ipc/glue/SharedMemoryBasic_android.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_ipc_SharedMemoryBasic_android_h
   8 #define mozilla_ipc_SharedMemoryBasic_android_h
   9
  10 #include "base/file_descriptor_posix.h"
  11
  12 #include "SharedMemory.h"
  13
  14 #ifdef FUZZING
  15 #  include "SharedMemoryFuzzer.h"
  16 #endif
  17
  18 //
  19 // This is a low-level wrapper around platform shared memory.  Don't
  20 // use it directly; use Shmem allocated through IPDL interfaces.
  21 //
  22
  23 namespace mozilla {
  24 namespace ipc {
  25
  26 class SharedMemoryBasic final
  27     : public SharedMemoryCommon<base::FileDescriptor> {
  28  public:
  29   SharedMemoryBasic();
  30
  31   virtual bool SetHandle(const Handle& aHandle, OpenRights aRights) override;
  32
  33   virtual bool Create(size_t aNbytes) override;
  34
  35   virtual bool Map(size_t nBytes, void* fixed_address = nullptr) override;
  36
  37   virtual void Unmap() override;
  38
  39   virtual void CloseHandle() override;
  40
  41   virtual void* memory() const override {
  42 #ifdef FUZZING
  43     return SharedMemoryFuzzer::MutateSharedMemory(mMemory, mAllocSize);
  44 #else
  45     return mMemory;
  46 #endif
  47   }
  48
  49   virtual SharedMemoryType Type() const override { return TYPE_BASIC; }
  50
  51   static Handle NULLHandle() { return Handle(); }
  52
  53   static void* FindFreeAddressSpace(size_t aSize);
  54
  55   virtual bool IsHandleValid(const Handle& aHandle) const override {
  56     return aHandle.fd >= 0;
  57   }
  58
  59   virtual bool ShareToProcess(base::ProcessId aProcessId,
  60                               Handle* aNewHandle) override;
  61
  62  private:
  63   ~SharedMemoryBasic();
  64
  65   // The /dev/ashmem fd we allocate.
  66   int mShmFd;
  67   // Pointer to mapped region, null if unmapped.
  68   void* mMemory;
  69   // Access rights to map an existing region with.
  70   OpenRights mOpenRights;
  71 };
  72
  73 }  // namespace ipc
  74 }  // namespace mozilla
  75
  76 #endif  // ifndef mozilla_ipc_SharedMemoryBasic_android_h