Make SharedMemoryHandle a class on Mac.

base/memory/shared_memory_mac.cc

Index: base/memory/shared_memory_mac.cc
diff --git a/base/memory/shared_memory_posix.cc b/base/memory/shared_memory_mac.cc
similarity index 88%
copy from base/memory/shared_memory_posix.cc
copy to base/memory/shared_memory_mac.cc
index 35d746e5394e0e042bbaac33421d94c8406e65e2..7f5e7289314b9e5a4d82f8731bf0d0b40a2b1f52 100644
--- a/base/memory/shared_memory_posix.cc
+++ b/base/memory/shared_memory_mac.cc
@@ -29,11 +29,6 @@
 #include "base/mac/foundation_util.h"
 #endif  // OS_MACOSX
 
-#if defined(OS_ANDROID)
-#include "base/os_compat_android.h"
-#include "third_party/ashmem/ashmem.h"
-#endif
-
 namespace base {
 
 namespace {
@@ -57,7 +52,6 @@ struct ScopedPathUnlinkerTraits {
 // Unlinks the FilePath when the object is destroyed.
 typedef ScopedGeneric<FilePath*, ScopedPathUnlinkerTraits> ScopedPathUnlinker;
 
-#if !defined(OS_ANDROID)
 // Makes a temporary file, fdopens it, and then unlinks it. |fp| is populated
 // with the fdopened FILE. |readonly_fd| is populated with the opened fd if
 // options.share_read_only is true. |path| is populated with the location of
@@ -106,7 +100,6 @@ bool CreateAnonymousSharedMemory(const SharedMemoryCreateOptions& options,
   }
   return true;
 }
-#endif  // !defined(OS_ANDROID)
 }
 
 SharedMemory::SharedMemory()
@@ -118,8 +111,8 @@ SharedMemory::SharedMemory()
       requested_size_(0) {
 }
 
-SharedMemory::SharedMemory(SharedMemoryHandle handle, bool read_only)
-    : mapped_file_(handle.fd),
+SharedMemory::SharedMemory(const SharedMemoryHandle& handle, bool read_only)
+    : mapped_file_(GetFdFromSharedMemoryHandle(handle)),
       readonly_mapped_file_(-1),
       mapped_size_(0),
       memory_(NULL),
@@ -127,9 +120,10 @@ SharedMemory::SharedMemory(SharedMemoryHandle handle, bool read_only)
       requested_size_(0) {
 }
 
-SharedMemory::SharedMemory(SharedMemoryHandle handle, bool read_only,
+SharedMemory::SharedMemory(const SharedMemoryHandle& handle,
+                           bool read_only,
                            ProcessHandle process)
-    : mapped_file_(handle.fd),
+    : mapped_file_(GetFdFromSharedMemoryHandle(handle)),
       readonly_mapped_file_(-1),
       mapped_size_(0),
       memory_(NULL),
@@ -147,7 +141,7 @@ SharedMemory::~SharedMemory() {
 
 // static
 bool SharedMemory::IsHandleValid(const SharedMemoryHandle& handle) {
-  return handle.fd >= 0;
+  return GetFdFromSharedMemoryHandle(handle) >= 0;
 }
 
 // static
@@ -157,8 +151,8 @@ SharedMemoryHandle SharedMemory::NULLHandle() {
 
 // static
 void SharedMemory::CloseHandle(const SharedMemoryHandle& handle) {
-  DCHECK_GE(handle.fd, 0);
-  if (close(handle.fd) < 0)
+  DCHECK_GE(GetFdFromSharedMemoryHandle(handle), 0);
+  if (close(GetFdFromSharedMemoryHandle(handle)) < 0)
     DPLOG(ERROR) << "close";
 }
 
@@ -170,28 +164,24 @@ size_t SharedMemory::GetHandleLimit() {
 // static
 SharedMemoryHandle SharedMemory::DuplicateHandle(
     const SharedMemoryHandle& handle) {
-  int duped_handle = HANDLE_EINTR(dup(handle.fd));
-  if (duped_handle < 0)
-    return base::SharedMemory::NULLHandle();
-  return base::FileDescriptor(duped_handle, true);
+  return handle.Duplicate();
 }
 
 // static
 int SharedMemory::GetFdFromSharedMemoryHandle(
     const SharedMemoryHandle& handle) {
-  return handle.fd;
+  return handle.GetFileDescriptor()->fd;
 }
 
 bool SharedMemory::CreateAndMapAnonymous(size_t size) {
   return CreateAnonymous(size) && Map(size);
 }
 
