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+/*
+ * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
+ * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef EVENT_INTERNAL_H_INCLUDED_
+#define EVENT_INTERNAL_H_INCLUDED_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "event2/event-config.h"
+#include "evconfig-private.h"
+
+#include <time.h>
+#include <sys/queue.h>
+#include "event2/event_struct.h"
+#include "minheap-internal.h"
+#include "evsignal-internal.h"
+#include "mm-internal.h"
+#include "defer-internal.h"
+
+/* map union members back */
+
+/* mutually exclusive */
+#define ev_signal_next ev_.ev_signal.ev_signal_next
+#define ev_io_next ev_.ev_io.ev_io_next
+#define ev_io_timeout ev_.ev_io.ev_timeout
+
+/* used only by signals */
+#define ev_ncalls ev_.ev_signal.ev_ncalls
+#define ev_pncalls ev_.ev_signal.ev_pncalls
+
+#define ev_pri ev_evcallback.evcb_pri
+#define ev_flags ev_evcallback.evcb_flags
+#define ev_closure ev_evcallback.evcb_closure
+#define ev_callback ev_evcallback.evcb_cb_union.evcb_callback
+#define ev_arg ev_evcallback.evcb_arg
+
+/** @name Event closure codes
+
+ Possible values for evcb_closure in struct event_callback
+
+ @{
+ */
+/** A regular event. Uses the evcb_callback callback */
+#define EV_CLOSURE_EVENT 0
+/** A signal event. Uses the evcb_callback callback */
+#define EV_CLOSURE_EVENT_SIGNAL 1
+/** A persistent non-signal event. Uses the evcb_callback callback */
+#define EV_CLOSURE_EVENT_PERSIST 2
+/** A simple callback. Uses the evcb_selfcb callback. */
+#define EV_CLOSURE_CB_SELF 3
+/** A finalizing callback. Uses the evcb_cbfinalize callback. */
+#define EV_CLOSURE_CB_FINALIZE 4
+/** A finalizing event. Uses the evcb_evfinalize callback. */
+#define EV_CLOSURE_EVENT_FINALIZE 5
+/** A finalizing event that should get freed after. Uses the evcb_evfinalize
+ * callback. */
+#define EV_CLOSURE_EVENT_FINALIZE_FREE 6
+/** @} */
+
+/** Structure to define the backend of a given event_base. */
+struct eventop {
+ /** The name of this backend. */
+ const char *name;
+ /** Function to set up an event_base to use this backend. It should
+ * create a new structure holding whatever information is needed to
+ * run the backend, and return it. The returned pointer will get
+ * stored by event_init into the event_base.evbase field. On failure,
+ * this function should return NULL. */
+ void *(*init)(struct event_base *);
+ /** Enable reading/writing on a given fd or signal. 'events' will be
+ * the events that we're trying to enable: one or more of EV_READ,
+ * EV_WRITE, EV_SIGNAL, and EV_ET. 'old' will be those events that
+ * were enabled on this fd previously. 'fdinfo' will be a structure
+ * associated with the fd by the evmap; its size is defined by the
+ * fdinfo field below. It will be set to 0 the first time the fd is
+ * added. The function should return 0 on success and -1 on error.
+ */
+ int (*add)(struct event_base *, evutil_socket_t fd, short old, short events, void *fdinfo);
+ /** As "add", except 'events' contains the events we mean to disable. */
+ int (*del)(struct event_base *, evutil_socket_t fd, short old, short events, void *fdinfo);
+ /** Function to implement the core of an event loop. It must see which
+ added events are ready, and cause event_active to be called for each
+ active event (usually via event_io_active or such). It should
+ return 0 on success and -1 on error.
+ */
+ int (*dispatch)(struct event_base *, struct timeval *);
+ /** Function to clean up and free our data from the event_base. */
+ void (*dealloc)(struct event_base *);
+ /** Flag: set if we need to reinitialize the event base after we fork.
+ */
+ int need_reinit;
+ /** Bit-array of supported event_method_features that this backend can
+ * provide. */
+ enum event_method_feature features;
+ /** Length of the extra information we should record for each fd that
+ has one or more active events. This information is recorded
+ as part of the evmap entry for each fd, and passed as an argument
+ to the add and del functions above.
