#ifndef XBT_FUNCTIONAL_HPP
#define XBT_FUNCTIONAL_HPP
+#include <cstddef>
#include <cstdlib>
+#include <cstring>
+#include <array>
#include <exception>
#include <functional>
-#include <future>
+#include <memory>
+#include <string>
+#include <tuple>
+#include <type_traits>
#include <utility>
+#include <vector>
#include <xbt/sysdep.h>
#include <xbt/utility.hpp>
namespace simgrid {
namespace xbt {
-class args {
+template<class F>
+class MainFunction {
private:
- int argc_ = 0;
- char** argv_ = nullptr;
+ F code_;
+ std::shared_ptr<const std::vector<std::string>> args_;
public:
-
- // Main constructors
- args() {}
-
- void assign(int argc, const char*const* argv)
- {
- clear();
- char** new_argv = xbt_new(char*,argc + 1);
- for (int i = 0; i < argc; i++)
- new_argv[i] = xbt_strdup(argv[i]);
- new_argv[argc] = nullptr;
- this->argc_ = argc;
- this->argv_ = new_argv;
- }
- args(int argc, const char*const* argv)
- {
- this->assign(argc, argv);
- }
-
- char** to_argv() const
+ MainFunction(F code, std::vector<std::string> args) :
+ code_(std::move(code)),
+ args_(std::make_shared<const std::vector<std::string>>(std::move(args)))
+ {}
+ void operator()() const
{
- const int argc = argc_;
- char** argv = xbt_new(char*, argc + 1);
- for (int i=0; i< argc; i++)
- argv[i] = xbt_strdup(argv_[i]);
+ const int argc = args_->size();
+ std::vector<std::string> args = *args_;
+ std::unique_ptr<char*[]> argv(new char*[argc + 1]);
+ for (int i = 0; i != argc; ++i)
+ argv[i] = args[i].empty() ? const_cast<char*>(""): &args[i].front();
argv[argc] = nullptr;
- return argv;
- }
-
- // Free
- void clear()
- {
- for (int i = 0; i < this->argc_; i++)
- std::free(this->argv_[i]);
- std::free(this->argv_);
- this->argc_ = 0;
- this->argv_ = nullptr;
- }
- ~args() { clear(); }
-
- // Copy
- args(args const& that)
- {
- this->assign(that.argc(), that.argv());
- }
- args& operator=(args const& that)
- {
- this->assign(that.argc(), that.argv());
- return *this;
- }
-
- // Move:
- args(args&& that) : argc_(that.argc_), argv_(that.argv_)
- {
- that.argc_ = 0;
- that.argv_ = nullptr;
- }
- args& operator=(args&& that)
- {
- this->argc_ = that.argc_;
- this->argv_ = that.argv_;
- that.argc_ = 0;
- that.argv_ = nullptr;
- return *this;
+ code_(argc, argv.get());
}
-
- int argc() const { return argc_; }
- char** argv() { return argv_; }
- const char*const* argv() const { return argv_; }
- char* operator[](std::size_t i) { return argv_[i]; }
};
template<class F> inline
-std::function<void()> wrapMain(F code, std::shared_ptr<simgrid::xbt::args> args)
-{
- return [=]() {
- code(args->argc(), args->argv());
- };
-}
-
-template<class F> inline
-std::function<void()> wrapMain(F code, simgrid::xbt::args args)
+std::function<void()> wrapMain(F code, std::vector<std::string> args)
{
- return wrapMain(std::move(code),
- std::unique_ptr<simgrid::xbt::args>(new simgrid::xbt::args(std::move(args))));
+ return MainFunction<F>(std::move(code), std::move(args));
}
template<class F> inline
-std::function<void()> wrapMain(F code, int argc, const char*const* argv)
+std::function<void()> wrapMain(F code, int argc, const char*const argv[])
{
- return wrapMain(std::move(code), args(argc, argv));
+ std::vector<std::string> args(argv, argv + argc);
+ return MainFunction<F>(std::move(code), std::move(args));
}
namespace bits {
>());
}
+template<class T> class Task;
+
+/** Type-erased run-once task
+ *
+ * * Like std::function but callable only once.
+ * However, it works with move-only types.
+ *
+ * * Like std::packaged_task<> but without the shared state.
+ */
+template<class R, class... Args>
+class Task<R(Args...)> {
+private:
+
+ // Placeholder for some class type:
+ struct whatever {};
+
+ // Union used for storage:
+#if 0
+ typedef typename std::aligned_union<0,
+ void*,
+ std::pair<void(*)(),void*>,
+ std::pair<void(whatever::*)(), whatever*>
+ >::type TaskUnion;
+#else
+ union TaskUnion {
+ void* ptr;
+ std::pair<void(*)(),void*> funcptr;
+ std::pair<void(whatever::*)(), whatever*> memberptr;
+ char any1[sizeof(std::pair<void(*)(),void*>)];
+ char any2[sizeof(std::pair<void(whatever::*)(), whatever*>)];
+ TaskUnion() {}
+ ~TaskUnion() {}
+ };
+#endif
+
+ // Is F suitable for small buffer optimization?
