X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/347996b4a10c4e8579080692afa60e0afb88b60a..f754aabeea56ded8bc234a5ffc7dda03428d6b88:/src/mc/AddressSpace.hpp

diff --git a/src/mc/AddressSpace.hpp b/src/mc/AddressSpace.hpp
index 7c75d44bcd..18969aaa0a 100644
--- a/src/mc/AddressSpace.hpp
+++ b/src/mc/AddressSpace.hpp
@@ -7,115 +7,18 @@
 #ifndef SIMGRID_MC_ADDRESS_SPACE_H
 #define SIMGRID_MC_ADDRESS_SPACE_H
 
+#include <cassert>
 #include <cstddef>
 #include <cstdint>
+#include <cstring>
 #include <type_traits>
 
-#include <xbt/misc.h>
-
 #include "src/mc/mc_forward.hpp"
+#include "src/mc/RemotePtr.hpp"
 
 namespace simgrid {
 namespace mc {
 
-/** Pointer to a remote address-space (process, snapshot)
- *
- *  With this we can clearly identify the expected type of an address in the
- *  remote process while avoiding to use native local pointers.
- *
- *  Some operators (+/-) assume use the size of the underlying element. This
- *  only works if the target applications is using the same target: it won't
- *  work for example, when inspecting a 32 bit application from a 64 bit
- *  model-checker.
- */
-template<class T> class remote_ptr {
-  std::uint64_t address_;
-public:
-  remote_ptr() : address_(0) {}
-  remote_ptr(std::uint64_t address) : address_(address) {}
-  remote_ptr(T* address) : address_((std::uintptr_t)address) {}
-  std::uint64_t address() const { return address_; }
-
-  operator bool() const
-  {
-    return address_;
-  }
-  bool operator!() const
-  {
-    return !address_;
-  }
-  operator remote_ptr<void>() const
-  {
-    return remote_ptr<void>(address_);
-  }
-  remote_ptr<T> operator+(std::uint64_t n) const
-  {
-    return remote_ptr<T>(address_ + n * sizeof(T));
-  }
-  remote_ptr<T> operator-(std::uint64_t n) const
-  {
-    return remote_ptr<T>(address_ - n * sizeof(T));
-  }
-  remote_ptr<T>& operator+=(std::uint64_t n)
-  {
-    address_ += n * sizeof(T);
-    return *this;
-  }
-  remote_ptr<T>& operator-=(std::uint64_t n)
-  {
-    address_ -= n * sizeof(T);
-    return *this;
-  }
-};
-
-template<class X, class Y>
-bool operator<(remote_ptr<X> const& x, remote_ptr<Y> const& y)
-{
-  return x.address() < y.address();
-}
-
-template<class X, class Y>
-bool operator>(remote_ptr<X> const& x, remote_ptr<Y> const& y)
-{
-  return x.address() > y.address();
-}
-
-template<class X, class Y>
-bool operator>=(remote_ptr<X> const& x, remote_ptr<Y> const& y)
-{
-  return x.address() >= y.address();
-}
-
-template<class X, class Y>
-bool operator<=(remote_ptr<X> const& x, remote_ptr<Y> const& y)
-{
-  return x.address() <= y.address();
-}
-
-template<class X, class Y>
-bool operator==(remote_ptr<X> const& x, remote_ptr<Y> const& y)
-{
-  return x.address() == y.address();
-}
-
-template<class X, class Y>
-bool operator!=(remote_ptr<X> const& x, remote_ptr<Y> const& y)
-{
-  return x.address() != y.address();
-}
-
-template<class T> inline
-remote_ptr<T> remote(T *p)
-{
-  return remote_ptr<T>(p);
-}
-
-template<class T=void> inline
-remote_ptr<T> remote(uint64_t p)
-{
-  return remote_ptr<T>(p);
-}
-
 /** Process index used when no process is available
  *
  *  The expected behaviour is that if a process index is needed it will fail.
@@ -189,6 +92,49 @@ public:
   static constexpr ReadOptions lazy() { return ReadOptions(1); }
 };
 
+/** A value from another process
+ *
+ *  This represents a value from another process:
+ *
+ *  * constructor/destructor are disabled;
+ *
+ *  * raw memory copy (std::memcpy) is used to copy Remote<T>;
+ *
+ *  * raw memory comparison is used to compare them;
+ *
+ *  * when T is a trivial type, Remote is convertible to a T.
+ *
+ *  We currently only handle the case where the type has the same layout
+ *  in the current process and in the target process: we don't handle
+ *  cross-architecture (such as 32-bit/64-bit access).
+ */
+template<class T>
+class Remote {
+private:
+  // If we use a union, it won't work with abstract types:
+  char buffer[sizeof(T)];
+public:
+  // HACK, some code currently cast this to T* which is **not** legal.
+  void*       data() { return buffer; }
+  const void* data() const { return buffer; }
+  constexpr std::size_t size() const { return sizeof(T); }
+  operator T() const {
+    static_assert(std::is_trivial<T>::value, "Cannot convert non trivial type");
+    T res;
+    std::memcpy(&res, buffer, sizeof(T));
+    return res;
+  }
+  Remote() {}
+  Remote(T const& x)
+  {
+    std::memcpy(&x, buffer, sizeof(T));
+  }
+  Remote& operator=(T const& x)
+  {
+    std::memcpy(&x, buffer, sizeof(T));
+  }
+};
+
 /** A given state of a given process (abstract base class)
  *
  *  Currently, this might either be:
@@ -215,23 +161,29 @@ public:
    *  @param options
    */
   virtual const void* read_bytes(void* buffer, std::size_t size,
-    remote_ptr<void> address, int process_index = ProcessIndexAny,
+    RemotePtr<void> address, int process_index = ProcessIndexAny,
     ReadOptions options = ReadOptions::none()) const = 0;
 
   /** Read a given data structure from the address space */
   template<class T> inline
-  void read(T *buffer, remote_ptr<T> ptr, int process_index = ProcessIndexAny)
+  void read(T *buffer, RemotePtr<T> ptr, int process_index = ProcessIndexAny)
   {
     this->read_bytes(buffer, sizeof(T), ptr, process_index);
   }
 
+  template<class T> inline
+  void read(Remote<T>& buffer, RemotePtr<T> ptr, int process_index = ProcessIndexAny)
+  {
+    this->read_bytes(buffer.data(), sizeof(T), ptr, process_index);
+  }
+
   /** Read a given data structure from the address space */
   template<class T> inline
-  T read(remote_ptr<T> ptr, int process_index = ProcessIndexMissing)
+  Remote<T> read(RemotePtr<T> ptr, int process_index = ProcessIndexMissing)
   {
-    static_assert(std::is_trivial<T>::value, "Cannot read a non-trivial type");
-    T res;
-    return *(T*)this->read_bytes(&res, sizeof(T), ptr, process_index);
+    Remote<T> res;
+    this->read_bytes(&res, sizeof(T), ptr, process_index);
+    return res;
   }
 };