+ */
+ size_t fdinfo_len;
+};
+
+#ifdef _WIN32
+/* If we're on win32, then file descriptors are not nice low densely packed
+ integers. Instead, they are pointer-like windows handles, and we want to
+ use a hashtable instead of an array to map fds to events.
+*/
+#define EVMAP_USE_HT
+#endif
+
+/* #define HT_CACHE_HASH_VALS */
+
+#ifdef EVMAP_USE_HT
+#define HT_NO_CACHE_HASH_VALUES
+#include "ht-internal.h"
+struct event_map_entry;
+HT_HEAD(event_io_map, event_map_entry);
+#else
+#define event_io_map event_signal_map
+#endif
+
+/* Used to map signal numbers to a list of events. If EVMAP_USE_HT is not
+ defined, this structure is also used as event_io_map, which maps fds to a
+ list of events.
+*/
+struct event_signal_map {
+ /* An array of evmap_io * or of evmap_signal *; empty entries are
+ * set to NULL. */
+ void **entries;
+ /* The number of entries available in entries */
+ int nentries;
+};
+
+/* A list of events waiting on a given 'common' timeout value. Ordinarily,
+ * events waiting for a timeout wait on a minheap. Sometimes, however, a
+ * queue can be faster.
+ **/
+struct common_timeout_list {
+ /* List of events currently waiting in the queue. */
+ struct event_list events;
+ /* 'magic' timeval used to indicate the duration of events in this
+ * queue. */
+ struct timeval duration;
+ /* Event that triggers whenever one of the events in the queue is
+ * ready to activate */
+ struct event timeout_event;
+ /* The event_base that this timeout list is part of */
+ struct event_base *base;
+};
+
+/** Mask used to get the real tv_usec value from a common timeout. */
+#define COMMON_TIMEOUT_MICROSECONDS_MASK 0x000fffff
+
+struct event_change;
+
+/* List of 'changes' since the last call to eventop.dispatch. Only maintained
+ * if the backend is using changesets. */
+struct event_changelist {
+ struct event_change *changes;
+ int n_changes;
+ int changes_size;
+};
+
+#ifndef EVENT__DISABLE_DEBUG_MODE
+/* Global internal flag: set to one if debug mode is on. */
+extern int event_debug_mode_on_;
+#define EVENT_DEBUG_MODE_IS_ON() (event_debug_mode_on_)
+#else
+#define EVENT_DEBUG_MODE_IS_ON() (0)
+#endif
+
+TAILQ_HEAD(evcallback_list, event_callback);
+
+/* Sets up an event for processing once */
+struct event_once {
+ LIST_ENTRY(event_once) next_once;
+ struct event ev;
+
+ void (*cb)(evutil_socket_t, short, void *);
+ void *arg;
+};
+
+struct event_base {
+ /** Function pointers and other data to describe this event_base's
+ * backend. */
+ const struct eventop *evsel;
+ /** Pointer to backend-specific data. */
+ void *evbase;
+
+ /** List of changes to tell backend about at next dispatch. Only used
+ * by the O(1) backends. */
+ struct event_changelist changelist;
+
+ /** Function pointers used to describe the backend that this event_base
+ * uses for signals */
+ const struct eventop *evsigsel;
+ /** Data to implement the common signal handler code. */
+ struct evsig_info sig;
+
+ /** Number of virtual events */
+ int virtual_event_count;
+ /** Maximum number of virtual events active */
+ int virtual_event_count_max;
+ /** Number of total events added to this event_base */
+ int event_count;
+ /** Maximum number of total events added to this event_base */
+ int event_count_max;
+ /** Number of total events active in this event_base */
+ int event_count_active;
+ /** Maximum number of total events active in this event_base */
+ int event_count_active_max;
+
+ /** Set if we should terminate the loop once we're done processing
+ * events. */
+ int event_gotterm;
+ /** Set if we should terminate the loop immediately */
+ int event_break;
+ /** Set if we should start a new instance of the loop immediately. */
+ int event_continue;
+
+ /** The currently running priority of events */
+ int event_running_priority;
+
+ /** Set if we're running the event_base_loop function, to prevent
+ * reentrant invocation. */
+ int running_loop;
+
+ /** Set to the number of deferred_cbs we've made 'active' in the
+ * loop. This is a hack to prevent starvation; it would be smarter
+ * to just use event_config_set_max_dispatch_interval's max_callbacks
+ * feature */
+ int n_deferreds_queued;
+
+ /* Active event management. */
+ /** An array of nactivequeues queues for active event_callbacks (ones
+ * that have triggered, and whose callbacks need to be called). Low
+ * priority numbers are more important, and stall higher ones.
