src/rx/rx_pthread.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   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
   8  */
   9
  10 /*
  11  * An implementation of the rx socket listener for pthreads (not using select).
  12  * This assumes that multiple read system calls may be extant at any given
  13  * time. Also implements the pthread-specific event handling for rx.
  14  *
  15  * rx_pthread.c is used for the thread safe RX package.
  16  */
  17
  18 #include <afsconfig.h>
  19 #include <afs/param.h>
  20
  21 #include <roken.h>
  22 #include <afs/opr.h>
  23
  24 #include <assert.h>
  25
  26 #ifdef AFS_PTHREAD_ENV
  27
  28 #include "rx.h"
  29 #include "rx_globals.h"
  30 #include "rx_pthread.h"
  31 #include "rx_clock.h"
  32 #include "rx_atomic.h"
  33 #include "rx_internal.h"
  34 #include "rx_pthread.h"
  35 #ifdef AFS_NT40_ENV
  36 #include "rx_xmit_nt.h"
  37 #endif
  38
  39 static void rxi_SetThreadNum(int threadID);
  40
  41 /* Set rx_pthread_event_rescheduled if event_handler should just try
  42  * again instead of sleeping.
  43  *
  44  * Protected by event_handler_mutex
  45  */
  46 static int rx_pthread_event_rescheduled = 0;
  47
  48 static void *rx_ListenerProc(void *);
  49
  50 /*
  51  * We supply an event handling thread for Rx's event processing.
  52  * The condition variable is used to wakeup the thread whenever a new
  53  * event is scheduled earlier than the previous earliest event.
  54  * This thread is also responsible for keeping time.
  55  */
  56 static pthread_t event_handler_thread;
  57 afs_kcondvar_t rx_event_handler_cond;
  58 afs_kmutex_t event_handler_mutex;
  59 afs_kcondvar_t rx_listener_cond;
  60 afs_kmutex_t listener_mutex;
  61 static int listeners_started = 0;
  62 afs_kmutex_t rx_clock_mutex;
  63 struct clock rxi_clockNow;
  64
  65 static rx_atomic_t threadHiNum;
  66
  67 int
  68 rx_NewThreadId(void) {
  69     return rx_atomic_inc_and_read(&threadHiNum);
  70 }
  71
  72 /*
  73  * Delay the current thread the specified number of seconds.
  74  */
  75 void
  76 rxi_Delay(int sec)
  77 {
  78     sleep(sec);
  79 }
  80
  81 /*
  82  * Called from rx_Init()
  83  */
  84 void
  85 rxi_InitializeThreadSupport(void)
  86 {
  87         /* listeners_started must only be reset if
  88          * the listener thread terminates */
  89         /* listeners_started = 0; */
  90     clock_GetTime(&rxi_clockNow);
  91 }
  92
  93 static void *
  94 server_entry(void *argp)
  95 {
  96     void (*server_proc) (void *) = (void (*)(void *))argp;
  97     server_proc(NULL);
  98     dpf(("rx_pthread.c: server_entry: Server proc returned unexpectedly\n"));
  99     return (void *) -1; /* reused as return value, see pthread(3) */
 100 }
 101
 102 /*
 103  * Start an Rx server process.
 104  */
 105 void
 106 rxi_StartServerProc(void *(*proc) (void *), int stacksize)
 107 {
 108     pthread_t thread;
 109     pthread_attr_t tattr;
 110     AFS_SIGSET_DECL;
 111
 112     if (pthread_attr_init(&tattr) != 0) {
 113         osi_Panic("Unable to Create Rx server thread (pthread_attr_init)\n");
 114     }
 115
 116     if (pthread_attr_setdetachstate(&tattr, PTHREAD_CREATE_DETACHED) != 0) {
 117         osi_Panic("Unable to Create Rx server thread (pthread_attr_setdetachstate)\n");
 118     }
 119
 120     /*
 121      * NOTE: We are ignoring the stack size parameter, for now.
 122      */
 123     AFS_SIGSET_CLEAR();
 124     if (pthread_create(&thread, &tattr, server_entry, (void *)proc) != 0) {
 125         osi_Panic("Unable to Create Rx server thread\n");
 126     }
 127     AFS_SIGSET_RESTORE();
 128 }
 129
 130 /*
 131  * The event handling process.
