2 * Copyright 2000, International Business Machines Corporation and others.
5 * This software has been released under the terms of the IBM Public
6 * License. For details, see the LICENSE file in the top-level source
7 * directory or online at http://www.openafs.org/dl/license10.html
10 /* rx_user.c contains routines specific to the user space UNIX implementation of rx */
12 #include <afsconfig.h>
13 #include <afs/param.h>
17 # include <sys/types.h> /* fd_set on older platforms */
21 # include <winsock2.h>
23 # include <unistd.h> /* select() prototype */
24 # include <sys/time.h> /* struct timeval, select() prototype */
26 # include <sys/select.h> /* fd_set on newer platforms */
28 # include <sys/socket.h>
29 # include <sys/file.h>
31 # include <sys/stat.h>
32 # include <netinet/in.h>
34 # include <sys/ioctl.h>
35 # include <sys/time.h>
38 # include "rx_globals.h"
41 #define MAXTHREADNAMELENGTH 64
43 extern int (*registerProgram)();
44 extern int (*swapNameProgram)();
46 int debugSelectFailure; /* # of times select failed */
48 * Sleep on the unique wait channel provided.
50 void rxi_Sleep(void *addr)
52 LWP_WaitProcess(addr);
56 * Wakeup any threads on the channel provided.
57 * They may be woken up spuriously, and must check any conditions.
59 void rxi_Wakeup(void *addr)
61 LWP_NoYieldSignal(addr);
64 PROCESS rx_listenerPid = 0; /* LWP process id of socket listener process */
65 static void rx_ListenerProc(void *dummy);
68 * Delay the current thread the specified number of seconds.
70 void rxi_Delay(int sec)
75 static int quitListening = 0;
77 /* This routine will kill the listener thread, if it exists. */
82 rxi_ReScheduleEvents();
85 /* This routine will get called by the event package whenever a new,
86 earlier than others, event is posted. If the Listener process
87 is blocked in selects, this will unblock it. It also can be called
88 to force a new trip through the rxi_Listener select loop when the set
89 of file descriptors it should be listening to changes... */
90 void rxi_ReScheduleEvents() {
91 if (rx_listenerPid) IOMGR_Cancel(rx_listenerPid);
94 void rxi_InitializeThreadSupport(void)
98 LWP_InitializeProcessSupport(LWP_NORMAL_PRIORITY, &junk);
100 FD_ZERO(&rx_selectMask);
103 void rxi_StartServerProc(proc, stacksize)
107 static int number = 0;
110 sprintf(name, "srv_%d", ++number);
111 LWP_CreateProcess(proc, stacksize, RX_PROCESS_PRIORITY,
112 0, "rx_ServerProc", &scratchPid);
114 (*registerProgram)(scratchPid, name);
117 void rxi_StartListener() {
118 /* Priority of listener should be high, so it can keep conns alive */
119 #define RX_LIST_STACK 24000
120 LWP_CreateProcess(rx_ListenerProc, RX_LIST_STACK, LWP_MAX_PRIORITY, 0,
121 "rx_Listener", &rx_listenerPid);
123 (*registerProgram)(rx_listenerPid, "listener");
126 /* The main loop which listens to the net for datagrams, and handles timeouts
127 and retransmissions, etc. It also is responsible for scheduling the
128 execution of pending events (in conjunction with event.c).
130 Note interaction of nextPollTime and lastPollWorked. The idea is that if rx is not
131 keeping up with the incoming stream of packets (because there are threads that
132 are interfering with its running sufficiently often), rx does a polling select
133 before doing a real IOMGR_Select system call. Doing a real select means that
134 we don't have to let other processes run before processing more packets.
136 So, our algorithm is that if the last poll on the file descriptor found useful data, or
137 we're at the time nextPollTime (which is advanced so that it occurs every 3 or 4 seconds),
138 then we try the polling select before the IOMGR_Select. If we eventually catch up
139 (which we can tell by the polling select returning no input packets ready), then we
140 don't do a polling select again until several seconds later (via nextPollTime mechanism).
