ipc/glue/DataPipe.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 https://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_ipc_DataPipe_h
   8 #define mozilla_ipc_DataPipe_h
   9
  10 #include "mozilla/ipc/SharedMemory.h"
  11 #include "mozilla/ipc/NodeController.h"
  12 #include "nsIAsyncInputStream.h"
  13 #include "nsIAsyncOutputStream.h"
  14 #include "nsIIPCSerializableInputStream.h"
  15 #include "nsISupports.h"
  16
  17 namespace mozilla {
  18 namespace ipc {
  19
  20 namespace data_pipe_detail {
  21
  22 class DataPipeAutoLock;
  23 class DataPipeLink;
  24
  25 class DataPipeBase {
  26  public:
  27   DataPipeBase(const DataPipeBase&) = delete;
  28   DataPipeBase& operator=(const DataPipeBase&) = delete;
  29
  30  protected:
  31   explicit DataPipeBase(bool aReceiverSide, nsresult aError);
  32   DataPipeBase(bool aReceiverSide, ScopedPort aPort,
  33                SharedMemory::Handle aShmemHandle, SharedMemory* aShmem,
  34                uint32_t aCapacity, nsresult aPeerStatus, uint32_t aOffset,
  35                uint32_t aAvailable);
  36
  37   void CloseInternal(DataPipeAutoLock&, nsresult aStatus) MOZ_REQUIRES(*mMutex);
  38
  39   void AsyncWaitInternal(already_AddRefed<nsIRunnable> aCallback,
  40                          already_AddRefed<nsIEventTarget> aTarget,
  41                          bool aClosureOnly) MOZ_EXCLUDES(*mMutex);
  42
  43   // Like `nsWriteSegmentFun` or `nsReadSegmentFun`.
  44   using ProcessSegmentFun =
  45       FunctionRef<nsresult(Span<char> aSpan, uint32_t aProcessedThisCall,
  46                            uint32_t* aProcessedCount)>;
  47   nsresult ProcessSegmentsInternal(uint32_t aCount,
  48                                    ProcessSegmentFun aProcessSegment,
  49                                    uint32_t* aProcessedCount)
  50       MOZ_EXCLUDES(*mMutex);
  51
  52   nsresult CheckStatus(DataPipeAutoLock&) MOZ_REQUIRES(*mMutex);
  53
  54   nsCString Describe(DataPipeAutoLock&) MOZ_REQUIRES(*mMutex);
  55
  56   // Thread safety helper to tell the analysis that `mLink->mMutex` is held when
  57   // `mMutex` is held.
  58   void AssertSameMutex(const std::shared_ptr<Mutex>& aMutex)
  59       MOZ_REQUIRES(*mMutex) MOZ_ASSERT_CAPABILITY(*aMutex) {
  60     MOZ_ASSERT(mMutex == aMutex);
  61   }
  62
  63   virtual ~DataPipeBase();
  64
  65   const std::shared_ptr<Mutex> mMutex;
  66   nsresult mStatus MOZ_GUARDED_BY(*mMutex) = NS_OK;
  67   RefPtr<DataPipeLink> mLink MOZ_GUARDED_BY(*mMutex);
  68 };
  69
  70 template <typename T>
  71 void DataPipeWrite(IPC::MessageWriter* aWriter, T* aParam);
  72
  73 template <typename T>
  74 bool DataPipeRead(IPC::MessageReader* aReader, RefPtr<T>* aResult);
  75
  76 }  // namespace data_pipe_detail
  77
  78 class DataPipeSender;
  79 class DataPipeReceiver;
  80
  81 #define NS_DATAPIPESENDER_IID                        \
  82   {                                                  \
  83     0x6698ed77, 0x9fff, 0x425d, {                    \
  84       0xb0, 0xa6, 0x1d, 0x30, 0x66, 0xee, 0xb8, 0x16 \
  85     }                                                \
  86   }
  87
  88 // Helper class for streaming data to another process.
