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| 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_EDK_SYSTEM_DATA_PIPE_H_ | |
| 6 #define MOJO_EDK_SYSTEM_DATA_PIPE_H_ | |
| 7 | |
| 8 #include <stdint.h> | |
| 9 | |
| 10 #include "base/macros.h" | |
| 11 #include "base/memory/ref_counted.h" | |
| 12 #include "base/memory/scoped_ptr.h" | |
| 13 #include "base/synchronization/lock.h" | |
| 14 #include "mojo/edk/system/handle_signals_state.h" | |
| 15 #include "mojo/edk/system/memory.h" | |
| 16 #include "mojo/edk/system/system_impl_export.h" | |
| 17 #include "mojo/public/c/system/data_pipe.h" | |
| 18 #include "mojo/public/c/system/types.h" | |
| 19 | |
| 20 namespace mojo { | |
| 21 namespace system { | |
| 22 | |
| 23 class Awakable; | |
| 24 class AwakableList; | |
| 25 | |
| 26 // |DataPipe| is a base class for secondary objects implementing data pipes, | |
| 27 // similar to |MessagePipe| (see the explanatory comment in core.cc). It is | |
| 28 // typically owned by the dispatcher(s) corresponding to the local endpoints. | |
| 29 // Its subclasses implement the three cases: local producer and consumer, local | |
| 30 // producer and remote consumer, and remote producer and local consumer. This | |
| 31 // class is thread-safe. | |
| 32 class MOJO_SYSTEM_IMPL_EXPORT DataPipe | |
| 33 : public base::RefCountedThreadSafe<DataPipe> { | |
| 34 public: | |
| 35 // The default options for |MojoCreateDataPipe()|. (Real uses should obtain | |
| 36 // this via |ValidateCreateOptions()| with a null |in_options|; this is | |
| 37 // exposed directly for testing convenience.) | |
| 38 static MojoCreateDataPipeOptions GetDefaultCreateOptions(); | |
| 39 | |
| 40 // Validates and/or sets default options for |MojoCreateDataPipeOptions|. If | |
| 41 // non-null, |in_options| must point to a struct of at least | |
| 42 // |in_options->struct_size| bytes. |out_options| must point to a (current) | |
| 43 // |MojoCreateDataPipeOptions| and will be entirely overwritten on success (it | |
| 44 // may be partly overwritten on failure). | |
| 45 static MojoResult ValidateCreateOptions( | |
| 46 UserPointer<const MojoCreateDataPipeOptions> in_options, | |
| 47 MojoCreateDataPipeOptions* out_options); | |
| 48 | |
| 49 // These are called by the producer dispatcher to implement its methods of | |
| 50 // corresponding names. | |
| 51 void ProducerCancelAllAwakables(); | |
| 52 void ProducerClose(); | |
| 53 MojoResult ProducerWriteData(UserPointer<const void> elements, | |
| 54 UserPointer<uint32_t> num_bytes, | |
| 55 bool all_or_none); | |
| 56 MojoResult ProducerBeginWriteData(UserPointer<void*> buffer, | |
| 57 UserPointer<uint32_t> buffer_num_bytes, | |
| 58 bool all_or_none); | |
| 59 MojoResult ProducerEndWriteData(uint32_t num_bytes_written); | |
| 60 HandleSignalsState ProducerGetHandleSignalsState(); | |
| 61 MojoResult ProducerAddAwakable(Awakable* awakable, | |
| 62 MojoHandleSignals signals, | |
| 63 uint32_t context, | |
| 64 HandleSignalsState* signals_state); | |
| 65 void ProducerRemoveAwakable(Awakable* awakable, | |
| 66 HandleSignalsState* signals_state); | |
| 67 bool ProducerIsBusy() const; | |
| 68 | |
| 69 // These are called by the consumer dispatcher to implement its methods of | |
| 70 // corresponding names. | |
| 71 void ConsumerCancelAllAwakables(); | |
