1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef MOJO_SYSTEM_LOCAL_DATA_PIPE_H_ 6 #define MOJO_SYSTEM_LOCAL_DATA_PIPE_H_ 7 8 #include "base/macros.h" 9 #include "base/memory/aligned_memory.h" 10 #include "base/memory/ref_counted.h" 11 #include "base/memory/scoped_ptr.h" 12 #include "mojo/system/data_pipe.h" 13 #include "mojo/system/system_impl_export.h" 14 15 namespace mojo { 16 namespace system { 17 18 // |LocalDataPipe| is a subclass that "implements" |DataPipe| for data pipes 19 // whose producer and consumer are both local. This class is thread-safe (with 20 // protection provided by |DataPipe|'s |lock_|. 21 class MOJO_SYSTEM_IMPL_EXPORT LocalDataPipe : public DataPipe { 22 public: 23 // |validated_options| should be the output of |DataPipe::ValidateOptions()|. 24 // In particular: |struct_size| is ignored (so |validated_options| must be the 25 // current version of the struct) and |capacity_num_bytes| must be nonzero. 26 explicit LocalDataPipe(const MojoCreateDataPipeOptions& validated_options); 27 28 private: 29 friend class base::RefCountedThreadSafe<LocalDataPipe>; 30 virtual ~LocalDataPipe(); 31 32 // |DataPipe| implementation: 33 virtual void ProducerCloseImplNoLock() OVERRIDE; 34 virtual MojoResult ProducerWriteDataImplNoLock( 35 UserPointer<const void> elements, 36 UserPointer<uint32_t> num_bytes, 37 uint32_t max_num_bytes_to_write, 38 uint32_t min_num_bytes_to_write) OVERRIDE; 39 virtual MojoResult ProducerBeginWriteDataImplNoLock( 40 UserPointer<void*> buffer, 41 UserPointer<uint32_t> buffer_num_bytes, 42 uint32_t min_num_bytes_to_write) OVERRIDE; 43 virtual MojoResult ProducerEndWriteDataImplNoLock( 44 uint32_t num_bytes_written) OVERRIDE; 45 virtual HandleSignalsState ProducerGetHandleSignalsStateImplNoLock() 46 const OVERRIDE; 47 virtual void ConsumerCloseImplNoLock() OVERRIDE; 48 virtual MojoResult ConsumerReadDataImplNoLock( 49 UserPointer<void> elements, 50 UserPointer<uint32_t> num_bytes, 51 uint32_t max_num_bytes_to_read, 52 uint32_t min_num_bytes_to_read) OVERRIDE; 53 virtual MojoResult ConsumerDiscardDataImplNoLock( 54 UserPointer<uint32_t> num_bytes, 55 uint32_t max_num_bytes_to_discard, 56 uint32_t min_num_bytes_to_discard) OVERRIDE; 57 virtual MojoResult ConsumerQueryDataImplNoLock( 58 UserPointer<uint32_t> num_bytes) OVERRIDE; 59 virtual MojoResult ConsumerBeginReadDataImplNoLock( 60 UserPointer<const void*> buffer, 61 UserPointer<uint32_t> buffer_num_bytes, 62 uint32_t min_num_bytes_to_read) OVERRIDE; 63 virtual MojoResult ConsumerEndReadDataImplNoLock( 64 uint32_t num_bytes_read) OVERRIDE; 65 virtual HandleSignalsState ConsumerGetHandleSignalsStateImplNoLock() 66 const OVERRIDE; 67 68 void EnsureBufferNoLock(); 69 void DestroyBufferNoLock(); 70 71 // Get the maximum (single) write/read size right now (in number of elements); 72 // result fits in a |uint32_t|. 73 size_t GetMaxNumBytesToWriteNoLock(); 74 size_t GetMaxNumBytesToReadNoLock(); 75 76 // Marks the given number of bytes as consumed/discarded. |num_bytes| must be 77 // greater than |current_num_bytes_|. 78 void MarkDataAsConsumedNoLock(size_t num_bytes); 79 80 // The members below are protected by |DataPipe|'s |lock_|: 81 scoped_ptr<char, base::AlignedFreeDeleter> buffer_; 82 // Circular buffer. 83 size_t start_index_; 84 size_t current_num_bytes_; 85 86 DISALLOW_COPY_AND_ASSIGN(LocalDataPipe); 87 }; 88 89 } // namespace system 90 } // namespace mojo 91 92 #endif // MOJO_SYSTEM_LOCAL_DATA_PIPE_H_ 93