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kc3-lang/libevent/bufferevent-internal.h
Nick Mathewson
- bufferevent-internal.h
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/* * Copyright (c) 2008-2009 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 "event-config.h" #include "evutil.h" #include "defer-internal.h" #include "evthread-internal.h" #include "event2/thread.h" /** 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, read is suspended until evbuffer some. */ unsigned read_suspended : 1; /** 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; /** Set to the events pending if we have deferred callbacks and * an events callback is pending. */ short eventcb_pending; /** Set to the current socket errno if we have deferred callbacks and * an events callback is pending. */ int errno_pending; /** 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; }; /** Possible operations for a control callback. */ enum bufferevent_ctrl_op { BEV_CTRL_SET_FD, BEV_CTRL_GET_FD, BEV_CTRL_GET_UNDERLYING, }; /** 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.*/ void (*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; /** 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, because its * read buffer is too full. */ void bufferevent_wm_suspend_read(struct bufferevent *bufev); /** For internal use: temporarily stop all reads on bufev, because its * read buffer is too full. */ void bufferevent_wm_unsuspend_read(struct bufferevent *bufev); /** 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: Drop the reference count on bufev, freeing as necessary, and * unlocking it otherwise. */ void _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. */ void _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. */ void _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) /** Internal: Given a bufferevent, return its corresponding * bufferevent_private. */ #define BEV_UPCAST(b) EVUTIL_UPCAST((b), struct bufferevent_private, bev) /** Internal: Grab the lock (if any) on a bufferevent */ #define BEV_LOCK(b) do { \ struct bufferevent_private *locking = BEV_UPCAST(b); \ if (locking->lock) \ EVLOCK_LOCK(locking->lock, EVTHREAD_WRITE); \ } while(0) /** Internal: Release the lock (if any) on a bufferevent */ #define BEV_UNLOCK(b) do { \ struct bufferevent_private *locking = BEV_UPCAST(b); \ if (locking->lock) \ EVLOCK_UNLOCK(locking->lock, EVTHREAD_WRITE); \ } while(0) #ifdef __cplusplus } #endif #endif /* _BUFFEREVENT_INTERNAL_H_ */