The Tor Browser: ipc/chromium/src/third_party/libevent/bufferevent.c@6474c204b198 (annotated)

ipc/chromium/src/third_party/libevent/bufferevent.c@6474c204b198 (annotated)

ipc/chromium/src/third_party/libevent/bufferevent.c

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /*
  * Copyright (c) 2002-2007 Niels Provos <provos@citi.umich.edu>
  * Copyright (c) 2007-2012 Niels Provos, 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.
  */
 #include <sys/types.h>
 #include "event2/event-config.h"
 #ifdef _EVENT_HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #ifdef _EVENT_HAVE_STDARG_H
 #include <stdarg.h>
 #endif
 #ifdef WIN32
 #include <winsock2.h>
 #endif
 #include <errno.h>
 #include "event2/util.h"
 #include "event2/buffer.h"
 #include "event2/buffer_compat.h"
 #include "event2/bufferevent.h"
 #include "event2/bufferevent_struct.h"
 #include "event2/bufferevent_compat.h"
 #include "event2/event.h"
 #include "log-internal.h"
 #include "mm-internal.h"
 #include "bufferevent-internal.h"
 #include "evbuffer-internal.h"
 #include "util-internal.h"
 static void _bufferevent_cancel_all(struct bufferevent *bev);
 void
 bufferevent_suspend_read(struct bufferevent *bufev, bufferevent_suspend_flags what)
 {
 	struct bufferevent_private *bufev_private =
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	BEV_LOCK(bufev);
 	if (!bufev_private->read_suspended)
 		bufev->be_ops->disable(bufev, EV_READ);
 	bufev_private->read_suspended |= what;
 	BEV_UNLOCK(bufev);
 }
 void
 bufferevent_unsuspend_read(struct bufferevent *bufev, bufferevent_suspend_flags what)
 {
 	struct bufferevent_private *bufev_private =
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	BEV_LOCK(bufev);
 	bufev_private->read_suspended &= ~what;
 	if (!bufev_private->read_suspended && (bufev->enabled & EV_READ))
 		bufev->be_ops->enable(bufev, EV_READ);
 	BEV_UNLOCK(bufev);
 }
 void
 bufferevent_suspend_write(struct bufferevent *bufev, bufferevent_suspend_flags what)
 {
 	struct bufferevent_private *bufev_private =
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	BEV_LOCK(bufev);
 	if (!bufev_private->write_suspended)
 		bufev->be_ops->disable(bufev, EV_WRITE);
 	bufev_private->write_suspended |= what;
 	BEV_UNLOCK(bufev);
 }
 void
 bufferevent_unsuspend_write(struct bufferevent *bufev, bufferevent_suspend_flags what)
 {
 	struct bufferevent_private *bufev_private =
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	BEV_LOCK(bufev);
 	bufev_private->write_suspended &= ~what;
 	if (!bufev_private->write_suspended && (bufev->enabled & EV_WRITE))
 		bufev->be_ops->enable(bufev, EV_WRITE);
 	BEV_UNLOCK(bufev);
 }
 /* Callback to implement watermarks on the input buffer.  Only enabled
  * if the watermark is set. */
 static void
 bufferevent_inbuf_wm_cb(struct evbuffer *buf,
     const struct evbuffer_cb_info *cbinfo,
     void *arg)
 {
 	struct bufferevent *bufev = arg;
 	size_t size;
 	size = evbuffer_get_length(buf);
 	if (size >= bufev->wm_read.high)
 		bufferevent_wm_suspend_read(bufev);
 	else
 		bufferevent_wm_unsuspend_read(bufev);
 }
 static void
 bufferevent_run_deferred_callbacks_locked(struct deferred_cb *_, void *arg)
 {
 	struct bufferevent_private *bufev_private = arg;
 	struct bufferevent *bufev = &bufev_private->bev;
 	BEV_LOCK(bufev);
