[3221] Added use of dhcp_ddns::WatchSocket and additonal queue methods

Integrated use of WatchSocket to NameChangeSender and NameChangeUDPSender.
Added addtional methods for accessing sender's send queue.
Created include and source for common dhcp_ddns lib test components.

src/lib/dhcp_ddns/ncr_io.cc

@@ -23,7 +23,7 @@ namespace dhcp_ddns {
 NameChangeProtocol stringToNcrProtocol(const std::string& protocol_str) {
     if (boost::iequals(protocol_str, "UDP")) {
         return (NCR_UDP);
-    } 
+    }
 
     if (boost::iequals(protocol_str, "TCP")) {
         return (NCR_TCP);
@@ -162,10 +162,7 @@ NameChangeSender::NameChangeSender(RequestSendHandler& send_handler,
       send_queue_max_(send_queue_max) {
 
     // Queue size must be big enough to hold at least 1 entry.
-    if (send_queue_max == 0) {
-        isc_throw(NcrSenderError, "NameChangeSender constructor"
-                  " queue size must be greater than zero");
-    }
+    setQueueMaxSize(send_queue_max);
 }
 
 void
@@ -318,5 +315,57 @@ NameChangeSender::clearSendQueue() {
     send_queue_.clear();
 }
 
+void
+NameChangeSender::setQueueMaxSize(const size_t new_max) {
+    if (new_max == 0) {
+        isc_throw(NcrSenderError, "NameChangeSender:"
+                  " queue size must be greater than zero");
+    }
+
+    send_queue_max_ = new_max;
+
+}
+const NameChangeRequestPtr&
+NameChangeSender::peekAt(const size_t index) const {
+    if (index >= getQueueSize()) {
+        isc_throw(NcrSenderError,
+                  "NameChangeSender::peekAt peek beyond end of queue attempted"
+                  << " index: " << index << " queue size: " << getQueueSize());
+    }
+
+    return (send_queue_.at(index));
+}
+
+
+void
+NameChangeSender::assumeQueue(NameChangeSender& sourceSender) {
+    if (sourceSender.amSending()) {
+        isc_throw(NcrSenderError, "Cannot assume queue:"
+                  " source sender is actively sending");
+    }
+
+    if (amSending()) {
+        isc_throw(NcrSenderError, "Cannot assume queue:"
+                  " target sender is actively sending");
+    }
+
+    if (getQueueMaxSize() < sourceSender.getQueueSize()) {
+        isc_throw(NcrSenderError, "Cannot assume queue:"
+                  " source queue count exceeds target queue max");
+    }
+
+    if (send_queue_.size() != 0) {
+        isc_throw(NcrSenderError, "Cannot assume queue:"
+                  " target queue is not empty");
+    }
+
+    send_queue_.swap(sourceSender.getSendQueue());
+}
+
+int
+NameChangeSender::getSelectFd() {
+    isc_throw(NotImplemented, "NameChangeSender::getSelectFd is not supported");
+}
+
 } // namespace isc::dhcp_ddns
 } // namespace isc

src/lib/dhcp_ddns/ncr_io.h

@@ -547,6 +547,36 @@ public:
     /// capacity.
     void sendRequest(NameChangeRequestPtr& ncr);
 
+    /// @brief Move all queued requests from a given sender into the send queue
+    ///
+    /// Moves all of the entries in the given sender's queue and places them
+    /// into send queue.  This provides a mechanism of reassigning queued
+    /// messages from one sender to another. This is useful for dealing with
+    /// dynamic configuration changes.
+    ///
+    /// @param Sender from whom the queued messages will be taken
+    ///
+    /// @throw NcrSenderError if either sender is in send mode, if the number of
+    /// messages in the source sender's queue is larger than this sender's
+    /// maxium queue size, or if this sender's queue is not empty.
+    void assumeQueue(NameChangeSender& fromSender);
+
+    /// @brief Returns a file description suitable for use with select
+    ///
+    /// The value returned is an open file descriptor which can be used with
+    /// select() system call to monitor the sender for IO events.  This allows
+    /// NameChangeSenders to be used in applications which use select, rather
+    /// than IOService to wait for IO events to occur.
+    ///
+    /// @note Attempting other use of this value may lead to unpredictable
+    /// behavior in the sender.
+    ///
+    /// @return Returns an "open" file descriptor
+    ///
+    /// @throw NcrSenderError if the sender is not in send mode,
+    /// NotImplemented if the implementation does not support such an fd.
+    virtual int getSelectFd();
+
 protected:
     /// @brief Dequeues and sends the next request on the send queue.
     ///
@@ -659,11 +689,39 @@ public:
         return (send_queue_max_);
     }
 