+ template<class F>
+ static constexpr bool canSBO()
+ {
+ return sizeof(F) <= sizeof(TaskUnion) &&
+ alignof(F) <= alignof(TaskUnion);
+ }
+
+ static_assert(canSBO<std::reference_wrapper<whatever>>(),
+ "SBO not working for reference_wrapper");
+
+ // Call (and possibly destroy) the function:
+ typedef R (*call_function)(TaskUnion&, Args...);
+ // Destroy the function (of needed):
+ typedef void (*destroy_function)(TaskUnion&);
+ // Move the function (otherwise memcpy):
+ typedef void (*move_function)(TaskUnion& dest, TaskUnion& src);
+
+ // Vtable of functions for manipulating whatever is in the TaskUnion:
+ struct TaskVtable {
+ call_function call;
+ destroy_function destroy;
+ move_function move;
+ };
+
+ TaskUnion buffer_;
+ const TaskVtable* vtable_ = nullptr;
+
+ void clear()
+ {
+ if (vtable_ && vtable_->destroy)
+ vtable_->destroy(buffer_);
+ }
+
+public:
+
+ Task() {}
+ Task(std::nullptr_t) {}
+ ~Task()
+ {
+ this->clear();
+ }
+
+ Task(Task const&) = delete;
+
+ Task(Task&& that)
+ {
+ if (that.vtable_ && that.vtable_->move)
+ that.vtable_->move(buffer_, that.buffer_);
+ else
+ std::memcpy(&buffer_, &that.buffer_, sizeof(buffer_));
+ vtable_ = that.vtable_;
+ that.vtable_ = nullptr;
+ }
+ Task& operator=(Task that)
+ {
+ this->clear();
+ if (that.vtable_ && that.vtable_->move)
+ that.vtable_->move(buffer_, that.buffer_);
+ else
+ std::memcpy(&buffer_, &that.buffer_, sizeof(buffer_));
+ vtable_ = that.vtable_;
+ that.vtable_ = nullptr;
+ return *this;
+ }
+
+private:
+
+ template<class F>
+ typename std::enable_if<canSBO<F>()>::type
+ init(F code)
+ {
+ const static TaskVtable vtable {
+ // Call:
+ [](TaskUnion& buffer, Args... args) -> R {
+ F* src = reinterpret_cast<F*>(&buffer);
+ F code = std::move(*src);
+ src->~F();
+ code(std::forward<Args>(args)...);
+ },
+ // Destroy:
+ std::is_trivially_destructible<F>::value ?
+ static_cast<destroy_function>(nullptr) :
+ [](TaskUnion& buffer) {
+ F* code = reinterpret_cast<F*>(&buffer);
+ code->~F();
+ },
+ // Move:
+ [](TaskUnion& dst, TaskUnion& src) {
+ F* src_code = reinterpret_cast<F*>(&src);
+ F* dst_code = reinterpret_cast<F*>(&dst);
+ new(dst_code) F(std::move(*src_code));
+ src_code->~F();
+ }
+ };
+ new(&buffer_) F(std::move(code));
+ vtable_ = &vtable;
+ }
+
+ template<class F>
+ typename std::enable_if<!canSBO<F>()>::type
+ init(F code)
+ {
+ const static TaskVtable vtable {
+ // Call:
+ [](TaskUnion& buffer, Args... args) -> R {
+ // Delete F when we go out of scope:
+ std::unique_ptr<F> code(*reinterpret_cast<F**>(&buffer));
+ return (*code)(std::forward<Args>(args)...);
+ },
+ // Destroy:
+ [](TaskUnion& buffer) {
+ F* code = *reinterpret_cast<F**>(&buffer);
+ delete code;
+ },
+ // Move:
+ nullptr
+ };
+ *reinterpret_cast<F**>(&buffer_) = new F(std::move(code));
+ vtable_ = &vtable;
+ }
+
+public:
+
+ template<class F>
+ Task(F code)
+ {
+ this->init(std::move(code));
+ }
+
+ operator bool() const { return vtable_ != nullptr; }
+ bool operator!() const { return vtable_ == nullptr; }
+
+ R operator()(Args... args)
+ {
+ if (vtable_ == nullptr)
+ throw std::bad_function_call();
+ const TaskVtable* vtable = vtable_;
+ vtable_ = nullptr;
+ return vtable->call(buffer_, std::forward<Args>(args)...);
+ }
+};
+
+template<class F, class... Args>
+class TaskImpl {
+private:
+ F code_;
+ std::tuple<Args...> args_;
+ typedef decltype(simgrid::xbt::apply(std::move(code_), std::move(args_))) result_type;
+public:
+ TaskImpl(F code, std::tuple<Args...> args) :
+ code_(std::move(code)),
+ args_(std::move(args))
+ {}
+ result_type operator()()
+ {
+ return simgrid::xbt::apply(std::move(code_), std::move(args_));
+ }
+};
+
+template<class F, class... Args>
+auto makeTask(F code, Args... args)
+-> Task< decltype(code(std::move(args)...))() >
+{
+ TaskImpl<F, Args...> task(std::move(code), std::make_tuple(std::move(args)...));
+ return std::move(task);
+}
+
}
}
