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

ipc/chromium/src/third_party/libevent/bufferevent-internal.h@6474c204b198 (annotated)

ipc/chromium/src/third_party/libevent/bufferevent-internal.h

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) 2008-2012 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 _BUFFEREVENT_INTERNAL_H_
 #define _BUFFEREVENT_INTERNAL_H_
 #ifdef __cplusplus
 extern "C" {
 #endif
 #include "event2/event-config.h"
 #include "event2/util.h"
 #include "defer-internal.h"
 #include "evthread-internal.h"
 #include "event2/thread.h"
 #include "ratelim-internal.h"
 #include "event2/bufferevent_struct.h"
 /* These flags are reasons that we might be declining to actually enable
    reading or writing on a bufferevent.
  */
 /* On a all bufferevents, for reading: used when we have read up to the
    watermark value.
    On a filtering bufferevent, for writing: used when the underlying
    bufferevent's write buffer has been filled up to its watermark
    value.
 */
 #define BEV_SUSPEND_WM 0x01
 /* On a base bufferevent: when we have emptied a bandwidth buckets */
 #define BEV_SUSPEND_BW 0x02
 /* On a base bufferevent: when we have emptied the group's bandwidth bucket. */
 #define BEV_SUSPEND_BW_GROUP 0x04
 /* On a socket bufferevent: can't do any operations while we're waiting for
  * name lookup to finish. */
 #define BEV_SUSPEND_LOOKUP 0x08
 /* On a base bufferevent, for reading: used when a filter has choked this
  * (underlying) bufferevent because it has stopped reading from it. */
 #define BEV_SUSPEND_FILT_READ 0x10
 typedef ev_uint16_t bufferevent_suspend_flags;
 struct bufferevent_rate_limit_group {
 	/** List of all members in the group */
 	TAILQ_HEAD(rlim_group_member_list, bufferevent_private) members;
 	/** Current limits for the group. */
 	struct ev_token_bucket rate_limit;
 	struct ev_token_bucket_cfg rate_limit_cfg;
 	/** True iff we don't want to read from any member of the group.until
 	 * the token bucket refills.  */
 	unsigned read_suspended : 1;
 	/** True iff we don't want to write from any member of the group.until
 	 * the token bucket refills.  */
 	unsigned write_suspended : 1;
 	/** True iff we were unable to suspend one of the bufferevents in the
 	 * group for reading the last time we tried, and we should try
 	 * again. */
 	unsigned pending_unsuspend_read : 1;
 	/** True iff we were unable to suspend one of the bufferevents in the
 	 * group for writing the last time we tried, and we should try
 	 * again. */
 	unsigned pending_unsuspend_write : 1;
 	/*@{*/
 	/** Total number of bytes read or written in this group since last
 	 * reset. */
 	ev_uint64_t total_read;
 	ev_uint64_t total_written;
 	/*@}*/
 	/** The number of bufferevents in the group. */
 	int n_members;
 	/** The smallest number of bytes that any member of the group should
 	 * be limited to read or write at a time. */
 	ev_ssize_t min_share;
 	ev_ssize_t configured_min_share;
 	/** Timeout event that goes off once a tick, when the bucket is ready
 	 * to refill. */
 	struct event master_refill_event;
 	/** Lock to protect the members of this group.  This lock should nest
 	 * within every bufferevent lock: if you are holding this lock, do
 	 * not assume you can lock another bufferevent. */
 	void *lock;
 };
 /** Fields for rate-limiting a single bufferevent. */
 struct bufferevent_rate_limit {
 	/* Linked-list elements for storing this bufferevent_private in a
 	 * group.
 	 *
 	 * Note that this field is supposed to be protected by the group
 	 * lock */
 	TAILQ_ENTRY(bufferevent_private) next_in_group;
 	/** The rate-limiting group for this bufferevent, or NULL if it is
 	 * only rate-limited on its own. */
 	struct bufferevent_rate_limit_group *group;
 	/* This bufferevent's current limits. */
 	struct ev_token_bucket limit;
 	/* Pointer to the rate-limit configuration for this bufferevent.