  89 class DataPipeSender final : public nsIAsyncOutputStream,
  90                              public data_pipe_detail::DataPipeBase {
  91  public:
  92   NS_DECLARE_STATIC_IID_ACCESSOR(NS_DATAPIPESENDER_IID)
  93   NS_DECL_THREADSAFE_ISUPPORTS
  94   NS_DECL_NSIOUTPUTSTREAM
  95   NS_DECL_NSIASYNCOUTPUTSTREAM
  96
  97  private:
  98   friend nsresult NewDataPipe(uint32_t, DataPipeSender**, DataPipeReceiver**);
  99   friend void data_pipe_detail::DataPipeWrite<DataPipeSender>(
 100       IPC::MessageWriter* aWriter, DataPipeSender* aParam);
 101   friend bool data_pipe_detail::DataPipeRead<DataPipeSender>(
 102       IPC::MessageReader* aReader, RefPtr<DataPipeSender>* aResult);
 103
 104   explicit DataPipeSender(nsresult aError)
 105       : data_pipe_detail::DataPipeBase(/* aReceiverSide */ false, aError) {}
 106   DataPipeSender(ScopedPort aPort, SharedMemory::Handle aShmemHandle,
 107                  SharedMemory* aShmem, uint32_t aCapacity, nsresult aPeerStatus,
 108                  uint32_t aOffset, uint32_t aAvailable)
 109       : data_pipe_detail::DataPipeBase(
 110             /* aReceiverSide */ false, std::move(aPort),
 111             std::move(aShmemHandle), aShmem, aCapacity, aPeerStatus, aOffset,
 112             aAvailable) {}
 113
 114   ~DataPipeSender() = default;
 115 };
 116
 117 NS_DEFINE_STATIC_IID_ACCESSOR(DataPipeSender, NS_DATAPIPESENDER_IID)
 118
 119 #define NS_DATAPIPERECEIVER_IID                      \
 120   {                                                  \
 121     0x0a185f83, 0x499e, 0x450c, {                    \
 122       0x95, 0x82, 0x27, 0x67, 0xad, 0x6d, 0x64, 0xb5 \
 123     }                                                \
 124   }
 125
 126 // Helper class for streaming data from another process.
 127 class DataPipeReceiver final : public nsIAsyncInputStream,
 128                                public nsIIPCSerializableInputStream,
 129                                public data_pipe_detail::DataPipeBase {
 130  public:
 131   NS_DECLARE_STATIC_IID_ACCESSOR(NS_DATAPIPERECEIVER_IID)
 132   NS_DECL_THREADSAFE_ISUPPORTS
 133   NS_DECL_NSIINPUTSTREAM
 134   NS_DECL_NSIASYNCINPUTSTREAM
 135   NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
 136
 137  private:
 138   friend nsresult NewDataPipe(uint32_t, DataPipeSender**, DataPipeReceiver**);
 139   friend void data_pipe_detail::DataPipeWrite<DataPipeReceiver>(
 140       IPC::MessageWriter* aWriter, DataPipeReceiver* aParam);
 141   friend bool data_pipe_detail::DataPipeRead<DataPipeReceiver>(
 142       IPC::MessageReader* aReader, RefPtr<DataPipeReceiver>* aResult);
 143
 144   explicit DataPipeReceiver(nsresult aError)
 145       : data_pipe_detail::DataPipeBase(/* aReceiverSide */ true, aError) {}
 146   DataPipeReceiver(ScopedPort aPort, SharedMemory::Handle aShmemHandle,
 147                    SharedMemory* aShmem, uint32_t aCapacity,
 148                    nsresult aPeerStatus, uint32_t aOffset, uint32_t aAvailable)
 149       : data_pipe_detail::DataPipeBase(
 150             /* aReceiverSide */ true, std::move(aPort), std::move(aShmemHandle),
 151             aShmem, aCapacity, aPeerStatus, aOffset, aAvailable) {}
 152
 153   ~DataPipeReceiver() = default;
 154 };
 155
 156 NS_DEFINE_STATIC_IID_ACCESSOR(DataPipeReceiver, NS_DATAPIPERECEIVER_IID)
 157
 158 constexpr uint32_t kDefaultDataPipeCapacity = 64 * 1024;
 159
 160 /**
 161  * Create a new DataPipe pair. The sender and receiver ends of the pipe may be
 162  * used to transfer data between processes. |aCapacity| is the capacity of the
 163  * underlying ring buffer. If `0` is passed, `kDefaultDataPipeCapacity` will be
 164  * used.
 165  */
 166 nsresult NewDataPipe(uint32_t aCapacity, DataPipeSender** aSender,
 167                      DataPipeReceiver** aReceiver);
 168
 169 }  // namespace ipc
 170 }  // namespace mozilla
 171
 172 namespace IPC {
 173
 174 template <>
 175 struct ParamTraits<mozilla::ipc::DataPipeSender*> {
 176   static void Write(MessageWriter* aWriter,
 177                     mozilla::ipc::DataPipeSender* aParam);
 178   static bool Read(MessageReader* aReader,
 179                    RefPtr<mozilla::ipc::DataPipeSender>* aResult);
 180 };
 181
 182 template <>
 183 struct ParamTraits<mozilla::ipc::DataPipeReceiver*> {
 184   static void Write(MessageWriter* aWriter,
 185                     mozilla::ipc::DataPipeReceiver* aParam);
 186   static bool Read(MessageReader* aReader,
 187                    RefPtr<mozilla::ipc::DataPipeReceiver>* aResult);
 188 };
 189
 190 }  // namespace IPC
 191
 192 #endif  // mozilla_ipc_DataPipe_h