fetcho~1.cc

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// Larbin
// Sebastien Ailleret
// 15-11-99 -> 14-02-00

#include <adns.h>
#include <iostream.h>
#include <errno.h>

#include "global.h"
#include "xutils/Site.h"
#include "xutils/Fifo.h"
#include "xutils/debug.h"

/* Opens sockets
 * Never block (eg only opens sockets on allready known sites)
 * Only one thread for this
 */
void *startFetchNonBlock (void *none) {
  crash("FetchNonBlock on");
  uint i=0;
  // Avoid active wait at the beginning
  sleep (2*global::waitDuration);
  for (;;) {
	stateNonBlock(i++);
	global::okSites->get()->fetchNonBlock();
  }
}

/* Number of pending dns calls */
uint nbCalls = 0;

/* Opens sockets
 * This function uses adns, which is non thread safe
 * so do not launch more than one thread with this function
 */
void *startFetchBlock (void *none) {
  crash("FetchBlock on");
  for (;;) {
	stateBlock(1);
	// Submit queries
	while (nbCalls == 0) {
	  // Avoid cpu use if no dns call are in progress
	  // No active wait
	  Site *site = global::dnsSites->get();
	  site->newQuery(&nbCalls);
	}
	stateBlock(2);
	while (nbCalls<global::dnsConn) {
	  Site *site = global::dnsSites->tryGet();
	  if (site == NULL) {
		break;
	  } else {
		site->newQuery(&nbCalls);
	  }
	}

	// Read answers
	// wait instead of check if nbCalls==global::dnsConn : avoid active wait
	assert (nbCalls);
	{
	  // Avoid active wait
	  Site *site;
	  adns_query quer = NULL;
	  adns_answer *ans;
	  crash("Wait for an adns query");
	stateBlock(31);
	  int res = adns_wait(global::ads, &quer, &ans, (void**)&site);
	stateBlock(32);
	  assert (res != ESRCH);
	  nbCalls--;
	  site->dnsAns(ans);
	  free(ans);
	}
	// Check
	for (;;) {
	  Site *site;
	  adns_query quer = NULL;
	  adns_answer *ans;
	  crash("Wait for an adns query");
	stateBlock(41);
	  int res = adns_check(global::ads, &quer, &ans, (void**)&site);
	stateBlock(42);
	  if (res == ESRCH || res == EAGAIN) {
		// No more query or no more answers
		break;
	  }
	  nbCalls--;
	  site->dnsAns(ans);
	  free(ans);
	}
  }
}