_REG_ADD_TEXT "epoll_ctl EPOLL_CTL_ADD"
+
+#define EVENT_REG_DEL_OP(e, f, ev) EVENT_REG_FD_OP((e), (f), (ev), EPOLL_CTL_DEL)
+#define EVENT_REG_DEL_READ(e, f) EVENT_REG_DEL_OP((e), (f), EPOLLIN)
+#define EVENT_REG_DEL_WRITE(e, f) EVENT_REG_DEL_OP((e), (f), EPOLLOUT)
+#define EVENT_REG_DEL_TEXT "epoll_ctl EPOLL_CTL_DEL"
+
+ /*
+ * Macros to retrieve event buffers from the kernel; see event_loop().
+ */
+typedef struct epoll_event EVENT_BUFFER;
+
+#define EVENT_BUFFER_READ(event_count, event_buf, buflen, delay) do { \
+ (event_count) = epoll_wait(event_epollfd, (event_buf), (buflen), \
+ (delay) < 0 ? -1 : (delay) * 1000); \
+ } while (0)
+#define EVENT_BUFFER_READ_TEXT "epoll_wait"
+
+ /*
+ * Macros to process event buffers from the kernel; see event_loop().
+ */
+#define EVENT_GET_FD(bp) ((bp)->data.fd)
+#define EVENT_GET_TYPE(bp) ((bp)->events)
+#define EVENT_TEST_READ(bp) (EVENT_GET_TYPE(bp) & EPOLLIN)
+#define EVENT_TEST_WRITE(bp) (EVENT_GET_TYPE(bp) & EPOLLOUT)
+
+#endif
+
+ /*
+ * Timer events. Timer requests are kept sorted, in a circular list. We use
+ * the RING abstraction, so we get to use a couple ugly macros.
+ *
+ * When a call-back function adds a timer request, we label the request with
+ * the event_loop() call instance that invoked the call-back. We use this to
+ * prevent zero-delay timer requests from running in a tight loop and
+ * starving I/O events.
+ */
+typedef struct EVENT_TIMER EVENT_TIMER;
+
+struct EVENT_TIMER {
+ time_t when; /* when event is wanted */
+ EVENT_NOTIFY_TIME_FN callback; /* callback function */
+ char *context; /* callback context */
+ long loop_instance; /* event_loop() call instance */
+ RING ring; /* linkage */
+};
+
+static RING event_timer_head; /* timer queue head */
+static long event_loop_instance; /* event_loop() call instance */
+
+#define RING_TO_TIMER(r) \
+ ((EVENT_TIMER *) ((void *) (r) - offsetof(EVENT_TIMER, ring)))
+
+#define FOREACH_QUEUE_ENTRY(entry, head) \
+ for (entry = ring_succ(head); entry != (head); entry = ring_succ(entry))
+
+#define FIRST_TIMER(head) \
+ (ring_succ(head) != (head) ? RING_TO_TIMER(ring_succ(head)) : 0)
+
+ /*
+ * Other private data structures.
+ */
+static time_t event_present; /* cached time of day */
+
+#define EVENT_INIT_NEEDED() (event_present == 0)
+
+/* event_init - set up tables and such */
+
+static void event_init(void)
+{
+ EVENT_FDTABLE *fdp;
+ int err;
+
+ if (!EVENT_INIT_NEEDED())
+ msg_panic("event_init: repeated call");
+
+ /*
+ * Initialize the file descriptor masks and the call-back table. Where
+ * possible we extend these data structures on the fly. With select(2)
+ * based implementations we can only handle FD_SETSIZE open files.
+ */
+#if (EVENTS_STYLE == EVENTS_STYLE_SELECT)
+ if ((event_fdlimit = open_limit(FD_SETSIZE)) < 0)
+ msg_fatal("unable to determine open file limit");
+#else
+ if ((event_fdlimit = open_limit(INT_MAX)) < 0)
+ msg_fatal("unable to determine open file limit");
+#endif
+ if (event_fdlimit < FD_SETSIZE / 2 && event_fdlimit < 256)
+ msg_warn("could allocate space for only %d open files", event_fdlimit);
+ event_fdslots = EVENT_ALLOC_INCR;
+ event_fdtable = (EVENT_FDTABLE *)
+ mymalloc(sizeof(EVENT_FDTABLE) * event_fdslots);
+ for (fdp = event_fdtable; fdp < event_fdtable + event_fdslots; fdp++) {
+ fdp->callback = 0;
+ fdp->context = 0;
+ }
+
+ /*
+ * Initialize the I/O event request masks.