+    /// @brief Sets the maxium queue size to the given value.
+    ///
+    /// Sets the maximum number of entries allowed in the queue to the
+    /// the given value.
+    ///
+    /// @param new_max the new value to use as the maximum
+    ///
+    /// @throw NcrSenderError if the value is less than one.
+    void setQueueMaxSize(const size_t new_max);
+
     /// @brief Returns the number of entries currently in the send queue.
     size_t getQueueSize() const {
         return (send_queue_.size());
     }
 
+    /// @brief Returns the entry at a given position in the queue.
+    ///
+    /// Note that the entry is not removed from the queue.
+    /// @param index the index of the entry in the queue to fetch.
+    /// Valid values are 0 (front of the queue) to (queue size - 1).
+    ///
+    /// @return Pointer reference to the queue entry.
+    ///
+    /// @throw NcrSenderError if the given index is beyond the
+    /// end of the queue.
+    const NameChangeRequestPtr& peekAt(const size_t index) const;
+
+protected:
+    /// @brief Returns a reference to the send queue.
+    SendQueue& getSendQueue() {
+        return (send_queue_);
+    }
+
 private:
     /// @brief Sets the sending indicator to the given value.
     ///

src/lib/dhcp_ddns/ncr_udp.cc

@@ -256,6 +256,8 @@ NameChangeUDPSender::open(isc::asiolink::IOService& io_service) {
                                        server_port_));
 
     send_callback_->setDataSource(server_endpoint_);
+
+    watch_socket_.reset(new WatchSocket());
 }
 
 void
@@ -282,6 +284,8 @@ NameChangeUDPSender::close() {
     }
 
     socket_.reset();
+
+    watch_socket_.reset();
 }
 
 void
@@ -298,11 +302,17 @@ NameChangeUDPSender::doSend(NameChangeRequestPtr& ncr) {
     // Call the socket's asychronous send, passing our callback
     socket_->asyncSend(send_callback_->getData(), send_callback_->getPutLen(),
                        send_callback_->getDataSource().get(), *send_callback_);
+
+    // Set IO ready marker so sender activity is visible to select() or poll().
+    watch_socket_->markReady();
 }
 
 void
 NameChangeUDPSender::sendCompletionHandler(const bool successful,
                                            const UDPCallback *send_callback) {
+    // Clear the IO ready marker.
+    watch_socket_->clearReady();
+
     Result result;
     if (successful) {
         result = SUCCESS;
@@ -324,5 +334,17 @@ NameChangeUDPSender::sendCompletionHandler(const bool successful,
     // Call the application's registered request send handler.
     invokeSendHandler(result);
 }
+
+int
+NameChangeUDPSender::getSelectFd() {
+    if (!amSending()) {
+        isc_throw(NotImplemented, "NameChangeUDPSender::getSelectFd"
+                                  " not in send mode");
+    }
+
+    return(watch_socket_->getSelectFd());
+}
+
+
 }; // end of isc::dhcp_ddns namespace
 }; // end of isc namespace

src/lib/dhcp_ddns/ncr_udp.h

@@ -112,10 +112,12 @@
 #include <asiolink/udp_endpoint.h>
 #include <asiolink/udp_socket.h>
 #include <dhcp_ddns/ncr_io.h>
+#include <dhcp_ddns/watch_socket.h>
 #include <util/buffer.h>
 
 #include <boost/shared_array.hpp>
 
+
 /// responsibility of the completion handler to perform the steps necessary
 /// to interpret the raw data provided by the service outcome.   The
 /// UDPCallback operator implementation is mostly a pass through.
@@ -524,6 +526,21 @@ public:
     void sendCompletionHandler(const bool successful,
                                const UDPCallback* send_callback);
 
+    /// @brief Returns a file description suitable for use with select
+    ///
+    /// The value returned is an open file descriptor which can be used with
+    /// select() system call to monitor the sender for IO events.  This allows
+    /// NameChangeUDPSenders to be used in applications which use select,
+    /// rather than IOService to wait for IO events to occur.
+    ///
+    /// @note Attempting other use of this value may lead to unpredictable
+    /// behavior in the sender.
+    ///
+    /// @return Returns an "open" file descriptor
+    ///
+    /// @throw NcrSenderError if the sender is not in send mode,
+    virtual int getSelectFd();
+
 private:
     /// @brief IP address from which to send.
     isc::asiolink::IOAddress ip_address_;
@@ -554,6 +571,8 @@ private:
 
