The Tor Browser / file revision

 /*

  * Copyright (c) 2009-2012 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_IOCP_INTERNAL_H

 #define _EVENT_IOCP_INTERNAL_H

 #ifdef __cplusplus

 extern "C" {

 #endif

 struct event_overlapped;

 struct event_iocp_port;

 struct evbuffer;

 typedef void (*iocp_callback)(struct event_overlapped *, ev_uintptr_t, ev_ssize_t, int success);

 /* This whole file is actually win32 only. We wrap the structures in a win32

  * ifdef so that we can test-compile code that uses these interfaces on

  * non-win32 platforms. */

 #ifdef WIN32

 /**

    Internal use only.  Wraps an OVERLAPPED that we're using for libevent

    functionality.  Whenever an event_iocp_port gets an event for a given

    OVERLAPPED*, it upcasts the pointer to an event_overlapped, and calls the

    iocp_callback function with the event_overlapped, the iocp key, and the

    number of bytes transferred as arguments.

  */

 struct event_overlapped {

 	OVERLAPPED overlapped;

 	iocp_callback cb;

 };

 /* Mingw's headers don't define LPFN_ACCEPTEX. */

 typedef BOOL (WINAPI *AcceptExPtr)(SOCKET, SOCKET, PVOID, DWORD, DWORD, DWORD, LPDWORD, LPOVERLAPPED);

 typedef BOOL (WINAPI *ConnectExPtr)(SOCKET, const struct sockaddr *, int, PVOID, DWORD, LPDWORD, LPOVERLAPPED);

 typedef void (WINAPI *GetAcceptExSockaddrsPtr)(PVOID, DWORD, DWORD, DWORD, LPSOCKADDR *, LPINT, LPSOCKADDR *, LPINT);

 /** Internal use only. Holds pointers to functions that only some versions of

     Windows provide.

  */

 struct win32_extension_fns {

 	AcceptExPtr AcceptEx;

 	ConnectExPtr ConnectEx;

 	GetAcceptExSockaddrsPtr GetAcceptExSockaddrs;

 };

 /**

     Internal use only. Stores a Windows IO Completion port, along with

     related data.

  */

 struct event_iocp_port {

 	/** The port itself */

 	HANDLE port;

 	/* A lock to cover internal structures. */

 	CRITICAL_SECTION lock;

 	/** Number of threads ever open on the port. */

 	short n_threads;

 	/** True iff we're shutting down all the threads on this port */

 	short shutdown;

 	/** How often the threads on this port check for shutdown and other

 	 * conditions */

 	long ms;

 	/* The threads that are waiting for events. */

 	HANDLE *threads;

 	/** Number of threads currently open on this port. */

 	short n_live_threads;

 	/** A semaphore to signal when we are done shutting down. */

 	HANDLE *shutdownSemaphore;

 };

 const struct win32_extension_fns *event_get_win32_extension_fns(void);

 #else

 /* Dummy definition so we can test-compile more things on unix. */

 struct event_overlapped {

 	iocp_callback cb;

 };

 #endif

 /** Initialize the fields in an event_overlapped.

     @param overlapped The struct event_overlapped to initialize

     @param cb The callback that should be invoked once the IO operation has

 	finished.

  */

 void event_overlapped_init(struct event_overlapped *, iocp_callback cb);

 /** Allocate and return a new evbuffer that supports overlapped IO on a given

     socket.  The socket must be associated with an IO completion port using

     event_iocp_port_associate.

 */

 struct evbuffer *evbuffer_overlapped_new(evutil_socket_t fd);

 /** XXXX Document (nickm) */

 evutil_socket_t _evbuffer_overlapped_get_fd(struct evbuffer *buf);

 void _evbuffer_overlapped_set_fd(struct evbuffer *buf, evutil_socket_t fd);

 /** Start reading data onto the end of an overlapped evbuffer.

     An evbuffer can only have one read pending at a time.  While the read

     is in progress, no other data may be added to the end of the buffer.

     The buffer must be created with event_overlapped_init().

     evbuffer_commit_read() must be called in the completion callback.

     @param buf The buffer to read onto

     @param n The number of bytes to try to read.

     @param ol Overlapped object with associated completion callback.

     @return 0 on success, -1 on error.

  */

 int evbuffer_launch_read(struct evbuffer *buf, size_t n, struct event_overlapped *ol);

 /** Start writing data from the start of an evbuffer.

     An evbuffer can only have one write pending at a time.  While the write is

     in progress, no other data may be removed from the front of the buffer.

     The buffer must be created with event_overlapped_init().

     evbuffer_commit_write() must be called in the completion callback.

     @param buf The buffer to read onto

     @param n The number of bytes to try to read.

     @param ol Overlapped object with associated completion callback.

     @return 0 on success, -1 on error.

  */

 int evbuffer_launch_write(struct evbuffer *buf, ev_ssize_t n, struct event_overlapped *ol);

 /** XXX document */

 void evbuffer_commit_read(struct evbuffer *, ev_ssize_t);

 void evbuffer_commit_write(struct evbuffer *, ev_ssize_t);

 /** Create an IOCP, and launch its worker threads.  Internal use only.

     This interface is unstable, and will change.

  */

 struct event_iocp_port *event_iocp_port_launch(int n_cpus);

 /** Associate a file descriptor with an iocp, such that overlapped IO on the

     fd will happen on one of the iocp's worker threads.

 */

 int event_iocp_port_associate(struct event_iocp_port *port, evutil_socket_t fd,

     ev_uintptr_t key);

 /** Tell all threads serving an iocp to stop.  Wait for up to waitMsec for all

     the threads to finish whatever they're doing.  If waitMsec is -1, wait

     as long as required.  If all the threads are done, free the port and return

     0. Otherwise, return -1.  If you get a -1 return value, it is safe to call

     this function again.

 */

 int event_iocp_shutdown(struct event_iocp_port *port, long waitMsec);

 /* FIXME document. */

 int event_iocp_activate_overlapped(struct event_iocp_port *port,

     struct event_overlapped *o,

     ev_uintptr_t key, ev_uint32_t n_bytes);

 struct event_base;

 /* FIXME document. */

 struct event_iocp_port *event_base_get_iocp(struct event_base *base);

 /* FIXME document. */

 int event_base_start_iocp(struct event_base *base, int n_cpus);

 void event_base_stop_iocp(struct event_base *base);

 /* FIXME document. */

 struct bufferevent *bufferevent_async_new(struct event_base *base,

     evutil_socket_t fd, int options);

 /* FIXME document. */

 void bufferevent_async_set_connected(struct bufferevent *bev);

 int bufferevent_async_can_connect(struct bufferevent *bev);

 int bufferevent_async_connect(struct bufferevent *bev, evutil_socket_t fd,

 	const struct sockaddr *sa, int socklen);

 #ifdef __cplusplus

 }

 #endif

 #endif