[#1147] Checkpoint: cleaned up alloc code

src/lib/dhcpsrv/alloc_engine.cc

@@ -866,10 +866,9 @@ AllocEngine::allocateUnreservedLeases6(ClientContext6& ctx) {
 
     CalloutHandle::CalloutNextStep callout_status = CalloutHandle::NEXT_STEP_CONTINUE;
 
-    while (subnet) {
+    for (; subnet; subnet = subnet->getNextSubnet(original_subnet)) {
 
         if (!subnet->clientSupported(ctx.query_->getClasses())) {
-            subnet = subnet->getNextSubnet(original_subnet);
             continue;
         }
 
@@ -882,12 +881,10 @@ AllocEngine::allocateUnreservedLeases6(ClientContext6& ctx) {
                              hint));
 
         // check if the pool is allowed
-        if (pool && !pool->clientSupported(ctx.query_->getClasses())) {
+        if (!pool || !pool->clientSupported(ctx.query_->getClasses())) {
-            pool.reset();
+            continue;
         }
 
-        if (pool) {
-
         // Check which host reservation mode is supported in this subnet.
         Network::HRMode hr_mode = subnet->getHostReservationMode();
 
@@ -931,11 +928,9 @@ AllocEngine::allocateUnreservedLeases6(ClientContext6& ctx) {
                     .arg(hint.toText());
             }
 
-            } else {
+        } else if (lease->expired()) {
 
             // If the lease is expired, we may likely reuse it, but...
-                if (lease->expired()) {
-
             ConstHostPtr host;
             if (hr_mode != Network::HR_DISABLED) {
                 host = HostMgr::instance().get6(subnet->getID(), hint);
@@ -965,10 +960,6 @@ AllocEngine::allocateUnreservedLeases6(ClientContext6& ctx) {
             }
         }
     }
-        }
-
-        subnet = subnet->getNextSubnet(original_subnet);
-    }
 
     uint64_t total_attempts = 0;
 
@@ -994,10 +985,9 @@ AllocEngine::allocateUnreservedLeases6(ClientContext6& ctx) {
 
     ctx.subnet_ = subnet = original_subnet;
 
-    while (subnet) {
+    for (; subnet; subnet = subnet->getNextSubnet(original_subnet)) {
 
         if (!subnet->clientSupported(ctx.query_->getClasses())) {
-            subnet = subnet->getNextSubnet(original_subnet);
             continue;
         }
 
@@ -1012,7 +1002,6 @@ AllocEngine::allocateUnreservedLeases6(ClientContext6& ctx) {
                                     ctx.query_->getClasses());
         // Try next subnet if there is no chance to get something
         if (possible_attempts == 0) {
-            subnet = subnet->getNextSubnet(original_subnet);
             continue;
         }
         uint64_t max_attempts = (attempts_ > 0 ? attempts_  : possible_attempts);
@@ -1084,8 +1073,7 @@ AllocEngine::allocateUnreservedLeases6(ClientContext6& ctx) {
                 // Although the address was free just microseconds ago, it may have
                 // been taken just now. If the lease insertion fails, we continue
                 // allocation attempts.
-            } else {
+            } else if (existing->expired()) {
-                if (existing->expired()) {
                 // Make sure it's not reserved.
                 if (hr_mode == Network::HR_ALL &&
                     HostMgr::instance().get6(subnet->getID(), candidate)) {
@@ -1108,9 +1096,6 @@ AllocEngine::allocateUnreservedLeases6(ClientContext6& ctx) {
         }
     }
 
-        subnet = subnet->getNextSubnet(original_subnet);
-    }
-
     // Unable to allocate an address, return an empty lease.
     LOG_WARN(alloc_engine_logger, ALLOC_ENGINE_V6_ALLOC_FAIL)
         .arg(ctx.query_->getLabel())
@@ -1201,16 +1186,14 @@ AllocEngine::allocateReservedLeases6(ClientContext6& ctx,
     // There is no lease for a reservation in this IA. So, let's now iterate
     // over reservations specified and try to allocate one of them for the IA.
 
-    Subnet6Ptr subnet = ctx.subnet_;
+    for (Subnet6Ptr subnet = ctx.subnet_; subnet;
-
+         subnet = subnet->getNextSubnet(ctx.subnet_)) {
-    while (subnet) {
 
         SubnetID subnet_id = subnet->getID();
 
         // No hosts for this subnet or the subnet not supported.
         if (!subnet->clientSupported(ctx.query_->getClasses()) ||
             ctx.hosts_.count(subnet_id) == 0) {
-            subnet = subnet->getNextSubnet(ctx.subnet_);
             continue;
         }
 
@@ -1289,10 +1272,7 @@ AllocEngine::allocateReservedLeases6(ClientContext6& ctx,
                 // would work for any number of reservations.
                 return;
             }
-
         }
-
-        subnet = subnet->getNextSubnet(ctx.subnet_);
     }
 }
 
@@ -4018,6 +3998,9 @@ AllocEngine::allocateUnreservedLease4(ClientContext4& ctx) {
         CalloutHandle::CalloutNextStep callout_status = CalloutHandle::NEXT_STEP_CONTINUE;
 
         for (uint64_t i = 0; i < max_attempts; ++i) {
+
+            ++total_attempts;
+
             IOAddress candidate = allocator->pickAddress(subnet,
                                                          ctx.query_->getClasses(),
                                                          client_id,
@@ -4048,8 +4031,6 @@ AllocEngine::allocateUnreservedLease4(ClientContext4& ctx) {
                subnet.reset();
                break;
             }
-
-            ++total_attempts;
         }
 
         // This pointer may be set to NULL if hooks set SKIP status.