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iocp-internal.h revision 1.1.1.3
      1 /*	$NetBSD: iocp-internal.h,v 1.1.1.3 2021/04/07 02:43:12 christos Exp $	*/
      2 /*
      3  * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. The name of the author may not be used to endorse or promote products
     14  *    derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #ifndef IOCP_INTERNAL_H_INCLUDED_
     29 #define IOCP_INTERNAL_H_INCLUDED_
     30 
     31 #ifdef __cplusplus
     32 extern "C" {
     33 #endif
     34 
     35 struct event_overlapped;
     36 struct event_iocp_port;
     37 struct evbuffer;
     38 typedef void (*iocp_callback)(struct event_overlapped *, ev_uintptr_t, ev_ssize_t, int success);
     39 
     40 /* This whole file is actually win32 only. We wrap the structures in a win32
     41  * ifdef so that we can test-compile code that uses these interfaces on
     42  * non-win32 platforms. */
     43 #ifdef _WIN32
     44 
     45 /**
     46    Internal use only.  Wraps an OVERLAPPED that we're using for libevent
     47    functionality.  Whenever an event_iocp_port gets an event for a given
     48    OVERLAPPED*, it upcasts the pointer to an event_overlapped, and calls the
     49    iocp_callback function with the event_overlapped, the iocp key, and the
     50    number of bytes transferred as arguments.
     51  */
     52 struct event_overlapped {
     53 	OVERLAPPED overlapped;
     54 	iocp_callback cb;
     55 };
     56 
     57 /* Mingw's headers don't define LPFN_ACCEPTEX. */
     58 
     59 typedef BOOL (WINAPI *AcceptExPtr)(SOCKET, SOCKET, PVOID, DWORD, DWORD, DWORD, LPDWORD, LPOVERLAPPED);
     60 typedef BOOL (WINAPI *ConnectExPtr)(SOCKET, const struct sockaddr *, int, PVOID, DWORD, LPDWORD, LPOVERLAPPED);
     61 typedef void (WINAPI *GetAcceptExSockaddrsPtr)(PVOID, DWORD, DWORD, DWORD, LPSOCKADDR *, LPINT, LPSOCKADDR *, LPINT);
     62 
     63 /** Internal use only. Holds pointers to functions that only some versions of
     64     Windows provide.
     65  */
     66 struct win32_extension_fns {
     67 	AcceptExPtr AcceptEx;
     68 	ConnectExPtr ConnectEx;
     69 	GetAcceptExSockaddrsPtr GetAcceptExSockaddrs;
     70 };
     71 
     72 /**
     73     Internal use only. Stores a Windows IO Completion port, along with
     74     related data.
     75  */
     76 struct event_iocp_port {
     77 	/** The port itself */
     78 	HANDLE port;
     79 	/* A lock to cover internal structures. */
     80 	CRITICAL_SECTION lock;
     81 	/** Number of threads ever open on the port. */
     82 	short n_threads;
     83 	/** True iff we're shutting down all the threads on this port */
     84 	short shutdown;
     85 	/** How often the threads on this port check for shutdown and other
     86 	 * conditions */
     87 	long ms;
     88 	/* The threads that are waiting for events. */
     89 	HANDLE *threads;
     90 	/** Number of threads currently open on this port. */
     91 	short n_live_threads;
     92 	/** A semaphore to signal when we are done shutting down. */
     93 	HANDLE *shutdownSemaphore;
     94 };
     95 
     96 EVENT2_EXPORT_SYMBOL
     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 EVENT2_EXPORT_SYMBOL
    112 void event_overlapped_init_(struct event_overlapped *, iocp_callback cb);
    113 
    114 /** Allocate and return a new evbuffer that supports overlapped IO on a given
    115     socket.  The socket must be associated with an IO completion port using
    116     event_iocp_port_associate_.
    117 */
    118 EVENT2_EXPORT_SYMBOL
    119 struct evbuffer *evbuffer_overlapped_new_(evutil_socket_t fd);
    120 
    121 /** XXXX Document (nickm) */
    122 evutil_socket_t evbuffer_overlapped_get_fd_(struct evbuffer *buf);
    123 
    124 void evbuffer_overlapped_set_fd_(struct evbuffer *buf, evutil_socket_t fd);
    125 
    126 /** Start reading data onto the end of an overlapped evbuffer.
