1 files changed, 98 insertions, 0 deletions
diff --git a/src/lib/dhcpsrv/resource_handler.cc b/src/lib/dhcpsrv/resource_handler.cc
new file mode 100644
index 0000000..9ae2ee5
--- /dev/null
+++ b/src/lib/dhcpsrv/resource_handler.cc
@@ -0,0 +1,98 @@
+// Copyright (C) 2020 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include <config.h>
+
+#include <dhcpsrv/resource_handler.h>
+#include <exceptions/exceptions.h>
+
+using namespace std;
+using namespace isc::asiolink;
+using namespace isc::util;
+
+namespace isc {
+namespace dhcp {
+
+mutex ResourceHandler::mutex_;
+
+ResourceHandler::ResourceContainer ResourceHandler::resources_;
+
+ResourceHandler::ResourceHandler() : owned_() {
+}
+
+ResourceHandler::~ResourceHandler() {
+    lock_guard<mutex> lock_(mutex_);
+    for (auto res : owned_) {
+        unLockInternal(res->type_, res->addr_);
+    }
+    owned_.clear();
+}
+
+ResourceHandler::ResourcePtr
+ResourceHandler::lookup(Lease::Type type, const asiolink::IOAddress& addr) {
+    auto key = boost::make_tuple(type, addr.toBytes());
+    auto it = resources_.find(key);
+    if (it == resources_.end()) {
+        return (ResourcePtr());
+    }
+    return (*it);
+}
+
+void
+ResourceHandler::lock(Lease::Type type, const asiolink::IOAddress& addr) {
+    ResourcePtr res(new Resource(type, addr));
+    // Assume insert will never fail so not checking its result.
+    resources_.insert(res);
+    owned_.insert(res);
+}
+
+void
+ResourceHandler::unLockInternal(Lease::Type type,
+                                const asiolink::IOAddress& addr) {
+    auto key = boost::make_tuple(type, addr.toBytes());
+    auto it = resources_.find(key);
+    if (it == resources_.end()) {
+        return;
+    }
+    resources_.erase(it);
+}
+
+bool
+ResourceHandler::tryLock(Lease::Type type, const asiolink::IOAddress& addr) {
+    ResourcePtr holder;
+    // Try to acquire the lock and return the holder when it failed.
+    lock_guard<mutex> lock_(mutex_);
+    holder = lookup(type, addr);
+    if (holder) {
+        return (false);
+    }
+    lock(type, addr);
+    return (true);
+}
+
+bool
+ResourceHandler::isLocked(Lease::Type type, const asiolink::IOAddress& addr) {
+    auto key = boost::make_tuple(type, addr.toBytes());
+    lock_guard<mutex> lock_(mutex_);
+    auto it = owned_.find(key);
+    return (it != owned_.end());
+}
+
+void
+ResourceHandler::unLock(Lease::Type type, const asiolink::IOAddress& addr) {
+    auto key = boost::make_tuple(type, addr.toBytes());
+    lock_guard<mutex> lock_(mutex_);
+    auto it = owned_.find(key);
+    if (it == owned_.end()) {
+        isc_throw(NotFound, "does not own " << Lease::typeToText(type)
+                  << " " << addr.toText());
+    }
+    unLockInternal(type, addr);
+    owned_.erase(it);
+}
+
+}  // namespace dhcp
+}  // namespace isc