dvander@28: /* vim: set ts=4 sw=4 tw=99 et:
dvander@28:  *
dvander@28:  * Copyright (C) 2012 David Anderson
dvander@28:  *
dvander@28:  * This file is part of JITCraft.
dvander@28:  *
dvander@28:  * JITCraft is free software: you can redistribute it and/or modify it under
dvander@28:  * the terms of the GNU General Public License as published by the Free
dvander@28:  * Software Foundation, either version 3 of the License, or (at your option)
dvander@28:  * any later version.
dvander@28:  * 
dvander@28:  * Foobar is distributed in the hope that it will be useful, but WITHOUT ANY
dvander@28:  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
dvander@28:  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
dvander@28:  *
dvander@28:  * You should have received a copy of the GNU General Public License along with
dvander@28:  * JITCraft. If not, see http://www.gnu.org/licenses/.
dvander@28:  */
dvander@28: #include <sys/mman.h>
dvander@251: #include <limits.h>
dvander@251: #include <string.h>
dvander@251: #include <stdlib.h>
dvander@28: #include "Platform.h"
dvander@28: 
danderson@91: using namespace ke;
dvander@28: 
dvander@28: static inline int
dvander@28: ToProtBits(OS::Protection prot)
dvander@28: {
dvander@28:     switch (prot) {
dvander@28:       case OS::Prot_ReadWrite:
dvander@28:         return PROT_READ | PROT_WRITE;
dvander@28:       case OS::Prot_ReadWriteExecute:
dvander@28:         return PROT_READ | PROT_WRITE | PROT_EXEC;
dvander@28:       default:
dvander@28:         assert(prot == OS::Prot_ReadExecute);
dvander@28:         return PROT_READ | PROT_EXEC;
dvander@28:     }
dvander@28: }
dvander@28: 
dvander@28: Address
dvander@28: OS::MapMemory(size_t amount, MapMode mode, Protection prot_)
dvander@28: {
dvander@28:     int prot = ToProtBits(prot_);
dvander@28:     void *addr = mmap(NULL, amount, prot, MAP_ANON | MAP_PRIVATE, -1, 0);
dvander@28:     if (addr == MAP_FAILED)
dvander@28:         return NULL;
dvander@28: 
dvander@28:     return Address(addr);
dvander@28: }
dvander@28: 
dvander@28: bool
dvander@28: OS::CommitMemory(Address address, size_t amount, Protection prot_)
dvander@28: {
dvander@28:     return true;
dvander@28: }
dvander@28: 
dvander@28: void
dvander@28: OS::UnmapMemory(Address address, size_t size)
dvander@28: {
dvander@28:     munmap(address, size);
dvander@28: }
dvander@28: 
dvander@28: OS::AlignableMapping
dvander@28: OS::MapAlignedMemory(size_t amount, size_t alignment, MapMode mode)
dvander@28: {
dvander@28:     assert(amount >= alignment);
dvander@28:     assert(IsPowerOfTwo(alignment));
dvander@28: 
dvander@28:     if (alignment == kPageAlignment) {
dvander@28:         Address address = MapMemory(amount, mode, Prot_ReadWrite);
dvander@28:         if (!address)
dvander@28:             return AlignableMapping();
dvander@28:         return AlignableMapping(address, alignment, amount);
dvander@28:     }
dvander@28: 
dvander@28:     size_t requested = Min(amount * 2, amount + 2 * alignment);
danderson@92:     Address address = MapMemory(requested, mode, Prot_ReadWrite);
dvander@28:     if (!address)
dvander@28:         return AlignableMapping();
dvander@28: 
dvander@28:     size_t begin = 0;
dvander@28:     Address aligned = AlignedBase(address, alignment);
dvander@28:     if (!IsAligned(address, alignment)) {
dvander@28:         // Shave off the first part of the unaligned region.
dvander@28:         aligned += alignment;
dvander@28:         begin = size_t(aligned - address);
dvander@28:         UnmapAlignedMemory(address, begin);
dvander@28:     }
dvander@28: 
dvander@28:     if (requested - begin > amount) {
dvander@28:         // Shave off the last part of the unaligned region.
danderson@92:         UnmapAlignedMemory(aligned + amount, requested - amount - begin);
dvander@28:     }
dvander@28: 
dvander@28:     return AlignableMapping(aligned, alignment, amount);
dvander@28: }
dvander@28: 
dvander@28: void
dvander@28: OS::UnmapAlignedMemory(Address address, size_t size)
dvander@28: {
dvander@28:     OS::UnmapMemory(address, size);
dvander@28: }
dvander@28: 
dvander@251: bool
dvander@251: OS::GetAbsolutePath(const char *path, AutoFree<char> &chars)
dvander@251: {
dvander@251:     chars = (char *)calloc(PATH_MAX, sizeof(char));
dvander@251:     if (!*chars)
dvander@251:         return false;
dvander@251: 
dvander@251:     char *ptr = realpath(path, *chars);
dvander@251:     if (!ptr)
dvander@251:         return false;
dvander@251: 
dvander@251:     return ptr == *chars;
dvander@251: }
dvander@251: 
dvander@251: bool
dvander@251: OS::SplitPath(const char *path, AutoFree<char> &base, AutoFree<char> &name)
dvander@251: {
dvander@251:     // dirname() and basename() pretty much suck.
dvander@251:     size_t len = strlen(path);
dvander@251: 
dvander@251:     // Skip trailing slashes.
dvander@251:     while (len > 1 && (path[len - 1] == '/'))
dvander@251:         len--;
dvander@251: 
dvander@251:     for (size_t i = len - 1; i < len; i--) {
dvander@251:         if (path[i] == '/') {
dvander@251:             name = (char *)calloc(len - i, sizeof(char));
dvander@251:             if (!*name)
dvander@251:                 return false;
dvander@251: 
dvander@251:             strcpy(*name, &path[i + 1]);
dvander@251: 
dvander@251:             base = (char *)calloc(i + 1, sizeof(char));
dvander@251:             if (!*base)
dvander@251:                 return false;
dvander@251: 
dvander@251:             memcpy(*base, path, i);
dvander@251:             (*base)[i] = '\0';
dvander@251:             return true;
dvander@251:         }
dvander@251:     }
dvander@251:     
dvander@251:     // The path should have been absolute, which contains at least one separator.
dvander@251:     return false;
dvander@251: }
dvander@251: 
dvander@251: const char *
dvander@251: OS::PathSeparator()
dvander@251: {
dvander@251:     return "/";
dvander@251: }
dvander@251: