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 /* This controls the size of an fd_set; it must be defined early before
13 * the system headers define that type and the macros that operate on it.
14 * Its value should be as large as the maximum file descriptor limit we
15 * are likely to run into on any platform. Right now, that is 65536
16 * which is the default hard fd limit on Solaris 9 */
18 #define FD_SETSIZE 65536
21 #include <afsconfig.h>
22 #include <afs/param.h>
27 # include <sys/types.h> /* fd_set on older platforms */
31 # include <winsock2.h>
33 # include <unistd.h> /* select() prototype */
34 # include <sys/time.h> /* struct timeval, select() prototype */
36 # include <sys/select.h> /* fd_set on newer platforms */
38 # include <sys/socket.h>
39 # include <sys/file.h>
41 # include <sys/stat.h>
42 # include <netinet/in.h>
44 # include <sys/ioctl.h>
45 # include <sys/time.h>
48 # include "rx_globals.h"
51 #define MAXTHREADNAMELENGTH 64
53 int debugSelectFailure; /* # of times select failed */
56 * Sleep on the unique wait channel provided.
61 LWP_WaitProcess(addr);
65 * Wakeup any threads on the channel provided.
66 * They may be woken up spuriously, and must check any conditions.
69 rxi_Wakeup(void *addr)
71 LWP_NoYieldSignal(addr);
74 PROCESS rx_listenerPid = 0; /* LWP process id of socket listener process */
75 static void* rx_ListenerProc(void *dummy);
78 * Delay the current thread the specified number of seconds.
86 static int quitListening = 0;
88 /* This routine will kill the listener thread, if it exists. */
90 rxi_StopListener(void)
93 rxi_ReScheduleEvents();
96 /* This routine will get called by the event package whenever a new,
97 earlier than others, event is posted. If the Listener process
98 is blocked in selects, this will unblock it. It also can be called
99 to force a new trip through the rxi_Listener select loop when the set
100 of file descriptors it should be listening to changes... */
102 rxi_ReScheduleEvents(void)
105 IOMGR_Cancel(rx_listenerPid);
109 rxi_InitializeThreadSupport(void)
113 LWP_InitializeProcessSupport(LWP_NORMAL_PRIORITY, &junk);
115 FD_ZERO(&rx_selectMask);
119 rxi_StartServerProc(void *(*proc) (void *), int stacksize)
122 static int number = 0;
125 sprintf(name, "srv_%d", ++number);
126 LWP_CreateProcess(proc, stacksize, RX_PROCESS_PRIORITY, NULL,
127 "rx_ServerProc", &scratchPid);
129 (*registerProgram) (scratchPid, name);
133 rxi_StartListener(void)
135 /* Priority of listener should be high, so it can keep conns alive */
136 #define RX_LIST_STACK 24000
137 LWP_CreateProcess(rx_ListenerProc, RX_LIST_STACK, LWP_MAX_PRIORITY,
138 NULL, "rx_Listener", &rx_listenerPid);
140 (*registerProgram) (rx_listenerPid, "listener");
143 /* The main loop which listens to the net for datagrams, and handles timeouts
144 and retransmissions, etc. It also is responsible for scheduling the
145 execution of pending events (in conjunction with event.c).
147 Note interaction of nextPollTime and lastPollWorked. The idea is that if rx is not
148 keeping up with the incoming stream of packets (because there are threads that
149 are interfering with its running sufficiently often), rx does a polling select
150 before doing a real IOMGR_Select system call. Doing a real select means that
151 we don't have to let other processes run before processing more packets.
153 So, our algorithm is that if the last poll on the file descriptor found useful data, or
154 we're at the time nextPollTime (which is advanced so that it occurs every 3 or 4 seconds),
155 then we try the polling select before the IOMGR_Select. If we eventually catch up
156 (which we can tell by the polling select returning no input packets ready), then we
157 don't do a polling select again until several seconds later (via nextPollTime mechanism).
