[trac751] Move some files from asiolink library to asiodns library

src/lib/asiodns/Makefile.am

@@ -11,12 +11,16 @@ CLEANFILES = *.gcno *.gcda
 
 lib_LTLIBRARIES = libasiodns.la
 libasiodns_la_SOURCES = dns_answer.h
+libasiodns_la_SOURCES += asiodef.cc asiodef.h
 libasiodns_la_SOURCES += dns_lookup.h
 libasiodns_la_SOURCES += dns_server.h
 libasiodns_la_SOURCES += dns_service.cc dns_service.h
 libasiodns_la_SOURCES += tcp_server.cc tcp_server.h
 libasiodns_la_SOURCES += udp_server.cc udp_server.h
 libasiodns_la_SOURCES += io_fetch.cc io_fetch.h
+libasiodns_la_SOURCES += qid_gen.cc qid_gen.h
+
+EXTRA_DIST = asiodef.msg
 
 # Note: the ordering matters: -Wno-... must follow -Wextra (defined in
 # B10_CXXFLAGS)

src/lib/asiodns/README

@@ -0,0 +1,157 @@
+The asiodns library is intended to provide an abstraction layer between
+BIND10 modules and asiolink library.
+
+These DNS server and client routines are written using the "stackless
+coroutine" pattern invented by Chris Kohlhoff and described at
+http://blog.think-async.com/2010/03/potted-guide-to-stackless-coroutines.html.
+This is intended to simplify development a bit, since it allows the
+routines to be written in a straightfowrard step-step-step fashion rather
+than as a complex chain of separate handler functions.
+
+Coroutine objects (i.e., UDPServer, TCPServer and IOFetch) are objects
+with reenterable operator() members.  When an instance of one of these
+classes is called as a function, it resumes at the position where it left
+off.  Thus, a UDPServer can issue an asynchronous I/O call and specify
+itself as the handler object; when the call completes, the UDPServer
+carries on at the same position.  As a result, the code can look as
+if it were using synchronous, not asynchronous, I/O, providing some of
+the benefit of threading but with minimal switching overhead.
+
+So, in simplified form, the behavior of a DNS Server is:
+
+  REENTER:
+    while true:
+      YIELD packet = read_packet
+      FORK
+      if not parent:
+        break
+
+    # This callback informs the caller that a packet has arrived, and
+    # gives it a chance to update configuration, etc
+    SimpleCallback(packet)
+    YIELD answer = DNSLookup(packet, this)
+    response = DNSAnswer(answer)
+    YIELD send(response)
+
+At each "YIELD" point, the coroutine initiates an asynchronous operation,
+then pauses and turns over control to some other task on the ASIO service
+queue.  When the operation completes, the coroutine resumes.
+
+DNSLookup, DNSAnswer and SimpleCallback define callback methods
+used by a DNS Server to communicate with the module that called it.
+They are abstract-only classes whose concrete implementations
+are supplied by the calling module.
+
+The DNSLookup callback always runs asynchronously.  Concrete
+implementations must be sure to call the server's "resume" method when
+it is finished.
+
+In an authoritative server, the DNSLookup implementation would examine
+the query, look up the answer, then call "resume".  (See the diagram
+in doc/auth_process.jpg.)
+
+In a recursive server, the DNSLookup impelemtation would initiate a
+DNSQuery, which in turn would be responsible for calling the server's
+"resume" method.  (See the diagram in doc/recursive_process.jpg.)
+
+A DNSQuery object is intended to handle resolution of a query over
+the network when the local authoritative data sources or cache are not
+sufficient.  The plan is that it will make use of subsidiary DNSFetch
+calls to get data from particular authoritative servers, and when it has
+gotten a complete answer, it calls "resume".
+
+In current form, however, DNSQuery is much simpler; it forwards queries
+to a single upstream resolver and passes the answers back to the client.
+It is constructed with the address of the forward server.  Queries are
+initiated with the question to ask the forward server, a buffer into
+which to write the answer, and a pointer to the coroutine to be resumed
+when the answer has arrived.  In simplified form, the DNSQuery routine is:
+
+  REENTER:
+    render the question into a wire-format query packet
+    YIELD send(query)
+    YIELD response = read_packet
+    server->resume
+
+Currently, DNSQuery is only implemented for UDP queries.  In future work
+it will be necessary to write code to fall back to TCP when circumstances
+require it.
+
+
+Upstream Fetches
+================
+Upstream fetches (queries by the resolver on behalf of a client) are made
+using a slightly-modified version of the pattern described above.
+
+Sockets
+-------
+First, it will be useful to understand the class hierarchy used in the
+fetch logic:
+
+        IOSocket
+           |
+      IOAsioSocket
+           |
+     +-----+-----+                
+     |           |
+UDPSocket    TCPSocket
+
+IOSocket is a wrapper class for a socket and is used by the authoritative
+server code.  It is an abstract base class, providing little more that the ability to hold the socket and to return the protocol in use.
+
+Built on this is IOAsioSocket, which adds the open, close, asyncSend and
+asyncReceive methods.  This is a template class, which takes as template
+argument the class of the object that will be used as the callback when the
+asynchronous operation completes. This object can be of any type, but must
+include an operator() method with the signature:
+
+   operator()(asio::error_code ec, size_t length)
+
+... the two arguments being the status of the completed I/O operation and
+the number of bytes transferred. (In the case of the open method, the second
+argument will be zero.)
+
+Finally, the TCPSocket and UDPSocket classes provide the body of the
+asynchronous operations.
+
+Fetch Sequence
+--------------
+The fetch is implemented by the IOFetch class, which takes as argument the
+protocol to use.  The sequence is:
+
+  REENTER:
+    render the question into a wire-format query packet
+    open()                           // Open socket and optionally connect
+    if (! synchronous) {
+        YIELD;
+    }
+    YIELD asyncSend(query)           // Send query 
+    do {
+        YIELD asyncReceive(response) // Read response
+    } while (! complete(response))
+    close()                          // Drop connection and close socket
+    server->resume
+
+The open() method opens a socket for use.  On TCP, it also makes a
+connection to the remote end.  So under UDP the operation will complete
+immediately, but under TCP it could take a long time.  One solution would be
+for the open operation to post an event to the I/O queue; then both cases
+could be regarded as being equivalent, with the completion being signalled
+by the posting of the completion event.  However UDP is the most common case
+and that would involve extra overhead.  So the open() returns a status
+indicating whether the operation completed asynchronously.  If it did, the
+code yields back to the coroutine; if not the yield is bypassed.
+
+The asynchronous send is straightforward, invoking the underlying ASIO
+function.  (Note that the address/port is supplied to both the open() and
+asyncSend() methods - it is used by the TCPSocket in open() and by the
+UDPSocket in asyncSend().)
+
+The asyncReceive() method issues an asynchronous read and waits for completion.
+The fetch object keeps track of the amount of data received so far and when
+the receive completes it calls a method on the socket to determine if the
+entire message has been received.  (This will always be the case for UDP.  On
+TCP though, the message is preceded by a count field as several reads may be
+required to read all the data.)  The fetch loops until all the data is read.
+
+Finally, the socket is closed and the server called to resume operation.