| 72 void ConsumerClose(); | |
| 73 // This does not validate its arguments, except to check that |*num_bytes| is | |
| 74 // a multiple of |element_num_bytes_|. | |
| 75 MojoResult ConsumerReadData(UserPointer<void> elements, | |
| 76 UserPointer<uint32_t> num_bytes, | |
| 77 bool all_or_none, | |
| 78 bool peek); | |
| 79 MojoResult ConsumerDiscardData(UserPointer<uint32_t> num_bytes, | |
| 80 bool all_or_none); | |
| 81 MojoResult ConsumerQueryData(UserPointer<uint32_t> num_bytes); | |
| 82 MojoResult ConsumerBeginReadData(UserPointer<const void*> buffer, | |
| 83 UserPointer<uint32_t> buffer_num_bytes, | |
| 84 bool all_or_none); | |
| 85 MojoResult ConsumerEndReadData(uint32_t num_bytes_read); | |
| 86 HandleSignalsState ConsumerGetHandleSignalsState(); | |
| 87 MojoResult ConsumerAddAwakable(Awakable* awakable, | |
| 88 MojoHandleSignals signals, | |
| 89 uint32_t context, | |
| 90 HandleSignalsState* signals_state); | |
| 91 void ConsumerRemoveAwakable(Awakable* awakable, | |
| 92 HandleSignalsState* signals_state); | |
| 93 bool ConsumerIsBusy() const; | |
| 94 | |
| 95 protected: | |
| 96 DataPipe(bool has_local_producer, | |
| 97 bool has_local_consumer, | |
| 98 const MojoCreateDataPipeOptions& validated_options); | |
| 99 | |
| 100 friend class base::RefCountedThreadSafe<DataPipe>; | |
| 101 virtual ~DataPipe(); | |
| 102 | |
| 103 virtual void ProducerCloseImplNoLock() = 0; | |
| 104 // |num_bytes.Get()| will be a nonzero multiple of |element_num_bytes_|. | |
| 105 virtual MojoResult ProducerWriteDataImplNoLock( | |
| 106 UserPointer<const void> elements, | |
| 107 UserPointer<uint32_t> num_bytes, | |
| 108 uint32_t max_num_bytes_to_write, | |
| 109 uint32_t min_num_bytes_to_write) = 0; | |
| 110 virtual MojoResult ProducerBeginWriteDataImplNoLock( | |
| 111 UserPointer<void*> buffer, | |
| 112 UserPointer<uint32_t> buffer_num_bytes, | |
| 113 uint32_t min_num_bytes_to_write) = 0; | |
| 114 virtual MojoResult ProducerEndWriteDataImplNoLock( | |
| 115 uint32_t num_bytes_written) = 0; | |
| 116 // Note: A producer should not be writable during a two-phase write. | |
| 117 virtual HandleSignalsState ProducerGetHandleSignalsStateImplNoLock() | |
| 118 const = 0; | |
| 119 | |
| 120 virtual void ConsumerCloseImplNoLock() = 0; | |
| 121 // |*num_bytes| will be a nonzero multiple of |element_num_bytes_|. | |
| 122 virtual MojoResult ConsumerReadDataImplNoLock(UserPointer<void> elements, | |
| 123 UserPointer<uint32_t> num_bytes, | |
| 124 uint32_t max_num_bytes_to_read, | |
| 125 uint32_t min_num_bytes_to_read, | |
| 126 bool peek) = 0; | |
| 127 virtual MojoResult ConsumerDiscardDataImplNoLock( | |
| 128 UserPointer<uint32_t> num_bytes, | |
| 129 uint32_t max_num_bytes_to_discard, | |
| 130 uint32_t min_num_bytes_to_discard) = 0; | |
| 131 // |*num_bytes| will be a nonzero multiple of |element_num_bytes_|. | |
| 132 virtual MojoResult ConsumerQueryDataImplNoLock( | |
| 133 UserPointer<uint32_t> num_bytes) = 0; | |
| 134 virtual MojoResult ConsumerBeginReadDataImplNoLock( | |
| 135 UserPointer<const void*> buffer, | |
| 136 UserPointer<uint32_t> buffer_num_bytes, | |
| 137 uint32_t min_num_bytes_to_read) = 0; | |
| 138 virtual MojoResult ConsumerEndReadDataImplNoLock(uint32_t num_bytes_read) = 0; | |
| 139 // Note: A consumer should not be writable during a two-phase read. | |
