C++ DEVICE::Lock方法代码示例

/*
 * DCR is locked before calling this routine
 */
static void locked_detach_dcr_from_dev(DCR *dcr)
{
   DEVICE *dev = dcr->dev;
   Dmsg0(500, "Enter detach_dcr_from_dev\n"); /* jcr is NULL in some cases */

   /* Detach this dcr only if attached */
   if (dcr->attached_to_dev && dev) {
      dcr->unreserve_device();
      dev->Lock();
      Dmsg4(200, "Detach Jid=%d dcr=%p size=%d to dev=%s\n", (uint32_t)dcr->jcr->JobId,
         dcr, dev->attached_dcrs->size(), dev->print_name());
      dcr->attached_to_dev = false;
      if (dev->attached_dcrs->size()) {
         dev->attached_dcrs->remove(dcr);  /* detach dcr from device */
      }
//    remove_dcr_from_dcrs(dcr);      /* remove dcr from jcr list */
      dev->Unlock();
   }
   dcr->attached_to_dev = false;
}

static void attach_dcr_to_dev(DCR *dcr)
{
   DEVICE *dev;
   JCR *jcr;

   P(dcr->m_mutex);
   dev = dcr->dev;
   jcr = dcr->jcr;
   if (jcr) Dmsg1(500, "JobId=%u enter attach_dcr_to_dev\n", (uint32_t)jcr->JobId);
   /* ***FIXME*** return error if dev not initiated */
   if (!dcr->attached_to_dev && dev->initiated && jcr && jcr->getJobType() != JT_SYSTEM) {
      dev->Lock();
      Dmsg4(200, "Attach Jid=%d dcr=%p size=%d dev=%s\n", (uint32_t)jcr->JobId,
         dcr, dev->attached_dcrs->size(), dev->print_name());
      dev->attached_dcrs->append(dcr);  /* attach dcr to device */
      dev->Unlock();
      dcr->attached_to_dev = true;
   }
   V(dcr->m_mutex);
}

/*
 * Wait for SysOp to mount a tape on a specific device
 *
 *   Returns: W_ERROR, W_TIMEOUT, W_POLL, W_MOUNT, or W_WAKE
 */
int wait_for_sysop(DCR *dcr)
{
   struct timeval tv;
   struct timezone tz;
   struct timespec timeout;
   time_t last_heartbeat = 0;
   time_t first_start = time(NULL);
   int status = 0;
   int add_wait;
   bool unmounted;
   DEVICE *dev = dcr->dev;
   JCR *jcr = dcr->jcr;

   dev->Lock();
   Dmsg1(dbglvl, "Enter blocked=%s\n", dev->print_blocked());

   /*
    * Since we want to mount a tape, make sure current one is
    *  not marked as using this drive.
    */
   volume_unused(dcr);

   unmounted = dev->is_device_unmounted();
   dev->poll = false;
   /*
    * Wait requested time (dev->rem_wait_sec).  However, we also wake up every
    *    HB_TIME seconds and send a heartbeat to the FD and the Director
    *    to keep stateful firewalls from closing them down while waiting
    *    for the operator.
    */
   add_wait = dev->rem_wait_sec;
   if (me->heartbeat_interval && add_wait > me->heartbeat_interval) {
      add_wait = me->heartbeat_interval;
   }
   /* If the user did not unmount the tape and we are polling, ensure
    *  that we poll at the correct interval.
    */
   if (!unmounted && dev->vol_poll_interval && add_wait > dev->vol_poll_interval) {
      add_wait = dev->vol_poll_interval;
   }

   if (!unmounted) {
      Dmsg1(dbglvl, "blocked=%s\n", dev->print_blocked());
      dev->dev_prev_blocked = dev->blocked();
      dev->set_blocked(BST_WAITING_FOR_SYSOP); /* indicate waiting for mount */
   }

   for ( ; !job_canceled(jcr); ) {
      time_t now, start, total_waited;

      gettimeofday(&tv, &tz);
      timeout.tv_nsec = tv.tv_usec * 1000;
      timeout.tv_sec = tv.tv_sec + add_wait;

      Dmsg4(dbglvl, "I'm going to sleep on device %s. HB=%d rem_wait=%d add_wait=%d\n",
         dev->print_name(), (int)me->heartbeat_interval, dev->rem_wait_sec, add_wait);
      start = time(NULL);