src/lib/asiolink/asiodef.cc

@@ -5,18 +5,18 @@
 #include <log/message_initializer.h>
 
 namespace isc {
-namespace asiolink {
-
-extern const isc::log::MessageID ASIO_FETCHCOMP = "FETCHCOMP";
-extern const isc::log::MessageID ASIO_FETCHSTOP = "FETCHSTOP";
-extern const isc::log::MessageID ASIO_OPENSOCK = "OPENSOCK";
-extern const isc::log::MessageID ASIO_RECVSOCK = "RECVSOCK";
-extern const isc::log::MessageID ASIO_RECVTMO = "RECVTMO";
-extern const isc::log::MessageID ASIO_SENDSOCK = "SENDSOCK";
-extern const isc::log::MessageID ASIO_UNKORIGIN = "UNKORIGIN";
-extern const isc::log::MessageID ASIO_UNKRESULT = "UNKRESULT";
-
-} // namespace asiolink
+namespace asiodns {
+
+extern const isc::log::MessageID ASIODNS_FETCHCOMP = "FETCHCOMP";
+extern const isc::log::MessageID ASIODNS_FETCHSTOP = "FETCHSTOP";
+extern const isc::log::MessageID ASIODNS_OPENSOCK = "OPENSOCK";
+extern const isc::log::MessageID ASIODNS_RECVSOCK = "RECVSOCK";
+extern const isc::log::MessageID ASIODNS_RECVTMO = "RECVTMO";
+extern const isc::log::MessageID ASIODNS_SENDSOCK = "SENDSOCK";
+extern const isc::log::MessageID ASIODNS_UNKORIGIN = "UNKORIGIN";
+extern const isc::log::MessageID ASIODNS_UNKRESULT = "UNKRESULT";
+
+} // namespace asiodns
 } // namespace isc
 
