xref: /netbsd-src/external/bsd/ntp/dist/sntp/libevent/iocp-internal.h (revision eabc0478de71e4e011a5b4e0392741e01d491794)
1 /*	$NetBSD: iocp-internal.h,v 1.6 2024/08/18 20:47:21 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 EVENT2_EXPORT_SYMBOL
98 const struct win32_extension_fns *event_get_win32_extension_fns_(void);
99 #else
100 /* Dummy definition so we can test-compile more things on unix. */
101 struct event_overlapped {
102 	iocp_callback cb;
103 };
104 #endif
105 
106 /** Initialize the fields in an event_overlapped.
107 
108     @param overlapped The struct event_overlapped to initialize
109     @param cb The callback that should be invoked once the IO operation has
110 	finished.
111  */
112 EVENT2_EXPORT_SYMBOL
113 void event_overlapped_init_(struct event_overlapped *, iocp_callback cb);
114 
115 /** Allocate and return a new evbuffer that supports overlapped IO on a given
116     socket.  The socket must be associated with an IO completion port using
117     event_iocp_port_associate_.
118 */
119 EVENT2_EXPORT_SYMBOL
120 struct evbuffer *evbuffer_overlapped_new_(evutil_socket_t fd);
121 
122 /** XXXX Document (nickm) */
123 evutil_socket_t evbuffer_overlapped_get_fd_(struct evbuffer *buf);
124 
125 void evbuffer_overlapped_set_fd_(struct evbuffer *buf, evutil_socket_t fd);
126 
127 /** Start reading data onto the end of an overlapped evbuffer.
128 
129     An evbuffer can only have one read pending at a time.  While the read
130     is in progress, no other data may be added to the end of the buffer.
131     The buffer must be created with event_overlapped_init_().
132     evbuffer_commit_read_() must be called in the completion callback.
133 
134     @param buf The buffer to read onto
135     @param n The number of bytes to try to read.
136     @param ol Overlapped object with associated completion callback.
137     @return 0 on success, -1 on error.
138  */
139 EVENT2_EXPORT_SYMBOL
140 int evbuffer_launch_read_(struct evbuffer *buf, size_t n, struct event_overlapped *ol);
141 
142 /** Start writing data from the start of an evbuffer.
143 
144     An evbuffer can only have one write pending at a time.  While the write is
145     in progress, no other data may be removed from the front of the buffer.
146     The buffer must be created with event_overlapped_init_().
147     evbuffer_commit_write_() must be called in the completion callback.
148 
149     @param buf The buffer to read onto
150     @param n The number of bytes to try to read.
151     @param ol Overlapped object with associated completion callback.
152     @return 0 on success, -1 on error.
153  */
154 EVENT2_EXPORT_SYMBOL
155 int evbuffer_launch_write_(struct evbuffer *buf, ev_ssize_t n, struct event_overlapped *ol);
156 
157 /** XXX document */
158 EVENT2_EXPORT_SYMBOL
159 void evbuffer_commit_read_(struct evbuffer *, ev_ssize_t);
160 EVENT2_EXPORT_SYMBOL
161 void evbuffer_commit_write_(struct evbuffer *, ev_ssize_t);
162 
163 /** Create an IOCP, and launch its worker threads.  Internal use only.
164 
165     This interface is unstable, and will change.
166  */
167 EVENT2_EXPORT_SYMBOL
168 struct event_iocp_port *event_iocp_port_launch_(int n_cpus);
169 
170 /** Associate a file descriptor with an iocp, such that overlapped IO on the
171     fd will happen on one of the iocp's worker threads.
172 */
173 EVENT2_EXPORT_SYMBOL
174 int event_iocp_port_associate_(struct event_iocp_port *port, evutil_socket_t fd,
175     ev_uintptr_t key);
176 
177 /** Tell all threads serving an iocp to stop.  Wait for up to waitMsec for all
178     the threads to finish whatever they're doing.  If waitMsec is -1, wait
179     as long as required.  If all the threads are done, free the port and return
180     0. Otherwise, return -1.  If you get a -1 return value, it is safe to call
181     this function again.
182 */
183 EVENT2_EXPORT_SYMBOL
184 int event_iocp_shutdown_(struct event_iocp_port *port, long waitMsec);
185 
186 /* FIXME document. */
187 EVENT2_EXPORT_SYMBOL
188 int event_iocp_activate_overlapped_(struct event_iocp_port *port,
189     struct event_overlapped *o,
190     ev_uintptr_t key, ev_uint32_t n_bytes);
191 
192 struct event_base;
193 /* FIXME document. */
194 EVENT2_EXPORT_SYMBOL
195 struct event_iocp_port *event_base_get_iocp_(struct event_base *base);
196 
197 /* FIXME document. */
198 EVENT2_EXPORT_SYMBOL
199 int event_base_start_iocp_(struct event_base *base, int n_cpus);
200 void event_base_stop_iocp_(struct event_base *base);
201 
202 /* FIXME document. */
203 EVENT2_EXPORT_SYMBOL
204 struct bufferevent *bufferevent_async_new_(struct event_base *base,
205     evutil_socket_t fd, int options);
206 
207 /* FIXME document. */
208 void bufferevent_async_set_connected_(struct bufferevent *bev);
209 int bufferevent_async_can_connect_(struct bufferevent *bev);
210 int bufferevent_async_connect_(struct bufferevent *bev, evutil_socket_t fd,
211 	const struct sockaddr *sa, int socklen);
212 
213 #ifdef __cplusplus
214 }
215 #endif
216 
217 #endif
218