      /* Wait required time */
      status = pthread_cond_timedwait(&dev->wait_next_vol, &dev->m_mutex, &timeout);

      Dmsg2(dbglvl, "Wokeup from sleep on device status=%d blocked=%s\n", status,
         dev->print_blocked());
      now = time(NULL);
      total_waited = now - first_start;
      dev->rem_wait_sec -= (now - start);

      /* Note, this always triggers the first time. We want that. */
      if (me->heartbeat_interval) {
         if (now - last_heartbeat >= me->heartbeat_interval) {
            /* send heartbeats */
            if (jcr->file_bsock) {
               jcr->file_bsock->signal(BNET_HEARTBEAT);
               Dmsg0(dbglvl, "Send heartbeat to FD.\n");
            }
            if (jcr->dir_bsock) {
               jcr->dir_bsock->signal(BNET_HEARTBEAT);
            }
            last_heartbeat = now;
         }
      }

      if (status == EINVAL) {
         berrno be;
         Jmsg1(jcr, M_FATAL, 0, _("pthread timedwait error. ERR=%s\n"), be.bstrerror(status));
         status = W_ERROR;             /* error */
         break;
      }

      /*
       * Continue waiting if operator is labeling volumes
       */
      if (dev->blocked() == BST_WRITING_LABEL) {
         continue;
      }
//.........这里部分代码省略.........

/*********************************************************************
 * Acquire device for reading.
 *  The drive should have previously been reserved by calling
 *  reserve_device_for_read(). We read the Volume label from the block and
 *  leave the block pointers just after the label.
 *
 *  Returns: NULL if failed for any reason
 *           dcr  if successful
 */
bool acquire_device_for_read(DCR *dcr)
{
   DEVICE *dev;
   JCR *jcr = dcr->jcr;
   bool ok = false;
   bool tape_previously_mounted;
   VOL_LIST *vol;
   bool try_autochanger = true;
   int i;
   int vol_label_status;
   int retry = 0;

   Enter(rdbglvl);
   dev = dcr->dev;
   dev->Lock_read_acquire();
   Dmsg2(rdbglvl, "dcr=%p dev=%p\n", dcr, dcr->dev);
   Dmsg2(rdbglvl, "MediaType dcr=%s dev=%s\n", dcr->media_type, dev->device->media_type);
   dev->dblock(BST_DOING_ACQUIRE);

   if (dev->num_writers > 0) {
      Jmsg2(jcr, M_FATAL, 0, _("Acquire read: num_writers=%d not zero. Job %d canceled.\n"),
         dev->num_writers, jcr->JobId);
      goto get_out;
   }

   /* Find next Volume, if any */
   vol = jcr->VolList;
   if (!vol) {
      char ed1[50];
      Jmsg(jcr, M_FATAL, 0, _("No volumes specified for reading. Job %s canceled.\n"),
         edit_int64(jcr->JobId, ed1));
      goto get_out;
   }
   jcr->CurReadVolume++;
   for (i=1; i<jcr->CurReadVolume; i++) {
      vol = vol->next;
   }
   if (!vol) {
      Jmsg(jcr, M_FATAL, 0, _("Logic error: no next volume to read. Numvol=%d Curvol=%d\n"),
         jcr->NumReadVolumes, jcr->CurReadVolume);
      goto get_out;                   /* should not happen */
   }
   set_dcr_from_vol(dcr, vol);

   Dmsg2(rdbglvl, "Want Vol=%s Slot=%d\n", vol->VolumeName, vol->Slot);

   /*
    * If the MediaType requested for this volume is not the
    *  same as the current drive, we attempt to find the same
    *  device that was used to write the orginal volume.  If
    *  found, we switch to using that device.
    *
    *  N.B. A lot of routines rely on the dcr pointer not changing
    *    read_records.c even has multiple dcrs cached, so we take care
    *    here to release all important parts of the dcr and re-acquire
    *    them such as the block pointer (size may change), but we do
    *    not release the dcr.
    */
   Dmsg2(rdbglvl, "MediaType dcr=%s dev=%s\n", dcr->media_type, dev->device->media_type);
   if (dcr->media_type[0] && !bstrcmp(dcr->media_type, dev->device->media_type)) {
      RCTX rctx;
      DIRSTORE *store;
      int status;