 namespace {

src/lib/asiodns/asiodef.h

@@ -0,0 +1,23 @@
+// File created from asiodef.msg on Mon Feb 28 17:15:30 2011
+
+#ifndef __ASIODEF_H
+#define __ASIODEF_H
+
+#include <log/message_types.h>
+
+namespace isc {
+namespace asiodns {
+
+extern const isc::log::MessageID ASIODNS_FETCHCOMP;
+extern const isc::log::MessageID ASIODNS_FETCHSTOP;
+extern const isc::log::MessageID ASIODNS_OPENSOCK;
+extern const isc::log::MessageID ASIODNS_RECVSOCK;
+extern const isc::log::MessageID ASIODNS_RECVTMO;
+extern const isc::log::MessageID ASIODNS_SENDSOCK;
+extern const isc::log::MessageID ASIODNS_UNKORIGIN;
+extern const isc::log::MessageID ASIODNS_UNKRESULT;
+
+} // namespace asiodns
+} // namespace isc
+
+#endif // __ASIODEF_H

src/lib/asiolink/asiodef.msg

@@ -12,8 +12,8 @@
 # OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 # PERFORMANCE OF THIS SOFTWARE.
 
-$PREFIX ASIO_
-$NAMESPACE asiolink
+$PREFIX ASIODNS_
+$NAMESPACE asiodns
 
 FETCHCOMP   upstream fetch to %s(%d) has now completed
 + A debug message, this records the the upstream fetch (a query made by the

src/lib/asiodns/io_fetch.cc

@@ -27,13 +27,10 @@
 #include <dns/opcode.h>
 #include <dns/rcode.h>
 #include <log/logger.h>
-
-#include <asiolink/qid_gen.h>
-
 #include <asio.hpp>
 #include <asio/deadline_timer.hpp>
-
-#include <asiolink/asiodef.h>
+#include <asiodns/qid_gen.h>
+#include <asiodns/asiodef.h>
 #include <asiolink/io_address.h>
 #include <asiolink/io_asio_socket.h>
 #include <asiolink/io_endpoint.h>
@@ -42,7 +39,6 @@
 #include <asiolink/tcp_socket.h>
 #include <asiolink/udp_endpoint.h>
 #include <asiolink/udp_socket.h>
-#include <asiolink/qid_gen.h>
 
 #include "io_fetch.h"
 
@@ -149,7 +145,7 @@ struct IOFetchData {
         offset(0),
         stopped(false),
         timeout(wait),
-        origin(ASIO_UNKORIGIN),
+        origin(ASIODNS_UNKORIGIN),
         staging(),
         qid(QidGenerator::getInstance().generateQid())
     {}
@@ -225,7 +221,7 @@ IOFetch::operator()(asio::error_code ec, size_t length) {
 