143 void rxi_ListenerProc(rfds, tnop, newcallp)
146 struct rx_call **newcallp;
150 register struct rx_packet *p = (struct rx_packet *)0;
153 afs_int32 nextPollTime; /* time to next poll FD before sleeping */
154 int lastPollWorked, doingPoll; /* true iff last poll was useful */
155 struct timeval tv, *tvp;
161 char name[MAXTHREADNAMELENGTH] = "srv_0";
166 code = LWP_CurrentProcess(&pid);
168 fprintf(stderr, "rxi_Listener: Can't get my pid.\n");
171 rx_listenerPid = pid;
173 (*swapNameProgram)(pid, "listener", &name);
176 /* Grab a new packet only if necessary (otherwise re-use the old one) */
178 rxi_RestoreDataBufs(p);
181 if (!(p = rxi_AllocPacket(RX_PACKET_CLASS_RECEIVE)))
182 osi_Panic("rxi_ListenerProc: no packets!"); /* Shouldn't happen */
184 /* Wait for the next event time or a packet to arrive. */
185 /* event_RaiseEvents schedules any events whose time has come and
186 then atomically computes the time to the next event, guaranteeing
187 that this is positive. If there is no next event, it returns 0 */
189 if (!rxevent_RaiseEvents(&cv)) tvp = (struct timeval *) 0;
191 /* It's important to copy cv to tv, because the 4.3 documentation
192 for select threatens that *tv may be updated after a select, in
193 future editions of the system, to indicate how much of the time
194 period has elapsed. So we shouldn't rely on tv not being altered. */
195 tv.tv_sec = cv.sec; /* Time to next event */
196 tv.tv_usec = cv.usec;
201 *rfds = rx_selectMask;
203 if (lastPollWorked || nextPollTime < clock_Sec()) {
204 /* we're catching up, or haven't tried to for a few seconds */
206 nextPollTime = clock_Sec() + 4; /* try again in 4 seconds no matter what */
207 tv.tv_sec = tv.tv_usec = 0; /* make sure we poll */
209 code = select(rx_maxSocketNumber+1, rfds, 0, 0, tvp);
213 code = IOMGR_Select(rx_maxSocketNumber+1, rfds, 0, 0, tvp);
215 lastPollWorked = 0; /* default is that it didn't find anything */
219 LWP_DestroyProcess(pid);
225 * If it was a timer interrupt then we can assume that
226 * the time has advanced by roughly the value of the
227 * previous timeout, and that there is now at least
233 /* select or IOMGR_Select returned failure */
234 debugSelectFailure++; /* update debugging counter */
239 * IOMGR_Cancel is invoked whenever a new event is
240 * posted that is earlier than any existing events.
241 * So we re-evaluate the time, and then go back to
248 /* Packets have arrived, presumably:
249 * If it wasn't a timer interrupt, then no event should have
250 * timed out yet (well some event may have, but only just...), so
251 * we don't bother looking to see if any have timed out, but just
252 * go directly to reading the data packets
255 if (doingPoll) lastPollWorked = 1;
257 for (i=0; p && i<rfds->fd_count; i++) {
258 socket = rfds->fd_array[i];
259 if (rxi_ReadPacket(socket, p, &host, &port)) {
261 p = rxi_ReceivePacket(p, socket, host, port,
263 if (newcallp && *newcallp) {
267 if (swapNameProgram) {
268 (*swapNameProgram)(rx_listenerPid, &name, 0);
276 for (socket = rx_minSocketNumber;
277 p && socket <= rx_maxSocketNumber; socket++) {
278 if (!FD_ISSET(socket, rfds))
280 if (rxi_ReadPacket(socket, p, &host, &port)) {
281 p = rxi_ReceivePacket(p, socket, host, port,
283 if (newcallp && *newcallp) {
287 if (swapNameProgram) {
288 (*swapNameProgram)(rx_listenerPid, &name, 0);
