release/src/router/dnscrypt/src/libevent-modified/iocp-internal.h

   1 /*
   2  * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  * 3. The name of the author may not be used to endorse or promote products
  13  *    derived from this software without specific prior written permission.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #ifndef _EVENT_IOCP_INTERNAL_H
  28 #define _EVENT_IOCP_INTERNAL_H
  29
  30 #ifdef __cplusplus
  31 extern "C" {
  32 #endif
  33
  34 struct event_overlapped;
  35 struct event_iocp_port;
  36 struct evbuffer;
  37 typedef void (*iocp_callback)(struct event_overlapped *, ev_uintptr_t, ev_ssize_t, int success);
  38
  39 /* This whole file is actually win32 only. We wrap the structures in a win32
  40  * ifdef so that we can test-compile code that uses these interfaces on
  41  * non-win32 platforms. */
  42 #ifdef WIN32
  43
  44 /**
  45    Internal use only.  Wraps an OVERLAPPED that we're using for libevent
  46    functionality.  Whenever an event_iocp_port gets an event for a given
  47    OVERLAPPED*, it upcasts the pointer to an event_overlapped, and calls the
  48    iocp_callback function with the event_overlapped, the iocp key, and the
  49    number of bytes transferred as arguments.
  50  */
  51 struct event_overlapped {
  52         OVERLAPPED overlapped;
  53         iocp_callback cb;
  54 };
  55
  56 /* Mingw's headers don't define LPFN_ACCEPTEX. */
  57
  58 typedef BOOL (WINAPI *AcceptExPtr)(SOCKET, SOCKET, PVOID, DWORD, DWORD, DWORD, LPDWORD, LPOVERLAPPED);
  59 typedef BOOL (WINAPI *ConnectExPtr)(SOCKET, const struct sockaddr *, int, PVOID, DWORD, LPDWORD, LPOVERLAPPED);
  60 typedef void (WINAPI *GetAcceptExSockaddrsPtr)(PVOID, DWORD, DWORD, DWORD, LPSOCKADDR *, LPINT, LPSOCKADDR *, LPINT);
  61
  62 /** Internal use only. Holds pointers to functions that only some versions of
  63     Windows provide.
  64  */
  65 struct win32_extension_fns {
  66         AcceptExPtr AcceptEx;
  67         ConnectExPtr ConnectEx;
  68         GetAcceptExSockaddrsPtr GetAcceptExSockaddrs;
  69 };
  70
  71 /**
  72     Internal use only. Stores a Windows IO Completion port, along with
  73     related data.
  74  */
  75 struct event_iocp_port {
  76         /** The port itself */
  77         HANDLE port;
  78         /* A lock to cover internal structures. */
  79         CRITICAL_SECTION lock;
  80         /** Number of threads ever open on the port. */
  81         short n_threads;
  82         /** True iff we're shutting down all the threads on this port */
  83         short shutdown;
  84         /** How often the threads on this port check for shutdown and other
  85          * conditions */
  86         long ms;
  87         /* The threads that are waiting for events. */
  88         HANDLE *threads;
  89         /** Number of threads currently open on this port. */
  90         short n_live_threads;
  91         /** A semaphore to signal when we are done shutting down. */
  92         HANDLE *shutdownSemaphore;
  93 };
  94
  95 const struct win32_extension_fns *event_get_win32_extension_fns(void);
  96 #else
  97 /* Dummy definition so we can test-compile more things on unix. */
  98 struct event_overlapped {
  99         iocp_callback cb;
 100 };
 101 #endif
 102
 103 /** Initialize the fields in an event_overlapped.
 104
 105     @param overlapped The struct event_overlapped to initialize
 106     @param cb The callback that should be invoked once the IO operation has
 107         finished.
 108  */
 109 void event_overlapped_init(struct event_overlapped *, iocp_callback cb);
 110
 111 /** Allocate and return a new evbuffer that supports overlapped IO on a given
 112     socket.  The socket must be associated with an IO completion port using
 113     event_iocp_port_associate.