 	if ((bufev_private->eventcb_pending & BEV_EVENT_CONNECTED) &&
 	    bufev->errorcb) {
 		/* The "connected" happened before any reads or writes, so
 		   send it first. */
 		bufev_private->eventcb_pending &= ~BEV_EVENT_CONNECTED;
 		bufev->errorcb(bufev, BEV_EVENT_CONNECTED, bufev->cbarg);
 	}
 	if (bufev_private->readcb_pending && bufev->readcb) {
 		bufev_private->readcb_pending = 0;
 		bufev->readcb(bufev, bufev->cbarg);
 	}
 	if (bufev_private->writecb_pending && bufev->writecb) {
 		bufev_private->writecb_pending = 0;
 		bufev->writecb(bufev, bufev->cbarg);
 	}
 	if (bufev_private->eventcb_pending && bufev->errorcb) {
 		short what = bufev_private->eventcb_pending;
 		int err = bufev_private->errno_pending;
 		bufev_private->eventcb_pending = 0;
 		bufev_private->errno_pending = 0;
 		EVUTIL_SET_SOCKET_ERROR(err);
 		bufev->errorcb(bufev, what, bufev->cbarg);
 	}
 	_bufferevent_decref_and_unlock(bufev);
 }
 static void
 bufferevent_run_deferred_callbacks_unlocked(struct deferred_cb *_, void *arg)
 {
 	struct bufferevent_private *bufev_private = arg;
 	struct bufferevent *bufev = &bufev_private->bev;
 	BEV_LOCK(bufev);
 #define UNLOCKED(stmt) \
 	do { BEV_UNLOCK(bufev); stmt; BEV_LOCK(bufev); } while(0)
 	if ((bufev_private->eventcb_pending & BEV_EVENT_CONNECTED) &&
 	    bufev->errorcb) {
 		/* The "connected" happened before any reads or writes, so
 		   send it first. */
 		bufferevent_event_cb errorcb = bufev->errorcb;
 		void *cbarg = bufev->cbarg;
 		bufev_private->eventcb_pending &= ~BEV_EVENT_CONNECTED;
 		UNLOCKED(errorcb(bufev, BEV_EVENT_CONNECTED, cbarg));
 	}
 	if (bufev_private->readcb_pending && bufev->readcb) {
 		bufferevent_data_cb readcb = bufev->readcb;
 		void *cbarg = bufev->cbarg;
 		bufev_private->readcb_pending = 0;
 		UNLOCKED(readcb(bufev, cbarg));
 	}
 	if (bufev_private->writecb_pending && bufev->writecb) {
 		bufferevent_data_cb writecb = bufev->writecb;
 		void *cbarg = bufev->cbarg;
 		bufev_private->writecb_pending = 0;
 		UNLOCKED(writecb(bufev, cbarg));
 	}
 	if (bufev_private->eventcb_pending && bufev->errorcb) {
 		bufferevent_event_cb errorcb = bufev->errorcb;
 		void *cbarg = bufev->cbarg;
 		short what = bufev_private->eventcb_pending;
 		int err = bufev_private->errno_pending;
 		bufev_private->eventcb_pending = 0;
 		bufev_private->errno_pending = 0;
 		EVUTIL_SET_SOCKET_ERROR(err);
 		UNLOCKED(errorcb(bufev,what,cbarg));
 	}
 	_bufferevent_decref_and_unlock(bufev);
 #undef UNLOCKED
 }
 #define SCHEDULE_DEFERRED(bevp)						\
 	do {								\
 		bufferevent_incref(&(bevp)->bev);			\
 		event_deferred_cb_schedule(				\
 			event_base_get_deferred_cb_queue((bevp)->bev.ev_base), \
 			&(bevp)->deferred);				\
 	} while (0)
 void
 _bufferevent_run_readcb(struct bufferevent *bufev)
 {
 	/* Requires that we hold the lock and a reference */
 	struct bufferevent_private *p =
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	if (bufev->readcb == NULL)
 		return;
 	if (p->options & BEV_OPT_DEFER_CALLBACKS) {
 		p->readcb_pending = 1;
 		if (!p->deferred.queued)
 			SCHEDULE_DEFERRED(p);
 	} else {
 		bufev->readcb(bufev, bufev->cbarg);
 	}
 }
 void
 _bufferevent_run_writecb(struct bufferevent *bufev)
 {
 	/* Requires that we hold the lock and a reference */
 	struct bufferevent_private *p =
