From 774b8688cace7d07b454dc1e6e20d5965ded3708 Mon Sep 17 00:00:00 2001
From: Michael Krasnyk <michael.krasnyk@gmail.com>
Date: Sun, 25 Dec 2016 16:53:10 +0100
Subject: [PATCH] read_only if shmem size is 0, read_write otherwise

---
 include/storage/shared_memory.hpp | 13 +++++--------
 src/storage/storage.cpp           |  4 ++--
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/include/storage/shared_memory.hpp b/include/storage/shared_memory.hpp
index 296552caa..2e2c452d1 100644
--- a/include/storage/shared_memory.hpp
+++ b/include/storage/shared_memory.hpp
@@ -52,12 +52,9 @@ class SharedMemory
     template <typename IdentifierT>
     SharedMemory(const boost::filesystem::path &lock_file,
                  const IdentifierT id,
-                 const uint64_t size = 0,
-                 bool read_write = false)
+                 const uint64_t size = 0)
         : key(lock_file.string().c_str(), id)
     {
-        const auto access =
-            read_write ? boost::interprocess::read_write : boost::interprocess::read_only;
         // open only
         if (0 == size)
         {
@@ -65,7 +62,7 @@ class SharedMemory
 
             util::Log(logDEBUG) << "opening " << shm.get_shmid() << " from id " << id;
 
-            region = boost::interprocess::mapped_region(shm, access);
+            region = boost::interprocess::mapped_region(shm, boost::interprocess::read_only);
         }
         // open or create
         else
@@ -83,7 +80,7 @@ class SharedMemory
                 }
             }
 #endif
-            region = boost::interprocess::mapped_region(shm, access);
+            region = boost::interprocess::mapped_region(shm, boost::interprocess::read_write);
         }
     }
 
@@ -232,7 +229,7 @@ class SharedMemory
 
 template <typename IdentifierT, typename LockFileT = OSRMLockFile>
 std::unique_ptr<SharedMemory>
-makeSharedMemory(const IdentifierT &id, const uint64_t size = 0, bool read_write = false)
+makeSharedMemory(const IdentifierT &id, const uint64_t size = 0)
 {
     try
     {
@@ -248,7 +245,7 @@ makeSharedMemory(const IdentifierT &id, const uint64_t size = 0, bool read_write
                 boost::filesystem::ofstream ofs(lock_file());
             }
         }
-        return std::make_unique<SharedMemory>(lock_file(), id, size, read_write);
+        return std::make_unique<SharedMemory>(lock_file(), id, size);
     }
     catch (const boost::interprocess::interprocess_exception &e)
     {
diff --git a/src/storage/storage.cpp b/src/storage/storage.cpp
index 4662eb6c3..b2b2ee36a 100644
--- a/src/storage/storage.cpp
+++ b/src/storage/storage.cpp
@@ -175,14 +175,14 @@ Storage::ReturnCode Storage::Run(int max_wait)
     // Allocate shared memory block
     auto regions_size = sizeof(layout) + layout.GetSizeOfLayout();
     util::Log() << "allocating shared memory of " << regions_size << " bytes";
-    auto shared_memory = makeSharedMemory(data_region, regions_size, true);
+    auto shared_memory = makeSharedMemory(data_region, regions_size);
 
     // Copy memory layout to shared memory and populate data
     char *shared_memory_ptr = static_cast<char *>(shared_memory->Ptr());
     memcpy(shared_memory_ptr, &layout, sizeof(layout));
     PopulateData(layout, shared_memory_ptr + sizeof(layout));
 
-    auto data_type_memory = makeSharedMemory(CURRENT_REGION, sizeof(SharedDataTimestamp), true);
+    auto data_type_memory = makeSharedMemory(CURRENT_REGION, sizeof(SharedDataTimestamp));
     SharedDataTimestamp *data_timestamp_ptr =
         static_cast<SharedDataTimestamp *>(data_type_memory->Ptr());