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iocp-internal.h revision 1.1
      1 /*	$NetBSD: iocp-internal.h,v 1.1 2013/12/27 23:31:25 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. The name of the author may not be used to endorse or promote products
     15  *    derived from this software without specific prior written permission.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #ifndef IOCP_INTERNAL_H_INCLUDED_
     30 #define IOCP_INTERNAL_H_INCLUDED_
     31 
     32 #ifdef __cplusplus
     33 extern "C" {
     34 #endif
     35 
     36 struct event_overlapped;
     37 struct event_iocp_port;
     38 struct evbuffer;
     39 typedef void (*iocp_callback)(struct event_overlapped *, ev_uintptr_t, ev_ssize_t, int success);
     40 
     41 /* This whole file is actually win32 only. We wrap the structures in a win32
     42  * ifdef so that we can test-compile code that uses these interfaces on
     43  * non-win32 platforms. */
     44 #ifdef _WIN32
     45 
     46 /**
     47    Internal use only.  Wraps an OVERLAPPED that we're using for libevent
     48    functionality.  Whenever an event_iocp_port gets an event for a given
     49    OVERLAPPED*, it upcasts the pointer to an event_overlapped, and calls the
     50    iocp_callback function with the event_overlapped, the iocp key, and the
     51    number of bytes transferred as arguments.
     52  */
     53 struct event_overlapped {
     54 	OVERLAPPED overlapped;
     55 	iocp_callback cb;
     56 };
     57 
     58 /* Mingw's headers don't define LPFN_ACCEPTEX. */
     59 
     60 typedef BOOL (WINAPI *AcceptExPtr)(SOCKET, SOCKET, PVOID, DWORD, DWORD, DWORD, LPDWORD, LPOVERLAPPED);
     61 typedef BOOL (WINAPI *ConnectExPtr)(SOCKET, const struct sockaddr *, int, PVOID, DWORD, LPDWORD, LPOVERLAPPED);
     62 typedef void (WINAPI *GetAcceptExSockaddrsPtr)(PVOID, DWORD, DWORD, DWORD, LPSOCKADDR *, LPINT, LPSOCKADDR *, LPINT);
     63 
     64 /** Internal use only. Holds pointers to functions that only some versions of
     65     Windows provide.
     66  */
     67 struct win32_extension_fns {
     68 	AcceptExPtr AcceptEx;
     69 	ConnectExPtr ConnectEx;
     70 	GetAcceptExSockaddrsPtr GetAcceptExSockaddrs;
     71 };
     72 
     73 /**
     74     Internal use only. Stores a Windows IO Completion port, along with
     75     related data.
     76  */
     77 struct event_iocp_port {
     78 	/** The port itself */
     79 	HANDLE port;
     80 	/* A lock to cover internal structures. */
     81 	CRITICAL_SECTION lock;
     82 	/** Number of threads ever open on the port. */
     83 	short n_threads;
     84 	/** True iff we're shutting down all the threads on this port */
     85 	short shutdown;
     86 	/** How often the threads on this port check for shutdown and other
     87 	 * conditions */
     88 	long ms;
     89 	/* The threads that are waiting for events. */
     90 	HANDLE *threads;
     91 	/** Number of threads currently open on this port. */
     92 	short n_live_threads;
     93 	/** A semaphore to signal when we are done shutting down. */
     94 	HANDLE *shutdownSemaphore;
     95 };
     96 
     97 const struct win32_extension_fns *event_get_win32_extension_fns_(void);
     98 #else
     99 /* Dummy definition so we can test-compile more things on unix. */
    100 struct event_overlapped {
    101 	iocp_callback cb;
    102 };
    103 #endif
    104 
    105 /** Initialize the fields in an event_overlapped.
    106 
    107     @param overlapped The struct event_overlapped to initialize
    108     @param cb The callback that should be invoked once the IO operation has
    109 	finished.
    110  */
    111 void event_overlapped_init_(struct event_overlapped *, iocp_callback cb);
    112 
    113 /** Allocate and return a new evbuffer that supports overlapped IO on a given
    114     socket.  The socket must be associated with an IO completion port using
    115     event_iocp_port_associate_.