| 140 virtual HandleSignalsState ConsumerGetHandleSignalsStateImplNoLock() | |
| 141 const = 0; | |
| 142 | |
| 143 // Thread-safe and fast (they don't take the lock): | |
| 144 bool may_discard() const { return may_discard_; } | |
| 145 size_t element_num_bytes() const { return element_num_bytes_; } | |
| 146 size_t capacity_num_bytes() const { return capacity_num_bytes_; } | |
| 147 | |
| 148 // Must be called under lock. | |
| 149 bool producer_open_no_lock() const { | |
| 150 lock_.AssertAcquired(); | |
| 151 return producer_open_; | |
| 152 } | |
| 153 bool consumer_open_no_lock() const { | |
| 154 lock_.AssertAcquired(); | |
| 155 return consumer_open_; | |
| 156 } | |
| 157 uint32_t producer_two_phase_max_num_bytes_written_no_lock() const { | |
| 158 lock_.AssertAcquired(); | |
| 159 return producer_two_phase_max_num_bytes_written_; | |
| 160 } | |
| 161 uint32_t consumer_two_phase_max_num_bytes_read_no_lock() const { | |
| 162 lock_.AssertAcquired(); | |
| 163 return consumer_two_phase_max_num_bytes_read_; | |
| 164 } | |
| 165 void set_producer_two_phase_max_num_bytes_written_no_lock( | |
| 166 uint32_t num_bytes) { | |
| 167 lock_.AssertAcquired(); | |
| 168 producer_two_phase_max_num_bytes_written_ = num_bytes; | |
| 169 } | |
| 170 void set_consumer_two_phase_max_num_bytes_read_no_lock(uint32_t num_bytes) { | |
| 171 lock_.AssertAcquired(); | |
| 172 consumer_two_phase_max_num_bytes_read_ = num_bytes; | |
| 173 } | |
| 174 bool producer_in_two_phase_write_no_lock() const { | |
| 175 lock_.AssertAcquired(); | |
| 176 return producer_two_phase_max_num_bytes_written_ > 0; | |
| 177 } | |
| 178 bool consumer_in_two_phase_read_no_lock() const { | |
| 179 lock_.AssertAcquired(); | |
| 180 return consumer_two_phase_max_num_bytes_read_ > 0; | |
| 181 } | |
| 182 | |
| 183 private: | |
| 184 void AwakeProducerAwakablesForStateChangeNoLock( | |
| 185 const HandleSignalsState& new_producer_state); | |
| 186 void AwakeConsumerAwakablesForStateChangeNoLock( | |
| 187 const HandleSignalsState& new_consumer_state); | |
| 188 | |
| 189 bool has_local_producer_no_lock() const { | |
| 190 lock_.AssertAcquired(); | |
| 191 return !!producer_awakable_list_; | |
| 192 } | |
| 193 bool has_local_consumer_no_lock() const { | |
| 194 lock_.AssertAcquired(); | |
| 195 return !!consumer_awakable_list_; | |
| 196 } | |
| 197 | |
| 198 const bool may_discard_; | |
| 199 const size_t element_num_bytes_; | |
| 200 const size_t capacity_num_bytes_; | |
| 201 | |
| 202 mutable base::Lock lock_; // Protects the following members. | |
| 203 // *Known* state of producer or consumer. | |
| 204 bool producer_open_; | |
| 205 bool consumer_open_; | |
| 206 // Non-null only if the producer or consumer, respectively, is local. | |
| 207 scoped_ptr<AwakableList> producer_awakable_list_; | |
| 208 scoped_ptr<AwakableList> consumer_awakable_list_; | |
| 209 // These are nonzero if and only if a two-phase write/read is in progress. | |
| 210 uint32_t producer_two_phase_max_num_bytes_written_; | |
| 211 uint32_t consumer_two_phase_max_num_bytes_read_; | |
| 212 | |
| 213 DISALLOW_COPY_AND_ASSIGN(DataPipe); | |
| 214 }; | |
| 215 | |
| 216 } // namespace system | |
| 217 } // namespace mojo | |
| 218 | |
| 219 #endif // MOJO_EDK_SYSTEM_DATA_PIPE_H_ | |
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