Skip error message only for tcp

fairmq/UnmanagedRegion.h

@@ -133,6 +133,7 @@ struct RegionConfig
     bool removeOnDestruction = true; /// remove the region on object destruction
     int creationFlags = 0; /// flags passed to the underlying transport on region creation
     int64_t userFlags = 0; /// custom flags that have no effect on the transport, but can be retrieved from the region by the user
+    uint64_t size = 0; /// region size
     std::string path = ""; /// file path, if the region is backed by a file
     std::optional<uint16_t> id = std::nullopt; /// region id
     uint32_t linger = 100; /// delay in ms before region destruction to collect outstanding events

fairmq/shmem/Common.h

@@ -28,6 +28,8 @@
 namespace fair::mq::shmem
 {
 
+static constexpr uint64_t kManagementSegmentSize = 6553600;
+
 struct SharedMemoryError : std::runtime_error { using std::runtime_error::runtime_error; };
 
 using SimpleSeqFitSegment = boost::interprocess::basic_managed_shared_memory<char,
@@ -58,19 +60,22 @@ struct RegionInfo
         : fPath("", alloc)
         , fCreationFlags(0)
         , fUserFlags(0)
+        , fSize(0)
         , fDestroyed(false)
     {}
 
-    RegionInfo(const char* path, const int flags, const uint64_t userFlags, const VoidAlloc& alloc)
+    RegionInfo(const char* path, int flags, uint64_t userFlags, uint64_t size, const VoidAlloc& alloc)
         : fPath(path, alloc)
         , fCreationFlags(flags)
         , fUserFlags(userFlags)
+        , fSize(size)
         , fDestroyed(false)
     {}
 
     Str fPath;
     int fCreationFlags;
     uint64_t fUserFlags;
+    uint64_t fSize;
     bool fDestroyed;
 };
 

fairmq/shmem/Manager.h

@@ -132,7 +132,7 @@ class Manager
         : fShmId64(config ? config->GetProperty<uint64_t>("shmid", makeShmIdUint64(sessionName)) : makeShmIdUint64(sessionName))
         , fShmId(makeShmIdStr(fShmId64))
         , fSegmentId(config ? config->GetProperty<uint16_t>("shm-segment-id", 0) : 0)
-        , fManagementSegment(boost::interprocess::open_or_create, std::string("fmq_" + fShmId + "_mng").c_str(), 6553600)
+        , fManagementSegment(boost::interprocess::open_or_create, std::string("fmq_" + fShmId + "_mng").c_str(), kManagementSegmentSize)
         , fShmVoidAlloc(fManagementSegment.get_segment_manager())
         , fShmMtx(fManagementSegment.find_or_construct<boost::interprocess::interprocess_mutex>(boost::interprocess::unique_instance)())
         , fNumObservedEvents(0)
@@ -228,6 +228,8 @@ class Manager
             fShmSegments = fManagementSegment.find_or_construct<Uint16SegmentInfoHashMap>(unique_instance)(fShmVoidAlloc);
             fShmRegions = fManagementSegment.find_or_construct<Uint16RegionInfoHashMap>(unique_instance)(fShmVoidAlloc);
 
+            bool createdSegment = false;
+
             try {
                 std::string segmentName("fmq_" + fShmId + "_m_" + std::to_string(fSegmentId));
                 auto it = fShmSegments->find(fSegmentId);
@@ -246,6 +248,7 @@ class Manager
                     if (zeroSegmentOnCreation) {
                         ZeroSegment(fSegmentId);
                     }
+                    createdSegment = true;
                 } else {
                     // found segment with the given id, opening
                     if (it->second.fAllocationAlgorithm == AllocationAlgorithm::rbtree_best_fit) {
@@ -278,7 +281,9 @@ class Manager
                 ZeroSegment(fSegmentId);
             }
 
-            (fEventCounter->fCount)++;
+            if (createdSegment) {
+                (fEventCounter->fCount)++;
+            }
 
 #ifdef FAIRMQ_DEBUG_MODE
             fMsgDebug = fManagementSegment.find_or_construct<Uint16MsgDebugMapHashMap>(unique_instance)(fShmVoidAlloc);
@@ -360,7 +365,7 @@ class Manager
     }
     bool Interrupted() { return fInterrupted.load(); }
 
