#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 <string>
+#include <vector>
#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.
+ * The expected behavior is that if a process index is needed it will fail.
* */
const int ProcessIndexMissing = -1;
static constexpr ReadOptions lazy() { return ReadOptions(1); }
};
+/** HACK, 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>
+union Remote {
+private:
+ T buffer;
+public:
+ Remote() {}
+ ~Remote() {}
+ Remote(Remote const& that)
+ {
+ std::memcpy(&buffer, &that.buffer, sizeof(buffer));
+ }
+ Remote& operator=(Remote const& that)
+ {
+ std::memcpy(&buffer, &that.buffer, sizeof(buffer));
+ return *this;
+ }
+ T* getBuffer() { return &buffer; }
+ const T* getBuffer() const { return &buffer; }
+ std::size_t getBufferSize() const { return sizeof(T); }
+ operator T() const {
+ static_assert(std::is_trivial<T>::value, "Cannot convert non trivial type");
+ return buffer;
+ }
+ void clear()
+ {
+ std::memset(static_cast<void*>(&buffer), 0, sizeof(T));
+ }
+};
+
/** A given state of a given process (abstract base class)
*
* Currently, this might either be:
* @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) const
{
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) const
+ {
+ this->read_bytes(buffer.getBuffer(), 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) const
{
- 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;
}
+
+ std::string read_string(RemotePtr<char> address, std::size_t len) const
+ {
+ // TODO, use std::vector with .data() in C++17 to avoid useless copies
+ std::vector<char> buffer(len);
+ buffer[len] = '\0';
+ this->read_bytes(buffer.data(), len, address);
+ return std::string(buffer.data(), buffer.size());
+ }
+
};
}