 	 * Can be shared.  XXX reference-count this? */
 	struct ev_token_bucket_cfg *cfg;
 	/* Timeout event used when one this bufferevent's buckets are
 	 * empty. */
 	struct event refill_bucket_event;
 };
 /** Parts of the bufferevent structure that are shared among all bufferevent
  * types, but not exposed in bufferevent_struct.h. */
 struct bufferevent_private {
 	/** The underlying bufferevent structure. */
 	struct bufferevent bev;
 	/** Evbuffer callback to enforce watermarks on input. */
 	struct evbuffer_cb_entry *read_watermarks_cb;
 	/** If set, we should free the lock when we free the bufferevent. */
 	unsigned own_lock : 1;
 	/** Flag: set if we have deferred callbacks and a read callback is
 	 * pending. */
 	unsigned readcb_pending : 1;
 	/** Flag: set if we have deferred callbacks and a write callback is
 	 * pending. */
 	unsigned writecb_pending : 1;
 	/** Flag: set if we are currently busy connecting. */
 	unsigned connecting : 1;
 	/** Flag: set if a connect failed prematurely; this is a hack for
 	 * getting around the bufferevent abstraction. */
 	unsigned connection_refused : 1;
 	/** Set to the events pending if we have deferred callbacks and
 	 * an events callback is pending. */
 	short eventcb_pending;
 	/** If set, read is suspended until one or more conditions are over.
 	 * The actual value here is a bitfield of those conditions; see the
 	 * BEV_SUSPEND_* flags above. */
 	bufferevent_suspend_flags read_suspended;
 	/** If set, writing is suspended until one or more conditions are over.
 	 * The actual value here is a bitfield of those conditions; see the
 	 * BEV_SUSPEND_* flags above. */
 	bufferevent_suspend_flags write_suspended;
 	/** Set to the current socket errno if we have deferred callbacks and
 	 * an events callback is pending. */
 	int errno_pending;
 	/** The DNS error code for bufferevent_socket_connect_hostname */
 	int dns_error;
 	/** Used to implement deferred callbacks */
 	struct deferred_cb deferred;
 	/** The options this bufferevent was constructed with */
 	enum bufferevent_options options;
 	/** Current reference count for this bufferevent. */
 	int refcnt;
 	/** Lock for this bufferevent.  Shared by the inbuf and the outbuf.
 	 * If NULL, locking is disabled. */
 	void *lock;
 	/** Rate-limiting information for this bufferevent */
 	struct bufferevent_rate_limit *rate_limiting;
 };
 /** Possible operations for a control callback. */
 enum bufferevent_ctrl_op {
 	BEV_CTRL_SET_FD,
 	BEV_CTRL_GET_FD,
 	BEV_CTRL_GET_UNDERLYING,
 	BEV_CTRL_CANCEL_ALL
 };
 /** Possible data types for a control callback */
 union bufferevent_ctrl_data {
 	void *ptr;
 	evutil_socket_t fd;
 };
 /**
    Implementation table for a bufferevent: holds function pointers and other
    information to make the various bufferevent types work.
 */
 struct bufferevent_ops {
 	/** The name of the bufferevent's type. */
 	const char *type;
 	/** At what offset into the implementation type will we find a
 	    bufferevent structure?
 	    Example: if the type is implemented as
 	    struct bufferevent_x {
 	       int extra_data;
 	       struct bufferevent bev;
 	    }
 	    then mem_offset should be offsetof(struct bufferevent_x, bev)
 	*/
 	off_t mem_offset;
 	/** Enables one or more of EV_READ|EV_WRITE on a bufferevent.  Does
 	    not need to adjust the 'enabled' field.  Returns 0 on success, -1
 	    on failure.
 	 */
 	int (*enable)(struct bufferevent *, short);
 	/** Disables one or more of EV_READ|EV_WRITE on a bufferevent.  Does
 	    not need to adjust the 'enabled' field.  Returns 0 on success, -1
 	    on failure.
 	 */
 	int (*disable)(struct bufferevent *, short);
 	/** Free any storage and deallocate any extra data or structures used
 	    in this implementation.
