src/comm/AcceptLimiter.cc

   1 #include "config.h"
   2 #include "comm/AcceptLimiter.h"
   3 #include "comm/TcpAcceptor.h"
   4 #include "fde.h"
   5
   6 Comm::AcceptLimiter Comm::AcceptLimiter::Instance_;
   7
   8 Comm::AcceptLimiter &Comm::AcceptLimiter::Instance()
   9 {
  10     return Instance_;
  11 }
  12
  13 void
  14 Comm::AcceptLimiter::defer(Comm::TcpAcceptor *afd)
  15 {
  16     afd->isLimited++;
  17     debugs(5, 5, HERE << "FD " << afd->fd << " x" << afd->isLimited);
  18     deferred.push_back(afd);
  19 }
  20
  21 void
  22 Comm::AcceptLimiter::removeDead(const Comm::TcpAcceptor *afd)
  23 {
  24     for (unsigned int i = 0; i < deferred.size() && afd->isLimited > 0; i++) {
  25         if (deferred[i] == afd) {
  26             deferred[i]->isLimited--;
  27             deferred[i] = NULL; // fast. kick() will skip empty entries later.
  28             debugs(5, 5, HERE << "FD " << afd->fd << " x" << afd->isLimited);
  29         }
  30     }
  31 }
  32
  33 void
  34 Comm::AcceptLimiter::kick()
  35 {
  36     // TODO: this could be optimized further with an iterator to search
  37     //       looking for first non-NULL, followed by dumping the first N
  38     //       with only one shift()/pop_front operation
  39
  40     debugs(5, 5, HERE << " size=" << deferred.size());
  41     while (deferred.size() > 0 && fdNFree() >= RESERVED_FD) {
  42         /* NP: shift() is equivalent to pop_front(). Giving us a FIFO queue. */
  43         TcpAcceptor *temp = deferred.shift();
  44         if (temp != NULL) {
  45             debugs(5, 5, HERE << " doing one.");
  46             temp->isLimited--;
  47             temp->acceptNext();
  48             break;
  49         }
  50     }
  51 }