         // Open a connection to the target system.  For speed, if the operation
         // is synchronous (i.e. UDP operation) we bypass the yield.
-        data_->origin = ASIO_OPENSOCK;
+        data_->origin = ASIODNS_OPENSOCK;
         if (data_->socket->isOpenSynchronous()) {
             data_->socket->open(data_->remote_snd.get(), *this);
         } else {
@@ -235,10 +231,10 @@ IOFetch::operator()(asio::error_code ec, size_t length) {
         do {
             // Begin an asynchronous send, and then yield.  When the send completes,
             // we will resume immediately after this point.
-            data_->origin = ASIO_SENDSOCK;
+            data_->origin = ASIODNS_SENDSOCK;
             CORO_YIELD data_->socket->asyncSend(data_->msgbuf->getData(),
                 data_->msgbuf->getLength(), data_->remote_snd.get(), *this);
-    
+
             // Now receive the response.  Since TCP may not receive the entire
             // message in one operation, we need to loop until we have received
             // it. (This can't be done within the asyncReceive() method because
@@ -257,8 +253,8 @@ IOFetch::operator()(asio::error_code ec, size_t length) {
             // the expected amount of data.  Then we need to loop until we have
             // received all the data before copying it back to the user's buffer.
             // And we want to minimise the amount of copying...
-    
-            data_->origin = ASIO_RECVSOCK;
+
+            data_->origin = ASIODNS_RECVSOCK;
             data_->cumulative = 0;          // No data yet received
             data_->offset = 0;              // First data into start of buffer
             data_->received->clear();       // Clear the receive buffer
@@ -274,7 +270,7 @@ IOFetch::operator()(asio::error_code ec, size_t length) {
 
         // Finished with this socket, so close it.  This will not generate an
         // I/O error, but reset the origin to unknown in case we change this.
-        data_->origin = ASIO_UNKORIGIN;
+        data_->origin = ASIODNS_UNKORIGIN;
         data_->socket->close();
 
         /// We are done
@@ -317,7 +313,7 @@ IOFetch::stop(Result result) {
         switch (result) {
             case TIME_OUT:
                 if (logger.isDebugEnabled(1)) {
-                    logger.debug(20, ASIO_RECVTMO,
+                    logger.debug(20, ASIODNS_RECVTMO,
                                  data_->remote_snd->getAddress().toText().c_str(),
                                  static_cast<int>(data_->remote_snd->getPort()));
                 }
@@ -325,7 +321,7 @@ IOFetch::stop(Result result) {
 
             case SUCCESS:
                 if (logger.isDebugEnabled(50)) {
-                    logger.debug(30, ASIO_FETCHCOMP,
+                    logger.debug(30, ASIODNS_FETCHCOMP,
                                  data_->remote_rcv->getAddress().toText().c_str(),
                                  static_cast<int>(data_->remote_rcv->getPort()));
                 }
@@ -335,13 +331,13 @@ IOFetch::stop(Result result) {
                 // Fetch has been stopped for some other reason.  This is
                 // allowed but as it is unusual it is logged, but with a lower
                 // debug level than a timeout (which is totally normal).
-                logger.debug(1, ASIO_FETCHSTOP,
+                logger.debug(1, ASIODNS_FETCHSTOP,
                              data_->remote_snd->getAddress().toText().c_str(),
                              static_cast<int>(data_->remote_snd->getPort()));
                 break;
 
             default:
-                logger.error(ASIO_UNKRESULT, static_cast<int>(result),
+                logger.error(ASIODNS_UNKRESULT, static_cast<int>(result),
                              data_->remote_snd->getAddress().toText().c_str(),
                              static_cast<int>(data_->remote_snd->getPort()));
         }
@@ -365,10 +361,10 @@ IOFetch::stop(Result result) {
 void IOFetch::logIOFailure(asio::error_code ec) {
 
     // Should only get here with a known error code.
-    assert((data_->origin == ASIO_OPENSOCK) ||
-           (data_->origin == ASIO_SENDSOCK) ||
-           (data_->origin == ASIO_RECVSOCK) ||
-           (data_->origin == ASIO_UNKORIGIN));
+    assert((data_->origin == ASIODNS_OPENSOCK) ||
+           (data_->origin == ASIODNS_SENDSOCK) ||
+           (data_->origin == ASIODNS_RECVSOCK) ||
+           (data_->origin == ASIODNS_UNKORIGIN));
 
     static const char* PROTOCOL[2] = {"TCP", "UDP"};
     logger.error(data_->origin,

src/lib/asiolink/qid_gen.cc

@@ -18,16 +18,16 @@
 // (and other parts where we need randomness, perhaps another thing
 // for a general libutil?)
 