-    std::pair<UnmanagedRegion*, uint16_t> CreateRegion(const size_t size,
+    std::pair<UnmanagedRegion*, uint16_t> CreateRegion(size_t size,
                                                        RegionCallback callback,
                                                        RegionBulkCallback bulkCallback,
                                                        RegionConfig cfg)
@@ -370,7 +375,7 @@ class Manager
             std::pair<UnmanagedRegion*, uint16_t> result;
 
             {
-                boost::interprocess::scoped_lock<boost::interprocess::interprocess_mutex> lock(*fShmMtx);
+                boost::interprocess::scoped_lock<boost::interprocess::interprocess_mutex> shmLock(*fShmMtx);
 
                 if (!cfg.id.has_value()) {
                     RegionCounter* rc = fManagementSegment.find<RegionCounter>(unique_instance).first;
@@ -390,23 +395,28 @@ class Manager
 
                 const uint16_t id = cfg.id.value();
 
-                auto res = fRegions.emplace(id, std::make_unique<UnmanagedRegion>(fShmId, size, false, cfg));
-                bool newRegionCreated = res.second;
-                UnmanagedRegion& region = *(res.first->second);
+                UnmanagedRegion* region = nullptr;
+                bool newRegionCreated = false;
+                {
+                    std::lock_guard<std::mutex> lock(fLocalRegionsMtx);
+                    auto res = fRegions.emplace(id, std::make_unique<UnmanagedRegion>(fShmId, size, false, cfg));
+                    newRegionCreated = res.second;
+                    region = res.first->second.get();
+                }
                 // LOG(debug) << "Created region with id '" << id << "', path: '" << cfg.path << "', flags: '" << cfg.creationFlags << "'";
 
                 if (!newRegionCreated) {
-                    region.fRemote = false; // TODO: this should be more clear, refactor it.
+                    region->fRemote = false; // TODO: this should be more clear, refactor it.
                 }
 
                 // start ack receiver only if a callback has been provided.
                 if (callback || bulkCallback) {
-                    region.SetCallbacks(callback, bulkCallback);
-                    region.InitializeQueues();
-                    region.StartAckSender();
-                    region.StartAckReceiver();
+                    region->SetCallbacks(callback, bulkCallback);
+                    region->InitializeQueues();
+                    region->StartAckSender();
+                    region->StartAckReceiver();
                 }
-                result.first = &(region);
+                result.first = region;
                 result.second = id;
             }
             fRegionsGen += 1; // signal TL cache invalidation
@@ -419,7 +429,7 @@ class Manager
         }
     }
 
-    UnmanagedRegion* GetRegion(const uint16_t id)
+    UnmanagedRegion* GetRegion(uint16_t id)
     {
         // NOTE: gcc optimizations. Prevent loading tls addresses many times in the fast path
         const auto &lTlCache = fTlRegionCache;
@@ -439,13 +449,14 @@ class Manager
             fTlRegionCache.fRegionsTLCache.clear();
         }
 
+        std::lock_guard<std::mutex> lock(fLocalRegionsMtx);
         auto* lRegion = GetRegionUnsafe(id, shmLock);
         fTlRegionCache.fRegionsTLCache.emplace_back(std::make_tuple(lRegion, id, fShmId64));
         fTlRegionCache.fRegionsTLCacheGen = fRegionsGen;
         return lRegion;
     }
 
-    UnmanagedRegion* GetRegionUnsafe(const uint16_t id, boost::interprocess::scoped_lock<boost::interprocess::interprocess_mutex>& lockedShmLock)
+    UnmanagedRegion* GetRegionUnsafe(uint16_t id, boost::interprocess::scoped_lock<boost::interprocess::interprocess_mutex>& lockedShmLock)
     {
         // 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);
@@ -479,12 +490,13 @@ class Manager
         }
     }
 