+ */
+ struct evcallback_list *activequeues;
+ /** The length of the activequeues array */
+ int nactivequeues;
+ /** A list of event_callbacks that should become active the next time
+ * we process events, but not this time. */
+ struct evcallback_list active_later_queue;
+
+ /* common timeout logic */
+
+ /** An array of common_timeout_list* for all of the common timeout
+ * values we know. */
+ struct common_timeout_list **common_timeout_queues;
+ /** The number of entries used in common_timeout_queues */
+ int n_common_timeouts;
+ /** The total size of common_timeout_queues. */
+ int n_common_timeouts_allocated;
+
+ /** Mapping from file descriptors to enabled (added) events */
+ struct event_io_map io;
+
+ /** Mapping from signal numbers to enabled (added) events. */
+ struct event_signal_map sigmap;
+
+ /** Priority queue of events with timeouts. */
+ struct min_heap timeheap;
+
+ /** Stored timeval: used to avoid calling gettimeofday/clock_gettime
+ * too often. */
+ struct timeval tv_cache;
+
+ struct evutil_monotonic_timer monotonic_timer;
+
+ /** Difference between internal time (maybe from clock_gettime) and
+ * gettimeofday. */
+ struct timeval tv_clock_diff;
+ /** Second in which we last updated tv_clock_diff, in monotonic time. */
+ time_t last_updated_clock_diff;
+
+#ifndef EVENT__DISABLE_THREAD_SUPPORT
+ /* threading support */
+ /** The thread currently running the event_loop for this base */
+ unsigned long th_owner_id;
+ /** A lock to prevent conflicting accesses to this event_base */
+ void *th_base_lock;
+ /** A condition that gets signalled when we're done processing an
+ * event with waiters on it. */
+ void *current_event_cond;
+ /** Number of threads blocking on current_event_cond. */
+ int current_event_waiters;
+#endif
+ /** The event whose callback is executing right now */
+ struct event_callback *current_event;
+
+#ifdef _WIN32
+ /** IOCP support structure, if IOCP is enabled. */
+ struct event_iocp_port *iocp;
+#endif
+
+ /** Flags that this base was configured with */
+ enum event_base_config_flag flags;
+
+ struct timeval max_dispatch_time;
+ int max_dispatch_callbacks;
+ int limit_callbacks_after_prio;
+
+ /* Notify main thread to wake up break, etc. */
+ /** True if the base already has a pending notify, and we don't need
+ * to add any more. */
+ int is_notify_pending;
+ /** A socketpair used by some th_notify functions to wake up the main
+ * thread. */
+ evutil_socket_t th_notify_fd[2];
+ /** An event used by some th_notify functions to wake up the main
+ * thread. */
+ struct event th_notify;
+ /** A function used to wake up the main thread from another thread. */
+ int (*th_notify_fn)(struct event_base *base);
+
+ /** Saved seed for weak random number generator. Some backends use
+ * this to produce fairness among sockets. Protected by th_base_lock. */
+ struct evutil_weakrand_state weakrand_seed;
+
+ /** List of event_onces that have not yet fired. */
+ LIST_HEAD(once_event_list, event_once) once_events;
+
+};
+
+struct event_config_entry {
+ TAILQ_ENTRY(event_config_entry) next;
+
+ const char *avoid_method;
+};
+
+/** Internal structure: describes the configuration we want for an event_base
+ * that we're about to allocate. */
+struct event_config {
+ TAILQ_HEAD(event_configq, event_config_entry) entries;
+
+ int n_cpus_hint;
+ struct timeval max_dispatch_interval;
+ int max_dispatch_callbacks;
+ int limit_callbacks_after_prio;
+ enum event_method_feature require_features;
+ enum event_base_config_flag flags;
+};
+
+/* Internal use only: Functions that might be missing from <sys/queue.h> */
+#ifndef LIST_END
+#define LIST_END(head) NULL
+#endif
+
+#ifndef TAILQ_FIRST
+#define TAILQ_FIRST(head) ((head)->tqh_first)
+#endif
+#ifndef TAILQ_END
+#define TAILQ_END(head) NULL
+#endif
+#ifndef TAILQ_NEXT
+#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
+#endif
+
+#ifndef TAILQ_FOREACH
+#define TAILQ_FOREACH(var, head, field) \
