Move mojo edk into mojo/edk

mojo/embedder/simple_platform_shared_buffer_posix.cc

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "mojo/embedder/simple_platform_shared_buffer.h"
-
-#include <stdint.h>
-#include <stdio.h>     // For |fileno()|.
-#include <sys/mman.h>  // For |mmap()|/|munmap()|.
-#include <sys/stat.h>
-#include <sys/types.h>  // For |off_t|.
-#include <unistd.h>
-
-#include <limits>
-
-#include "base/files/file_path.h"
-#include "base/files/file_util.h"
-#include "base/files/scoped_file.h"
-#include "base/logging.h"
-#include "base/macros.h"
-#include "base/posix/eintr_wrapper.h"
-#include "base/sys_info.h"
-#include "base/threading/thread_restrictions.h"
-#include "mojo/embedder/platform_handle.h"
-
-// We assume that |size_t| and |off_t| (type for |ftruncate()|) fits in a
-// |uint64_t|.
-static_assert(sizeof(size_t) <= sizeof(uint64_t), "size_t too big");
-static_assert(sizeof(off_t) <= sizeof(uint64_t), "off_t too big");
-
-namespace mojo {
-namespace embedder {
-
-// SimplePlatformSharedBuffer --------------------------------------------------
-
-bool SimplePlatformSharedBuffer::Init() {
-  DCHECK(!handle_.is_valid());
-
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
-
-  if (static_cast<uint64_t>(num_bytes_) >
-      static_cast<uint64_t>(std::numeric_limits<off_t>::max())) {
-    return false;
-  }
-
-  // TODO(vtl): This is stupid. The implementation of
-  // |CreateAndOpenTemporaryFileInDir()| starts with an FD, |fdopen()|s to get a
-  // |FILE*|, and then we have to |dup(fileno(fp))| to get back to an FD that we
-  // can own. (base/memory/shared_memory_posix.cc does this too, with more
-  // |fstat()|s thrown in for good measure.)
-  base::FilePath shared_buffer_dir;
-  if (!base::GetShmemTempDir(false, &shared_buffer_dir)) {
-    LOG(ERROR) << "Failed to get temporary directory for shared memory";
-    return false;
-  }
-  base::FilePath shared_buffer_file;
-  base::ScopedFILE fp(base::CreateAndOpenTemporaryFileInDir(
-      shared_buffer_dir, &shared_buffer_file));
-  if (!fp) {
-    LOG(ERROR) << "Failed to create/open temporary file for shared memory";
-    return false;
-  }
-  // Note: |unlink()| is not interruptible.
-  if (unlink(shared_buffer_file.value().c_str()) != 0) {
-    PLOG(WARNING) << "unlink";
-    // This isn't "fatal" (e.g., someone else may have unlinked the file first),
-    // so we may as well continue.
-  }
-
-  // Note: |dup()| is not interruptible (but |dup2()|/|dup3()| are).
-  base::ScopedFD fd(dup(fileno(fp.get())));
-  if (!fd.is_valid()) {
-    PLOG(ERROR) << "dup";
-    return false;
-  }
-
-  if (HANDLE_EINTR(ftruncate(fd.get(), static_cast<off_t>(num_bytes_))) != 0) {
-    PLOG(ERROR) << "ftruncate";
-    return false;
-  }
-
-  handle_.reset(PlatformHandle(fd.release()));
-  return true;
-}
-
-bool SimplePlatformSharedBuffer::InitFromPlatformHandle(
-    ScopedPlatformHandle platform_handle) {
-  DCHECK(!handle_.is_valid());
-
-  if (static_cast<uint64_t>(num_bytes_) >
-      static_cast<uint64_t>(std::numeric_limits<off_t>::max())) {
-    return false;
-  }
-
-  struct stat sb = {};
-  // Note: |fstat()| isn't interruptible.
-  if (fstat(platform_handle.get().fd, &sb) != 0) {
-    PLOG(ERROR) << "fstat";
-    return false;
-  }
-
-  if (!S_ISREG(sb.st_mode)) {
-    LOG(ERROR) << "Platform handle not to a regular file";
-    return false;
-  }
-
-  if (sb.st_size != static_cast<off_t>(num_bytes_)) {
-    LOG(ERROR) << "Shared memory file has the wrong size";
-    return false;
-  }
-
-  // TODO(vtl): More checks?
-
-  handle_ = platform_handle.Pass();
-  return true;
-}
-
-scoped_ptr<PlatformSharedBufferMapping> SimplePlatformSharedBuffer::MapImpl(
-    size_t offset,
-    size_t length) {
-  size_t offset_rounding = offset % base::SysInfo::VMAllocationGranularity();
-  size_t real_offset = offset - offset_rounding;
-  size_t real_length = length + offset_rounding;
-
-  // This should hold (since we checked |num_bytes| versus the maximum value of
-  // |off_t| on creation, but it never hurts to be paranoid.
-  DCHECK_LE(static_cast<uint64_t>(real_offset),
-            static_cast<uint64_t>(std::numeric_limits<off_t>::max()));
-
-  void* real_base = mmap(nullptr,
-                         real_length,
-                         PROT_READ | PROT_WRITE,
-                         MAP_SHARED,
-                         handle_.get().fd,
-                         static_cast<off_t>(real_offset));
-  // |mmap()| should return |MAP_FAILED| (a.k.a. -1) on error. But it shouldn't
-  // return null either.
-  if (real_base == MAP_FAILED || !real_base) {
-    PLOG(ERROR) << "mmap";
-    return nullptr;
-  }
-
-  void* base = static_cast<char*>(real_base) + offset_rounding;
-  return make_scoped_ptr(new SimplePlatformSharedBufferMapping(
-      base, length, real_base, real_length));
-}
-
-// SimplePlatformSharedBufferMapping -------------------------------------------
-
-void SimplePlatformSharedBufferMapping::Unmap() {
-  int result = munmap(real_base_, real_length_);
-  PLOG_IF(ERROR, result != 0) << "munmap";
-}
-
-}  // namespace embedder
-}  // namespace mojo