-    void RemoveRegion(const uint16_t id)
+    void RemoveRegion(uint16_t id)
     {
         try {
+            std::lock_guard<std::mutex> lock(fLocalRegionsMtx);
             fRegions.at(id)->StopAcks();
             {
-                boost::interprocess::scoped_lock<boost::interprocess::interprocess_mutex> lock(*fShmMtx);
+                boost::interprocess::scoped_lock<boost::interprocess::interprocess_mutex> shmLock(*fShmMtx);
                 if (fRegions.at(id)->RemoveOnDestruction()) {
                     fShmRegions->at(id).fDestroyed = true;
                     (fEventCounter->fCount)++;
@@ -800,6 +812,7 @@ class Manager
     VoidAlloc fShmVoidAlloc;
     boost::interprocess::interprocess_mutex* fShmMtx;
 
+    std::mutex fLocalRegionsMtx;
     std::mutex fRegionEventsMtx;
     std::condition_variable fRegionEventsCV;
     std::thread fRegionEventThread;

fairmq/shmem/Monitor.cxx

@@ -6,9 +6,10 @@
  *                  copied verbatim in the file "LICENSE"                       *
  ********************************************************************************/
 
-#include "Monitor.h"
 #include "Common.h"
-#include "UnmanagedRegion.h"
+#include "Monitor.h"
+#include "Segment.h"
+#include <fairmq/shmem/UnmanagedRegion.h>
 
 #include <fairmq/tools/IO.h>
 #include <fairmq/tools/Strings.h>
@@ -267,13 +268,14 @@ bool Monitor::PrintShm(const ShmId& shmId)
             ss << "\n   unmanaged regions:";
             for (const auto& r : *shmRegions) {
                 ss << "\n      [" << r.first << "]: " << (r.second.fDestroyed ? "destroyed" : "alive");
+                ss << ", size: " << r.second.fSize;
 
-                try {
-                    boost::interprocess::message_queue q(open_only, std::string("fmq_" + std::string(shmId) + "_rgq_" + to_string(r.first)).c_str());
-                    ss << ", ack queue: " << q.get_num_msg() << " messages";
-                } catch (bie&) {
-                    ss << ", ack queue: not found";
-                }
+                // try {
+                //     boost::interprocess::message_queue q(open_only, std::string("fmq_" + std::string(shmId) + "_rgq_" + to_string(r.first)).c_str());
+                //     ss << ", ack queue: " << q.get_num_msg() << " messages";
+                // } catch (bie&) {
+                //     ss << ", ack queue: not found";
+                // }
             }
         }
         LOGV(info, user1) << ss.str();
@@ -414,24 +416,28 @@ void Monitor::PrintDebugInfo(const ShmId& shmId __attribute__((unused)))
 
         size_t numMessages = 0;
 
-        for (const auto& e : *debug) {
-            numMessages += e.second.size();
-        }
-        LOG(info) << endl << "found " << numMessages << " messages.";
-
-        for (const auto& s : *debug) {
-            for (const auto& e : s.second) {
-                using time_point = chrono::system_clock::time_point;
-                time_point tmpt{chrono::duration_cast<time_point::duration>(chrono::nanoseconds(e.second.fCreationTime))};
-                time_t t = chrono::system_clock::to_time_t(tmpt);
-                uint64_t ms = e.second.fCreationTime % 1000000;
-                auto tm = localtime(&t);
-                LOG(info) << "segment: " << setw(3) << setfill(' ') << s.first
-                     << ", offset: " << setw(12) << setfill(' ') << e.first
-                     << ", size: " << setw(10) << setfill(' ') << e.second.fSize
-                     << ", creator PID: " << e.second.fPid << setfill('0')
-                     << ", at: " << setw(2) << tm->tm_hour << ":" << setw(2) << tm->tm_min << ":" << setw(2) << tm->tm_sec << "." << setw(6) << ms;
+        if (debug) {
+            for (const auto& e : *debug) {
+                numMessages += e.second.size();
             }
+            LOG(info) << endl << "found " << numMessages << " messages.";
+
+            for (const auto& s : *debug) {
+                for (const auto& e : s.second) {
+                    using time_point = chrono::system_clock::time_point;
+                    time_point tmpt{chrono::duration_cast<time_point::duration>(chrono::nanoseconds(e.second.fCreationTime))};
+                    time_t t = chrono::system_clock::to_time_t(tmpt);
+                    uint64_t ms = e.second.fCreationTime % 1000000;
+                    auto tm = localtime(&t);
+                    LOG(info) << "segment: " << setw(3) << setfill(' ') << s.first
+                        << ", offset: " << setw(12) << setfill(' ') << e.first
+                        << ", size: " << setw(10) << setfill(' ') << e.second.fSize
+                        << ", creator PID: " << e.second.fPid << setfill('0')
+                        << ", at: " << setw(2) << tm->tm_hour << ":" << setw(2) << tm->tm_min << ":" << setw(2) << tm->tm_sec << "." << setw(6) << ms;
+                }
+            }
+        } else {
+            LOG(info) << "no debug data found";
         }
     } catch (bie&) {
         LOG(info) << "no segments found";
@@ -462,11 +468,16 @@ unordered_map<uint16_t, std::vector<BufferDebugInfo>> Monitor::GetDebugInfo(cons
 