+ */
+#if (EVENTS_STYLE == EVENTS_STYLE_SELECT)
+ EVENT_MASK_ZERO(&event_rmask);
+ EVENT_MASK_ZERO(&event_wmask);
+ EVENT_MASK_ZERO(&event_xmask);
+#else
+ EVENT_MASK_ALLOC(&event_rmask, event_fdslots);
+ EVENT_MASK_ALLOC(&event_wmask, event_fdslots);
+ EVENT_MASK_ALLOC(&event_xmask, event_fdslots);
+
+ /*
+ * Initialize the kernel-based filter.
+ */
+ EVENT_REG_INIT_HANDLE(err, event_fdslots);
+ if (err < 0)
+ msg_fatal("%s: %m", EVENT_REG_INIT_TEXT);
+#endif
+
+ /*
+ * Initialize timer stuff.
+ */
+ ring_init(&event_timer_head);
+ (void) time(&event_present);
+
+ /*
+ * Avoid an infinite initialization loop.
+ */
+ if (EVENT_INIT_NEEDED())
+ msg_panic("event_init: unable to initialize");
+}
+
+/* event_extend - make room for more descriptor slots */
+
+static void event_extend(int fd)
+{
+ const char *myname = "event_extend";
+ int old_slots = event_fdslots;
+ int new_slots = (event_fdslots > fd / 2 ?
+ 2 * old_slots : fd + EVENT_ALLOC_INCR);
+ EVENT_FDTABLE *fdp;
+
+#ifdef EVENT_REG_UPD_HANDLE
+ int err;
+
+#endif
+
+ if (msg_verbose > 2)
+ msg_info("%s: fd %d", myname, fd);
+ event_fdtable = (EVENT_FDTABLE *)
+ myrealloc((void *) event_fdtable, sizeof(EVENT_FDTABLE) * new_slots);
+ event_fdslots = new_slots;
+ for (fdp = event_fdtable + old_slots;
+ fdp < event_fdtable + new_slots; fdp++) {
+ fdp->callback = 0;
+ fdp->context = 0;
+ }
+
+ /*
+ * Initialize the I/O event request masks.
+ */
+#if (EVENTS_STYLE != EVENTS_STYLE_SELECT)
+ EVENT_MASK_REALLOC(&event_rmask, new_slots);
+ EVENT_MASK_REALLOC(&event_wmask, new_slots);
+ EVENT_MASK_REALLOC(&event_xmask, new_slots);
+#endif
+#ifdef EVENT_REG_UPD_HANDLE
+ EVENT_REG_UPD_HANDLE(err, new_slots);
+ if (err < 0)
+ msg_fatal("%s: %s: %m", myname, EVENT_REG_UPD_TEXT);
+#endif
+}
+
+/* event_time - look up cached time of day */
+
+time_t event_time(void)
+{
+ if (EVENT_INIT_NEEDED())
+ event_init();
+
+ return (event_present);
+}
+
+/* event_drain - loop until all pending events are done */
+
+void event_drain(int time_limit)
+{
+ EVENT_MASK zero_mask;
+ time_t max_time;
+
+ if (EVENT_INIT_NEEDED())
+ return;
+
+#if (EVENTS_STYLE == EVENTS_STYLE_SELECT)
+ EVENT_MASK_ZERO(&zero_mask);
+#else
+ EVENT_MASK_ALLOC(&zero_mask, event_fdslots);
+#endif
+ (void) time(&event_present);
+ max_time = event_present + time_limit;
+ while (event_present < max_time
+ && (event_timer_head.pred != &event_timer_head
+ || EVENT_MASK_CMP(&zero_mask, &event_xmask) != 0)) {
+ event_loop(1);
+#if (EVENTS_STYLE != EVENTS_STYLE_SELECT)
+ if (EVENT_MASK_BYTE_COUNT(&zero_mask)
+ != EVENT_MASK_BYTES_NEEDED(event_fdslots))
+ EVENT_MASK_REALLOC(&zero_mask, event_fdslots);
+#endif
+ }
+#if (EVENTS_STYLE != EVENTS_STYLE_SELECT)
+ EVENT_MASK_FREE(&zero_mask);
+#endif
+}
+
+/* event_fork - resume event processing after fork() */
+
+void event_fork(void)
+{
+#if (EVENTS_STYLE != EVENTS_STYLE_SELECT)
+ EVENT_FDTABLE *fdp;
+ int err;
+ int fd;
+
+ /*
+ * No event was ever registered, so there's nothing to be done.