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	if (bufev->writecb == NULL)
 		return;
 	if (p->options & BEV_OPT_DEFER_CALLBACKS) {
 		p->writecb_pending = 1;
 		if (!p->deferred.queued)
 			SCHEDULE_DEFERRED(p);
 	} else {
 		bufev->writecb(bufev, bufev->cbarg);
 	}
 }
 void
 _bufferevent_run_eventcb(struct bufferevent *bufev, short what)
 {
 	/* Requires that we hold the lock and a reference */
 	struct bufferevent_private *p =
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	if (bufev->errorcb == NULL)
 		return;
 	if (p->options & BEV_OPT_DEFER_CALLBACKS) {
 		p->eventcb_pending |= what;
 		p->errno_pending = EVUTIL_SOCKET_ERROR();
 		if (!p->deferred.queued)
 			SCHEDULE_DEFERRED(p);
 	} else {
 		bufev->errorcb(bufev, what, bufev->cbarg);
 	}
 }
 int
 bufferevent_init_common(struct bufferevent_private *bufev_private,
     struct event_base *base,
     const struct bufferevent_ops *ops,
     enum bufferevent_options options)
 {
 	struct bufferevent *bufev = &bufev_private->bev;
 	if (!bufev->input) {
 		if ((bufev->input = evbuffer_new()) == NULL)
 			return -1;
 	}
 	if (!bufev->output) {
 		if ((bufev->output = evbuffer_new()) == NULL) {
 			evbuffer_free(bufev->input);
 			return -1;
 		}
 	}
 	bufev_private->refcnt = 1;
 	bufev->ev_base = base;
 	/* Disable timeouts. */
 	evutil_timerclear(&bufev->timeout_read);
 	evutil_timerclear(&bufev->timeout_write);
 	bufev->be_ops = ops;
 	/*
 	 * Set to EV_WRITE so that using bufferevent_write is going to
 	 * trigger a callback.  Reading needs to be explicitly enabled
 	 * because otherwise no data will be available.
 	 */
 	bufev->enabled = EV_WRITE;
 #ifndef _EVENT_DISABLE_THREAD_SUPPORT
 	if (options & BEV_OPT_THREADSAFE) {
 		if (bufferevent_enable_locking(bufev, NULL) < 0) {
 			/* cleanup */
 			evbuffer_free(bufev->input);
 			evbuffer_free(bufev->output);
 			bufev->input = NULL;
 			bufev->output = NULL;
 			return -1;
 		}
 	}
 #endif
 	if ((options & (BEV_OPT_DEFER_CALLBACKS|BEV_OPT_UNLOCK_CALLBACKS))
 	    == BEV_OPT_UNLOCK_CALLBACKS) {
 		event_warnx("UNLOCK_CALLBACKS requires DEFER_CALLBACKS");
 		return -1;
 	}
 	if (options & BEV_OPT_DEFER_CALLBACKS) {
 		if (options & BEV_OPT_UNLOCK_CALLBACKS)
 			event_deferred_cb_init(&bufev_private->deferred,
 			    bufferevent_run_deferred_callbacks_unlocked,
 			    bufev_private);
 		else
 			event_deferred_cb_init(&bufev_private->deferred,
 			    bufferevent_run_deferred_callbacks_locked,
 			    bufev_private);
 	}
 	bufev_private->options = options;
 	evbuffer_set_parent(bufev->input, bufev);
 	evbuffer_set_parent(bufev->output, bufev);
 	return 0;
 }
 void
 bufferevent_setcb(struct bufferevent *bufev,
     bufferevent_data_cb readcb, bufferevent_data_cb writecb,
     bufferevent_event_cb eventcb, void *cbarg)
 {
 	BEV_LOCK(bufev);
 	bufev->readcb = readcb;
 	bufev->writecb = writecb;
 	bufev->errorcb = eventcb;
 	bufev->cbarg = cbarg;
 	BEV_UNLOCK(bufev);
 }
 struct evbuffer *
 bufferevent_get_input(struct bufferevent *bufev)
 {
 	return bufev->input;
 }
 struct evbuffer *
 bufferevent_get_output(struct bufferevent *bufev)
 {
 	return bufev->output;
 }
 struct event_base *
 bufferevent_get_base(struct bufferevent *bufev)
 {
 	return bufev->ev_base;
 }
 int