-#if !defined(OS_ANDROID)
 // static
 int SharedMemory::GetSizeFromSharedMemoryHandle(
     const SharedMemoryHandle& handle) {
   struct stat st;
-  if (fstat(handle.fd, &st) != 0)
+  if (fstat(GetFdFromSharedMemoryHandle(handle), &st) != 0)
     return -1;
   return st.st_size;
 }
@@ -298,19 +288,7 @@ bool SharedMemory::Create(const SharedMemoryCreateOptions& options) {
     requested_size_ = options.size;
   }
   if (fp == NULL) {
-#if !defined(OS_MACOSX)
-    PLOG(ERROR) << "Creating shared memory in " << path.value() << " failed";
-    FilePath dir = path.DirName();
-    if (access(dir.value().c_str(), W_OK | X_OK) < 0) {
-      PLOG(ERROR) << "Unable to access(W_OK|X_OK) " << dir.value();
-      if (dir.value() == "/dev/shm") {
-        LOG(FATAL) << "This is frequently caused by incorrect permissions on "
-                   << "/dev/shm.  Try 'sudo chmod 1777 /dev/shm' to fix.";
-      }
-    }
-#else
     PLOG(ERROR) << "Creating shared memory in " << path.value() << " failed";
-#endif
     return false;
   }
 
@@ -348,7 +326,6 @@ bool SharedMemory::Open(const std::string& name, bool read_only) {
   }
   return PrepareMapFile(fp.Pass(), readonly_fd.Pass());
 }
-#endif  // !defined(OS_ANDROID)
 
 bool SharedMemory::MapAt(off_t offset, size_t bytes) {
   if (mapped_file_ == -1)
@@ -360,18 +337,6 @@ bool SharedMemory::MapAt(off_t offset, size_t bytes) {
   if (memory_)
     return false;
 
-#if defined(OS_ANDROID)
-  // On Android, Map can be called with a size and offset of zero to use the
-  // ashmem-determined size.
-  if (bytes == 0) {
-    DCHECK_EQ(0, offset);
-    int ashmem_bytes = ashmem_get_size_region(mapped_file_);
-    if (ashmem_bytes < 0)
-      return false;
-    bytes = ashmem_bytes;
-  }
-#endif
-
   memory_ = mmap(NULL, bytes, PROT_READ | (read_only_ ? 0 : PROT_WRITE),
                  MAP_SHARED, mapped_file_, offset);
 
@@ -398,7 +363,7 @@ bool SharedMemory::Unmap() {
 }
 
 SharedMemoryHandle SharedMemory::handle() const {
-  return FileDescriptor(mapped_file_, false);
+  return SharedMemoryHandle(FileDescriptor(mapped_file_, false));
 }
 
 void SharedMemory::Close() {
@@ -424,7 +389,6 @@ void SharedMemory::UnlockDeprecated() {
   g_thread_lock_.Get().Release();
 }
 
-#if !defined(OS_ANDROID)
 bool SharedMemory::PrepareMapFile(ScopedFILE fp, ScopedFD readonly_fd) {

[Nico, 2015/06/17 04:03:21]

There's a lot of code in this file that's just copied without any modifications.
Do you have a preview of how much this file is going to change in follow-ups?

[erikchen, 2015/06/17 17:38:55]

I don't have a preview to show you, but pretty much everything is changing.

In the short term, every function has to support both Mach and POSIX backed
shared memory.
In the long term, every function will only support Mach backed shared memory.

   DCHECK_EQ(-1, mapped_file_);
   DCHECK_EQ(-1, readonly_mapped_file_);
@@ -477,19 +441,10 @@ bool SharedMemory::FilePathForMemoryName(const std::string& mem_name,
   if (!GetShmemTempDir(false, &temp_dir))
     return false;
 
-#if !defined(OS_MACOSX)
-#if defined(GOOGLE_CHROME_BUILD)
-  std::string name_base = std::string("com.google.Chrome");
-#else
-  std::string name_base = std::string("org.chromium.Chromium");
-#endif
-#else  // OS_MACOSX
   std::string name_base = std::string(base::mac::BaseBundleID());
-#endif  // OS_MACOSX
   *path = temp_dir.AppendASCII(name_base + ".shmem." + mem_name);
   return true;
 }
-#endif  // !defined(OS_ANDROID)
 
 void SharedMemory::LockOrUnlockCommon(int function) {
   DCHECK_GE(mapped_file_, 0);
@@ -533,8 +488,7 @@ bool SharedMemory::ShareToProcessCommon(ProcessHandle process,
     return false;
   }
 
-  new_handle->fd = new_fd;
-  new_handle->auto_close = true;
+  new_handle->SetFileHandle(new_fd, true);
 
   if (close_self) {
     Unmap();