-#include <asiolink/qid_gen.h>
+#include <asiodns/qid_gen.h>
 
 #include <sys/time.h>
 
 namespace {
-    isc::asiolink::QidGenerator qid_generator_instance;
+    isc::asiodns::QidGenerator qid_generator_instance;
 }
 
 namespace isc {
-namespace asiolink {
+namespace asiodns {
 
 QidGenerator&
 QidGenerator::getInstance() {
@@ -52,5 +52,5 @@ QidGenerator::generateQid() {
     return (vgen_());
 }
 
-} // namespace asiolink
+} // namespace asiodns
 } // namespace isc

src/lib/asiolink/qid_gen.h

@@ -28,7 +28,7 @@
 
 
 namespace isc {
-namespace asiolink {
+namespace asiodns {
 
 /// This class generates Qids for outgoing queries
 ///
@@ -81,7 +81,7 @@ private:
 };
 
 
-} // namespace asiolink
+} // namespace asiodns
 } // namespace isc
 
 #endif // __QID_GEN_H

src/lib/asiodns/tests/Makefile.am

@@ -21,6 +21,7 @@ run_unittests_SOURCES += $(top_srcdir)/src/lib/dns/tests/unittest_util.cc
 run_unittests_SOURCES += io_service_unittest.cc
 run_unittests_SOURCES += dns_server_unittest.cc
 run_unittests_SOURCES += io_fetch_unittest.cc
+run_unittests_SOURCES += qid_gen_unittest.cc
 
 run_unittests_CPPFLAGS = $(AM_CPPFLAGS) $(GTEST_INCLUDES)
 

src/lib/asiolink/tests/qid_gen_unittest.cc

@@ -32,15 +32,15 @@
 
 #include <gtest/gtest.h>
 
-#include <asiolink/qid_gen.h>
+#include <asiodns/qid_gen.h>
 #include <dns/message.h>
 
 // Tests the operation of the Qid generator
 
 // Check that getInstance returns a singleton
 TEST(QidGenerator, singleton) {
-    isc::asiolink::QidGenerator& g1 = isc::asiolink::QidGenerator::getInstance();
-    isc::asiolink::QidGenerator& g2 = isc::asiolink::QidGenerator::getInstance();
+    isc::asiodns::QidGenerator& g1 = isc::asiodns::QidGenerator::getInstance();
+    isc::asiodns::QidGenerator& g2 = isc::asiodns::QidGenerator::getInstance();
 
     EXPECT_TRUE(&g1 == &g2);
 }
@@ -51,7 +51,7 @@ TEST(QidGenerator, generate) {
     // test (http://xkcd.com/221/), and check if three consecutive
     // generates are not all the same.
     isc::dns::qid_t one, two, three;
-    isc::asiolink::QidGenerator& gen = isc::asiolink::QidGenerator::getInstance();
+    isc::asiodns::QidGenerator& gen = isc::asiodns::QidGenerator::getInstance();
     one = gen.generateQid();
     two = gen.generateQid();
     three = gen.generateQid();

src/lib/asiolink/Makefile.am

@@ -14,7 +14,6 @@ CLEANFILES = *.gcno *.gcda
 lib_LTLIBRARIES = libasiolink.la
 libasiolink_la_SOURCES  = asiolink.h
 libasiolink_la_SOURCES += asiolink_utilities.h
-libasiolink_la_SOURCES += asiodef.cc asiodef.h
 libasiolink_la_SOURCES += dummy_io_cb.h
 libasiolink_la_SOURCES += interval_timer.cc interval_timer.h
 libasiolink_la_SOURCES += io_address.cc io_address.h
@@ -22,7 +21,6 @@ libasiolink_la_SOURCES += io_asio_socket.h
 libasiolink_la_SOURCES += io_endpoint.cc io_endpoint.h
 libasiolink_la_SOURCES += io_error.h
 libasiolink_la_SOURCES += io_message.h
-libasiolink_la_SOURCES += qid_gen.cc qid_gen.h
 libasiolink_la_SOURCES += io_service.h io_service.cc
 libasiolink_la_SOURCES += io_socket.h io_socket.cc
 libasiolink_la_SOURCES += simple_callback.h
@@ -31,8 +29,6 @@ libasiolink_la_SOURCES += tcp_socket.h
 libasiolink_la_SOURCES += udp_endpoint.h
 libasiolink_la_SOURCES += udp_socket.h
 
-EXTRA_DIST = asiodef.msg
-
 # Note: the ordering matters: -Wno-... must follow -Wextra (defined in
 # B10_CXXFLAGS)
 libasiolink_la_CXXFLAGS = $(AM_CXXFLAGS)

src/lib/asiolink/README

@@ -16,167 +16,7 @@ including:
     them in only one place allows us to relax strictness here, while
     leaving it in place elsewhere.
 