     /// @brief Flag which enables the reuse address socket option if true.
     bool reuse_address_;
+
+    WatchSocketPtr watch_socket_;
 };
 
 } // namespace isc::dhcp_ddns

src/lib/dhcp_ddns/tests/Makefile.am

@@ -29,6 +29,7 @@ TESTS += libdhcp_ddns_unittests
 libdhcp_ddns_unittests_SOURCES  = run_unittests.cc
 libdhcp_ddns_unittests_SOURCES += ncr_unittests.cc
 libdhcp_ddns_unittests_SOURCES += ncr_udp_unittests.cc
+libdhcp_ddns_unittests_SOURCES += test_utils.cc test_utils.h
 libdhcp_ddns_unittests_SOURCES += watch_socket_unittests.cc
 
 libdhcp_ddns_unittests_CPPFLAGS = $(AM_CPPFLAGS) $(GTEST_INCLUDES) $(LOG4CPLUS_INCLUDES)

src/lib/dhcp_ddns/tests/ncr_udp_unittests.cc

@@ -16,6 +16,7 @@
 #include <dhcp_ddns/ncr_io.h>
 #include <dhcp_ddns/ncr_udp.h>
 #include <util/time_utilities.h>
+#include <test_utils.h>
 
 #include <asio/ip/udp.hpp>
 #include <boost/function.hpp>
@@ -23,6 +24,8 @@
 #include <gtest/gtest.h>
 #include <algorithm>
 
+#include <sys/select.h>
+
 using namespace std;
 using namespace isc;
 using namespace isc::dhcp_ddns;
@@ -68,6 +71,7 @@ const char *valid_msgs[] =
 };
 
 const char* TEST_ADDRESS = "127.0.0.1";
+//const char* TEST_ADDRESS = "192.0.2.10";
 const uint32_t LISTENER_PORT = 5301;
 const uint32_t SENDER_PORT = LISTENER_PORT+1;
 const long TEST_TIMEOUT = 5 * 1000;
@@ -113,6 +117,7 @@ TEST(NameChangeUDPListenerBasicTest, basicListenTests) {
 
     // Verify that we can start listening.
     EXPECT_NO_THROW(listener->startListening(io_service));
+
     // Verify that we are in listening mode.
     EXPECT_TRUE(listener->amListening());
     // Verify that a read is in progress.
@@ -310,8 +315,8 @@ TEST(NameChangeUDPSenderBasicTest, constructionTests) {
 /// @brief Tests NameChangeUDPSender basic send functionality
 /// This test verifies that:
 TEST(NameChangeUDPSenderBasicTest, basicSendTests) {
-    isc::asiolink::IOAddress ip_address(TEST_ADDRESS);
-    uint32_t port = SENDER_PORT;
+    isc::asiolink::IOAddress ip_address("127.0.0.1");
+    uint32_t port = 5301;
     isc::asiolink::IOService io_service;
     SimpleSendHandler ncr_handler;
 
@@ -320,7 +325,8 @@ TEST(NameChangeUDPSenderBasicTest, basicSendTests) {
 
     // Create the sender, setting the queue max equal to the number of
     // messages we will have in the list.
-    NameChangeUDPSender sender(ip_address, port, ip_address, port,
+    isc::asiolink::IOAddress any("0.0.0.0");
+    NameChangeUDPSender sender(any, 0, ip_address, port,
                                FMT_JSON, ncr_handler, num_msgs);
 
     // Verify that we can start sending.
@@ -341,30 +347,55 @@ TEST(NameChangeUDPSenderBasicTest, basicSendTests) {
     EXPECT_NO_THROW(sender.startSending(io_service));
     EXPECT_TRUE(sender.amSending());
 