         result.reserve(debug->size());
 
-        for (const auto& s : *debug) {
-            result[s.first].reserve(s.second.size());
-            for (const auto& e : s.second) {
-                result[s.first][e.first] = BufferDebugInfo(e.first, e.second.fPid, e.second.fSize, e.second.fCreationTime);
+
+        if (debug) {
+            for (const auto& s : *debug) {
+                result[s.first].reserve(s.second.size());
+                for (const auto& e : s.second) {
+                    result[s.first][e.first] = BufferDebugInfo(e.first, e.second.fPid, e.second.fSize, e.second.fCreationTime);
+                }
             }
+        } else {
+            LOG(info) << "no debug data found";
         }
     } catch (bie&) {
         LOG(info) << "no segments found";
@@ -552,15 +563,16 @@ std::pair<std::string, bool> Remove(const std::string& name, bool verbose)
     }
 }
 
-std::vector<std::pair<std::string, bool>> Monitor::Cleanup(const ShmId& shmId, bool verbose /* = true */)
+std::vector<std::pair<std::string, bool>> Monitor::Cleanup(const ShmId& shmIdT, bool verbose /* = true */)
 {
+    std::string shmId = shmIdT.shmId;
     std::vector<std::pair<std::string, bool>> result;
 
     if (verbose) {
-        LOG(info) << "Cleaning up for shared memory id '" << shmId.shmId << "'...";
+        LOG(info) << "Cleaning up for shared memory id '" << shmId << "'...";
     }
 
-    string managementSegmentName("fmq_" + shmId.shmId + "_mng");
+    string managementSegmentName("fmq_" + shmId + "_mng");
     try {
         bipc::managed_shared_memory managementSegment(bipc::open_only, managementSegmentName.c_str());
 
@@ -578,22 +590,21 @@ std::vector<std::pair<std::string, bool>> Monitor::Cleanup(const ShmId& shmId, b
                     LOG(info) << "Found RegionInfo with path: '" << path << "', flags: " << flags << ", fDestroyed: " << info.fDestroyed << ".";
                 }
                 if (!path.empty()) {
-                    result.emplace_back(Remove<bipc::file_mapping>(path + "fmq_" + shmId.shmId + "_rg_" + to_string(id), verbose));
+                    result.emplace_back(Remove<bipc::file_mapping>(path + "fmq_" + shmId + "_rg_" + to_string(id), verbose));
                 } else {
-                    result.emplace_back(Remove<bipc::shared_memory_object>("fmq_" + shmId.shmId + "_rg_" + to_string(id), verbose));
+                    result.emplace_back(Remove<bipc::shared_memory_object>("fmq_" + shmId + "_rg_" + to_string(id), verbose));
                 }
-                result.emplace_back(Remove<bipc::message_queue>("fmq_" + shmId.shmId + "_rgq_" + to_string(id), verbose));
+                result.emplace_back(Remove<bipc::message_queue>("fmq_" + shmId + "_rgq_" + to_string(id), verbose));
             }
         }
 