-Currently, the asiolink library only supports DNS servers (i.e., b10-auth
-and b10-resolver).  The plan is to make it more generic and allow it to
-support other modules as well.
-
 Some of the classes defined here--for example, IOSocket, IOEndpoint,
 and IOAddress--are to be used by BIND 10 modules as wrappers around
 ASIO-specific classes.
 
-Other classes implement the DNS protocol on behalf of BIND 10 modules.
-
-These DNS server and client routines are written using the "stackless
-coroutine" pattern invented by Chris Kohlhoff and described at
-http://blog.think-async.com/2010/03/potted-guide-to-stackless-coroutines.html.
-This is intended to simplify development a bit, since it allows the
-routines to be written in a straightfowrard step-step-step fashion rather
-than as a complex chain of separate handler functions.
-
-Coroutine objects (i.e., UDPServer, TCPServer and IOFetch) are objects
-with reenterable operator() members.  When an instance of one of these
-classes is called as a function, it resumes at the position where it left
-off.  Thus, a UDPServer can issue an asynchronous I/O call and specify
-itself as the handler object; when the call completes, the UDPServer
-carries on at the same position.  As a result, the code can look as
-if it were using synchronous, not asynchronous, I/O, providing some of
-the benefit of threading but with minimal switching overhead.
-
-So, in simplified form, the behavior of a DNS Server is:
-
-  REENTER:
-    while true:
-      YIELD packet = read_packet
-      FORK
-      if not parent:
-        break
-
-    # This callback informs the caller that a packet has arrived, and
-    # gives it a chance to update configuration, etc
-    SimpleCallback(packet)
-    YIELD answer = DNSLookup(packet, this)
-    response = DNSAnswer(answer)
-    YIELD send(response)
-
-At each "YIELD" point, the coroutine initiates an asynchronous operation,
-then pauses and turns over control to some other task on the ASIO service
-queue.  When the operation completes, the coroutine resumes.
-
-DNSLookup, DNSAnswer and SimpleCallback define callback methods
-used by a DNS Server to communicate with the module that called it.
-They are abstract-only classes whose concrete implementations
-are supplied by the calling module.
-
-The DNSLookup callback always runs asynchronously.  Concrete
-implementations must be sure to call the server's "resume" method when
-it is finished.
-
-In an authoritative server, the DNSLookup implementation would examine
-the query, look up the answer, then call "resume".  (See the diagram
-in doc/auth_process.jpg.)
-
-In a recursive server, the DNSLookup impelemtation would initiate a
-DNSQuery, which in turn would be responsible for calling the server's
-"resume" method.  (See the diagram in doc/recursive_process.jpg.)
-
-A DNSQuery object is intended to handle resolution of a query over
-the network when the local authoritative data sources or cache are not
-sufficient.  The plan is that it will make use of subsidiary DNSFetch
-calls to get data from particular authoritative servers, and when it has
-gotten a complete answer, it calls "resume".
-
-In current form, however, DNSQuery is much simpler; it forwards queries
-to a single upstream resolver and passes the answers back to the client.
-It is constructed with the address of the forward server.  Queries are
-initiated with the question to ask the forward server, a buffer into
-which to write the answer, and a pointer to the coroutine to be resumed
-when the answer has arrived.  In simplified form, the DNSQuery routine is:
-
-  REENTER:
-    render the question into a wire-format query packet
-    YIELD send(query)
-    YIELD response = read_packet
-    server->resume
-
-Currently, DNSQuery is only implemented for UDP queries.  In future work
-it will be necessary to write code to fall back to TCP when circumstances
-require it.
-
-
-Upstream Fetches
-================
-Upstream fetches (queries by the resolver on behalf of a client) are made
-using a slightly-modified version of the pattern described above.
-
-Sockets
--------
-First, it will be useful to understand the class hierarchy used in the
-fetch logic:
-
-        IOSocket
-           |
-      IOAsioSocket
-           |
-     +-----+-----+                
-     |           |
-UDPSocket    TCPSocket
-
-IOSocket is a wrapper class for a socket and is used by the authoritative
-server code.  It is an abstract base class, providing little more that the ability to hold the socket and to return the protocol in use.
-
-Built on this is IOAsioSocket, which adds the open, close, asyncSend and
-asyncReceive methods.  This is a template class, which takes as template
-argument the class of the object that will be used as the callback when the
-asynchronous operation completes. This object can be of any type, but must
-include an operator() method with the signature:
-
-   operator()(asio::error_code ec, size_t length)
-
-... the two arguments being the status of the completed I/O operation and
-the number of bytes transferred. (In the case of the open method, the second
-argument will be zero.)
-
-Finally, the TCPSocket and UDPSocket classes provide the body of the
-asynchronous operations.
-
-Fetch Sequence
---------------
-The fetch is implemented by the IOFetch class, which takes as argument the
-protocol to use.  The sequence is:
-
-  REENTER:
-    render the question into a wire-format query packet
-    open()                           // Open socket and optionally connect
-    if (! synchronous) {
-        YIELD;
-    }
-    YIELD asyncSend(query)           // Send query 
-    do {
-        YIELD asyncReceive(response) // Read response
-    } while (! complete(response))
-    close()                          // Drop connection and close socket
-    server->resume
-
-The open() method opens a socket for use.  On TCP, it also makes a
-connection to the remote end.  So under UDP the operation will complete
-immediately, but under TCP it could take a long time.  One solution would be
-for the open operation to post an event to the I/O queue; then both cases
-could be regarded as being equivalent, with the completion being signalled
-by the posting of the completion event.  However UDP is the most common case
-and that would involve extra overhead.  So the open() returns a status
-indicating whether the operation completed asynchronously.  If it did, the
-code yields back to the coroutine; if not the yield is bypassed.
-
-The asynchronous send is straightforward, invoking the underlying ASIO
-function.  (Note that the address/port is supplied to both the open() and
-asyncSend() methods - it is used by the TCPSocket in open() and by the
-UDPSocket in asyncSend().)
-
-The asyncReceive() method issues an asynchronous read and waits for completion.
-The fetch object keeps track of the amount of data received so far and when
-the receive completes it calls a method on the socket to determine if the
-entire message has been received.  (This will always be the case for UDP.  On
-TCP though, the message is preceded by a count field as several reads may be
-required to read all the data.)  The fetch loops until all the data is read.
-
-Finally, the socket is closed and the server called to resume operation.