161 rxi_ListenerProc(fd_set * rfds, int *tnop, struct rx_call **newcallp)
165 register struct rx_packet *p = (struct rx_packet *)0;
168 afs_int32 nextPollTime; /* time to next poll FD before sleeping */
169 int lastPollWorked, doingPoll; /* true iff last poll was useful */
170 struct timeval tv, *tvp;
176 char name[MAXTHREADNAMELENGTH] = "srv_0";
181 code = LWP_CurrentProcess(&pid);
183 fprintf(stderr, "rxi_Listener: Can't get my pid.\n");
186 rx_listenerPid = pid;
188 (*swapNameProgram) (pid, "listener", &name[0]);
191 /* Grab a new packet only if necessary (otherwise re-use the old one) */
193 rxi_RestoreDataBufs(p);
195 if (!(p = rxi_AllocPacket(RX_PACKET_CLASS_RECEIVE)))
196 osi_Panic("rxi_ListenerProc: no packets!"); /* Shouldn't happen */
198 /* Wait for the next event time or a packet to arrive. */
199 /* event_RaiseEvents schedules any events whose time has come and
200 * then atomically computes the time to the next event, guaranteeing
201 * that this is positive. If there is no next event, it returns 0 */
203 if (!rxevent_RaiseEvents(&cv))
206 /* It's important to copy cv to tv, because the 4.3 documentation
207 * for select threatens that *tv may be updated after a select, in
208 * future editions of the system, to indicate how much of the time
209 * period has elapsed. So we shouldn't rely on tv not being altered. */
210 tv.tv_sec = cv.sec; /* Time to next event */
211 tv.tv_usec = cv.usec;
216 *rfds = rx_selectMask;
218 if (lastPollWorked || nextPollTime < clock_Sec()) {
219 /* we're catching up, or haven't tried to for a few seconds */
221 nextPollTime = clock_Sec() + 4; /* try again in 4 seconds no matter what */
222 tv.tv_sec = tv.tv_usec = 0; /* make sure we poll */
224 code = select((int)(rx_maxSocketNumber + 1), rfds, 0, 0, tvp);
227 code = IOMGR_Select((int)(rx_maxSocketNumber + 1), rfds, 0, 0, tvp);
229 lastPollWorked = 0; /* default is that it didn't find anything */
233 LWP_DestroyProcess(pid);
239 * If it was a timer interrupt then we can assume that
240 * the time has advanced by roughly the value of the
241 * previous timeout, and that there is now at least
247 /* select or IOMGR_Select returned failure */
248 debugSelectFailure++; /* update debugging counter */
253 * IOMGR_Cancel is invoked whenever a new event is
254 * posted that is earlier than any existing events.
255 * So we re-evaluate the time, and then go back to
262 /* Packets have arrived, presumably:
263 * If it wasn't a timer interrupt, then no event should have
264 * timed out yet (well some event may have, but only just...), so
265 * we don't bother looking to see if any have timed out, but just
266 * go directly to reading the data packets
272 for (i = 0; p && i < rfds->fd_count; i++) {
273 socket = rfds->fd_array[i];
274 if (rxi_ReadPacket(socket, p, &host, &port)) {
276 p = rxi_ReceivePacket(p, socket, host, port, tnop,
278 if (newcallp && *newcallp) {
282 if (swapNameProgram) {
283 (*swapNameProgram) (rx_listenerPid, name, 0);
291 for (socket = rx_minSocketNumber;
292 p && socket <= rx_maxSocketNumber; socket++) {
293 if (!FD_ISSET(socket, rfds))
295 if (rxi_ReadPacket(socket, p, &host, &port)) {
296 p = rxi_ReceivePacket(p, socket, host, port, tnop,
298 if (newcallp && *newcallp) {
302 if (swapNameProgram) {
303 (*swapNameProgram) (rx_listenerPid, name, 0);
317 /* This is the listener process request loop. The listener process loop
