src/rx/rx_multi.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 #include <afsconfig.h>
  11 #include <afs/param.h>
  12
  13 #ifdef  KERNEL
  14 # include "afs/sysincludes.h"
  15 #else /* KERNEL */
  16 # include <roken.h>
  17 # include <afs/opr.h>
  18 #endif /* KERNEL */
  19
  20 #include "rx.h"
  21
  22 /*
  23  * multi.c and multi.h, together with some rxgen hooks, provide a way of
  24  * making multiple, but similar, rx calls to multiple hosts simultaneously
  25  */
  26
  27 struct multi_handle *
  28 multi_Init(struct rx_connection **conns, int nConns)
  29 {
  30     struct rx_call **calls;
  31     short *ready;
  32     struct multi_handle *mh;
  33     int i;
  34
  35     /*
  36      * Note: all structures that are possibly referenced by other
  37      * processes must be allocated.  In some kernels variables allocated on
  38      * a process stack will not be accessible to other processes
  39      */
  40
  41     calls = osi_Alloc(sizeof(struct rx_call *) * nConns);
  42     ready = osi_Alloc(sizeof(short) * nConns);
  43     mh = osi_Alloc(sizeof(struct multi_handle));
  44     if (!calls || !ready || !mh)
  45         osi_Panic("multi_Rx: no mem\n");
  46     memset(mh, 0, sizeof(struct multi_handle));
  47     mh->calls = calls;
  48     mh->nextReady = mh->firstNotReady = mh->ready = ready;
  49     mh->nReady = 0;
  50     mh->nConns = nConns;
  51
  52     MUTEX_INIT(&mh->lock, "rx_multi_lock", MUTEX_DEFAULT, 0);
  53     CV_INIT(&mh->cv, "rx_multi_cv", CV_DEFAULT, 0);
  54     for (i = 0; i < nConns; i++) {
  55         struct rx_call *call;
  56         call = mh->calls[i] = rx_NewCall(conns[i]);
  57         rx_SetArrivalProc(call, multi_Ready, (void *) mh, i);
  58     }
  59     return mh;
  60 }
  61
  62 /* Return the user's connection index of the most recently ready call; that is, a call that has received at least one reply packet */
  63 int
  64 multi_Select(struct multi_handle *mh)
  65 {
  66     int index;
  67     SPLVAR;
  68     NETPRI;
  69     MUTEX_ENTER(&mh->lock);
  70     while (mh->nextReady == mh->firstNotReady) {
  71         if (mh->nReady == mh->nConns) {
  72             MUTEX_EXIT(&mh->lock);
  73             USERPRI;
  74             return -1;
  75         }
  76 #ifdef RX_ENABLE_LOCKS
  77         CV_WAIT(&mh->cv, &mh->lock);
  78 #else /* RX_ENABLE_LOCKS */
  79         osi_rxSleep(mh);
  80 #endif /* RX_ENABLE_LOCKS */
  81     }
  82     index = *(mh->nextReady);
  83     (mh->nextReady) += 1;
  84     MUTEX_EXIT(&mh->lock);
  85     USERPRI;
  86     return index;
  87 }
  88
  89 /* Called by Rx when the first reply packet of a call is received, or the call is aborted. */
  90 void
  91 multi_Ready(struct rx_call *call, void *amh,
  92             int index)
  93 {
  94     struct multi_handle *mh = (struct multi_handle *)amh;
  95     MUTEX_ENTER(&mh->lock);
  96     *mh->firstNotReady++ = index;
  97     mh->nReady++;
  98 #ifdef RX_ENABLE_LOCKS
  99     CV_SIGNAL(&mh->cv);
 100 #else /* RX_ENABLE_LOCKS */
 101     osi_rxWakeup(mh);
 102 #endif /* RX_ENABLE_LOCKS */
 103     MUTEX_EXIT(&mh->lock);
 104 }
 105
 106 /* Called when the multi rx call is over, or when the user aborts it (by using the macro multi_Abort) */
 107 void
 108 multi_Finalize(struct multi_handle *mh)
 109 {
 110     int i;
 111     int nCalls = mh->nConns;
 112     for (i = 0; i < nCalls; i++) {
 113         struct rx_call *call = mh->calls[i];
 114         if (call)
 115             rx_EndCall(call, RX_USER_ABORT);
 116     }
 117     MUTEX_DESTROY(&mh->lock);
 118     CV_DESTROY(&mh->cv);
 119     osi_Free(mh->calls, sizeof(struct rx_call *) * nCalls);
 120     osi_Free(mh->ready, sizeof(short) * nCalls);
 121     osi_Free(mh, sizeof(struct multi_handle));
 122 }
 123
 124 /* ignores all remaining multiRx calls */
 125 void
 126 multi_Finalize_Ignore(struct multi_handle *mh)
 127 {
 128     int i;
 129     int nCalls = mh->nConns;
 130     for (i = 0; i < nCalls; i++) {
 131         struct rx_call *call = mh->calls[i];
 132         if (call)
 133             rx_EndCall(call, 0);
 134     }
 135     MUTEX_DESTROY(&mh->lock);
 136     CV_DESTROY(&mh->cv);
 137     osi_Free(mh->calls, sizeof(struct rx_call *) * nCalls);
 138     osi_Free(mh->ready, sizeof(short) * nCalls);
 139     osi_Free(mh, sizeof(struct multi_handle));
 140 }