+ */
+ if (EVENT_INIT_NEEDED())
+ return;
+
+ /*
+ * Close the existing filter handle and open a new kernel-based filter.
+ */
+ EVENT_REG_FORK_HANDLE(err, event_fdslots);
+ if (err < 0)
+ msg_fatal("%s: %m", EVENT_REG_INIT_TEXT);
+
+ /*
+ * Populate the new kernel-based filter with events that were registered
+ * in the parent process.
+ */
+ for (fd = 0; fd <= event_max_fd; fd++) {
+ if (EVENT_MASK_ISSET(fd, &event_wmask)) {
+ EVENT_MASK_CLR(fd, &event_wmask);
+ fdp = event_fdtable + fd;
+ event_enable_write(fd, fdp->callback, fdp->context);
+ } else if (EVENT_MASK_ISSET(fd, &event_rmask)) {
+ EVENT_MASK_CLR(fd, &event_rmask);
+ fdp = event_fdtable + fd;
+ event_enable_read(fd, fdp->callback, fdp->context);
+ }
+ }
+#endif
+}
+
+/* event_enable_read - enable read events */
+
+void event_enable_read(int fd, EVENT_NOTIFY_RDWR_FN callback, void *context)
+{
+ const char *myname = "event_enable_read";
+ EVENT_FDTABLE *fdp;
+ int err;
+
+ if (EVENT_INIT_NEEDED())
+ event_init();
+
+ /*
+ * Sanity checks.
+ */
+ if (fd < 0 || fd >= event_fdlimit)
+ msg_panic("%s: bad file descriptor: %d", myname, fd);
+
+ if (msg_verbose > 2)
+ msg_info("%s: fd %d", myname, fd);
+
+ if (fd >= event_fdslots)
+ event_extend(fd);
+
+ /*
+ * Disallow mixed (i.e. read and write) requests on the same descriptor.
+ */
+ if (EVENT_MASK_ISSET(fd, &event_wmask))
+ msg_panic("%s: fd %d: read/write I/O request", myname, fd);
+
+ /*
+ * Postfix 2.4 allows multiple event_enable_read() calls on the same
+ * descriptor without requiring event_disable_readwrite() calls between
+ * them. With kernel-based filters (kqueue, /dev/poll, epoll) it's
+ * wasteful to make system calls when we change only application
+ * call-back information. It has a noticeable effect on smtp-source
+ * performance.
+ */
+ if (EVENT_MASK_ISSET(fd, &event_rmask) == 0) {
+ EVENT_MASK_SET(fd, &event_xmask);
+ EVENT_MASK_SET(fd, &event_rmask);
+ if (event_max_fd < fd)
+ event_max_fd = fd;
+#if (EVENTS_STYLE != EVENTS_STYLE_SELECT)
+ EVENT_REG_ADD_READ(err, fd);
+ if (err < 0)
+ msg_fatal("%s: %s: %m", myname, EVENT_REG_ADD_TEXT);
+#endif
+ }
+ fdp = event_fdtable + fd;
+ if (fdp->callback != callback || fdp->context != context) {
+ fdp->callback = callback;
+ fdp->context = context;
+ }
+}
+
+/* event_enable_write - enable write events */
+
+void event_enable_write(int fd, EVENT_NOTIFY_RDWR_FN callback, void *context)
+{
+ const char *myname = "event_enable_write";
+ EVENT_FDTABLE *fdp;
+ int err;
+
+ if (EVENT_INIT_NEEDED())
+ event_init();
+
+ /*
+ * Sanity checks.
+ */
+ if (fd < 0 || fd >= event_fdlimit)
+ msg_panic("%s: bad file descriptor: %d", myname, fd);
+
+ if (msg_verbose > 2)
+ msg_info("%s: fd %d", myname, fd);
+
+ if (fd >= event_fdslots)
+ event_extend(fd);
+
+ /*
+ * Disallow mixed (i.e. read and write) requests on the same descriptor.