 	 */
 	void (*destruct)(struct bufferevent *);
 	/** Called when the timeouts on the bufferevent have changed.*/
 	int (*adj_timeouts)(struct bufferevent *);
 	/** Called to flush data. */
 	int (*flush)(struct bufferevent *, short, enum bufferevent_flush_mode);
 	/** Called to access miscellaneous fields. */
 	int (*ctrl)(struct bufferevent *, enum bufferevent_ctrl_op, union bufferevent_ctrl_data *);
 };
 extern const struct bufferevent_ops bufferevent_ops_socket;
 extern const struct bufferevent_ops bufferevent_ops_filter;
 extern const struct bufferevent_ops bufferevent_ops_pair;
 #define BEV_IS_SOCKET(bevp) ((bevp)->be_ops == &bufferevent_ops_socket)
 #define BEV_IS_FILTER(bevp) ((bevp)->be_ops == &bufferevent_ops_filter)
 #define BEV_IS_PAIR(bevp) ((bevp)->be_ops == &bufferevent_ops_pair)
 #ifdef WIN32
 extern const struct bufferevent_ops bufferevent_ops_async;
 #define BEV_IS_ASYNC(bevp) ((bevp)->be_ops == &bufferevent_ops_async)
 #else
 #define BEV_IS_ASYNC(bevp) 0
 #endif
 /** Initialize the shared parts of a bufferevent. */
 int bufferevent_init_common(struct bufferevent_private *, struct event_base *, const struct bufferevent_ops *, enum bufferevent_options options);
 /** For internal use: temporarily stop all reads on bufev, until the conditions
  * in 'what' are over. */
 void bufferevent_suspend_read(struct bufferevent *bufev, bufferevent_suspend_flags what);
 /** For internal use: clear the conditions 'what' on bufev, and re-enable
  * reading if there are no conditions left. */
 void bufferevent_unsuspend_read(struct bufferevent *bufev, bufferevent_suspend_flags what);
 /** For internal use: temporarily stop all writes on bufev, until the conditions
  * in 'what' are over. */
 void bufferevent_suspend_write(struct bufferevent *bufev, bufferevent_suspend_flags what);
 /** For internal use: clear the conditions 'what' on bufev, and re-enable
  * writing if there are no conditions left. */
 void bufferevent_unsuspend_write(struct bufferevent *bufev, bufferevent_suspend_flags what);
 #define bufferevent_wm_suspend_read(b) \
 	bufferevent_suspend_read((b), BEV_SUSPEND_WM)
 #define bufferevent_wm_unsuspend_read(b) \
 	bufferevent_unsuspend_read((b), BEV_SUSPEND_WM)
 /*
   Disable a bufferevent.  Equivalent to bufferevent_disable(), but
   first resets 'connecting' flag to force EV_WRITE down for sure.
   XXXX this method will go away in the future; try not to add new users.
     See comment in evhttp_connection_reset() for discussion.
   @param bufev the bufferevent to be disabled
   @param event any combination of EV_READ | EV_WRITE.
   @return 0 if successful, or -1 if an error occurred
   @see bufferevent_disable()
  */
 int bufferevent_disable_hard(struct bufferevent *bufev, short event);
 /** Internal: Set up locking on a bufferevent.  If lock is set, use it.
  * Otherwise, use a new lock. */
 int bufferevent_enable_locking(struct bufferevent *bufev, void *lock);
 /** Internal: Increment the reference count on bufev. */
 void bufferevent_incref(struct bufferevent *bufev);
 /** Internal: Lock bufev and increase its reference count.
  * unlocking it otherwise. */
 void _bufferevent_incref_and_lock(struct bufferevent *bufev);
 /** Internal: Decrement the reference count on bufev.  Returns 1 if it freed
  * the bufferevent.*/
 int bufferevent_decref(struct bufferevent *bufev);
 /** Internal: Drop the reference count on bufev, freeing as necessary, and
  * unlocking it otherwise.  Returns 1 if it freed the bufferevent. */
 int _bufferevent_decref_and_unlock(struct bufferevent *bufev);
 /** Internal: If callbacks are deferred and we have a read callback, schedule
  * a readcb.  Otherwise just run the readcb. */
 void _bufferevent_run_readcb(struct bufferevent *bufev);
 /** Internal: If callbacks are deferred and we have a write callback, schedule
  * a writecb.  Otherwise just run the writecb. */
 void _bufferevent_run_writecb(struct bufferevent *bufev);
 /** Internal: If callbacks are deferred and we have an eventcb, schedule
  * it to run with events "what".  Otherwise just run the eventcb. */
 void _bufferevent_run_eventcb(struct bufferevent *bufev, short what);
 /** Internal: Add the event 'ev' with timeout tv, unless tv is set to 0, in
  * which case add ev with no timeout. */
 int _bufferevent_add_event(struct event *ev, const struct timeval *tv);
 /* =========
  * These next functions implement timeouts for bufferevents that aren't doing
  * anything else with ev_read and ev_write, to handle timeouts.
