data: indexer processes

* TaskBuildIndex starts seperate indexer processes and communicates via shared memory
* indexer processes get restarted if they fail
* indexer processes are killed when the app closes or crashes
* added utility class SharedMemory to allocate and access shared memory, providing basic data structures
* added SharedMemoryGarbageCollector for keeping track of running instances and cleaning up shared memory in case of a crash
* show errors for source files that crashed during indexing
* added basic exception handling to task scheduling
* added option to turn off processes and use threads in preferences, but still use shared memory

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src/test/CMakeLists.txt

@@ -23,6 +23,7 @@ add_files(
     SettingsTestSuite.h
 	SettingsMigratorTestSuite.h
 	SearchIndexTestSuite.h
+	SharedMemoryTestSuite.h
 	SourceLocationCollectionTestSuite.h
 	SqliteBookmarkStorageTestSuite.h
 	SqliteIndexStorageTestSuite.h

src/test/JavaParserTestSuite.h

@@ -12,7 +12,6 @@
 
 #include "helper/TestParserClient.h"
 
-
 class JavaParserTestSuite: public CxxTest::TestSuite
 {
 public:

src/test/SharedMemoryTestSuite.h

@@ -0,0 +1,95 @@
+#include <cxxtest/TestSuite.h>
+
+#include "utility/interprocess/SharedMemory.h"
+
+class SharedMemoryTestSuite : public CxxTest::TestSuite
+{
+public:
+	void test_shared_memory(void)
+	{
+		SharedMemory memory("memory", 1000, SharedMemory::CREATE_AND_DELETE);
+
+		{
+			SharedMemory::ScopedAccess access(&memory);
+
+			TS_ASSERT_EQUALS(access.getMemorySize(), 1000);
+			*access.accessValue<int>("count") = 0;
+		}
+
+		std::vector<std::shared_ptr<std::thread>> threads;
+		for (unsigned int i = 0; i < 4; i++)
+		{
+			threads.push_back(std::make_shared<std::thread>(
+				[]()
+				{
+					SharedMemory memory("memory", 0, SharedMemory::OPEN_ONLY);
+
+					SharedMemory::ScopedAccess access(&memory);
+
+					if (access.getMemorySize() < 5000)
+					{
+						access.growMemory(5000 - access.getMemorySize());
+					}
+
+					int* count = access.accessValue<int>("count");
+					*count += 1;
+
+					SharedMemory::String* str = access.accessValueWithAllocator<SharedMemory::String>("string");
+					str->append("hi");
+
+					SharedMemory::Vector<int>* nums = access.accessValueWithAllocator<SharedMemory::Vector<int>>("nums");
+					nums->push_back(nums->size());
+
+					SharedMemory::Vector<SharedMemory::String>* strings =
+						access.accessValueWithAllocator<SharedMemory::Vector<SharedMemory::String>>("strings");
+					strings->push_back(SharedMemory::String("ho", access.getAllocator()));
+
+					SharedMemory::Map<int, int>* vals =
+						access.accessValueWithAllocator<SharedMemory::Map<int, int>>("vals");
+					vals->emplace(vals->size(), vals->size() * vals->size());
+				}
+			));
+		}
+
+		for (auto thread : threads)
+		{
+			thread->join();
+		}
+		threads.clear();
+
+		{
+			SharedMemory::ScopedAccess access(&memory);
+
+			TS_ASSERT_EQUALS(access.getMemorySize(), 5000);
+			TS_ASSERT_EQUALS(*access.accessValue<int>("count"), 4);
+			TS_ASSERT_EQUALS(access.accessValueWithAllocator<SharedMemory::String>("string")->c_str(), "hihihihi");
+
+			SharedMemory::Vector<int>* nums = access.accessValueWithAllocator<SharedMemory::Vector<int>>("nums");
+			TS_ASSERT_EQUALS(nums->size(), 4);
+			for (int i : *nums)
+			{
+				TS_ASSERT_EQUALS(i, i);
+			}
+
+			SharedMemory::Vector<SharedMemory::String>* strings =
+				access.accessValueWithAllocator<SharedMemory::Vector<SharedMemory::String>>("strings");
+			TS_ASSERT_EQUALS(strings->size(), 4);
+			for (SharedMemory::String str : *strings)
+			{
+				TS_ASSERT_EQUALS(str, "ho");
+			}
+
+			SharedMemory::Map<int, int>* vals =
+				access.accessValueWithAllocator<SharedMemory::Map<int, int>>("vals");
+			TS_ASSERT_EQUALS(vals->size(), 4);
+
+			size_t i = 0;
+			for (auto val : *vals)
+			{
+				TS_ASSERT_EQUALS(val.first, i);
+				TS_ASSERT_EQUALS(val.second, i * i);
+				i++;
+			}
+		}
+	}
+};