1 // Copyright 2014 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 // Note: This header should be compilable as C. 6 7 #ifndef MOJO_PUBLIC_PLATFORM_NATIVE_SYSTEM_THUNKS_H_ 8 #define MOJO_PUBLIC_PLATFORM_NATIVE_SYSTEM_THUNKS_H_ 9 10 #include <stddef.h> 11 12 #include "mojo/public/c/system/core.h" 13 14 // The embedder needs to bind the basic Mojo Core functions of a DSO to those of 15 // the embedder when loading a DSO that is dependent on mojo_system. 16 // The typical usage would look like: 17 // base::ScopedNativeLibrary app_library( 18 // base::LoadNativeLibrary(app_path_, &error)); 19 // typedef MojoResult (*MojoSetSystemThunksFn)(MojoSystemThunks*); 20 // MojoSetSystemThunksFn mojo_set_system_thunks_fn = 21 // reinterpret_cast<MojoSetSystemThunksFn>(app_library.GetFunctionPointer( 22 // "MojoSetSystemThunks")); 23 // MojoSystemThunks system_thunks = MojoMakeSystemThunks(); 24 // size_t expected_size = mojo_set_system_thunks_fn(&system_thunks); 25 // if (expected_size > sizeof(MojoSystemThunks)) { 26 // LOG(ERROR) 27 // << "Invalid DSO. Expected MojoSystemThunks size: " 28 // << expected_size; 29 // break; 30 // } 31 32 // Structure used to bind the basic Mojo Core functions of a DSO to those of 33 // the embedder. 34 // This is the ABI between the embedder and the DSO. It can only have new 35 // functions added to the end. No other changes are supported. 36 #pragma pack(push, 8) 37 struct MojoSystemThunks { 38 size_t size; // Should be set to sizeof(MojoSystemThunks). 39 MojoTimeTicks (*GetTimeTicksNow)(); 40 MojoResult (*Close)(MojoHandle handle); 41 MojoResult (*Wait)(MojoHandle handle, 42 MojoHandleSignals signals, 43 MojoDeadline deadline); 44 MojoResult (*WaitMany)(const MojoHandle* handles, 45 const MojoHandleSignals* signals, 46 uint32_t num_handles, 47 MojoDeadline deadline); 48 MojoResult (*CreateMessagePipe)( 49 const struct MojoCreateMessagePipeOptions* options, 50 MojoHandle* message_pipe_handle0, 51 MojoHandle* message_pipe_handle1); 52 MojoResult (*WriteMessage)(MojoHandle message_pipe_handle, 53 const void* bytes, 54 uint32_t num_bytes, 55 const MojoHandle* handles, 56 uint32_t num_handles, 57 MojoWriteMessageFlags flags); 58 MojoResult (*ReadMessage)(MojoHandle message_pipe_handle, 59 void* bytes, 60 uint32_t* num_bytes, 61 MojoHandle* handles, 62 uint32_t* num_handles, 63 MojoReadMessageFlags flags); 64 MojoResult (*CreateDataPipe)(const struct MojoCreateDataPipeOptions* options, 65 MojoHandle* data_pipe_producer_handle, 66 MojoHandle* data_pipe_consumer_handle); 67 MojoResult (*WriteData)(MojoHandle data_pipe_producer_handle, 68 const void* elements, 69 uint32_t* num_elements, 70 MojoWriteDataFlags flags); 71 MojoResult (*BeginWriteData)(MojoHandle data_pipe_producer_handle, 72 void** buffer, 73 uint32_t* buffer_num_elements, 74 MojoWriteDataFlags flags); 75 MojoResult (*EndWriteData)(MojoHandle data_pipe_producer_handle, 76 uint32_t num_elements_written); 77 MojoResult (*ReadData)(MojoHandle data_pipe_consumer_handle, 78 void* elements, 79 uint32_t* num_elements, 80 MojoReadDataFlags flags); 81 MojoResult (*BeginReadData)(MojoHandle data_pipe_consumer_handle, 82 const void** buffer, 83 uint32_t* buffer_num_elements, 84 MojoReadDataFlags flags); 85 MojoResult (*EndReadData)(MojoHandle data_pipe_consumer_handle, 86 uint32_t num_elements_read); 87 MojoResult (*CreateSharedBuffer)( 88 const struct MojoCreateSharedBufferOptions* options, 89 uint64_t num_bytes, 90 MojoHandle* shared_buffer_handle); 91 MojoResult (*DuplicateBufferHandle)( 92 MojoHandle buffer_handle, 93 const struct MojoDuplicateBufferHandleOptions* options, 94 MojoHandle* new_buffer_handle); 95 MojoResult (*MapBuffer)(MojoHandle buffer_handle, 96 uint64_t offset, 97 uint64_t num_bytes, 98 void** buffer, 99 MojoMapBufferFlags flags); 100 MojoResult (*UnmapBuffer)(void* buffer); 101 }; 102 #pragma pack(pop) 103 104 105 #ifdef __cplusplus 106 // Intended to be called from the embedder. Returns a |MojoCore| initialized 107 // to contain pointers to each of the embedder's MojoCore functions. 108 inline MojoSystemThunks MojoMakeSystemThunks() { 109 MojoSystemThunks system_thunks = { 110 sizeof(MojoSystemThunks), 111 MojoGetTimeTicksNow, 112 MojoClose, 113 MojoWait, 114 MojoWaitMany, 115 MojoCreateMessagePipe, 116 MojoWriteMessage, 117 MojoReadMessage, 118 MojoCreateDataPipe, 119 MojoWriteData, 120 MojoBeginWriteData, 121 MojoEndWriteData, 122 MojoReadData, 123 MojoBeginReadData, 124 MojoEndReadData, 125 MojoCreateSharedBuffer, 126 MojoDuplicateBufferHandle, 127 MojoMapBuffer, 128 MojoUnmapBuffer 129 }; 130 return system_thunks; 131 } 132 #endif 133 134 135 // Use this type for the function found by dynamically discovering it in 136 // a DSO linked with mojo_system. For example: 137 // MojoSetSystemThunksFn mojo_set_system_thunks_fn = 138 // reinterpret_cast<MojoSetSystemThunksFn>(app_library.GetFunctionPointer( 139 // "MojoSetSystemThunks")); 140 // The expected size of |system_thunks} is returned. 141 // The contents of |system_thunks| are copied. 142 typedef size_t (*MojoSetSystemThunksFn)( 143 const struct MojoSystemThunks* system_thunks); 144 145 #endif // MOJO_PUBLIC_PLATFORM_NATIVE_SYSTEM_THUNKS_H_ 146