+ for ((var) = TAILQ_FIRST(head); \
+ (var) != TAILQ_END(head); \
+ (var) = TAILQ_NEXT(var, field))
+#endif
+
+#ifndef TAILQ_INSERT_BEFORE
+#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
+ (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
+ (elm)->field.tqe_next = (listelm); \
+ *(listelm)->field.tqe_prev = (elm); \
+ (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \
+} while (0)
+#endif
+
+#define N_ACTIVE_CALLBACKS(base) \
+ ((base)->event_count_active)
+
+int evsig_set_handler_(struct event_base *base, int evsignal,
+ void (*fn)(int));
+int evsig_restore_handler_(struct event_base *base, int evsignal);
+
+int event_add_nolock_(struct event *ev,
+ const struct timeval *tv, int tv_is_absolute);
+/** Argument for event_del_nolock_. Tells event_del not to block on the event
+ * if it's running in another thread. */
+#define EVENT_DEL_NOBLOCK 0
+/** Argument for event_del_nolock_. Tells event_del to block on the event
+ * if it's running in another thread, regardless of its value for EV_FINALIZE
+ */
+#define EVENT_DEL_BLOCK 1
+/** Argument for event_del_nolock_. Tells event_del to block on the event
+ * if it is running in another thread and it doesn't have EV_FINALIZE set.
+ */
+#define EVENT_DEL_AUTOBLOCK 2
+/** Argument for event_del_nolock_. Tells event_del to proceed even if the
+ * event is set up for finalization rather for regular use.*/
+#define EVENT_DEL_EVEN_IF_FINALIZING 3
+int event_del_nolock_(struct event *ev, int blocking);
+int event_remove_timer_nolock_(struct event *ev);
+
+void event_active_nolock_(struct event *ev, int res, short count);
+EVENT2_EXPORT_SYMBOL
+int event_callback_activate_(struct event_base *, struct event_callback *);
+int event_callback_activate_nolock_(struct event_base *, struct event_callback *);
+int event_callback_cancel_(struct event_base *base,
+ struct event_callback *evcb);
+
+void event_callback_finalize_nolock_(struct event_base *base, unsigned flags, struct event_callback *evcb, void (*cb)(struct event_callback *, void *));
+EVENT2_EXPORT_SYMBOL
+void event_callback_finalize_(struct event_base *base, unsigned flags, struct event_callback *evcb, void (*cb)(struct event_callback *, void *));
+int event_callback_finalize_many_(struct event_base *base, int n_cbs, struct event_callback **evcb, void (*cb)(struct event_callback *, void *));
+
+
+EVENT2_EXPORT_SYMBOL
+void event_active_later_(struct event *ev, int res);
+void event_active_later_nolock_(struct event *ev, int res);
+int event_callback_activate_later_nolock_(struct event_base *base,
+ struct event_callback *evcb);
+int event_callback_cancel_nolock_(struct event_base *base,
+ struct event_callback *evcb, int even_if_finalizing);
+void event_callback_init_(struct event_base *base,
+ struct event_callback *cb);
+
+/* FIXME document. */
+EVENT2_EXPORT_SYMBOL
+void event_base_add_virtual_(struct event_base *base);
+void event_base_del_virtual_(struct event_base *base);
+
+/** For debugging: unless assertions are disabled, verify the referential
+ integrity of the internal data structures of 'base'. This operation can
+ be expensive.
+
+ Returns on success; aborts on failure.
+*/
+EVENT2_EXPORT_SYMBOL
+void event_base_assert_ok_(struct event_base *base);
+void event_base_assert_ok_nolock_(struct event_base *base);
+
+
+/* Helper function: Call 'fn' exactly once every inserted or active event in
+ * the event_base 'base'.
+ *
+ * If fn returns 0, continue on to the next event. Otherwise, return the same
+ * value that fn returned.
+ *
+ * Requires that 'base' be locked.
+ */
+int event_base_foreach_event_nolock_(struct event_base *base,
+ event_base_foreach_event_cb cb, void *arg);
+
+/* Cleanup function to reset debug mode during shutdown.
+ *
+ * Calling this function doesn't mean it'll be possible to re-enable
+ * debug mode if any events were added.
+ */
+void event_disable_debug_mode(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* EVENT_INTERNAL_H_INCLUDED_ */