Remove unused locking functionality from base::SharedMemory.

base/memory/shared_memory_posix.cc

 // Copyright (c) 2012 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 "base/memory/shared_memory.h"
 
-#include <errno.h>
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
-#include <sys/types.h>
 #include <unistd.h>
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_file.h"
-#include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/process/process_metrics.h"
 #include "base/profiler/scoped_tracker.h"
-#include "base/safe_strerror_posix.h"
 #include "base/scoped_generic.h"
 #include "base/strings/utf_string_conversions.h"
-#include "base/synchronization/lock.h"
-#include "base/threading/platform_thread.h"
-#include "base/threading/thread_restrictions.h"
 
 #if defined(OS_MACOSX)
 #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 {
 
-LazyInstance<Lock>::Leaky g_thread_lock_ = LAZY_INSTANCE_INITIALIZER;
-
 struct ScopedPathUnlinkerTraits {
   static FilePath* InvalidValue() { return nullptr; }
 
   static void Free(FilePath* path) {
     // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466437
     // is fixed.
     tracked_objects::ScopedTracker tracking_profile(
         FROM_HERE_WITH_EXPLICIT_FUNCTION(
             "466437 SharedMemory::Create::Unlink"));
     if (unlink(path->value().c_str()))
@@ skipping 372 matching lines @@
       PLOG(ERROR) << "close";
     mapped_file_ = -1;
   }
   if (readonly_mapped_file_ > 0) {
     if (close(readonly_mapped_file_) < 0)
       PLOG(ERROR) << "close";
     readonly_mapped_file_ = -1;
   }
 }
 
-void SharedMemory::LockDeprecated() {
-  g_thread_lock_.Get().Acquire();
-  LockOrUnlockCommon(F_LOCK);
-}
-
-void SharedMemory::UnlockDeprecated() {
-  LockOrUnlockCommon(F_ULOCK);
-  g_thread_lock_.Get().Release();
-}
-
 #if !defined(OS_ANDROID)
 bool SharedMemory::PrepareMapFile(ScopedFILE fp, ScopedFD readonly_fd) {
   DCHECK_EQ(-1, mapped_file_);
   DCHECK_EQ(-1, readonly_mapped_file_);
   if (fp == NULL)
     return false;
 
   // This function theoretically can block on the disk, but realistically
   // the temporary files we create will just go into the buffer cache
   // and be deleted before they ever make it out to disk.
@@ skipping 48 matching lines @@
   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);
-  while (lockf(mapped_file_, function, 0) < 0) {
-    if (errno == EINTR) {
-      continue;
-    } else if (errno == ENOLCK) {
-      // temporary kernel resource exaustion
-      base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(500));
-      continue;
-    } else {
-      NOTREACHED() << "lockf() failed."
-                   << " function:" << function
-                   << " fd:" << mapped_file_
-                   << " errno:" << errno
-                   << " msg:" << safe_strerror(errno);
-    }
-  }
-}
-
 bool SharedMemory::ShareToProcessCommon(ProcessHandle process,
                                         SharedMemoryHandle* new_handle,
                                         bool close_self,
                                         ShareMode share_mode) {
   int handle_to_dup = -1;
   switch(share_mode) {
     case SHARE_CURRENT_MODE:
       handle_to_dup = mapped_file_;
       break;
     case SHARE_READONLY:
@@ skipping 15 matching lines @@
 
   if (close_self) {
     Unmap();
     Close();
   }
 
   return true;
 }
 
 }  // namespace base