      Jmsg3(jcr, M_INFO, 0, _("Changing read device. Want Media Type=\"%s\" have=\"%s\"\n"
                              "  device=%s\n"),
            dcr->media_type, dev->device->media_type, dev->print_name());
      Dmsg3(rdbglvl, "Changing read device. Want Media Type=\"%s\" have=\"%s\"\n"
                     "  device=%s\n",
            dcr->media_type, dev->device->media_type, dev->print_name());

      dev->dunblock(DEV_UNLOCKED);

      lock_reservations();
      memset(&rctx, 0, sizeof(RCTX));
      rctx.jcr = jcr;
      jcr->read_dcr = dcr;
      jcr->reserve_msgs = New(alist(10, not_owned_by_alist));
      rctx.any_drive = true;
      rctx.device_name = vol->device;
      store = new DIRSTORE;
      memset(store, 0, sizeof(DIRSTORE));
      store->name[0] = 0; /* No dir name */
      bstrncpy(store->media_type, vol->MediaType, sizeof(store->media_type));
      bstrncpy(store->pool_name, dcr->pool_name, sizeof(store->pool_name));
      bstrncpy(store->pool_type, dcr->pool_type, sizeof(store->pool_type));
      store->append = false;
      rctx.store = store;
      clean_device(dcr);                     /* clean up the dcr */

      /*
//.........这里部分代码省略.........

/*
 * This job is done, so release the device. From a Unix standpoint,
 *  the device remains open.
 *
 * Note, if we were spooling, we may enter with the device blocked.
 *   We unblock at the end, only if it was us who blocked the
 *   device.
 *
 */
bool release_device(DCR *dcr)
{
   utime_t now;
   JCR *jcr = dcr->jcr;
   DEVICE *dev = dcr->dev;
   bool ok = true;
   char tbuf[100];
   int was_blocked = BST_NOT_BLOCKED;

   /*
    * Capture job statistics now that we are done using this device.
    */
   now = (utime_t)time(NULL);
   update_job_statistics(jcr, now);

   dev->Lock();
   if (!dev->is_blocked()) {
      block_device(dev, BST_RELEASING);
   } else {
      was_blocked = dev->blocked();
      dev->set_blocked(BST_RELEASING);
   }
   lock_volumes();
   Dmsg2(100, "release_device device %s is %s\n", dev->print_name(), dev->is_tape() ? "tape" : "disk");

   /*
    * If device is reserved, job never started, so release the reserve here
    */
   dcr->clear_reserved();

   if (dev->can_read()) {
      VOLUME_CAT_INFO *vol = &dev->VolCatInfo;
      dev->clear_read();              /* clear read bit */
      Dmsg2(150, "dir_update_vol_info. label=%d Vol=%s\n",
         dev->is_labeled(), vol->VolCatName);
      if (dev->is_labeled() && vol->VolCatName[0] != 0) {
         dcr->dir_update_volume_info(false, false); /* send Volume info to Director */
         remove_read_volume(jcr, dcr->VolumeName);
         volume_unused(dcr);
      }
   } else if (dev->num_writers > 0) {
      /*
       * Note if WEOT is set, we are at the end of the tape and may not be positioned correctly,
       * so the job_media_record and update_vol_info have already been done,
       * which means we skip them here.
       */
      dev->num_writers--;
      Dmsg1(100, "There are %d writers in release_device\n", dev->num_writers);
      if (dev->is_labeled()) {
         Dmsg2(200, "dir_create_jobmedia. Release vol=%s dev=%s\n",
               dev->getVolCatName(), dev->print_name());
         if (!dev->at_weot() && !dcr->dir_create_jobmedia_record(false)) {
            Jmsg2(jcr, M_FATAL, 0, _("Could not create JobMedia record for Volume=\"%s\" Job=%s\n"),
               dcr->getVolCatName(), jcr->Job);
         }

         /*
          * If no more writers, and no errors, and wrote something, write an EOF
          */
         if (!dev->num_writers && dev->can_write() && dev->block_num > 0) {
            dev->weof(1);
            write_ansi_ibm_labels(dcr, ANSI_EOF_LABEL, dev->VolHdr.VolumeName);
         }
         if (!dev->at_weot()) {
            dev->VolCatInfo.VolCatFiles = dev->file;   /* set number of files */