 132  */
 133 static void *
 134 event_handler(void *argp)
 135 {
 136     unsigned long rx_pthread_n_event_expired = 0;
 137     unsigned long rx_pthread_n_event_waits = 0;
 138     long rx_pthread_n_event_woken = 0;
 139     unsigned long rx_pthread_n_event_error = 0;
 140     struct timespec rx_pthread_next_event_time = { 0, 0 };
 141     int error;
 142
 143     MUTEX_ENTER(&event_handler_mutex);
 144
 145     for (;;) {
 146         struct clock cv;
 147         struct clock next;
 148
 149         MUTEX_EXIT(&event_handler_mutex);
 150
 151         next.sec = 30;          /* Time to sleep if there are no events scheduled */
 152         next.usec = 0;
 153         clock_GetTime(&cv);
 154         rxevent_RaiseEvents(&next);
 155
 156         MUTEX_ENTER(&event_handler_mutex);
 157         if (rx_pthread_event_rescheduled) {
 158             rx_pthread_event_rescheduled = 0;
 159             continue;
 160         }
 161
 162         clock_Add(&cv, &next);
 163         rx_pthread_next_event_time.tv_sec = cv.sec;
 164         rx_pthread_next_event_time.tv_nsec = cv.usec * 1000;
 165         rx_pthread_n_event_waits++;
 166         error = CV_TIMEDWAIT(&rx_event_handler_cond, &event_handler_mutex, &rx_pthread_next_event_time);
 167         if (error == 0) {
 168             rx_pthread_n_event_woken++;
 169         }
 170 #ifdef AFS_NT40_ENV
 171         else if (error == ETIMEDOUT) {
 172             rx_pthread_n_event_expired++;
 173         } else {
 174             rx_pthread_n_event_error++;
 175         }
 176 #else
 177         else if (errno == ETIMEDOUT) {
 178             rx_pthread_n_event_expired++;
 179         } else {
 180             rx_pthread_n_event_error++;
 181         }
 182 #endif
 183         rx_pthread_event_rescheduled = 0;
 184     }
 185     AFS_UNREACHED(return(NULL));
 186 }
 187
 188
 189 /*
 190  * This routine will get called by the event package whenever a new,
 191  * earlier than others, event is posted. */
 192 void
 193 rxi_ReScheduleEvents(void)
 194 {
 195     MUTEX_ENTER(&event_handler_mutex);
 196     CV_SIGNAL(&rx_event_handler_cond);
 197     rx_pthread_event_rescheduled = 1;
 198     MUTEX_EXIT(&event_handler_mutex);
 199 }
 200
 201
 202 /* Loop to listen on a socket. Return setting *newcallp if this
 203  * thread should become a server thread.  */
 204 static void
 205 rxi_ListenerProc(osi_socket sock, int *tnop, struct rx_call **newcallp)
 206 {
 207     unsigned int host;
 208     u_short port;
 209     struct rx_packet *p = (struct rx_packet *)0;
 210
 211     MUTEX_ENTER(&listener_mutex);
 212     while (!listeners_started) {
 213         CV_WAIT(&rx_listener_cond, &listener_mutex);
 214     }
 215     MUTEX_EXIT(&listener_mutex);
 216
 217     for (;;) {
 218         /* See if a check for additional packets was issued */
 219         rx_CheckPackets();
 220
 221         /*
 222          * Grab a new packet only if necessary (otherwise re-use the old one)
 223          */
 224         if (p) {
 225             rxi_RestoreDataBufs(p);
 226         } else {
 227             if (!(p = rxi_AllocPacket(RX_PACKET_CLASS_RECEIVE))) {
 228                 /* Could this happen with multiple socket listeners? */
 229                 osi_Panic("rxi_Listener: no packets!"); /* Shouldn't happen */
 230             }
 231         }
 232
 233         if (rxi_ReadPacket(sock, p, &host, &port)) {
 234             clock_NewTime();
 235             p = rxi_ReceivePacket(p, sock, host, port, tnop, newcallp);
 236             if (newcallp && *newcallp) {
 237                 if (p)
 238                     rxi_FreePacket(p);
 239                 return;
 240             }
 241         }
 242     }
 243     /* NOTREACHED */
 244 }
 245
 246 /* This is the listener process request loop. The listener process loop
 247  * becomes a server thread when rxi_ListenerProc returns, and stays
 248  * server thread until rxi_ServerProc returns. */
 249 static void *
 250 rx_ListenerProc(void *argp)
 251 {
 252     int threadID;
 253     osi_socket sock = (osi_socket)(intptr_t)argp;