 bufferevent_write(struct bufferevent *bufev, const void *data, size_t size)
 {
 	if (evbuffer_add(bufev->output, data, size) == -1)
 		return (-1);
 	return 0;
 }
 int
 bufferevent_write_buffer(struct bufferevent *bufev, struct evbuffer *buf)
 {
 	if (evbuffer_add_buffer(bufev->output, buf) == -1)
 		return (-1);
 	return 0;
 }
 size_t
 bufferevent_read(struct bufferevent *bufev, void *data, size_t size)
 {
 	return (evbuffer_remove(bufev->input, data, size));
 }
 int
 bufferevent_read_buffer(struct bufferevent *bufev, struct evbuffer *buf)
 {
 	return (evbuffer_add_buffer(buf, bufev->input));
 }
 int
 bufferevent_enable(struct bufferevent *bufev, short event)
 {
 	struct bufferevent_private *bufev_private =
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	short impl_events = event;
 	int r = 0;
 	_bufferevent_incref_and_lock(bufev);
 	if (bufev_private->read_suspended)
 		impl_events &= ~EV_READ;
 	if (bufev_private->write_suspended)
 		impl_events &= ~EV_WRITE;
 	bufev->enabled |= event;
 	if (impl_events && bufev->be_ops->enable(bufev, impl_events) < 0)
 		r = -1;
 	_bufferevent_decref_and_unlock(bufev);
 	return r;
 }
 int
 bufferevent_set_timeouts(struct bufferevent *bufev,
 			 const struct timeval *tv_read,
 			 const struct timeval *tv_write)
 {
 	int r = 0;
 	BEV_LOCK(bufev);
 	if (tv_read) {
 		bufev->timeout_read = *tv_read;
 	} else {
 		evutil_timerclear(&bufev->timeout_read);
 	}
 	if (tv_write) {
 		bufev->timeout_write = *tv_write;
 	} else {
 		evutil_timerclear(&bufev->timeout_write);
 	}
 	if (bufev->be_ops->adj_timeouts)
 		r = bufev->be_ops->adj_timeouts(bufev);
 	BEV_UNLOCK(bufev);
 	return r;
 }
 /* Obsolete; use bufferevent_set_timeouts */
 void
 bufferevent_settimeout(struct bufferevent *bufev,
 		       int timeout_read, int timeout_write)
 {
 	struct timeval tv_read, tv_write;
 	struct timeval *ptv_read = NULL, *ptv_write = NULL;
 	memset(&tv_read, 0, sizeof(tv_read));
 	memset(&tv_write, 0, sizeof(tv_write));
 	if (timeout_read) {
 		tv_read.tv_sec = timeout_read;
 		ptv_read = &tv_read;
 	}
 	if (timeout_write) {
 		tv_write.tv_sec = timeout_write;
 		ptv_write = &tv_write;
 	}
 	bufferevent_set_timeouts(bufev, ptv_read, ptv_write);
 }
 int
 bufferevent_disable_hard(struct bufferevent *bufev, short event)
 {
 	int r = 0;
 	struct bufferevent_private *bufev_private =
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	BEV_LOCK(bufev);
 	bufev->enabled &= ~event;
 	bufev_private->connecting = 0;
 	if (bufev->be_ops->disable(bufev, event) < 0)
 		r = -1;
 	BEV_UNLOCK(bufev);
 	return r;
 }
 int
 bufferevent_disable(struct bufferevent *bufev, short event)
 {
 	int r = 0;
 	BEV_LOCK(bufev);
 	bufev->enabled &= ~event;
 	if (bufev->be_ops->disable(bufev, event) < 0)
 		r = -1;
 	BEV_UNLOCK(bufev);
 	return r;
 }
 /*
  * Sets the water marks
  */
 void
 bufferevent_setwatermark(struct bufferevent *bufev, short events,
     size_t lowmark, size_t highmark)
 {
 	struct bufferevent_private *bufev_private =
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	BEV_LOCK(bufev);
 	if (events & EV_WRITE) {
 		bufev->wm_write.low = lowmark;
 		bufev->wm_write.high = highmark;
 	}
 	if (events & EV_READ) {
 		bufev->wm_read.low = lowmark;
 		bufev->wm_read.high = highmark;
 		if (highmark) {
 			/* There is now a new high-water mark for read.