 114 */
 115 struct evbuffer *evbuffer_overlapped_new(evutil_socket_t fd);
 116
 117 /** XXXX Document (nickm) */
 118 evutil_socket_t _evbuffer_overlapped_get_fd(struct evbuffer *buf);
 119
 120 void _evbuffer_overlapped_set_fd(struct evbuffer *buf, evutil_socket_t fd);
 121
 122 /** Start reading data onto the end of an overlapped evbuffer.
 123
 124     An evbuffer can only have one read pending at a time.  While the read
 125     is in progress, no other data may be added to the end of the buffer.
 126     The buffer must be created with event_overlapped_init().
 127     evbuffer_commit_read() must be called in the completion callback.
 128
 129     @param buf The buffer to read onto
 130     @param n The number of bytes to try to read.
 131     @param ol Overlapped object with associated completion callback.
 132     @return 0 on success, -1 on error.
 133  */
 134 int evbuffer_launch_read(struct evbuffer *buf, size_t n, struct event_overlapped *ol);
 135
 136 /** Start writing data from the start of an evbuffer.
 137
 138     An evbuffer can only have one write pending at a time.  While the write is
 139     in progress, no other data may be removed from the front of the buffer.
 140     The buffer must be created with event_overlapped_init().
 141     evbuffer_commit_write() must be called in the completion callback.
 142
 143     @param buf The buffer to read onto
 144     @param n The number of bytes to try to read.
 145     @param ol Overlapped object with associated completion callback.
 146     @return 0 on success, -1 on error.
 147  */
 148 int evbuffer_launch_write(struct evbuffer *buf, ev_ssize_t n, struct event_overlapped *ol);
 149
 150 /** XXX document */
 151 void evbuffer_commit_read(struct evbuffer *, ev_ssize_t);
 152 void evbuffer_commit_write(struct evbuffer *, ev_ssize_t);
 153
 154 /** Create an IOCP, and launch its worker threads.  Internal use only.
 155
 156     This interface is unstable, and will change.
 157  */
 158 struct event_iocp_port *event_iocp_port_launch(int n_cpus);
 159
 160 /** Associate a file descriptor with an iocp, such that overlapped IO on the
 161     fd will happen on one of the iocp's worker threads.
 162 */
 163 int event_iocp_port_associate(struct event_iocp_port *port, evutil_socket_t fd,
 164     ev_uintptr_t key);
 165
 166 /** Tell all threads serving an iocp to stop.  Wait for up to waitMsec for all
 167     the threads to finish whatever they're doing.  If waitMsec is -1, wait
 168     as long as required.  If all the threads are done, free the port and return
 169     0. Otherwise, return -1.  If you get a -1 return value, it is safe to call
 170     this function again.
 171 */
 172 int event_iocp_shutdown(struct event_iocp_port *port, long waitMsec);
 173
 174 /* FIXME document. */
 175 int event_iocp_activate_overlapped(struct event_iocp_port *port,
 176     struct event_overlapped *o,
 177     ev_uintptr_t key, ev_uint32_t n_bytes);
 178
 179 struct event_base;
 180 /* FIXME document. */
 181 struct event_iocp_port *event_base_get_iocp(struct event_base *base);
 182
 183 /* FIXME document. */
 184 int event_base_start_iocp(struct event_base *base, int n_cpus);
 185 void event_base_stop_iocp(struct event_base *base);
 186
 187 /* FIXME document. */
 188 struct bufferevent *bufferevent_async_new(struct event_base *base,
 189     evutil_socket_t fd, int options);
 190
 191 /* FIXME document. */
 192 void bufferevent_async_set_connected(struct bufferevent *bev);
 193 int bufferevent_async_can_connect(struct bufferevent *bev);
 194 int bufferevent_async_connect(struct bufferevent *bev, evutil_socket_t fd,
 195         const struct sockaddr *sa, int socklen);
 196
 197 #ifdef __cplusplus
 198 }
 199 #endif
 200
 201 #endif