 254     struct rx_call *newcall;
 255
 256     while (1) {
 257         newcall = NULL;
 258         threadID = -1;
 259         rxi_ListenerProc(sock, &threadID, &newcall);
 260         /* osi_Assert(threadID != -1); */
 261         /* osi_Assert(newcall != NULL); */
 262         sock = OSI_NULLSOCKET;
 263         rxi_SetThreadNum(threadID);
 264         rxi_ServerProc(threadID, newcall, &sock);
 265         /* osi_Assert(sock != OSI_NULLSOCKET); */
 266     }
 267     AFS_UNREACHED(return(NULL));
 268 }
 269
 270 /* This is the server process request loop. The server process loop
 271  * becomes a listener thread when rxi_ServerProc returns, and stays
 272  * listener thread until rxi_ListenerProc returns. */
 273 void *
 274 rx_ServerProc(void * dummy)
 275 {
 276     osi_socket sock;
 277     int threadID;
 278     struct rx_call *newcall = NULL;
 279
 280     rxi_MorePackets(rx_maxReceiveWindow + 2);   /* alloc more packets */
 281     MUTEX_ENTER(&rx_quota_mutex);
 282     rxi_dataQuota += rx_initSendWindow; /* Reserve some pkts for hard times */
 283     /* threadID is used for making decisions in GetCall.  Get it by bumping
 284      * number of threads handling incoming calls */
 285     /* Unique thread ID: used for scheduling purposes *and* as index into
 286      * the host hold table (fileserver).
 287      * The previously used rxi_availProcs is unsuitable as it
 288      * will already go up and down as packets arrive while the server
 289      * threads are still initialising! The recently introduced
 290      * rxi_pthread_hinum does not necessarily lead to a server
 291      * thread with id 0, which is not allowed to hop through the
 292      * incoming call queue.
 293      * So either introduce yet another counter or flag the FCFS
 294      * thread... chose the latter.
 295      */
 296     MUTEX_ENTER(&rx_pthread_mutex);
 297     threadID = rx_NewThreadId();
 298     if (rxi_fcfs_thread_num == 0 && rxi_fcfs_thread_num != threadID)
 299         rxi_fcfs_thread_num = threadID;
 300     MUTEX_EXIT(&rx_pthread_mutex);
 301     ++rxi_availProcs;
 302     MUTEX_EXIT(&rx_quota_mutex);
 303
 304     while (1) {
 305         sock = OSI_NULLSOCKET;
 306         rxi_SetThreadNum(threadID);
 307         rxi_ServerProc(threadID, newcall, &sock);
 308         /* osi_Assert(sock != OSI_NULLSOCKET); */
 309         newcall = NULL;
 310         rxi_ListenerProc(sock, &threadID, &newcall);
 311         /* osi_Assert(threadID != -1); */
 312         /* osi_Assert(newcall != NULL); */
 313     }
 314     AFS_UNREACHED(return(NULL));
 315 }
 316
 317 /*
 318  * Historically used to start the listener process. We now have multiple
 319  * listener processes (one for each socket); these are started by GetUdpSocket.
 320  *
 321  * The event handling process *is* started here (the old listener used
 322  * to also handle events). The listener threads can't actually start
 323  * listening until rxi_StartListener is called because most of R may not
 324  * be initialized when rxi_Listen is called.
 325  */
 326 void
 327 rxi_StartListener(void)
 328 {
 329     pthread_attr_t tattr;
 330     AFS_SIGSET_DECL;
 331
 332         if (listeners_started)
 333                 return;
 334
 335     if (pthread_attr_init(&tattr) != 0) {
 336         osi_Panic("Unable to create Rx event handling thread (pthread_attr_init)\n");
 337     }
 338
 339     if (pthread_attr_setdetachstate(&tattr, PTHREAD_CREATE_DETACHED) != 0) {
 340         osi_Panic("Unable to create Rx event handling thread (pthread_attr_setdetachstate)\n");
 341     }
 342
 343     AFS_SIGSET_CLEAR();
 344     if (pthread_create(&event_handler_thread, &tattr, event_handler, NULL) !=
 345         0) {
 346         osi_Panic("Unable to create Rx event handling thread\n");
 347     }
 348     rx_NewThreadId();
 349     AFS_SIGSET_RESTORE();
 350
 351     MUTEX_ENTER(&listener_mutex);
 352     CV_BROADCAST(&rx_listener_cond);
 353     listeners_started = 1;
 354     MUTEX_EXIT(&listener_mutex);
 355
 356 }
 357
 358 /*
 359  * Listen on the specified socket.