+ */
+ if (EVENT_MASK_ISSET(fd, &event_rmask))
+ msg_panic("%s: fd %d: read/write I/O request", myname, fd);
+
+ /*
+ * Postfix 2.4 allows multiple event_enable_write() calls on the same
+ * descriptor without requiring event_disable_readwrite() calls between
+ * them. With kernel-based filters (kqueue, /dev/poll, epoll) it's
+ * incredibly wasteful to make unregister and register system calls when
+ * we change only application call-back information. It has a noticeable
+ * effect on smtp-source performance.
+ */
+ if (EVENT_MASK_ISSET(fd, &event_wmask) == 0) {
+ EVENT_MASK_SET(fd, &event_xmask);
+ EVENT_MASK_SET(fd, &event_wmask);
+ if (event_max_fd < fd)
+ event_max_fd = fd;
+#if (EVENTS_STYLE != EVENTS_STYLE_SELECT)
+ EVENT_REG_ADD_WRITE(err, fd);
+ if (err < 0)
+ msg_fatal("%s: %s: %m", myname, EVENT_REG_ADD_TEXT);
+#endif
+ }
+ fdp = event_fdtable + fd;
+ if (fdp->callback != callback || fdp->context != context) {
+ fdp->callback = callback;
+ fdp->context = context;
+ }
+}
+
+/* event_disable_readwrite - disable request for read or write events */
+
+void event_disable_readwrite(int fd)
+{
+ const char *myname = "event_disable_readwrite";
+ EVENT_FDTABLE *fdp;
+ int err;
+
+ if (EVENT_INIT_NEEDED())
+ event_init();
+
+ /*
+ * Sanity checks.
+ */
+ if (fd < 0 || fd >= event_fdlimit)
+ msg_panic("%s: bad file descriptor: %d", myname, fd);
+
+ if (msg_verbose > 2)
+ msg_info("%s: fd %d", myname, fd);
+
+ /*
+ * Don't complain when there is nothing to cancel. The request may have
+ * been canceled from another thread.
+ */
+ if (fd >= event_fdslots)
+ return;
+#if (EVENTS_STYLE != EVENTS_STYLE_SELECT)
+#ifdef EVENT_REG_DEL_BOTH
+ /* XXX Can't seem to disable READ and WRITE events selectively. */
+ if (EVENT_MASK_ISSET(fd, &event_rmask)
+ || EVENT_MASK_ISSET(fd, &event_wmask)) {
+ EVENT_REG_DEL_BOTH(err, fd);
+ if (err < 0)
+ msg_fatal("%s: %s: %m", myname, EVENT_REG_DEL_TEXT);
+ }
+#else
+ if (EVENT_MASK_ISSET(fd, &event_rmask)) {
+ EVENT_REG_DEL_READ(err, fd);
+ if (err < 0)
+ msg_fatal("%s: %s: %m", myname, EVENT_REG_DEL_TEXT);
+ } else if (EVENT_MASK_ISSET(fd, &event_wmask)) {
+ EVENT_REG_DEL_WRITE(err, fd);
+ if (err < 0)
+ msg_fatal("%s: %s: %m", myname, EVENT_REG_DEL_TEXT);
+ }
+#endif /* EVENT_REG_DEL_BOTH */
+#endif /* != EVENTS_STYLE_SELECT */
+ EVENT_MASK_CLR(fd, &event_xmask);
+ EVENT_MASK_CLR(fd, &event_rmask);
+ EVENT_MASK_CLR(fd, &event_wmask);
+ fdp = event_fdtable + fd;
+ fdp->callback = 0;
+ fdp->context = 0;
+}
+
+/* event_request_timer - (re)set timer */
+
+time_t event_request_timer(EVENT_NOTIFY_TIME_FN callback, void *context, int delay)
+{
+ const char *myname = "event_request_timer";
+ RING *ring;
+ EVENT_TIMER *timer;
+
+ if (EVENT_INIT_NEEDED())
+ event_init();
+
+ /*
+ * Sanity checks.
+ */
+ if (delay < 0)
+ msg_panic("%s: invalid delay: %d", myname, delay);
+
+ /*
+ * Make sure we schedule this event at the right time.
