ObjectId::MachineAndPid ObjectId::genMachineAndPid()
{
qint64 n = QScopedPointer<SecureRandom>(SecureRandom::create())->nextInt64();
ObjectId::MachineAndPid x = ourMachine = reinterpret_cast<ObjectId::MachineAndPid&>(n);
foldInPid(x);
return x;
}
void OID::justForked() {
MachineAndPid x = ourMachine;
// we let the random # for machine go into all 5 bytes of MachineAndPid, and then
// xor in the pid into _pid. this reduces the probability of collisions.
foldInPid(x);
ourMachineAndPid = genMachineAndPid();
verify( x != ourMachineAndPid );
ourMachineAndPid = x;
}
OID::MachineAndPid OID::genMachineAndPid() {
BOOST_STATIC_ASSERT( sizeof(mongo::OID::MachineAndPid) == 5 );
// we only call this once per process
scoped_ptr<SecureRandom> sr( SecureRandom::create() );
int64_t n = sr->nextInt64();
OID::MachineAndPid x = ourMachine = reinterpret_cast<OID::MachineAndPid&>(n);
foldInPid(x);
return x;
}
OID::MachineAndPid OID::genMachineAndPid() {
BOOST_STATIC_ASSERT( sizeof(mongo::OID::MachineAndPid) == 5 );
// this is not called often, so the following is not expensive, and gives us some
// testing that nonce generation is working right and that our OIDs are (perhaps) ok.
{
nonce64 a = Security::getNonceDuringInit();
nonce64 b = Security::getNonceDuringInit();
nonce64 c = Security::getNonceDuringInit();
verify( !(a==b && b==c) );
}
unsigned long long n = Security::getNonceDuringInit();
OID::MachineAndPid x = ourMachine = (OID::MachineAndPid&) n;
foldInPid(x);
return x;
}
static OID::MachineAndPid __gen() {
unsigned long long n = security.getNonce();
OID::MachineAndPid x = ourMachine = (OID::MachineAndPid&) n;
foldInPid(x);
return x;
}