Initial megacommit.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@4 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Core/Common/Src/MemArena.cpp

@@ -0,0 +1,126 @@
+// Copyright (C) 2003-2008 Dolphin Project.
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, version 2.0.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License 2.0 for more details.
+
+// A copy of the GPL 2.0 should have been included with the program.
+// If not, see http://www.gnu.org/licenses/
+
+// Official SVN repository and contact information can be found at
+// http://code.google.com/p/dolphin-emu/
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#endif
+
+#include "Common.h"
+#include "MemArena.h"
+
+
+const char* ram_temp_file = "/tmp/gc_mem.tmp";
+
+void MemArena::GrabLowMemSpace(size_t size)
+{
+#ifdef _WIN32
+	hMemoryMapping = CreateFileMapping(NULL, NULL, PAGE_READWRITE, 0, (DWORD)(size), _T("All GC Memory"));
+#else
+	mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
+	fd = open(ram_temp_file, O_RDWR | O_CREAT, mode);
+	ftruncate(fd, size);
+	return;
+#endif
+
+}
+
+
+void MemArena::ReleaseSpace()
+{
+#ifdef _WIN32
+	CloseHandle(hMemoryMapping);
+	hMemoryMapping = 0;
+#else
+	close(fd);
+	unlink(ram_temp_file);
+#endif
+}
+
+
+void* MemArena::CreateView(s64 offset, size_t size, bool ensure_low_mem)
+{
+#ifdef _WIN32
+	return(MapViewOfFile(hMemoryMapping, FILE_MAP_ALL_ACCESS, 0, (DWORD)((u64)offset), size));
+
+#else
+	void* ptr = mmap(0, size,
+			PROT_READ | PROT_WRITE,
+			MAP_SHARED | (ensure_low_mem ? MAP_32BIT : 0),
+			fd, offset);
+
+	if (!ptr)
+	{
+		PanicAlert("Failed to create view");
+	}
+
+	return(ptr);
+#endif
+
+}
+
+
+void* MemArena::CreateViewAt(s64 offset, size_t size, void* base)
+{
+#ifdef _WIN32
+	return(MapViewOfFileEx(hMemoryMapping, FILE_MAP_ALL_ACCESS, 0, (DWORD)((u64)offset), size, base));
+
+#else
+	return(mmap(base, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, fd, offset));
+#endif
+
+}
+
+
+void MemArena::ReleaseView(void* view, size_t size)
+{
+#ifdef _WIN32
+	UnmapViewOfFile(view);
+#else
+	munmap(view, size);
+#endif
+}
+
+
+u64 MemArena::Find4GBBase()
+{
+#ifdef _M_X64
+#ifdef _WIN32
+	u8* base = (u8*)VirtualAlloc(0, 0x100000000, MEM_RESERVE, PAGE_READWRITE);
+	VirtualFree(base, 0, MEM_RELEASE);
+	return((u64)base);
+
+#else
+	// Very precarious - mmap cannot return an error when trying to map already used pages.
+	// This makes the Windows approach above unusable on Linux, so we will simply pray...
+	return(0x2300000000ULL);
+#endif
+
+#else
+	// Only grab a bit less than 1GB
+	u8* base = (u8*)VirtualAlloc(0, 0x31000000, MEM_RESERVE, PAGE_READWRITE);
+	VirtualFree(base, 0, MEM_RELEASE);
+	return((u64)base);
+#endif
+
+}
+
+