MemArena: Split into three separate files for each OS.

Source/Core/Common/MemArenaWin.cpp

@@ -0,0 +1,61 @@
+// Copyright 2008 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "Common/MemArena.h"
+
+#include <cstddef>
+#include <cstdlib>
+#include <set>
+#include <string>
+
+#include <windows.h>
+
+#include "Common/CommonFuncs.h"
+#include "Common/CommonTypes.h"
+#include "Common/Logging/Log.h"
+#include "Common/MsgHandler.h"
+#include "Common/StringUtil.h"
+
+namespace Common
+{
+void MemArena::GrabSHMSegment(size_t size)
+{
+  const std::string name = "dolphin-emu." + std::to_string(GetCurrentProcessId());
+  hMemoryMapping = CreateFileMapping(INVALID_HANDLE_VALUE, nullptr, PAGE_READWRITE, 0,
+                                     static_cast<DWORD>(size), UTF8ToTStr(name).c_str());
+}
+
+void MemArena::ReleaseSHMSegment()
+{
+  CloseHandle(hMemoryMapping);
+  hMemoryMapping = 0;
+}
+
+void* MemArena::CreateView(s64 offset, size_t size, void* base)
+{
+  return MapViewOfFileEx(hMemoryMapping, FILE_MAP_ALL_ACCESS, 0, (DWORD)((u64)offset), size, base);
+}
+
+void MemArena::ReleaseView(void* view, size_t size)
+{
+  UnmapViewOfFile(view);
+}
+
+u8* MemArena::FindMemoryBase()
+{
+#if _ARCH_32
+  const size_t memory_size = 0x31000000;
+#else
+  const size_t memory_size = 0x400000000;
+#endif
+
+  u8* base = static_cast<u8*>(VirtualAlloc(nullptr, memory_size, MEM_RESERVE, PAGE_READWRITE));
+  if (!base)
+  {
+    PanicAlertFmt("Failed to map enough memory space: {}", GetLastErrorString());
+    return nullptr;
+  }
+  VirtualFree(base, 0, MEM_RELEASE);
+  return base;
+}
+}  // namespace Common