302 /* This is the listener process request loop. The listener process loop
303 * becomes a server thread when rxi_ListenerProc returns, and stays
304 * server thread until rxi_ServerProc returns. */
305 static void rx_ListenerProc(void *dummy)
309 struct rx_call *newcall;
312 if (!(rfds = IOMGR_AllocFDSet())) {
313 osi_Panic("rx_ListenerProc: no fd_sets!\n");
319 rxi_ListenerProc(rfds, &threadID, &newcall);
320 /* assert(threadID != -1); */
321 /* assert(newcall != NULL); */
322 sock = OSI_NULLSOCKET;
323 rxi_ServerProc(threadID, newcall, &sock);
324 /* assert(sock != OSI_NULLSOCKET); */
329 /* This is the server process request loop. The server process loop
330 * becomes a listener thread when rxi_ServerProc returns, and stays
331 * listener thread until rxi_ListenerProc returns. */
336 struct rx_call *newcall = NULL;
339 if (!(rfds = IOMGR_AllocFDSet())) {
340 osi_Panic("rxi_ListenerProc: no fd_sets!\n");
343 rxi_MorePackets(rx_maxReceiveWindow+2); /* alloc more packets */
344 rxi_dataQuota += rx_initSendWindow; /* Reserve some pkts for hard times */
345 /* threadID is used for making decisions in GetCall. Get it by bumping
346 * number of threads handling incoming calls */
347 threadID = rxi_availProcs++;
350 sock = OSI_NULLSOCKET;
351 rxi_ServerProc(threadID, newcall, &sock);
352 /* assert(sock != OSI_NULLSOCKET); */
354 rxi_ListenerProc(rfds, &threadID, &newcall);
355 /* assert(threadID != -1); */
356 /* assert(newcall != NULL); */
362 * Called from GetUDPSocket.
363 * Called from a single thread at startup.
364 * Returns 0 on success; -1 on failure.
371 * Put the socket into non-blocking mode so that rx_Listener
372 * can do a polling read before entering select
374 #ifndef AFS_DJGPP_ENV
375 if (fcntl(sock, F_SETFL, FNDELAY) == -1) {
377 (osi_Msg "rxi_Listen: unable to set non-blocking mode on socket\n");
381 if ( __djgpp_set_socket_blocking_mode(sock, 1) < 0 ) {
382 perror("__djgpp_set_socket_blocking_mode");
383 (osi_Msg "rxi_Listen: unable to set non-blocking mode on socket\n");
386 #endif /* AFS_DJGPP_ENV */
388 if (sock > FD_SETSIZE-1) {
389 (osi_Msg "rxi_Listen: socket descriptor > (FD_SETSIZE-1) = %d\n",
395 FD_SET(sock, &rx_selectMask);
396 if (sock > rx_maxSocketNumber) rx_maxSocketNumber = sock;
397 if (sock < rx_minSocketNumber) rx_minSocketNumber = sock;
404 int rxi_Recvmsg(osi_socket socket, struct msghdr *msg_p, int flags)
406 return recvmsg((int) socket, msg_p, flags);
410 * Simulate a blocking sendmsg on the non-blocking socket.
411 * It's non blocking because it was set that way for recvmsg.
413 int rxi_Sendmsg(osi_socket socket, struct msghdr *msg_p, int flags)
415 fd_set *sfds = (fd_set*)0;
416 while (sendmsg(socket, msg_p, flags) == -1) {
418 rx_stats.sendSelects++;
421 if ( !(sfds = IOMGR_AllocFDSet())) {
422 (osi_Msg "rx failed to alloc fd_set: ");
423 perror("rx_sendmsg");
426 FD_SET(socket, sfds);
431 #elif defined(AFS_LINUX22_ENV)
432 /* linux unfortunately returns ECONNREFUSED if the target port
433 * is no longer in use */
434 if (errno != EWOULDBLOCK && errno != ENOBUFS && errno != ECONNREFUSED)
436 if (errno != EWOULDBLOCK && errno != ENOBUFS)
439 (osi_Msg "rx failed to send packet: ");
440 perror("rx_sendmsg");
443 while ((err = select(socket+1, 0, sfds, 0, 0)) != 1) {
444 if (err >= 0 || errno != EINTR)
445 osi_Panic("rxi_sendmsg: select error %d.%d", err, errno);
449 IOMGR_FreeFDSet(sfds);