base/shared_memory_nacl.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/shared_memory.h"
   6
   7 #include <errno.h>
   8 #include <fcntl.h>
   9 #include <sys/mman.h>
  10 #include <sys/stat.h>
  11 #include <unistd.h>
  12
  13 #include "base/logging.h"
  14
  15 namespace base {
  16
  17 SharedMemory::SharedMemory()
  18     : mapped_file_(-1),
  19       mapped_size_(0),
  20       inode_(0),
  21       memory_(NULL),
  22       read_only_(false),
  23       created_size_(0) {
  24 }
  25
  26 SharedMemory::SharedMemory(SharedMemoryHandle handle, bool read_only)
  27     : mapped_file_(handle.fd),
  28       mapped_size_(0),
  29       inode_(0),
  30       memory_(NULL),
  31       read_only_(read_only),
  32       created_size_(0) {
  33 }
  34
  35 SharedMemory::SharedMemory(SharedMemoryHandle handle, bool read_only,
  36                            ProcessHandle process)
  37     : mapped_file_(handle.fd),
  38       mapped_size_(0),
  39       inode_(0),
  40       memory_(NULL),
  41       read_only_(read_only),
  42       created_size_(0) {
  43   NOTREACHED();
  44 }
  45
  46 SharedMemory::~SharedMemory() {
  47   Close();
  48 }
  49
  50 // static
  51 bool SharedMemory::IsHandleValid(const SharedMemoryHandle& handle) {
  52   return handle.fd >= 0;
  53 }
  54
  55 // static
  56 SharedMemoryHandle SharedMemory::NULLHandle() {
  57   return SharedMemoryHandle();
  58 }
  59
  60 // static
  61 void SharedMemory::CloseHandle(const SharedMemoryHandle& handle) {
  62   DCHECK_GE(handle.fd, 0);
  63   if (close(handle.fd) < 0)
  64     DPLOG(ERROR) << "close";
  65 }
  66
  67 bool SharedMemory::CreateAndMapAnonymous(uint32 size) {
  68   // Untrusted code can't create descriptors or handles.
  69   return false;
  70 }
  71
  72 bool SharedMemory::Create(const SharedMemoryCreateOptions& options) {
  73   // Untrusted code can't create descriptors or handles.
  74   return false;
  75 }
  76
  77 bool SharedMemory::Delete(const std::string& name) {
  78   return false;
  79 }
  80
  81 bool SharedMemory::Open(const std::string& name, bool read_only) {
  82   return false;
  83 }
  84
  85 bool SharedMemory::Map(uint32 bytes) {
  86   if (mapped_file_ == -1)
  87     return false;
  88
  89   memory_ = mmap(NULL, bytes, PROT_READ | (read_only_ ? 0 : PROT_WRITE),
  90                  MAP_SHARED, mapped_file_, 0);
  91
  92   bool mmap_succeeded = memory_ != MAP_FAILED && memory_ != NULL;
  93   if (mmap_succeeded) {
  94     mapped_size_ = bytes;
  95     DCHECK_EQ(0U, reinterpret_cast<uintptr_t>(memory_) &
  96         (SharedMemory::MAP_MINIMUM_ALIGNMENT - 1));
  97   } else {
  98     memory_ = NULL;
  99   }
 100
 101   return mmap_succeeded;
 102 }
 103
 104 bool SharedMemory::Unmap() {
 105   if (memory_ == NULL)
 106     return false;
 107
 108   if (munmap(memory_, mapped_size_) < 0)
 109     DPLOG(ERROR) << "munmap";
 110   memory_ = NULL;
 111   mapped_size_ = 0;
 112   return true;
 113 }
 114
 115 SharedMemoryHandle SharedMemory::handle() const {
 116   return FileDescriptor(mapped_file_, false);
 117 }
 118
 119 void SharedMemory::Close() {
 120   Unmap();
 121
 122   if (mapped_file_ > 0) {
 123     if (close(mapped_file_) < 0)
 124       DPLOG(ERROR) << "close";
 125     mapped_file_ = -1;
 126   }
 127 }
 128
 129 void SharedMemory::Lock() {
 130   NOTIMPLEMENTED();
 131 }
 132
 133 void SharedMemory::Unlock() {
 134   NOTIMPLEMENTED();
 135 }
 136
 137 bool SharedMemory::ShareToProcessCommon(ProcessHandle process,
 138                                         SharedMemoryHandle *new_handle,
 139                                         bool close_self) {
 140   return false;
 141 }
 142
 143 }  // namespace base