         Uint16SegmentInfoHashMap* shmSegments = managementSegment.find<Uint16SegmentInfoHashMap>(bipc::unique_instance).first;
-
         if (shmSegments) {
             if (verbose) {
                 LOG(info) << "Found " << shmSegments->size() << " managed segments...";
             }
             for (const auto& segment : *shmSegments) {
-                result.emplace_back(Remove<bipc::shared_memory_object>("fmq_" + shmId.shmId + "_m_" + to_string(segment.first), verbose));
+                result.emplace_back(Remove<bipc::shared_memory_object>("fmq_" + shmId + "_m_" + to_string(segment.first), verbose));
             }
         } else {
             if (verbose) {
@@ -636,41 +647,49 @@ std::vector<std::pair<std::string, bool>> Monitor::CleanupFull(const SessionId&
     return CleanupFull(shmId, verbose);
 }
 
-void Monitor::ResetContent(const ShmId& shmId, bool verbose /* = true */)
+void Monitor::ResetContent(const ShmId& shmIdT, bool verbose /* = true */)
 {
+    std::string shmId = shmIdT.shmId;
     if (verbose) {
-        cout << "Resetting segments content for shared memory id '" << shmId.shmId << "'..." << endl;
+        cout << "Resetting segments content for shared memory id '" << shmId << "'..." << endl;
     }
 
-    string managementSegmentName("fmq_" + shmId.shmId + "_mng");
+    string managementSegmentName("fmq_" + shmId + "_mng");
     try {
         using namespace boost::interprocess;
         managed_shared_memory managementSegment(open_only, managementSegmentName.c_str());
 
         Uint16SegmentInfoHashMap* segmentInfos = managementSegment.find<Uint16SegmentInfoHashMap>(unique_instance).first;
-
         for (const auto& s : *segmentInfos) {
             if (verbose) {
-                cout << "Resetting content of segment '" << "fmq_" << shmId.shmId << "_m_" << s.first << "'..." << endl;
+                cout << "Resetting content of segment '" << "fmq_" << shmId << "_m_" << s.first << "'..." << endl;
             }
             try {
                 if (s.second.fAllocationAlgorithm == AllocationAlgorithm::rbtree_best_fit) {
-                    RBTreeBestFitSegment segment(open_only, std::string("fmq_" + shmId.shmId + "_m_" + to_string(s.first)).c_str());
+                    RBTreeBestFitSegment segment(open_only, std::string("fmq_" + shmId + "_m_" + to_string(s.first)).c_str());
                     void* ptr = segment.get_segment_manager();
                     size_t size = segment.get_segment_manager()->get_size();
                     new(ptr) segment_manager<char, rbtree_best_fit<mutex_family, offset_ptr<void>>, null_index>(size);
                 } else {
-                    SimpleSeqFitSegment segment(open_only, std::string("fmq_" + shmId.shmId + "_m_" + to_string(s.first)).c_str());
+                    SimpleSeqFitSegment segment(open_only, std::string("fmq_" + shmId + "_m_" + to_string(s.first)).c_str());
                     void* ptr = segment.get_segment_manager();
                     size_t size = segment.get_segment_manager()->get_size();
                     new(ptr) segment_manager<char, simple_seq_fit<mutex_family, offset_ptr<void>>, null_index>(size);
                 }
             } catch (bie& e) {
                 if (verbose) {
-                    cout << "Error resetting content of segment '" << std::string("fmq_" + shmId.shmId + "_m_" + to_string(s.first)) << "': " << e.what() << endl;
+                    cout << "Error resetting content of segment '" << std::string("fmq_" + shmId + "_m_" + to_string(s.first)) << "': " << e.what() << endl;
                 }
             }
         }
+
+        Uint16RegionInfoHashMap* shmRegions = managementSegment.find<Uint16RegionInfoHashMap>(bipc::unique_instance).first;
+        if (shmRegions) {
+            for (const auto& region : *shmRegions) {
+                uint16_t id = region.first;
+                Remove<bipc::message_queue>("fmq_" + shmId + "_rgq_" + to_string(id), verbose);
+            }
+        }
     } catch (bie& e) {
         if (verbose) {
             cout << "Could not find '" << managementSegmentName << "' segment. Nothing to cleanup." << endl;
@@ -679,7 +698,7 @@ void Monitor::ResetContent(const ShmId& shmId, bool verbose /* = true */)
     }
 
     if (verbose) {
-        cout << "Done resetting segment content for shared memory id '" << shmId.shmId << "'." << endl;
+        cout << "Done resetting segment content for shared memory id '" << shmId << "'." << endl;
     }
 }
 
