1 /* Copyright (c) 2008-2015. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
7 #ifndef SIMGRID_MC_ADDRESS_SPACE_H
8 #define SIMGRID_MC_ADDRESS_SPACE_H
14 #include <type_traits>
19 #include "src/mc/mc_forward.hpp"
20 #include "src/mc/RemotePtr.hpp"
25 /** Process index used when no process is available
27 * The expected behavior is that if a process index is needed it will fail.
29 const int ProcessIndexMissing = -1;
31 /** Process index used when we don't care about the process index
33 const int ProcessIndexDisabled = -2;
35 /** Constant used when any process will do.
37 * This is is index of the first process.
39 const int ProcessIndexAny = 0;
41 /** Options for read operations
43 * This is a set of flags managed with bitwise operators. Only the
44 * meaningful operations are defined: addition, conversions to/from
45 * integers are not allowed.
49 constexpr explicit ReadOptions(std::uint32_t value) : value_(value) {}
51 constexpr ReadOptions() : value_(0) {}
53 constexpr operator bool() const { return value_ != 0; }
54 constexpr bool operator!() const { return value_ == 0; }
56 constexpr ReadOptions operator|(ReadOptions const& that) const
58 return ReadOptions(value_ | that.value_);
60 constexpr ReadOptions operator&(ReadOptions const& that) const
62 return ReadOptions(value_ & that.value_);
64 constexpr ReadOptions operator^(ReadOptions const& that) const
66 return ReadOptions(value_ ^ that.value_);
68 constexpr ReadOptions operator~() const
70 return ReadOptions(~value_);
73 ReadOptions& operator|=(ReadOptions const& that)
75 value_ |= that.value_;
78 ReadOptions& operator&=(ReadOptions const& that)
80 value_ &= that.value_;
83 ReadOptions& operator^=(ReadOptions const& that)
85 value_ &= that.value_;
89 /** Copy the data to the given buffer */
90 static constexpr ReadOptions none() { return ReadOptions(0); }
92 /** Allows to return a pointer to another buffer where the data is
93 * available instead of copying the data into the buffer
95 static constexpr ReadOptions lazy() { return ReadOptions(1); }
98 /** HACK, A value from another process
100 * This represents a value from another process:
102 * * constructor/destructor are disabled;
104 * * raw memory copy (std::memcpy) is used to copy Remote<T>;
106 * * raw memory comparison is used to compare them;
108 * * when T is a trivial type, Remote is convertible to a T.
110 * We currently only handle the case where the type has the same layout
111 * in the current process and in the target process: we don't handle
112 * cross-architecture (such as 32-bit/64-bit access).
121 Remote(Remote const& that)
123 std::memcpy(&buffer, &that.buffer, sizeof(buffer));
125 Remote& operator=(Remote const& that)
127 std::memcpy(&buffer, &that.buffer, sizeof(buffer));
130 T* getBuffer() { return &buffer; }
131 const T* getBuffer() const { return &buffer; }
132 std::size_t getBufferSize() const { return sizeof(T); }
134 static_assert(std::is_trivial<T>::value, "Cannot convert non trivial type");
139 std::memset(static_cast<void*>(&buffer), 0, sizeof(T));
143 /** A given state of a given process (abstract base class)
145 * Currently, this might either be:
147 * * the current state of an existing process;
155 AddressSpace(Process* process) : process_(process) {}
156 virtual ~AddressSpace();
158 simgrid::mc::Process* process() const { return process_; }
160 /** Read data from the address space
162 * @param buffer target buffer for the data
163 * @param size number of bytes
164 * @param address remote source address of the data
165 * @param process_index which process (used for SMPI privatization)
168 virtual const void* read_bytes(void* buffer, std::size_t size,
169 RemotePtr<void> address, int process_index = ProcessIndexAny,
170 ReadOptions options = ReadOptions::none()) const = 0;
172 /** Read a given data structure from the address space */
173 template<class T> inline
174 void read(T *buffer, RemotePtr<T> ptr, int process_index = ProcessIndexAny) const
176 this->read_bytes(buffer, sizeof(T), ptr, process_index);
179 template<class T> inline
180 void read(Remote<T>& buffer, RemotePtr<T> ptr, int process_index = ProcessIndexAny) const
182 this->read_bytes(buffer.getBuffer(), sizeof(T), ptr, process_index);
185 /** Read a given data structure from the address space */
186 template<class T> inline
187 Remote<T> read(RemotePtr<T> ptr, int process_index = ProcessIndexMissing) const
190 this->read_bytes(&res, sizeof(T), ptr, process_index);
194 std::string read_string(RemotePtr<char> address, std::size_t len) const
196 // TODO, use std::vector with .data() in C++17 to avoid useless copies
197 std::vector<char> buffer(len);
199 this->read_bytes(buffer.data(), len, address);
200 return std::string(buffer.data(), buffer.size());