FairMQ: Introduce callbacks for the FairMQUnmanagedRegion.

Callbacks are called when the data buffer of the message assiciated
with the corresponding region is no longer needed by the transport.
Example in examples/advanced/Region/

fairmq/shmem/Manager.cxx

@@ -0,0 +1,141 @@
+/********************************************************************************
+ *    Copyright (C) 2014 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH    *
+ *                                                                              *
+ *              This software is distributed under the terms of the             *
+ *         GNU Lesser General Public Licence version 3 (LGPL) version 3,        *
+ *                  copied verbatim in the file "LICENSE"                       *
+ ********************************************************************************/
+
+ #include "Manager.h"
+ #include "Common.h"
+
+namespace fair
+{
+namespace mq
+{
+namespace shmem
+{
+
+using namespace std;
+namespace bipc = boost::interprocess;
+
+Manager::Manager(const string& name, size_t size)
+    : fName(name)
+    , fSegment(bipc::open_or_create, fName.c_str(), size)
+    , fManagementSegment(bipc::open_or_create, "fmq_shm_management", 65536)
+    , fRegions()
+{}
+
+bipc::managed_shared_memory& Manager::Segment()
+{
+    return fSegment;
+}
+
+void Manager::Interrupt()
+{
+}
+
+void Manager::Resume()
+{
+    // close remote regions before processing new transfers
+    for (auto it = fRegions.begin(); it != fRegions.end(); /**/)
+    {
+        if (it->second.fRemote)
+        {
+           it = fRegions.erase(it);
+        }
+        else
+        {
+            ++it;
+        }
+    }
+}
+
+bipc::mapped_region* Manager::CreateRegion(const size_t size, const uint64_t id, FairMQRegionCallback callback)
+{
+    auto it = fRegions.find(id);
+    if (it != fRegions.end())
+    {
+        LOG(ERROR) << "shmem: Trying to create a region that already exists";
+        return nullptr;
+    }
+    else
+    {
+        auto r = fRegions.emplace(id, Region{*this, id, size, false, callback});
+
+        r.first->second.StartReceivingAcks();
+
+        return &(r.first->second.fRegion);
+    }
+}
+
+bipc::mapped_region* Manager::GetRemoteRegion(const uint64_t id)
+{
+    // remote region could actually be a local one if a message originates from this device (has been sent out and returned)
+    auto it = fRegions.find(id);
+    if (it != fRegions.end())
+    {
+        return &(it->second.fRegion);
+    }
+    else
+    {
+        try
+        {
+            auto r = fRegions.emplace(id, Region{*this, id, 0, true, nullptr});
+            return &(r.first->second.fRegion);
+        }
+        catch (bipc::interprocess_exception& e)
+        {
+            // LOG(WARN) << "remote region (" << id << ") no longer exists";
+            return nullptr;
+        }
+
+    }
+}
+
+void Manager::RemoveRegion(const uint64_t id)
+{
+    fRegions.erase(id);
+}
+
+bipc::message_queue* Manager::GetRegionQueue(const uint64_t id)
+{
+    try
+    {
+        return fRegions.at(id).fQueue.get();
+    }
+    catch (out_of_range& oor)
+    {
+        return nullptr;
+    }
+}
+
+void Manager::RemoveSegment()
+{
+    if (bipc::shared_memory_object::remove(fName.c_str()))
+    {
+        LOG(DEBUG) << "shmem: successfully removed " << fName << " segment after the device has stopped.";
+    }
+    else
+    {
+        LOG(DEBUG) << "shmem: did not remove " << fName << " segment after the device stopped. Already removed?";
+    }
+
+    if (bipc::shared_memory_object::remove("fmq_shm_management"))
+    {
+        LOG(DEBUG) << "shmem: successfully removed \"fmq_shm_management\" segment after the device has stopped.";
+    }
+    else
+    {
+        LOG(DEBUG) << "shmem: did not remove \"fmq_shm_management\" segment after the device stopped. Already removed?";
+    }
+}
+
+bipc::managed_shared_memory& Manager::ManagementSegment()
+{
+    return fManagementSegment;
+}
+
+} // namespace shmem
+} // namespace mq
+} // namespace fair