318 * becomes a server thread when rxi_ListenerProc returns, and stays
319 * server thread until rxi_ServerProc returns. */
321 rx_ListenerProc(void *dummy)
325 struct rx_call *newcall;
328 if (!(rfds = IOMGR_AllocFDSet())) {
329 osi_Panic("rx_ListenerProc: no fd_sets!\n");
335 rxi_ListenerProc(rfds, &threadID, &newcall);
336 /* assert(threadID != -1); */
337 /* assert(newcall != NULL); */
338 sock = OSI_NULLSOCKET;
339 rxi_ServerProc(threadID, newcall, &sock);
340 /* assert(sock != OSI_NULLSOCKET); */
346 /* This is the server process request loop. The server process loop
347 * becomes a listener thread when rxi_ServerProc returns, and stays
348 * listener thread until rxi_ListenerProc returns. */
350 rx_ServerProc(void * unused)
354 struct rx_call *newcall = NULL;
357 if (!(rfds = IOMGR_AllocFDSet())) {
358 osi_Panic("rxi_ListenerProc: no fd_sets!\n");
361 rxi_MorePackets(rx_maxReceiveWindow + 2); /* alloc more packets */
362 rxi_dataQuota += rx_initSendWindow; /* Reserve some pkts for hard times */
363 /* threadID is used for making decisions in GetCall. Get it by bumping
364 * number of threads handling incoming calls */
365 threadID = rxi_availProcs++;
368 sock = OSI_NULLSOCKET;
369 rxi_ServerProc(threadID, newcall, &sock);
370 /* assert(sock != OSI_NULLSOCKET); */
372 rxi_ListenerProc(rfds, &threadID, &newcall);
373 /* assert(threadID != -1); */
374 /* assert(newcall != NULL); */
381 * Called from GetUDPSocket.
382 * Called from a single thread at startup.
383 * Returns 0 on success; -1 on failure.
386 rxi_Listen(osi_socket sock)
390 * Put the socket into non-blocking mode so that rx_Listener
391 * can do a polling read before entering select
393 if (fcntl(sock, F_SETFL, FNDELAY) == -1) {
395 (osi_Msg "rxi_Listen: unable to set non-blocking mode on socket\n");
399 if (sock > FD_SETSIZE - 1) {
400 (osi_Msg "rxi_Listen: socket descriptor > (FD_SETSIZE-1) = %d\n",
406 FD_SET(sock, &rx_selectMask);
407 if (sock > rx_maxSocketNumber)
408 rx_maxSocketNumber = sock;
409 if (sock < rx_minSocketNumber)
410 rx_minSocketNumber = sock;
418 rxi_Recvmsg(osi_socket socket, struct msghdr *msg_p, int flags)
420 #if defined(HAVE_LINUX_ERRQUEUE_H) && defined(ADAPT_PMTU)
421 while((rxi_HandleSocketError(socket)) > 0)
424 return recvmsg(socket, msg_p, flags);
428 * Simulate a blocking sendmsg on the non-blocking socket.
429 * It's non blocking because it was set that way for recvmsg.
432 rxi_Sendmsg(osi_socket socket, struct msghdr *msg_p, int flags)
434 fd_set *sfds = (fd_set *) 0;
435 while (sendmsg(socket, msg_p, flags) == -1) {
437 rx_stats.sendSelects++;
440 if (!(sfds = IOMGR_AllocFDSet())) {
441 (osi_Msg "rx failed to alloc fd_set: ");
442 perror("rx_sendmsg");
445 FD_SET(socket, sfds);
447 #if defined(HAVE_LINUX_ERRQUEUE_H) && defined(ADAPT_PMTU)
448 while((rxi_HandleSocketError(socket)) > 0)
452 if (WSAGetLastError())
453 #elif defined(AFS_LINUX22_ENV)
454 /* linux unfortunately returns ECONNREFUSED if the target port
455 * is no longer in use */
456 /* and EAGAIN if a UDP checksum is incorrect */
457 if (errno != EWOULDBLOCK && errno != ENOBUFS && errno != ECONNREFUSED
460 if (errno != EWOULDBLOCK && errno != ENOBUFS)
463 (osi_Msg "rx failed to send packet: ");
464 perror("rx_sendmsg");
467 while ((err = select(socket + 1, 0, sfds, 0, 0)) != 1) {
468 if (err >= 0 || errno != EINTR)
469 osi_Panic("rxi_sendmsg: select error %d.%d", err, errno);
473 IOMGR_FreeFDSet(sfds);