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 <afs/param.h>
13 # include <sys/types.h> /* fd_set on older platforms */
17 # include <winsock2.h>
19 # include <unistd.h> /* select() prototype */
20 # include <sys/time.h> /* struct timeval, select() prototype */
22 # include <sys/select.h> /* fd_set on newer platforms */
24 # include <sys/socket.h>
25 # include <sys/file.h>
27 # include <sys/stat.h>
28 # include <netinet/in.h>
30 # include <sys/ioctl.h>
31 # include <sys/time.h>
34 # include "rx_globals.h"
37 #define MAXTHREADNAMELENGTH 64
39 extern int (*registerProgram)();
40 extern int (*swapNameProgram)();
42 int debugSelectFailure; /* # of times select failed */
44 * Sleep on the unique wait channel provided.
46 void rxi_Sleep(void *addr)
48 LWP_WaitProcess(addr);
52 * Wakeup any threads on the channel provided.
53 * They may be woken up spuriously, and must check any conditions.
55 void rxi_Wakeup(void *addr)
57 LWP_NoYieldSignal(addr);
60 PROCESS rx_listenerPid = 0; /* LWP process id of socket listener process */
61 void rx_ListenerProc(void *dummy);
64 * Delay the current thread the specified number of seconds.
66 void rxi_Delay(int sec)
71 static int quitListening = 0;
73 /* This routine will kill the listener thread, if it exists. */
78 rxi_ReScheduleEvents();
81 /* This routine will get called by the event package whenever a new,
82 earlier than others, event is posted. If the Listener process
83 is blocked in selects, this will unblock it. It also can be called
84 to force a new trip through the rxi_Listener select loop when the set
85 of file descriptors it should be listening to changes... */
86 void rxi_ReScheduleEvents() {
87 if (rx_listenerPid) IOMGR_Cancel(rx_listenerPid);
90 void rxi_InitializeThreadSupport(void)
94 LWP_InitializeProcessSupport(LWP_NORMAL_PRIORITY, &junk);
96 FD_ZERO(&rx_selectMask);
99 void rxi_StartServerProc(proc, stacksize)
103 static int number = 0;
106 sprintf(name, "srv_%d", ++number);
107 LWP_CreateProcess(proc, stacksize, RX_PROCESS_PRIORITY,
108 0, "rx_ServerProc", &scratchPid);
110 (*registerProgram)(scratchPid, name);
113 void rxi_StartListener() {
114 /* Priority of listener should be high, so it can keep conns alive */
115 #define RX_LIST_STACK 24000
116 LWP_CreateProcess(rx_ListenerProc, RX_LIST_STACK, LWP_MAX_PRIORITY, 0,
117 "rx_Listener", &rx_listenerPid);
119 (*registerProgram)(rx_listenerPid, "listener");
122 /* The main loop which listens to the net for datagrams, and handles timeouts
123 and retransmissions, etc. It also is responsible for scheduling the
124 execution of pending events (in conjunction with event.c).
126 Note interaction of nextPollTime and lastPollWorked. The idea is that if rx is not
127 keeping up with the incoming stream of packets (because there are threads that
128 are interfering with its running sufficiently often), rx does a polling select
129 before doing a real IOMGR_Select system call. Doing a real select means that
130 we don't have to let other processes run before processing more packets.
132 So, our algorithm is that if the last poll on the file descriptor found useful data, or
133 we're at the time nextPollTime (which is advanced so that it occurs every 3 or 4 seconds),
134 then we try the polling select before the IOMGR_Select. If we eventually catch up
135 (which we can tell by the polling select returning no input packets ready), then we
136 don't do a polling select again until several seconds later (via nextPollTime mechanism).
139 void rxi_ListenerProc(rfds, tnop, newcallp)
142 struct rx_call **newcallp;
146 register struct rx_packet *p = (struct rx_packet *)0;
149 afs_int32 nextPollTime; /* time to next poll FD before sleeping */
150 int lastPollWorked, doingPoll; /* true iff last poll was useful */
151 struct timeval tv, *tvp;
154 char name[MAXTHREADNAMELENGTH] = "srv_0";
159 code = LWP_CurrentProcess(&pid);
161 fprintf(stderr, "rxi_Listener: Can't get my pid.\n");
164 rx_listenerPid = pid;
166 (*swapNameProgram)(pid, "listener", &name);
169 /* Grab a new packet only if necessary (otherwise re-use the old one) */
171 rxi_RestoreDataBufs(p);
174 if (!(p = rxi_AllocPacket(RX_PACKET_CLASS_RECEIVE)))
175 osi_Panic("rxi_ListenerProc: no packets!"); /* Shouldn't happen */
177 /* Wait for the next event time or a packet to arrive. */
178 /* event_RaiseEvents schedules any events whose time has come and
179 then atomically computes the time to the next event, guaranteeing
180 that this is positive. If there is no next event, it returns 0 */
182 if (!rxevent_RaiseEvents(&cv)) tvp = (struct timeval *) 0;
184 /* It's important to copy cv to tv, because the 4.3 documentation
185 for select threatens that *tv may be updated after a select, in
186 future editions of the system, to indicate how much of the time
187 period has elapsed. So we shouldn't rely on tv not being altered. */
188 tv.tv_sec = cv.sec; /* Time to next event */
189 tv.tv_usec = cv.usec;
194 *rfds = rx_selectMask;
196 if (lastPollWorked || nextPollTime < clock_Sec()) {
197 /* we're catching up, or haven't tried to for a few seconds */
199 nextPollTime = clock_Sec() + 4; /* try again in 4 seconds no matter what */
200 tv.tv_sec = tv.tv_usec = 0; /* make sure we poll */
202 code = select(rx_maxSocketNumber+1, rfds, 0, 0, tvp);
206 code = IOMGR_Select(rx_maxSocketNumber+1, rfds, 0, 0, tvp);
208 lastPollWorked = 0; /* default is that it didn't find anything */
212 LWP_DestroyProcess(pid);
218 * If it was a timer interrupt then we can assume that
219 * the time has advanced by roughly the value of the
220 * previous timeout, and that there is now at least
226 /* select or IOMGR_Select returned failure */
227 debugSelectFailure++; /* update debugging counter */
232 * IOMGR_Cancel is invoked whenever a new event is
233 * posted that is earlier than any existing events.