 			   enable the callback if needed, and see if we should
 			   suspend/bufferevent_wm_unsuspend. */
 			if (bufev_private->read_watermarks_cb == NULL) {
 				bufev_private->read_watermarks_cb =
 				    evbuffer_add_cb(bufev->input,
 						    bufferevent_inbuf_wm_cb,
 						    bufev);
 			}
 			evbuffer_cb_set_flags(bufev->input,
 				      bufev_private->read_watermarks_cb,
 				      EVBUFFER_CB_ENABLED|EVBUFFER_CB_NODEFER);
 			if (evbuffer_get_length(bufev->input) > highmark)
 				bufferevent_wm_suspend_read(bufev);
 			else if (evbuffer_get_length(bufev->input) < highmark)
 				bufferevent_wm_unsuspend_read(bufev);
 		} else {
 			/* There is now no high-water mark for read. */
 			if (bufev_private->read_watermarks_cb)
 				evbuffer_cb_clear_flags(bufev->input,
 				    bufev_private->read_watermarks_cb,
 				    EVBUFFER_CB_ENABLED);
 			bufferevent_wm_unsuspend_read(bufev);
 		}
 	}
 	BEV_UNLOCK(bufev);
 }
 int
 bufferevent_flush(struct bufferevent *bufev,
     short iotype,
     enum bufferevent_flush_mode mode)
 {
 	int r = -1;
 	BEV_LOCK(bufev);
 	if (bufev->be_ops->flush)
 		r = bufev->be_ops->flush(bufev, iotype, mode);
 	BEV_UNLOCK(bufev);
 	return r;
 }
 void
 _bufferevent_incref_and_lock(struct bufferevent *bufev)
 {
 	struct bufferevent_private *bufev_private =
 	    BEV_UPCAST(bufev);
 	BEV_LOCK(bufev);
 	++bufev_private->refcnt;
 }
 #if 0
 static void
 _bufferevent_transfer_lock_ownership(struct bufferevent *donor,
     struct bufferevent *recipient)
 {
 	struct bufferevent_private *d = BEV_UPCAST(donor);
 	struct bufferevent_private *r = BEV_UPCAST(recipient);
 	if (d->lock != r->lock)
 		return;
 	if (r->own_lock)
 		return;
 	if (d->own_lock) {
 		d->own_lock = 0;
 		r->own_lock = 1;
 	}
 }
 #endif
 int
 _bufferevent_decref_and_unlock(struct bufferevent *bufev)
 {
 	struct bufferevent_private *bufev_private =
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	struct bufferevent *underlying;
 	EVUTIL_ASSERT(bufev_private->refcnt > 0);
 	if (--bufev_private->refcnt) {
 		BEV_UNLOCK(bufev);
 		return 0;
 	}
 	underlying = bufferevent_get_underlying(bufev);
 	/* Clean up the shared info */
 	if (bufev->be_ops->destruct)
 		bufev->be_ops->destruct(bufev);
 	/* XXX what happens if refcnt for these buffers is > 1?
 	 * The buffers can share a lock with this bufferevent object,
 	 * but the lock might be destroyed below. */
 	/* evbuffer will free the callbacks */
 	evbuffer_free(bufev->input);
 	evbuffer_free(bufev->output);
 	if (bufev_private->rate_limiting) {
 		if (bufev_private->rate_limiting->group)
 			bufferevent_remove_from_rate_limit_group_internal(bufev,0);
 		if (event_initialized(&bufev_private->rate_limiting->refill_bucket_event))
 			event_del(&bufev_private->rate_limiting->refill_bucket_event);
 		event_debug_unassign(&bufev_private->rate_limiting->refill_bucket_event);
 		mm_free(bufev_private->rate_limiting);
 		bufev_private->rate_limiting = NULL;
 	}
 	event_debug_unassign(&bufev->ev_read);
 	event_debug_unassign(&bufev->ev_write);
 	BEV_UNLOCK(bufev);
 	if (bufev_private->own_lock)
 		EVTHREAD_FREE_LOCK(bufev_private->lock,
 		    EVTHREAD_LOCKTYPE_RECURSIVE);
 	/* Free the actual allocated memory. */
 	mm_free(((char*)bufev) - bufev->be_ops->mem_offset);
 	/* Release the reference to underlying now that we no longer need the
 	 * reference to it.  We wait this long mainly in case our lock is
 	 * shared with underlying.