    116 */
    117 struct evbuffer *evbuffer_overlapped_new_(evutil_socket_t fd);
    118 
    119 /** XXXX Document (nickm) */
    120 evutil_socket_t evbuffer_overlapped_get_fd_(struct evbuffer *buf);
    121 
    122 void evbuffer_overlapped_set_fd_(struct evbuffer *buf, evutil_socket_t fd);
    123 
    124 /** Start reading data onto the end of an overlapped evbuffer.
    125 
    126     An evbuffer can only have one read pending at a time.  While the read
    127     is in progress, no other data may be added to the end of the buffer.
    128     The buffer must be created with event_overlapped_init_().
    129     evbuffer_commit_read_() must be called in the completion callback.
    130 
    131     @param buf The buffer to read onto
    132     @param n The number of bytes to try to read.
    133     @param ol Overlapped object with associated completion callback.
    134     @return 0 on success, -1 on error.
    135  */
    136 int evbuffer_launch_read_(struct evbuffer *buf, size_t n, struct event_overlapped *ol);
    137 
    138 /** Start writing data from the start of an evbuffer.
    139 
    140     An evbuffer can only have one write pending at a time.  While the write is
    141     in progress, no other data may be removed from the front of the buffer.
    142     The buffer must be created with event_overlapped_init_().
    143     evbuffer_commit_write_() must be called in the completion callback.
    144 
    145     @param buf The buffer to read onto
    146     @param n The number of bytes to try to read.
    147     @param ol Overlapped object with associated completion callback.
    148     @return 0 on success, -1 on error.
    149  */
    150 int evbuffer_launch_write_(struct evbuffer *buf, ev_ssize_t n, struct event_overlapped *ol);
    151 
    152 /** XXX document */
    153 void evbuffer_commit_read_(struct evbuffer *, ev_ssize_t);
    154 void evbuffer_commit_write_(struct evbuffer *, ev_ssize_t);
    155 
    156 /** Create an IOCP, and launch its worker threads.  Internal use only.
    157 
    158     This interface is unstable, and will change.
    159  */
    160 struct event_iocp_port *event_iocp_port_launch_(int n_cpus);
    161 
    162 /** Associate a file descriptor with an iocp, such that overlapped IO on the
    163     fd will happen on one of the iocp's worker threads.
    164 */
    165 int event_iocp_port_associate_(struct event_iocp_port *port, evutil_socket_t fd,
    166     ev_uintptr_t key);
    167 
    168 /** Tell all threads serving an iocp to stop.  Wait for up to waitMsec for all
    169     the threads to finish whatever they're doing.  If waitMsec is -1, wait
    170     as long as required.  If all the threads are done, free the port and return
    171     0. Otherwise, return -1.  If you get a -1 return value, it is safe to call
    172     this function again.
    173 */
    174 int event_iocp_shutdown_(struct event_iocp_port *port, long waitMsec);
    175 
    176 /* FIXME document. */
    177 int event_iocp_activate_overlapped_(struct event_iocp_port *port,
    178     struct event_overlapped *o,
    179     ev_uintptr_t key, ev_uint32_t n_bytes);
    180 
    181 struct event_base;
    182 /* FIXME document. */
    183 struct event_iocp_port *event_base_get_iocp_(struct event_base *base);
    184 
    185 /* FIXME document. */
    186 int event_base_start_iocp_(struct event_base *base, int n_cpus);
    187 void event_base_stop_iocp_(struct event_base *base);
    188 
    189 /* FIXME document. */
    190 struct bufferevent *bufferevent_async_new_(struct event_base *base,
    191     evutil_socket_t fd, int options);
    192 
    193 /* FIXME document. */
    194 void bufferevent_async_set_connected_(struct bufferevent *bev);
    195 int bufferevent_async_can_connect_(struct bufferevent *bev);
    196 int bufferevent_async_connect_(struct bufferevent *bev, evutil_socket_t fd,
    197 	const struct sockaddr *sa, int socklen);
    198 
    199 #ifdef __cplusplus
    200 }
    201 #endif
    202 
    203 #endif
    204