@@ -692,6 +711,43 @@ void Monitor::ResetContent(const SessionId& sessionId, bool verbose /* = true */
     ResetContent(shmId, verbose);
 }
 
+void Monitor::ResetContent(const ShmId& shmIdT, const std::vector<SegmentConfig>& segmentCfgs, const std::vector<RegionConfig>& regionCfgs, bool verbose /* = true */)
+{
+    using namespace boost::interprocess;
+
+    std::string shmId = shmIdT.shmId;
+    std::string managementSegmentName("fmq_" + shmId + "_mng");
+    // reset managed segments
+    ResetContent(shmIdT, verbose);
+    // delete management segment
+    Remove<bipc::shared_memory_object>(managementSegmentName, verbose);
+    // recreate management segment
+    managed_shared_memory mngSegment(create_only, managementSegmentName.c_str(), kManagementSegmentSize);
+    // fill management segment with segment & region infos
+    for (const auto& s : segmentCfgs) {
+        if (s.allocationAlgorithm == "rbtree_best_fit") {
+            Segment::Register(shmId, s.id, AllocationAlgorithm::rbtree_best_fit);
+        } else if (s.allocationAlgorithm == "simple_seq_fit") {
+            Segment::Register(shmId, s.id, AllocationAlgorithm::simple_seq_fit);
+        } else {
+            LOG(error) << "Unknown allocation algorithm provided: " << s.allocationAlgorithm;
+            throw MonitorError("Unknown allocation algorithm provided: " + s.allocationAlgorithm);
+        }
+    }
+    for (const auto& r : regionCfgs) {
+        fair::mq::shmem::UnmanagedRegion::Register(shmId, r);
+    }
+}
+
+void Monitor::ResetContent(const SessionId& sessionId, const std::vector<SegmentConfig>& segmentCfgs, const std::vector<RegionConfig>& regionCfgs, bool verbose /* = true */)
+{
+    ShmId shmId{makeShmIdStr(sessionId.sessionId)};
+    if (verbose) {
+        cout << "ResetContent called with session id '" << sessionId.sessionId << "', translating to shared memory id '" << shmId.shmId << "'" << endl;
+    }
+    ResetContent(shmId, segmentCfgs, regionCfgs, verbose);
+}
+
 Monitor::~Monitor()
 {
     if (fSignalThread.joinable()) {

fairmq/shmem/Monitor.h

@@ -8,6 +8,8 @@
 #ifndef FAIR_MQ_SHMEM_MONITOR_H_
 #define FAIR_MQ_SHMEM_MONITOR_H_
 
+#include <fairmq/UnmanagedRegion.h>
+
 #include <fairlogger/Logger.h>
 
 #include <thread>
@@ -49,6 +51,13 @@ struct BufferDebugInfo
     uint64_t fCreationTime;
 };
 
+struct SegmentConfig
+{
+    uint16_t id;
+    uint64_t size;
+    std::string allocationAlgorithm;
+};
+
 class Monitor
 {
   public:
@@ -88,6 +97,14 @@ class Monitor
     /// @param sessionId session id
     /// Only call this when segment is not in use
     static void ResetContent(const SessionId& sessionId, bool verbose = true);
+    /// @brief [EXPERIMENTAL] cleanup the content of the shem segment, without recreating it
+    /// @param shmId shared memory id
+    /// Only call this when segment is not in use
+    static void ResetContent(const ShmId& shmId, const std::vector<SegmentConfig>& segmentCfgs, const std::vector<RegionConfig>& regionCfgs, bool verbose = true);
+    /// @brief [EXPERIMENTAL] cleanup the content of the shem segment, without recreating it
+    /// @param sessionId session id
+    /// Only call this when segment is not in use
+    static void ResetContent(const SessionId& sessionId, const std::vector<SegmentConfig>& segmentCfgs, const std::vector<RegionConfig>& regionCfgs, bool verbose = true);
 