 	 *
 	 * The 'destruct' function will also drop a reference to underlying
 	 * if BEV_OPT_CLOSE_ON_FREE is set.
 	 *
 	 * XXX Should we/can we just refcount evbuffer/bufferevent locks?
 	 * It would probably save us some headaches.
 	 */
 	if (underlying)
 		bufferevent_decref(underlying);
 	return 1;
 }
 int
 bufferevent_decref(struct bufferevent *bufev)
 {
 	BEV_LOCK(bufev);
 	return _bufferevent_decref_and_unlock(bufev);
 }
 void
 bufferevent_free(struct bufferevent *bufev)
 {
 	BEV_LOCK(bufev);
 	bufferevent_setcb(bufev, NULL, NULL, NULL, NULL);
 	_bufferevent_cancel_all(bufev);
 	_bufferevent_decref_and_unlock(bufev);
 }
 void
 bufferevent_incref(struct bufferevent *bufev)
 {
 	struct bufferevent_private *bufev_private =
 	    EVUTIL_UPCAST(bufev, struct bufferevent_private, bev);
 	BEV_LOCK(bufev);
 	++bufev_private->refcnt;
 	BEV_UNLOCK(bufev);
 }
 int
 bufferevent_enable_locking(struct bufferevent *bufev, void *lock)
 {
 #ifdef _EVENT_DISABLE_THREAD_SUPPORT
 	return -1;
 #else
 	struct bufferevent *underlying;
 	if (BEV_UPCAST(bufev)->lock)
 		return -1;
 	underlying = bufferevent_get_underlying(bufev);
 	if (!lock && underlying && BEV_UPCAST(underlying)->lock) {
 		lock = BEV_UPCAST(underlying)->lock;
 		BEV_UPCAST(bufev)->lock = lock;
 		BEV_UPCAST(bufev)->own_lock = 0;
 	} else if (!lock) {
 		EVTHREAD_ALLOC_LOCK(lock, EVTHREAD_LOCKTYPE_RECURSIVE);
 		if (!lock)
 			return -1;
 		BEV_UPCAST(bufev)->lock = lock;
 		BEV_UPCAST(bufev)->own_lock = 1;
 	} else {
 		BEV_UPCAST(bufev)->lock = lock;
 		BEV_UPCAST(bufev)->own_lock = 0;
 	}
 	evbuffer_enable_locking(bufev->input, lock);
 	evbuffer_enable_locking(bufev->output, lock);
 	if (underlying && !BEV_UPCAST(underlying)->lock)
 		bufferevent_enable_locking(underlying, lock);
 	return 0;
 #endif
 }
 int
 bufferevent_setfd(struct bufferevent *bev, evutil_socket_t fd)
 {
 	union bufferevent_ctrl_data d;
 	int res = -1;
 	d.fd = fd;
 	BEV_LOCK(bev);
 	if (bev->be_ops->ctrl)
 		res = bev->be_ops->ctrl(bev, BEV_CTRL_SET_FD, &d);
 	BEV_UNLOCK(bev);
 	return res;
 }
 evutil_socket_t
 bufferevent_getfd(struct bufferevent *bev)
 {
 	union bufferevent_ctrl_data d;
 	int res = -1;
 	d.fd = -1;
 	BEV_LOCK(bev);
 	if (bev->be_ops->ctrl)
 		res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_FD, &d);
 	BEV_UNLOCK(bev);
 	return (res<0) ? -1 : d.fd;
 }
 static void
 _bufferevent_cancel_all(struct bufferevent *bev)
 {
 	union bufferevent_ctrl_data d;
 	memset(&d, 0, sizeof(d));
 	BEV_LOCK(bev);
 	if (bev->be_ops->ctrl)
 		bev->be_ops->ctrl(bev, BEV_CTRL_CANCEL_ALL, &d);
 	BEV_UNLOCK(bev);
 }
 short
 bufferevent_get_enabled(struct bufferevent *bufev)
 {
 	short r;
 	BEV_LOCK(bufev);
 	r = bufev->enabled;
 	BEV_UNLOCK(bufev);
 	return r;
 }
 struct bufferevent *