234 * So we re-evaluate the time, and then go back to
241 /* Packets have arrived, presumably:
242 * If it wasn't a timer interrupt, then no event should have
243 * timed out yet (well some event may have, but only just...), so
244 * we don't bother looking to see if any have timed out, but just
245 * go directly to reading the data packets
248 if (doingPoll) lastPollWorked = 1;
250 for (i=0; p && i<rfds->fd_count; i++) {
251 socket = rfds->fd_array[i];
252 if (rxi_ReadPacket(socket, p, &host, &port)) {
254 p = rxi_ReceivePacket(p, socket, host, port,
256 if (newcallp && *newcallp) {
260 if (swapNameProgram) {
261 (*swapNameProgram)(rx_listenerPid, &name, 0);
269 for (socket = rx_minSocketNumber;
270 p && socket <= rx_maxSocketNumber; socket++) {
271 if (!FD_ISSET(socket, rfds))
273 if (rxi_ReadPacket(socket, p, &host, &port)) {
274 p = rxi_ReceivePacket(p, socket, host, port,
276 if (newcallp && *newcallp) {
280 if (swapNameProgram) {
281 (*swapNameProgram)(rx_listenerPid, &name, 0);
295 /* This is the listener process request loop. The listener process loop
296 * becomes a server thread when rxi_ListenerProc returns, and stays
297 * server thread until rxi_ServerProc returns. */
298 static void rx_ListenerProc(void *dummy)
302 struct rx_call *newcall;
305 if (!(rfds = IOMGR_AllocFDSet())) {
306 osi_Panic("rx_ListenerProc: no fd_sets!\n");
312 rxi_ListenerProc(rfds, &threadID, &newcall);
313 /* assert(threadID != -1); */
314 /* assert(newcall != NULL); */
315 sock = OSI_NULLSOCKET;
316 rxi_ServerProc(threadID, newcall, &sock);
317 /* assert(sock != OSI_NULLSOCKET); */
322 /* This is the server process request loop. The server process loop
323 * becomes a listener thread when rxi_ServerProc returns, and stays
324 * listener thread until rxi_ListenerProc returns. */
329 struct rx_call *newcall = NULL;
332 if (!(rfds = IOMGR_AllocFDSet())) {
333 osi_Panic("rxi_ListenerProc: no fd_sets!\n");
336 rxi_MorePackets(rx_maxReceiveWindow+2); /* alloc more packets */
337 rxi_dataQuota += rx_initSendWindow; /* Reserve some pkts for hard times */
338 /* threadID is used for making decisions in GetCall. Get it by bumping
339 * number of threads handling incoming calls */
340 threadID = rxi_availProcs++;
343 sock = OSI_NULLSOCKET;
344 rxi_ServerProc(threadID, newcall, &sock);
345 /* assert(sock != OSI_NULLSOCKET); */
347 rxi_ListenerProc(rfds, &threadID, &newcall);
348 /* assert(threadID != -1); */
349 /* assert(newcall != NULL); */
355 * Called from GetUDPSocket.
356 * Called from a single thread at startup.
357 * Returns 0 on success; -1 on failure.
364 * Put the socket into non-blocking mode so that rx_Listener
365 * can do a polling read before entering select
367 if (fcntl(sock, F_SETFL, FNDELAY) == -1) {
369 (osi_Msg "rxi_Listen: unable to set non-blocking mode on socket\n");
373 if (sock > FD_SETSIZE-1) {
374 (osi_Msg "rxi_Listen: socket descriptor > (FD_SETSIZE-1) = %d\n",
380 FD_SET(sock, &rx_selectMask);
381 if (sock > rx_maxSocketNumber) rx_maxSocketNumber = sock;
382 if (sock < rx_minSocketNumber) rx_minSocketNumber = sock;
389 int rxi_Recvmsg(osi_socket socket, struct msghdr *msg_p, int flags)
391 return recvmsg((int) socket, msg_p, flags);
395 * Simulate a blocking sendmsg on the non-blocking socket.
396 * It's non blocking because it was set that way for recvmsg.
398 int rxi_Sendmsg(osi_socket socket, struct msghdr *msg_p, int flags)
400 fd_set *sfds = (fd_set*)0;
401 while (sendmsg(socket, msg_p, flags) == -1) {
403 rx_stats.sendSelects++;
406 if ( !(sfds = IOMGR_AllocFDSet())) {
407 (osi_Msg "rx failed to alloc fd_set: ");
408 perror("rx_sendmsg");
411 FD_SET(socket, sfds);
416 #elif defined(AFS_LINUX22_ENV)
417 /* linux unfortunately returns ECONNREFUSED if the target port
418 * is no longer in use */
419 if (errno != EWOULDBLOCK && errno != ENOBUFS && errno != ECONNREFUSED)
421 if (errno != EWOULDBLOCK && errno != ENOBUFS)
424 (osi_Msg "rx failed to send packet: ");
425 perror("rx_sendmsg");
428 while ((err = select(socket+1, 0, sfds, 0, 0)) != 1) {
429 if (err >= 0 || errno != EINTR)
430 osi_Panic("rxi_sendmsg: select error %d.%d", err, errno);
434 IOMGR_FreeFDSet(sfds);