+ */
+ time(&event_present);
+
+ /*
+ * See if they are resetting an existing timer request. If so, take the
+ * request away from the timer queue so that it can be inserted at the
+ * right place.
+ */
+ FOREACH_QUEUE_ENTRY(ring, &event_timer_head) {
+ timer = RING_TO_TIMER(ring);
+ if (timer->callback == callback && timer->context == context) {
+ timer->when = event_present + delay;
+ timer->loop_instance = event_loop_instance;
+ ring_detach(ring);
+ if (msg_verbose > 2)
+ msg_info("%s: reset 0x%lx 0x%lx %d", myname,
+ (long) callback, (long) context, delay);
+ break;
+ }
+ }
+
+ /*
+ * If not found, schedule a new timer request.
+ */
+ if (ring == &event_timer_head) {
+ timer = (EVENT_TIMER *) mymalloc(sizeof(EVENT_TIMER));
+ timer->when = event_present + delay;
+ timer->callback = callback;
+ timer->context = context;
+ timer->loop_instance = event_loop_instance;
+ if (msg_verbose > 2)
+ msg_info("%s: set 0x%lx 0x%lx %d", myname,
+ (long) callback, (long) context, delay);
+ }
+
+ /*
+ * Timer requests are kept sorted to reduce lookup overhead in the event
+ * loop.
+ *
+ * XXX Append the new request after existing requests for the same time
+ * slot. The event_loop() routine depends on this to avoid starving I/O
+ * events when a call-back function schedules a zero-delay timer request.
+ */
+ FOREACH_QUEUE_ENTRY(ring, &event_timer_head) {
+ if (timer->when < RING_TO_TIMER(ring)->when)
+ break;
+ }
+ ring_prepend(ring, &timer->ring);
+
+ return (timer->when);
+}
+
+/* event_cancel_timer - cancel timer */
+
+int event_cancel_timer(EVENT_NOTIFY_TIME_FN callback, void *context)
+{
+ const char *myname = "event_cancel_timer";
+ RING *ring;
+ EVENT_TIMER *timer;
+ int time_left = -1;
+
+ if (EVENT_INIT_NEEDED())
+ event_init();
+
+ /*
+ * See if they are canceling an existing timer request. Do not complain
+ * when the request is not found. It might have been canceled from some
+ * other thread.
+ */
+ FOREACH_QUEUE_ENTRY(ring, &event_timer_head) {
+ timer = RING_TO_TIMER(ring);
+ if (timer->callback == callback && timer->context == context) {
+ if ((time_left = timer->when - event_present) < 0)
+ time_left = 0;
+ ring_detach(ring);
+ myfree((void *) timer);
+ break;
+ }
+ }
+ if (msg_verbose > 2)
+ msg_info("%s: 0x%lx 0x%lx %d", myname,
+ (long) callback, (long) context, time_left);
+ return (time_left);
+}
+
+/* event_loop - wait for the next event */
+
+void event_loop(int delay)
+{
+ const char *myname = "event_loop";
+ static int nested;
+
+#if (EVENTS_STYLE == EVENTS_STYLE_SELECT)
+ fd_set rmask;
+ fd_set wmask;
+ fd_set xmask;
+ struct timeval tv;
+ struct timeval *tvp;
+ int new_max_fd;
+
+#else
+ EVENT_BUFFER event_buf[100];
+ EVENT_BUFFER *bp;
+
+#endif
+ int event_count;
+ EVENT_TIMER *timer;
+ int fd;
+ EVENT_FDTABLE *fdp;
+ int select_delay;
+
+ if (EVENT_INIT_NEEDED())
+ event_init();
+
+ /*
+ * XXX Also print the select() masks?
+ */
+ if (msg_verbose > 2) {
+ RING *ring;
+
+ FOREACH_QUEUE_ENTRY(ring, &event_timer_head) {
+ timer = RING_TO_TIMER(ring);
+ msg_info("%s: time left %3d for 0x%lx 0x%lx", myname,
+ (int) (timer->when - event_present),
+ (long) timer->callback, (long) timer->context);
+ }
+ }
+
+ /*
+ * Find out when the next timer would go off. Timer requests are sorted.
+ * If any timer is scheduled, adjust the delay appropriately.