 bufferevent_get_underlying(struct bufferevent *bev)
 {
 	union bufferevent_ctrl_data d;
 	int res = -1;
 	d.ptr = NULL;
 	BEV_LOCK(bev);
 	if (bev->be_ops->ctrl)
 		res = bev->be_ops->ctrl(bev, BEV_CTRL_GET_UNDERLYING, &d);
 	BEV_UNLOCK(bev);
 	return (res<0) ? NULL : d.ptr;
 }
 static void
 bufferevent_generic_read_timeout_cb(evutil_socket_t fd, short event, void *ctx)
 {
 	struct bufferevent *bev = ctx;
 	_bufferevent_incref_and_lock(bev);
 	bufferevent_disable(bev, EV_READ);
 	_bufferevent_run_eventcb(bev, BEV_EVENT_TIMEOUT|BEV_EVENT_READING);
 	_bufferevent_decref_and_unlock(bev);
 }
 static void
 bufferevent_generic_write_timeout_cb(evutil_socket_t fd, short event, void *ctx)
 {
 	struct bufferevent *bev = ctx;
 	_bufferevent_incref_and_lock(bev);
 	bufferevent_disable(bev, EV_WRITE);
 	_bufferevent_run_eventcb(bev, BEV_EVENT_TIMEOUT|BEV_EVENT_WRITING);
 	_bufferevent_decref_and_unlock(bev);
 }
 void
 _bufferevent_init_generic_timeout_cbs(struct bufferevent *bev)
 {
 	evtimer_assign(&bev->ev_read, bev->ev_base,
 	    bufferevent_generic_read_timeout_cb, bev);
 	evtimer_assign(&bev->ev_write, bev->ev_base,
 	    bufferevent_generic_write_timeout_cb, bev);
 }
 int
 _bufferevent_del_generic_timeout_cbs(struct bufferevent *bev)
 {
 	int r1,r2;
 	r1 = event_del(&bev->ev_read);
 	r2 = event_del(&bev->ev_write);
 	if (r1<0 || r2<0)
 		return -1;
 	return 0;
 }
 int
 _bufferevent_generic_adj_timeouts(struct bufferevent *bev)
 {
 	const short enabled = bev->enabled;
 	struct bufferevent_private *bev_p =
 	    EVUTIL_UPCAST(bev, struct bufferevent_private, bev);
 	int r1=0, r2=0;
 	if ((enabled & EV_READ) && !bev_p->read_suspended &&
 	    evutil_timerisset(&bev->timeout_read))
 		r1 = event_add(&bev->ev_read, &bev->timeout_read);
 	else
 		r1 = event_del(&bev->ev_read);
 	if ((enabled & EV_WRITE) && !bev_p->write_suspended &&
 	    evutil_timerisset(&bev->timeout_write) &&
 	    evbuffer_get_length(bev->output))
 		r2 = event_add(&bev->ev_write, &bev->timeout_write);
 	else
 		r2 = event_del(&bev->ev_write);
 	if (r1 < 0 || r2 < 0)
 		return -1;
 	return 0;
 }
 int
 _bufferevent_add_event(struct event *ev, const struct timeval *tv)
 {
 	if (tv->tv_sec == 0 && tv->tv_usec == 0)
 		return event_add(ev, NULL);
 	else
 		return event_add(ev, tv);
 }
 /* For use by user programs only; internally, we should be calling
    either _bufferevent_incref_and_lock(), or BEV_LOCK. */
 void
 bufferevent_lock(struct bufferevent *bev)
 {
 	_bufferevent_incref_and_lock(bev);
 }
 void
 bufferevent_unlock(struct bufferevent *bev)
 {
 	_bufferevent_decref_and_unlock(bev);
 }

The Tor Browser / annotate

ipc/chromium/src/third_party/libevent/bufferevent.c@6474c204b198 (annotated)

ipc/chromium/src/third_party/libevent/bufferevent.c