 360  */
 361 int
 362 rxi_Listen(osi_socket sock)
 363 {
 364     pthread_t thread;
 365     pthread_attr_t tattr;
 366     AFS_SIGSET_DECL;
 367
 368     if (pthread_attr_init(&tattr) != 0) {
 369         osi_Panic("Unable to create socket listener thread (pthread_attr_init)\n");
 370     }
 371
 372     if (pthread_attr_setdetachstate(&tattr, PTHREAD_CREATE_DETACHED) != 0) {
 373         osi_Panic("Unable to create socket listener thread (pthread_attr_setdetachstate)\n");
 374     }
 375
 376     AFS_SIGSET_CLEAR();
 377     if (pthread_create(&thread, &tattr, rx_ListenerProc, (void *)(intptr_t)sock) != 0) {
 378         osi_Panic("Unable to create socket listener thread\n");
 379     }
 380     rx_NewThreadId();
 381     AFS_SIGSET_RESTORE();
 382     return 0;
 383 }
 384
 385
 386 /*
 387  * Recvmsg.
 388  *
 389  */
 390 int
 391 rxi_Recvmsg(osi_socket socket, struct msghdr *msg_p, int flags)
 392 {
 393     int ret;
 394     ret = recvmsg(socket, msg_p, flags);
 395
 396 #ifdef AFS_RXERRQ_ENV
 397     if (ret < 0) {
 398         while (rxi_HandleSocketError(socket) > 0)
 399             ;
 400     }
 401 #endif
 402
 403     return ret;
 404 }
 405
 406 /*
 407  * Sendmsg.
 408  */
 409 int
 410 rxi_Sendmsg(osi_socket socket, struct msghdr *msg_p, int flags)
 411 {
 412     int ret;
 413     ret = sendmsg(socket, msg_p, flags);
 414
 415 #ifdef AFS_RXERRQ_ENV
 416     if (ret < 0) {
 417         while (rxi_HandleSocketError(socket) > 0)
 418             ;
 419         return ret;
 420     }
 421 #else
 422 # ifdef AFS_LINUX22_ENV
 423     /* linux unfortunately returns ECONNREFUSED if the target port
 424      * is no longer in use */
 425     /* and EAGAIN if a UDP checksum is incorrect */
 426     if (ret == -1 && errno != ECONNREFUSED && errno != EAGAIN) {
 427 # else
 428     if (ret == -1) {
 429 # endif
 430         dpf(("rxi_sendmsg failed, error %d\n", errno));
 431         fflush(stdout);
 432 # ifndef AFS_NT40_ENV
 433         if (errno > 0)
 434           return -errno;
 435 # else
 436             if (WSAGetLastError() > 0)
 437               return -WSAGetLastError();
 438 # endif
 439         return -1;
 440     }
 441 #endif /* !AFS_RXERRQ_ENV */
 442     return 0;
 443 }
 444
 445 struct rx_ts_info_t * rx_ts_info_init(void) {
 446     struct rx_ts_info_t * rx_ts_info;
 447     rx_ts_info = calloc(1, sizeof(rx_ts_info_t));
 448     osi_Assert(rx_ts_info != NULL && pthread_setspecific(rx_ts_info_key, rx_ts_info) == 0);
 449 #ifdef RX_ENABLE_TSFPQ
 450     opr_queue_Init(&rx_ts_info->_FPQ.queue);
 451
 452     MUTEX_ENTER(&rx_packets_mutex);
 453     rx_TSFPQMaxProcs++;
 454     RX_TS_FPQ_COMPUTE_LIMITS;
 455     MUTEX_EXIT(&rx_packets_mutex);
 456 #endif /* RX_ENABLE_TSFPQ */
 457     return rx_ts_info;
 458 }
 459
 460 int
 461 rx_GetThreadNum(void) {
 462     return (intptr_t)pthread_getspecific(rx_thread_id_key);
 463 }
 464
 465 static void
 466 rxi_SetThreadNum(int threadID) {
 467     osi_Assert(pthread_setspecific(rx_thread_id_key,
 468                                    (void *)(intptr_t)threadID) == 0);
 469 }
 470
 471 int
 472 rx_SetThreadNum(void) {
 473     int threadId;
 474
 475     threadId = rx_NewThreadId();
 476     rxi_SetThreadNum(threadId);
 477     return threadId;
 478 }
 479
 480 #endif