    127 
    128     An evbuffer can only have one read pending at a time.  While the read
    129     is in progress, no other data may be added to the end of the buffer.
    130     The buffer must be created with event_overlapped_init_().
    131     evbuffer_commit_read_() must be called in the completion callback.
    132 
    133     @param buf The buffer to read onto
    134     @param n The number of bytes to try to read.
    135     @param ol Overlapped object with associated completion callback.
    136     @return 0 on success, -1 on error.
    137  */
    138 EVENT2_EXPORT_SYMBOL
    139 int evbuffer_launch_read_(struct evbuffer *buf, size_t n, struct event_overlapped *ol);
    140 
    141 /** Start writing data from the start of an evbuffer.
    142 
    143     An evbuffer can only have one write pending at a time.  While the write is
    144     in progress, no other data may be removed from the front of the buffer.
    145     The buffer must be created with event_overlapped_init_().
    146     evbuffer_commit_write_() must be called in the completion callback.
    147 
    148     @param buf The buffer to read onto
    149     @param n The number of bytes to try to read.
    150     @param ol Overlapped object with associated completion callback.
    151     @return 0 on success, -1 on error.
    152  */
    153 EVENT2_EXPORT_SYMBOL
    154 int evbuffer_launch_write_(struct evbuffer *buf, ev_ssize_t n, struct event_overlapped *ol);
    155 
    156 /** XXX document */
    157 EVENT2_EXPORT_SYMBOL
    158 void evbuffer_commit_read_(struct evbuffer *, ev_ssize_t);
    159 EVENT2_EXPORT_SYMBOL
    160 void evbuffer_commit_write_(struct evbuffer *, ev_ssize_t);
    161 
    162 /** Create an IOCP, and launch its worker threads.  Internal use only.
    163 
    164     This interface is unstable, and will change.
    165  */
    166 EVENT2_EXPORT_SYMBOL
    167 struct event_iocp_port *event_iocp_port_launch_(int n_cpus);
    168 
    169 /** Associate a file descriptor with an iocp, such that overlapped IO on the
    170     fd will happen on one of the iocp's worker threads.
    171 */
    172 EVENT2_EXPORT_SYMBOL
    173 int event_iocp_port_associate_(struct event_iocp_port *port, evutil_socket_t fd,
    174     ev_uintptr_t key);
    175 
    176 /** Tell all threads serving an iocp to stop.  Wait for up to waitMsec for all
    177     the threads to finish whatever they're doing.  If waitMsec is -1, wait
    178     as long as required.  If all the threads are done, free the port and return
    179     0. Otherwise, return -1.  If you get a -1 return value, it is safe to call
    180     this function again.
    181 */
    182 EVENT2_EXPORT_SYMBOL
    183 int event_iocp_shutdown_(struct event_iocp_port *port, long waitMsec);
    184 
    185 /* FIXME document. */
    186 EVENT2_EXPORT_SYMBOL
    187 int event_iocp_activate_overlapped_(struct event_iocp_port *port,
    188     struct event_overlapped *o,
    189     ev_uintptr_t key, ev_uint32_t n_bytes);
    190 
    191 struct event_base;
    192 /* FIXME document. */
    193 EVENT2_EXPORT_SYMBOL
    194 struct event_iocp_port *event_base_get_iocp_(struct event_base *base);
    195 
    196 /* FIXME document. */
    197 EVENT2_EXPORT_SYMBOL
    198 int event_base_start_iocp_(struct event_base *base, int n_cpus);
    199 void event_base_stop_iocp_(struct event_base *base);
    200 
    201 /* FIXME document. */
    202 EVENT2_EXPORT_SYMBOL
    203 struct bufferevent *bufferevent_async_new_(struct event_base *base,
    204     evutil_socket_t fd, int options);
    205 
    206 /* FIXME document. */
    207 void bufferevent_async_set_connected_(struct bufferevent *bev);
    208 int bufferevent_async_can_connect_(struct bufferevent *bev);
    209 int bufferevent_async_connect_(struct bufferevent *bev, evutil_socket_t fd,
    210 	const struct sockaddr *sa, int socklen);
    211 
    212 #ifdef __cplusplus
    213 }
    214 #endif
    215 
    216 #endif
    217