+ */
+ if ((timer = FIRST_TIMER(&event_timer_head)) != 0) {
+ event_present = time((time_t *) 0);
+ if ((select_delay = timer->when - event_present) < 0) {
+ select_delay = 0;
+ } else if (delay >= 0 && select_delay > delay) {
+ select_delay = delay;
+ }
+ } else {
+ select_delay = delay;
+ }
+ if (msg_verbose > 2)
+ msg_info("event_loop: select_delay %d", select_delay);
+
+ /*
+ * Negative delay means: wait until something happens. Zero delay means:
+ * poll. Positive delay means: wait at most this long.
+ */
+#if (EVENTS_STYLE == EVENTS_STYLE_SELECT)
+ if (select_delay < 0) {
+ tvp = 0;
+ } else {
+ tvp = &tv;
+ tv.tv_usec = 0;
+ tv.tv_sec = select_delay;
+ }
+
+ /*
+ * Pause until the next event happens. When select() has a problem, don't
+ * go into a tight loop. Allow select() to be interrupted due to the
+ * arrival of a signal.
+ */
+ rmask = event_rmask;
+ wmask = event_wmask;
+ xmask = event_xmask;
+
+ event_count = select(event_max_fd + 1, &rmask, &wmask, &xmask, tvp);
+ if (event_count < 0) {
+ if (errno != EINTR)
+ msg_fatal("event_loop: select: %m");
+ return;
+ }
+#else
+ EVENT_BUFFER_READ(event_count, event_buf,
+ sizeof(event_buf) / sizeof(event_buf[0]),
+ select_delay);
+ if (event_count < 0) {
+ if (errno != EINTR)
+ msg_fatal("event_loop: " EVENT_BUFFER_READ_TEXT ": %m");
+ return;
+ }
+#endif
+
+ /*
+ * Before entering the application call-back routines, make sure we
+ * aren't being called from a call-back routine. Doing so would make us
+ * vulnerable to all kinds of race conditions.
+ */
+ if (nested++ > 0)
+ msg_panic("event_loop: recursive call");
+
+ /*
+ * Deliver timer events. Allow the application to add/delete timer queue
+ * requests while it is being called back. Requests are sorted: we keep
+ * running over the timer request queue from the start, and stop when we
+ * reach the future or the list end. We also stop when we reach a timer
+ * request that was added by a call-back that was invoked from this
+ * event_loop() call instance, for reasons that are explained below.
+ *
+ * To avoid dangling pointer problems 1) we must remove a request from the
+ * timer queue before delivering its event to the application and 2) we
+ * must look up the next timer request *after* calling the application.
+ * The latter complicates the handling of zero-delay timer requests that
+ * are added by event_loop() call-back functions.
+ *
+ * XXX When a timer event call-back function adds a new timer request,
+ * event_request_timer() labels the request with the event_loop() call
+ * instance that invoked the timer event call-back. We use this instance
+ * label here to prevent zero-delay timer requests from running in a
+ * tight loop and starving I/O events. To make this solution work,
+ * event_request_timer() appends a new request after existing requests
+ * for the same time slot.
+ */
+ event_present = time((time_t *) 0);
+ event_loop_instance += 1;
+
+ while ((timer = FIRST_TIMER(&event_timer_head)) != 0) {
+ if (timer->when > event_present)
+ break;
+ if (timer->loop_instance == event_loop_instance)
+ break;
+ ring_detach(&timer->ring); /* first this */
+ if (msg_verbose > 2)
+ msg_info("%s: timer 0x%lx 0x%lx", myname,
+ (long) timer->callback, (long) timer->context);
+ timer->callback(EVENT_TIME, timer->context); /* then this */
+ myfree((void *) timer);
+ }
+
+ /*
+ * Deliver I/O events. Allow the application to cancel event requests
+ * while it is being called back. To this end, we keep an eye on the
+ * contents of event_xmask, so that we deliver only events that are still
+ * wanted. We do not change the event request masks. It is up to the
+ * application to determine when a read or write is complete.