src/lib/asiolink/asiodef.h

@@ -1,23 +0,0 @@
-// File created from asiodef.msg on Mon Feb 28 17:15:30 2011
-
-#ifndef __ASIODEF_H
-#define __ASIODEF_H
-
-#include <log/message_types.h>
-
-namespace isc {
-namespace asiolink {
-
-extern const isc::log::MessageID ASIO_FETCHCOMP;
-extern const isc::log::MessageID ASIO_FETCHSTOP;
-extern const isc::log::MessageID ASIO_OPENSOCK;
-extern const isc::log::MessageID ASIO_RECVSOCK;
-extern const isc::log::MessageID ASIO_RECVTMO;
-extern const isc::log::MessageID ASIO_SENDSOCK;
-extern const isc::log::MessageID ASIO_UNKORIGIN;
-extern const isc::log::MessageID ASIO_UNKRESULT;
-
-} // namespace asiolink
-} // namespace isc
-
-#endif // __ASIODEF_H

src/lib/asiolink/tests/Makefile.am

@@ -27,7 +27,6 @@ run_unittests_SOURCES += tcp_endpoint_unittest.cc
 run_unittests_SOURCES += tcp_socket_unittest.cc
 run_unittests_SOURCES += udp_endpoint_unittest.cc
 run_unittests_SOURCES += udp_socket_unittest.cc
-run_unittests_SOURCES += qid_gen_unittest.cc
 
 run_unittests_CPPFLAGS = $(AM_CPPFLAGS) $(GTEST_INCLUDES)