1/*	$NetBSD: iocp-internal.h,v 1.5 2020/05/25 20:47:33 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
33extern "C" {
34#endif
35
36struct event_overlapped;
37struct event_iocp_port;
38struct evbuffer;
39typedef 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 */
53struct event_overlapped {
54	OVERLAPPED overlapped;
55	iocp_callback cb;
56};
57
58/* Mingw's headers don't define LPFN_ACCEPTEX. */
59
60typedef BOOL (WINAPI *AcceptExPtr)(SOCKET, SOCKET, PVOID, DWORD, DWORD, DWORD, LPDWORD, LPOVERLAPPED);
61typedef BOOL (WINAPI *ConnectExPtr)(SOCKET, const struct sockaddr *, int, PVOID, DWORD, LPDWORD, LPOVERLAPPED);
62typedef 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 */
67struct 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 */
77struct 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
97const struct win32_extension_fns *event_get_win32_extension_fns_(void);
98#else
99/* Dummy definition so we can test-compile more things on unix. */
100struct 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 */
111void 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*/
117struct evbuffer *evbuffer_overlapped_new_(evutil_socket_t fd);
118
119/** XXXX Document (nickm) */
120evutil_socket_t evbuffer_overlapped_get_fd_(struct evbuffer *buf);
121
122void 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 */
136int 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 */
150int evbuffer_launch_write_(struct evbuffer *buf, ev_ssize_t n, struct event_overlapped *ol);
151
152/** XXX document */
153void evbuffer_commit_read_(struct evbuffer *, ev_ssize_t);
154void 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 */
160struct 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*/
165int 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*/
174int event_iocp_shutdown_(struct event_iocp_port *port, long waitMsec);
175
176/* FIXME document. */
177int 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
181struct event_base;
182/* FIXME document. */
183struct event_iocp_port *event_base_get_iocp_(struct event_base *base);
184
185/* FIXME document. */
186int event_base_start_iocp_(struct event_base *base, int n_cpus);
187void event_base_stop_iocp_(struct event_base *base);
188
189/* FIXME document. */
190struct bufferevent *bufferevent_async_new_(struct event_base *base,
191    evutil_socket_t fd, int options);
192
193/* FIXME document. */
194void bufferevent_async_set_connected_(struct bufferevent *bev);
195int bufferevent_async_can_connect_(struct bufferevent *bev);
196int 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