+    // Fetch the sender's select-fd.
+    int select_fd = sender.getSelectFd();
+
+    // Verify select_fd is valid and currently shows no ready to read.
+    ASSERT_NE(dhcp_ddns::WatchSocket::INVALID_SOCKET, select_fd);
+    ASSERT_EQ(0, selectCheck(select_fd));
+
     // Iterate over a series of messages, sending each one. Since we
     // do not invoke IOService::run, then the messages should accumulate
     // in the queue.
     NameChangeRequestPtr ncr;
+    NameChangeRequestPtr ncr2;
     for (int i = 0; i < num_msgs; i++) {
         ASSERT_NO_THROW(ncr = NameChangeRequest::fromJSON(valid_msgs[i]));
         EXPECT_NO_THROW(sender.sendRequest(ncr));
         // Verify that the queue count increments in step with each send.
         EXPECT_EQ(i+1, sender.getQueueSize());
+
+        // Verify that peekAt(i) returns the NCR we just added.
+        ASSERT_NO_THROW(ncr2 = sender.peekAt(i));
+        ASSERT_TRUE(ncr2);
+        EXPECT_TRUE(*ncr == *ncr2);
     }
 
+    // Verify that attempting to peek beyond the end of the queue, throws.
+    ASSERT_THROW(sender.peekAt(sender.getQueueSize()+1), NcrSenderError);
+
     // Verify that attempting to send an additional message results in a
     // queue full exception.
     EXPECT_THROW(sender.sendRequest(ncr), NcrSenderQueueFull);
 
-    // Loop for the number of valid messages and invoke IOService::run_one.
-    // This should send exactly one message and the queue count should
-    // decrement accordingly.
+    // Loop for the number of valid messages. So long as there is at least
+    // on NCR in the queue, select-fd indicate ready to read. Invoke
+    // IOService::run_one. This should complete the send of exactly one
+    // message and the queue count should decrement accordingly.
     for (int i = num_msgs; i > 0; i--) {
+        // Verify that sender shows IO ready.
+        ASSERT_TRUE(selectCheck(select_fd) > 0);
+
+        // Execute at one ready handler.
         io_service.run_one();
+
         // Verify that the queue count decrements in step with each run.
         EXPECT_EQ(i-1, sender.getQueueSize());
     }
 
+    // Verify that sender shows no IO ready.
+    EXPECT_EQ(0, selectCheck(select_fd));
+
     // Verify that the queue is empty.
     EXPECT_EQ(0, sender.getQueueSize());
 
@@ -395,6 +426,72 @@ TEST(NameChangeUDPSenderBasicTest, basicSendTests) {
     EXPECT_EQ(0, sender.getQueueSize());
 }
 
+/// @brief Test the NameChangeSender::assumeQueue method.
+TEST(NameChangeSender, assumeQueue) {
+    isc::asiolink::IOAddress ip_address(TEST_ADDRESS);
+    uint32_t port = SENDER_PORT;
+    isc::asiolink::IOService io_service;
+    SimpleSendHandler ncr_handler;
+    NameChangeRequestPtr ncr;
+
+    // Tests are based on a list of messages, get the count now.
+    int num_msgs = sizeof(valid_msgs)/sizeof(char*);
+
+    // Create two senders with queue max equal to the number of
+    // messages we will have in the list.
+    NameChangeUDPSender sender1(ip_address, port, ip_address, port,
+                               FMT_JSON, ncr_handler, num_msgs);
+
+    NameChangeUDPSender sender2(ip_address, port+1, ip_address, port,
+                                FMT_JSON, ncr_handler, num_msgs);
+
+    // Place sender1 into send mode and queue up messages.
+    ASSERT_NO_THROW(sender1.startSending(io_service));
+    for (int i = 0; i < num_msgs; i++) {
+        ASSERT_NO_THROW(ncr = NameChangeRequest::fromJSON(valid_msgs[i]));
+        ASSERT_NO_THROW(sender1.sendRequest(ncr));
+    }
+
+    // Make sure sender1's queue count is as expected.
+    ASSERT_EQ(num_msgs, sender1.getQueueSize());
+
+    // Verify sender1 is sending, sender2 is not.
+    ASSERT_TRUE(sender1.amSending());
+    ASSERT_FALSE(sender2.amSending());
+
+    // Transfer from sender1 to sender2 should fail because
+    // sender1 is in send mode.
+    ASSERT_THROW(sender2.assumeQueue(sender1), NcrSenderError);
+
+    // Take sender1 out of send mode.
+    ASSERT_NO_THROW(sender1.stopSending());
+    ASSERT_FALSE(sender1.amSending());
+
+    // Transfer should succeed. Verify sender1 has none,
+    // and sender2 has num_msgs queued.
+    EXPECT_NO_THROW(sender2.assumeQueue(sender1));
+    EXPECT_EQ(0, sender1.getQueueSize());
+    EXPECT_EQ(num_msgs, sender2.getQueueSize());
+
+    // Reduce sender1's max queue size.
+    ASSERT_NO_THROW(sender1.setQueueMaxSize(num_msgs - 1));
+
+    // Transfer should fail as sender1's queue is not large enough.
+    ASSERT_THROW(sender1.assumeQueue(sender2), NcrSenderError);
+
+    // Place sender1 into send mode and queue up a message.
+    ASSERT_NO_THROW(sender1.startSending(io_service));
+    ASSERT_NO_THROW(ncr = NameChangeRequest::fromJSON(valid_msgs[0]));
+    ASSERT_NO_THROW(sender1.sendRequest(ncr));
+
+    // Take sender1 out of send mode.
+    ASSERT_NO_THROW(sender1.stopSending());
+
+    // Try to transfer from sender1 to sender2. This should fail
+    // as sender2's queue is not empty.
+    ASSERT_THROW(sender2.assumeQueue(sender1), NcrSenderError);
+}
+
 /// @brief Text fixture that allows testing a listener and sender together
 /// It derives from both the receive and send handler classes and contains
 /// and instance of UDP listener and UDP sender.