     /// @brief Outputs list of messages in shmem (if compiled with FAIRMQ_DEBUG_MODE=ON)
     /// @param shmId shmem id

fairmq/shmem/Segment.h

@@ -26,6 +26,8 @@ static const RBTreeBestFit rbTreeBestFit = RBTreeBestFit();
 
 struct Segment
 {
+    friend class Monitor;
+
     Segment(const std::string& shmId, uint16_t id, size_t size, SimpleSeqFit)
         : fSegment(SimpleSeqFitSegment(boost::interprocess::open_or_create,
                                        std::string("fmq_" + shmId + "_m_" + std::to_string(id)).c_str(),
@@ -66,15 +68,12 @@ struct Segment
     static void Register(const std::string& shmId, uint16_t id, AllocationAlgorithm allocAlgo)
     {
         using namespace boost::interprocess;
-        managed_shared_memory mngSegment(open_or_create, std::string("fmq_" + shmId + "_mng").c_str(), 6553600);
+        managed_shared_memory mngSegment(open_or_create, std::string("fmq_" + shmId + "_mng").c_str(), kManagementSegmentSize);
         VoidAlloc alloc(mngSegment.get_segment_manager());
 
         Uint16SegmentInfoHashMap* shmSegments = mngSegment.find_or_construct<Uint16SegmentInfoHashMap>(unique_instance)(alloc);
 
-        EventCounter* eventCounter = mngSegment.find<EventCounter>(unique_instance).first;
-        if (!eventCounter) {
-            eventCounter = mngSegment.construct<EventCounter>(unique_instance)(0);
-        }
+        EventCounter* eventCounter = mngSegment.find_or_construct<EventCounter>(unique_instance)(0);
 
         bool newSegmentRegistered = shmSegments->emplace(id, allocAlgo).second;
         if (newSegmentRegistered) {

fairmq/shmem/UnmanagedRegion.h

@@ -41,6 +41,7 @@ struct UnmanagedRegion
 {
     friend class Message;
     friend class Manager;
+    friend class Monitor;
 
     UnmanagedRegion(const std::string& shmId, uint16_t id, uint64_t size)
         : UnmanagedRegion(shmId,  size, false, makeRegionConfig(id))
@@ -50,6 +51,10 @@ struct UnmanagedRegion
         : UnmanagedRegion(shmId, size, false, std::move(cfg))
     {}
 
+    UnmanagedRegion(const std::string& shmId, RegionConfig cfg)
+        : UnmanagedRegion(shmId, cfg.size, false, std::move(cfg))
+    {}
+
     UnmanagedRegion(const std::string& shmId, uint64_t size, bool remote, RegionConfig cfg)
         : fRemote(remote)
         , fRemoveOnDestruction(cfg.removeOnDestruction)
@@ -66,6 +71,9 @@ struct UnmanagedRegion
     {
         using namespace boost::interprocess;
 
+        // TODO: refactor this
+        cfg.size = size;
+
         if (!cfg.path.empty()) {
             fName = std::string(cfg.path + fName);
 
@@ -91,16 +99,25 @@ struct UnmanagedRegion
             fRegion = mapped_region(fFileMapping, read_write, 0, size, 0, cfg.creationFlags);
         } else {
             try {
-                fShmemObject = shared_memory_object(open_or_create, fName.c_str(), read_write);
-                if (size != 0) {
+                // if opening fails, create
+                try {
+                    fShmemObject = shared_memory_object(open_only, fName.c_str(), read_write);
+                } catch (interprocess_exception& e) {
+                    LOG(debug) << "Could not open " << (remote ? "remote" : "local") << " shared_memory_object for region id '" << cfg.id.value() << "': " << e.what() << ", creating...";
+                    fShmemObject = shared_memory_object(create_only, fName.c_str(), read_write);
                     fShmemObject.truncate(size);
                 }
             } catch (interprocess_exception& e) {
                 LOG(error) << "Failed " << (remote ? "opening" : "creating") << " shared_memory_object for region id '" << cfg.id.value() << "': " << e.what();
                 throw;
             }
+
             try {
                 fRegion = mapped_region(fShmemObject, read_write, 0, 0, 0, cfg.creationFlags);
+                if (size != 0 && size != fRegion.get_size()) {
+                    LOG(error) << "Created/opened region size (" << fRegion.get_size() << ") does not match configured size (" << size << ")";
+                    throw TransportError(tools::ToString("Created/opened region size (", fRegion.get_size(), ") does not match configured size (", size, ")"));
+                }
             } catch (interprocess_exception& e) {
                 LOG(error) << "Failed mapping shared_memory_object for region id '" << cfg.id.value() << "': " << e.what();
                 throw;
@@ -223,20 +240,17 @@ struct UnmanagedRegion
         return regionCfg;
     }
 