            /*
             * Note! do volume update before close, which zaps VolCatInfo
             */
            dcr->dir_update_volume_info(false, false); /* send Volume info to Director */
            Dmsg2(200, "dir_update_vol_info. Release vol=%s dev=%s\n",
                  dev->getVolCatName(), dev->print_name());
         }
         if (dev->num_writers == 0) {         /* if not being used */
            volume_unused(dcr);               /*  we obviously are not using the volume */
         }
      }

   } else {
      /*
       * If we reach here, it is most likely because the job has failed,
       * since the device is not in read mode and there are no writers.
       * It was probably reserved.
       */
      volume_unused(dcr);
   }

   Dmsg3(100, "%d writers, %d reserve, dev=%s\n", dev->num_writers, dev->num_reserved(), dev->print_name());

   /*
    * If no writers, close if file or !CAP_ALWAYS_OPEN
//.........这里部分代码省略.........

/*
 * Acquire device for writing. We permit multiple writers.
 *  If this is the first one, we read the label.
 *
 *  Returns: NULL if failed for any reason
 *           dcr if successful.
 *   Note, normally reserve_device_for_append() is called
 *   before this routine.
 */
DCR *acquire_device_for_append(DCR *dcr)
{
   DEVICE *dev = dcr->dev;
   JCR *jcr = dcr->jcr;
   bool ok = false;
   bool have_vol = false;

   Enter(200);
   init_device_wait_timers(dcr);

   dev->Lock_acquire();             /* only one job at a time */
   dev->Lock();
   Dmsg1(100, "acquire_append device is %s\n", dev->is_tape() ? "tape" : "disk");

   /*
    * With the reservation system, this should not happen
    */
   if (dev->can_read()) {
      Jmsg1(jcr, M_FATAL, 0, _("Want to append, but device %s is busy reading.\n"), dev->print_name());
      Dmsg1(200, "Want to append but device %s is busy reading.\n", dev->print_name());
      goto get_out;
   }

   dev->clear_unload();

   /*
    * have_vol defines whether or not mount_next_write_volume should
    *   ask the Director again about what Volume to use.
    */
   if (dev->can_append() && dcr->is_suitable_volume_mounted() &&
       !bstrcmp(dcr->VolCatInfo.VolCatStatus, "Recycle")) {
      Dmsg0(190, "device already in append.\n");
      /*
       * At this point, the correct tape is already mounted, so
       *   we do not need to do mount_next_write_volume(), unless
       *   we need to recycle the tape.
       */
       if (dev->num_writers == 0) {
          dev->VolCatInfo = dcr->VolCatInfo;   /* structure assignment */
       }
       have_vol = dcr->is_tape_position_ok();
   }

   if (!have_vol) {
      dev->rLock(true);
      block_device(dev, BST_DOING_ACQUIRE);
      dev->Unlock();
      Dmsg1(190, "jid=%u Do mount_next_write_vol\n", (uint32_t)jcr->JobId);
      if (!dcr->mount_next_write_volume()) {
         if (!job_canceled(jcr)) {
            /* Reduce "noise" -- don't print if job canceled */
            Jmsg(jcr, M_FATAL, 0, _("Could not ready device %s for append.\n"),
               dev->print_name());
            Dmsg1(200, "Could not ready device %s for append.\n",
               dev->print_name());
         }
         dev->Lock();
         unblock_device(dev);
         goto get_out;
      }
      Dmsg2(190, "Output pos=%u:%u\n", dcr->dev->file, dcr->dev->block_num);
      dev->Lock();
      unblock_device(dev);
   }

   dev->num_writers++;                /* we are now a writer */
   if (jcr->NumWriteVolumes == 0) {
      jcr->NumWriteVolumes = 1;
   }
   dev->VolCatInfo.VolCatJobs++;              /* increment number of jobs on vol */
   Dmsg4(100, "=== nwriters=%d nres=%d vcatjob=%d dev=%s\n",
         dev->num_writers, dev->num_reserved(), dev->VolCatInfo.VolCatJobs, dev->print_name());
   dcr->dir_update_volume_info(false, false); /* send Volume info to Director */
   ok = true;

get_out:
   /* Don't plugin close here, we might have multiple writers */
   dcr->clear_reserved();
   dev->Unlock();
   dev->Unlock_acquire();
   Leave(200);
   return ok ? dcr : NULL;
}