Fix cman integration to exit immediately on loss of quorum.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@801740 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 62 insertions, 4 deletions

diff --git a/cpp/src/qpid/cluster/Quorum_cman.cpp b/cpp/src/qpid/cluster/Quorum_cman.cpp
index 32ed5c1d91..277adaf7b1 100644
--- a/cpp/src/qpid/cluster/Quorum_cman.cpp
+++ b/cpp/src/qpid/cluster/Quorum_cman.cpp
@@ -18,28 +18,86 @@
  * under the License.
  *
  */
+
 #include "qpid/cluster/Quorum_cman.h"
+#include "qpid/cluster/Cluster.h"
 #include "qpid/log/Statement.h"
 #include "qpid/Options.h"
 #include "qpid/sys/Time.h"
+#include "qpid/sys/posix/PrivatePosix.h"
 
 namespace qpid {
 namespace cluster {
 
-Quorum::Quorum() : enable(false), cman(0) {}
+namespace {
+
+boost::function<void()> errorFn;
 
-Quorum::~Quorum() { if (cman) cman_finish(cman); }
+void cmanCallbackFn(cman_handle_t handle, void */*privdata*/, int reason, int arg) {
+    if (reason == CMAN_REASON_STATECHANGE && arg == 0) {
+        QPID_LOG(critical, "Lost contact with cluster quorum.");
+        if (errorFn) errorFn();
+        cman_stop_notification(handle);
+    }
+}
+}
+
+Quorum::Quorum(boost::function<void()> err) : enable(false), cman(0), cmanFd(0) {
+    errorFn = err;
+}
+
+Quorum::~Quorum() {
+    dispatchHandle.reset();
+    if (cman) cman_finish(cman);
+}
 
-void Quorum::init() {
+void Quorum::start(boost::shared_ptr<sys::Poller> p) {
+    poller = p;
     enable = true;
+    QPID_LOG(debug, "Connecting to quorum service.");
     cman = cman_init(0);
     if (cman == 0) throw ErrnoException("Can't connect to cman service");
     if (!cman_is_quorate(cman)) {
         QPID_LOG(notice, "Waiting for cluster quorum.");
         while(!cman_is_quorate(cman)) sys::sleep(5);
     }
+    int err = cman_start_notification(cman, cmanCallbackFn);
+    if (err != 0) throw ErrnoException("Can't register for cman notifications");
+    watch(getFd());
 }
 
-bool Quorum::isQuorate() { return enable ? cman_is_quorate(cman) : true; }
+void Quorum::watch(int fd) {
+    cmanFd = fd;
+    dispatchHandle.reset(
+        new sys::DispatchHandleRef(
+            sys::PosixIOHandle(cmanFd),
+            boost::bind(&Quorum::dispatch, this, _1), // read
+            0, // write
+            boost::bind(&Quorum::disconnect, this, _1)  // disconnect
+        ));
+    dispatchHandle->startWatch(poller);
+}
+
+int Quorum::getFd() {
+    int fd = cman_get_fd(cman);
+    if (fd == 0) throw ErrnoException("Can't get cman file descriptor");
+    return fd;
+}
+
+void Quorum::dispatch(sys::DispatchHandle&) {
+    try {
+        cman_dispatch(cman, CMAN_DISPATCH_ALL);
+        int fd = getFd();
+        if (fd != cmanFd) watch(fd);
+    } catch (const std::exception& e) {
+        QPID_LOG(critical, "Error in quorum dispatch: " << e.what());
+        errorFn();
+    }
+}
+
+void Quorum::disconnect(sys::DispatchHandle&) {
+    QPID_LOG(critical, "Disconnected from quorum service");
+    errorFn();
+}
 
 }} // namespace qpid::cluster