  * ========= */
 /** Internal use: Set up the ev_read and ev_write callbacks so that
  * the other "generic_timeout" functions will work on it.  Call this from
  * the constructor function. */
 void _bufferevent_init_generic_timeout_cbs(struct bufferevent *bev);
 /** Internal use: Delete the ev_read and ev_write callbacks if they're pending.
  * Call this from the destructor function. */
 int _bufferevent_del_generic_timeout_cbs(struct bufferevent *bev);
 /** Internal use: Add or delete the generic timeout events as appropriate.
  * (If an event is enabled and a timeout is set, we add the event.  Otherwise
  * we delete it.)  Call this from anything that changes the timeout values,
  * that enabled EV_READ or EV_WRITE, or that disables EV_READ or EV_WRITE. */
 int _bufferevent_generic_adj_timeouts(struct bufferevent *bev);
 /** Internal use: We have just successfully read data into an inbuf, so
  * reset the read timeout (if any). */
 #define BEV_RESET_GENERIC_READ_TIMEOUT(bev)				\
 	do {								\
 		if (evutil_timerisset(&(bev)->timeout_read))		\
 			event_add(&(bev)->ev_read, &(bev)->timeout_read); \
 	} while (0)
 /** Internal use: We have just successfully written data from an inbuf, so
  * reset the read timeout (if any). */
 #define BEV_RESET_GENERIC_WRITE_TIMEOUT(bev)				\
 	do {								\
 		if (evutil_timerisset(&(bev)->timeout_write))		\
 			event_add(&(bev)->ev_write, &(bev)->timeout_write); \
 	} while (0)
 #define BEV_DEL_GENERIC_READ_TIMEOUT(bev)	\
 		event_del(&(bev)->ev_read)
 #define BEV_DEL_GENERIC_WRITE_TIMEOUT(bev)	\
 		event_del(&(bev)->ev_write)
 /** Internal: Given a bufferevent, return its corresponding
  * bufferevent_private. */
 #define BEV_UPCAST(b) EVUTIL_UPCAST((b), struct bufferevent_private, bev)
 #ifdef _EVENT_DISABLE_THREAD_SUPPORT
 #define BEV_LOCK(b) _EVUTIL_NIL_STMT
 #define BEV_UNLOCK(b) _EVUTIL_NIL_STMT
 #else
 /** Internal: Grab the lock (if any) on a bufferevent */
 #define BEV_LOCK(b) do {						\
 		struct bufferevent_private *locking =  BEV_UPCAST(b);	\
 		EVLOCK_LOCK(locking->lock, 0);				\
 	} while (0)
 /** Internal: Release the lock (if any) on a bufferevent */
 #define BEV_UNLOCK(b) do {						\
 		struct bufferevent_private *locking =  BEV_UPCAST(b);	\
 		EVLOCK_UNLOCK(locking->lock, 0);			\
 	} while (0)
 #endif
 /* ==== For rate-limiting. */
 int _bufferevent_decrement_write_buckets(struct bufferevent_private *bev,
     ev_ssize_t bytes);
 int _bufferevent_decrement_read_buckets(struct bufferevent_private *bev,
     ev_ssize_t bytes);
 ev_ssize_t _bufferevent_get_read_max(struct bufferevent_private *bev);
 ev_ssize_t _bufferevent_get_write_max(struct bufferevent_private *bev);
 #ifdef __cplusplus
 }
 #endif
 #endif /* _BUFFEREVENT_INTERNAL_H_ */

The Tor Browser / annotate

ipc/chromium/src/third_party/libevent/bufferevent-internal.h@6474c204b198 (annotated)

ipc/chromium/src/third_party/libevent/bufferevent-internal.h