-    static void Register(const std::string& shmId, RegionConfig& cfg)
+    static void Register(const std::string& shmId, const RegionConfig& cfg)
     {
         using namespace boost::interprocess;
-        managed_shared_memory mngSegment(open_or_create, std::string("fmq_" + shmId + "_mng").c_str(), 6553600);
+        managed_shared_memory mngSegment(open_or_create, std::string("fmq_" + shmId + "_mng").c_str(), kManagementSegmentSize);
         VoidAlloc alloc(mngSegment.get_segment_manager());
 
         Uint16RegionInfoHashMap* shmRegions = mngSegment.find_or_construct<Uint16RegionInfoHashMap>(unique_instance)(alloc);
 
-        EventCounter* eventCounter = mngSegment.find<EventCounter>(unique_instance).first;
-        if (!eventCounter) {
-            eventCounter = mngSegment.construct<EventCounter>(unique_instance)(0);
-        }
+        EventCounter* eventCounter = mngSegment.find_or_construct<EventCounter>(unique_instance)(0);
 
-        bool newShmRegionCreated = shmRegions->emplace(cfg.id.value(), RegionInfo(cfg.path.c_str(), cfg.creationFlags, cfg.userFlags, alloc)).second;
+        bool newShmRegionCreated = shmRegions->emplace(cfg.id.value(), RegionInfo(cfg.path.c_str(), cfg.creationFlags, cfg.userFlags, cfg.size, alloc)).second;
         if (newShmRegionCreated) {
             (eventCounter->fCount)++;
         }

fairmq/zeromq/Common.h

@@ -27,7 +27,11 @@ inline bool Bind(void* socket, const std::string& address, const std::string& id
         if (errno == EADDRINUSE) {
             // do not print error in this case, this is handled upstream in case no
             // connection could be established after trying a number of random ports from a range.
-            return false;
+            size_t protocolPos = address.find(':');
+            std::string protocol = address.substr(0, protocolPos);
+            if (protocol == "tcp") {
+              return false;
+            }
         } else if (errno == EACCES) {
             // check if TCP port 1 was given, if yes then it will be handeled upstream, print debug only
             size_t protocolPos = address.find(':');

test/region/_region.cxx

@@ -25,6 +25,26 @@ namespace
 using namespace std;
 using namespace fair::mq;
 
+void RegionsSizeMismatch()
+{
+    size_t session = tools::UuidHash();
+
+    ProgOptions config;
+    config.SetProperty<string>("session", to_string(session));
+    config.SetProperty<size_t>("shm-segment-size", 100000000);
+
+    auto factory = TransportFactory::CreateTransportFactory("shmem", tools::Uuid(), &config);
+
+    fair::mq::RegionConfig rCfg;
+    rCfg.id = 10;
+    UnmanagedRegionPtr region1 = nullptr;
+    ASSERT_NO_THROW(region1 = factory->CreateUnmanagedRegion(10000, [](void*, size_t, void*) {}, rCfg));
+    ASSERT_NE(region1, nullptr);
+    UnmanagedRegionPtr region2 = nullptr;
+    ASSERT_THROW(region2 = factory->CreateUnmanagedRegion(16000, [](void*, size_t, void*) {}, rCfg), fair::mq::TransportError);
+    ASSERT_EQ(region2, nullptr);
+}
+
 void RegionsCache(const string& transport, const string& address)
 {
     size_t session1 = tools::UuidHash();
@@ -226,6 +246,11 @@ void RegionCallbacks(const string& transport, const string& _address)
     LOG(info) << "2 done.";
 }
 
+TEST(RegionsSizeMismatch, shmem)
+{
+    RegionsSizeMismatch();
+}
+
 TEST(Cache, zeromq)
 {
     RegionsCache("zeromq", "ipc://test_region_cache");