+ */
+#if (EVENTS_STYLE == EVENTS_STYLE_SELECT)
+ if (event_count > 0) {
+ for (new_max_fd = 0, fd = 0; fd <= event_max_fd; fd++) {
+ if (FD_ISSET(fd, &event_xmask)) {
+ new_max_fd = fd;
+ /* In case event_fdtable is updated. */
+ fdp = event_fdtable + fd;
+ if (FD_ISSET(fd, &xmask)) {
+ if (msg_verbose > 2)
+ msg_info("%s: exception fd=%d act=0x%lx 0x%lx", myname,
+ fd, (long) fdp->callback, (long) fdp->context);
+ fdp->callback(EVENT_XCPT, fdp->context);
+ } else if (FD_ISSET(fd, &wmask)) {
+ if (msg_verbose > 2)
+ msg_info("%s: write fd=%d act=0x%lx 0x%lx", myname,
+ fd, (long) fdp->callback, (long) fdp->context);
+ fdp->callback(EVENT_WRITE, fdp->context);
+ } else if (FD_ISSET(fd, &rmask)) {
+ if (msg_verbose > 2)
+ msg_info("%s: read fd=%d act=0x%lx 0x%lx", myname,
+ fd, (long) fdp->callback, (long) fdp->context);
+ fdp->callback(EVENT_READ, fdp->context);
+ }
+ }
+ }
+ event_max_fd = new_max_fd;
+ }
+#else
+ for (bp = event_buf; bp < event_buf + event_count; bp++) {
+ fd = EVENT_GET_FD(bp);
+ if (fd < 0 || fd > event_max_fd)
+ msg_panic("%s: bad file descriptor: %d", myname, fd);
+ if (EVENT_MASK_ISSET(fd, &event_xmask)) {
+ fdp = event_fdtable + fd;
+ if (EVENT_TEST_READ(bp)) {
+ if (msg_verbose > 2)
+ msg_info("%s: read fd=%d act=0x%lx 0x%lx", myname,
+ fd, (long) fdp->callback, (long) fdp->context);
+ fdp->callback(EVENT_READ, fdp->context);
+ } else if (EVENT_TEST_WRITE(bp)) {
+ if (msg_verbose > 2)
+ msg_info("%s: write fd=%d act=0x%lx 0x%lx", myname,
+ fd, (long) fdp->callback,
+ (long) fdp->context);
+ fdp->callback(EVENT_WRITE, fdp->context);
+ } else {
+ if (msg_verbose > 2)
+ msg_info("%s: other fd=%d act=0x%lx 0x%lx", myname,
+ fd, (long) fdp->callback, (long) fdp->context);
+ fdp->callback(EVENT_XCPT, fdp->context);
+ }
+ }
+ }
+#endif
+ nested--;
+}
+
+#ifdef TEST
+
+ /*
+ * Proof-of-concept test program for the event manager. Schedule a series of
+ * events at one-second intervals and let them happen, while echoing any
+ * lines read from stdin.
+ */
+#include <stdio.h>
+#include <ctype.h>
+#include <stdlib.h>
+
+/* timer_event - display event */
+
+static void timer_event(int unused_event, void *context)
+{
+ printf("%ld: %s\n", (long) event_present, context);
+ fflush(stdout);
+}
+
+/* echo - echo text received on stdin */
+
+static void echo(int unused_event, void *unused_context)
+{
+ char buf[BUFSIZ];
+
+ if (fgets(buf, sizeof(buf), stdin) == 0)
+ exit(0);
+ printf("Result: %s", buf);
+}
+
+/* request - request a bunch of timer events */
+
+static void request(int unused_event, void *unused_context)
+{
+ event_request_timer(timer_event, "3 first", 3);
+ event_request_timer(timer_event, "3 second", 3);
+ event_request_timer(timer_event, "4 first", 4);
+ event_request_timer(timer_event, "4 second", 4);
+ event_request_timer(timer_event, "2 first", 2);
+ event_request_timer(timer_event, "2 second", 2);
+ event_request_timer(timer_event, "1 first", 1);
+ event_request_timer(timer_event, "1 second", 1);
+ event_request_timer(timer_event, "0 first", 0);
+ event_request_timer(timer_event, "0 second", 0);
+}
+
+int main(int argc, void **argv)
+{
+ if (argv[1])
+ msg_verbose = atoi(argv[1]);
+ event_request_timer(request, (void *) 0, 0);
+ event_enable_read(fileno(stdin), echo, (void *) 0);
+ event_drain(10);
+ exit(0);
+}
+
+#endif