LLVM API Documentation
00001 //===- Interix/Memory.cpp - Interix Memory Implementation -------*- C++ -*-===// 00002 // 00003 // The LLVM Compiler Infrastructure 00004 // 00005 // This file was developed by Reid Spencer and is distributed under the 00006 // University of Illinois Open Source License. See LICENSE.TXT for details. 00007 // 00008 //===----------------------------------------------------------------------===// 00009 // 00010 // This file provides the Interix specific implementation of various Memory 00011 // management utilities 00012 // 00013 //===----------------------------------------------------------------------===// 00014 00015 // Include the generic unix implementation 00016 #include "../Unix/Memory.cpp" 00017 #include "llvm/System/Process.h" 00018 #include <fcntl.h> 00019 #include <sys/mman.h> 00020 00021 namespace llvm { 00022 using namespace sys; 00023 00024 //===----------------------------------------------------------------------===// 00025 //=== WARNING: Implementation here must contain only Interix specific code 00026 //=== and must not be generic UNIX code (see ../Unix/Memory.cpp) 00027 //===----------------------------------------------------------------------===// 00028 00029 MemoryBlock Memory::AllocateRWX(unsigned NumBytes) { 00030 if (NumBytes == 0) return MemoryBlock(); 00031 00032 static const long pageSize = Process::GetPageSize(); 00033 unsigned NumPages = (NumBytes+pageSize-1)/pageSize; 00034 00035 int fd = open("/dev/zero", O_RDWR); 00036 if (fd == -1) { 00037 throw std::string("Can't open /dev/zero device: ") + strerror(errno); 00038 } 00039 00040 void *pa = mmap(0, pageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC, 00041 MAP_SHARED, fd, 0); 00042 if (pa == (void*)-1) { 00043 throw std::string("Can't allocate RWX Memory: ") + strerror(errno); 00044 } 00045 MemoryBlock result; 00046 result.Address = pa; 00047 result.Size = NumPages*pageSize; 00048 return result; 00049 } 00050 00051 void Memory::ReleaseRWX(MemoryBlock& M) { 00052 if (M.Address == 0 || M.Size == 0) return; 00053 if (0 != munmap(M.Address, M.Size)) { 00054 throw std::string("Can't release RWX Memory: ") + strerror(errno); 00055 } 00056 } 00057 00058 } 00059 00060 // vim: sw=2 smartindent smarttab tw=80 autoindent expandtab