src/lib/dhcp_ddns/tests/test_utils.cc

@@ -0,0 +1,43 @@
+// Copyright (C) 2014  Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#include <gtest/gtest.h>
+
+#include <sys/select.h>
+#include <sys/ioctl.h>
+
+using namespace std;
+
+namespace isc {
+namespace dhcp_ddns {
+
+int selectCheck(int fd_to_check) {
+    fd_set read_fds;
+    int maxfd = 0;
+
+    FD_ZERO(&read_fds);
+
+    // Add this socket to listening set
+    FD_SET(fd_to_check,  &read_fds);
+    maxfd = fd_to_check;
+
+    struct timeval select_timeout;
+    select_timeout.tv_sec = 0;
+    select_timeout.tv_usec = 0;
+
+    return (select(maxfd + 1, &read_fds, NULL, NULL, &select_timeout));
+}
+
+}; // namespace isc::d2
+}; // namespace isc

src/lib/dhcp_ddns/tests/test_utils.h

@@ -0,0 +1,37 @@
+// Copyright (C) 2014  Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#ifndef TEST_UTILS_H
+#define TEST_UTILS_H
+
+/// @file test_utils.h Common dhcp_ddns testing elements
+
+#include <gtest/gtest.h>
+
+
+namespace isc {
+namespace dhcp_ddns {
+
+/// @brief Returns the result of select() given an fd to check for read status.
+///
+/// @param fd_to_check The file descriptor to test
+///
+/// @return Returns less than one on an error, 0 if the fd is not ready to
+/// read, > 0 if it is ready to read. 
+int selectCheck(int fd_to_check);
+
+}; // namespace isc::dhcp_ddns;
+}; // namespace isc;
+
+#endif 

src/lib/dhcp_ddns/tests/watch_socket_unittests.cc

@@ -13,6 +13,7 @@
 // PERFORMANCE OF THIS SOFTWARE.
 
 #include <dhcp_ddns/watch_socket.h>
+#include <test_utils.h>
 
 #include <gtest/gtest.h>
 
@@ -25,31 +26,6 @@ using namespace isc::dhcp_ddns;
 
 namespace {
 
-/// @brief Returns the result of select() given an fd to check for read status.
-///
-/// @param fd_to_check The file descriptor to test
-/// @return Returns less than one on an error, 0 if the fd is not ready to
-/// read, > 0 if it is ready to read. 
-int selectCheck(int fd_to_check). 
-
-int selectCheck(int fd_to_check) {
-    fd_set read_fds;
-    int maxfd = 0;
-
-    FD_ZERO(&read_fds);
-
-    // Add this socket to listening set
-    FD_SET(fd_to_check,  &read_fds);
-    maxfd = fd_to_check;
-
-    struct timeval select_timeout;
-    select_timeout.tv_sec = 0;
-    select_timeout.tv_usec = 0;
-
-    return (select(maxfd + 1, &read_fds, NULL, NULL, &select_timeout));
-}
-
-
 /// @brief Tests the basic functionality of WatchSocket.
 TEST(WatchSocketTest, basics) {
     WatchSocketPtr watch;