genode/repos/base-hw/src/core/cpu_thread_allocator.h
Norman Feske 6b289a1423 base/core: use references instead of pointers
This patch replaces the former prominent use of pointers by references
wherever feasible. This has the following benefits:

* The contract between caller and callee becomes more obvious. When
  passing a reference, the contract says that the argument cannot be
  a null pointer. The caller is responsible to ensure that. Therefore,
  the use of reference eliminates the need to add defensive null-pointer
  checks at the callee site, which sometimes merely exist to be on the
  safe side. The bottom line is that the code becomes easier to follow.

* Reference members must be initialized via an object initializer,
  which promotes a programming style that avoids intermediate object-
  construction states. Within core, there are still a few pointers
  as member variables left though. E.g., caused by the late association
  of 'Platform_thread' objects with their 'Platform_pd' objects.

* If no pointers are present as member variables, we don't need to
  manually provide declarations of a private copy constructor and
  an assignment operator to avoid -Weffc++ errors "class ... has
  pointer data members [-Werror=effc++]".

This patch also changes a few system bindings on NOVA and Fiasco.OC,
e.g., the return value of the global 'cap_map' accessor has become a
reference. Hence, the patch touches a few places outside of core.

Fixes #3135
2019-02-12 10:33:13 +01:00

75 lines
1.7 KiB
C++

/*
* \brief Platform specific parts of the core CPU session
* \author Martin Stein
* \date 2012-03-21
*/
/*
* Copyright (C) 2012-2017 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU Affero General Public License version 3.
*/
#ifndef _CORE__CPU_THREAD_ALLOCATOR_H_
#define _CORE__CPU_THREAD_ALLOCATOR_H_
/* Genode includes */
#include <base/log.h>
#include <base/allocator.h>
/* core includes */
#include <assertion.h>
namespace Genode
{
/**
* Thread allocator for cores CPU service
*
* Normally one would use a SLAB for threads because usually they
* are tiny objects, but in 'base-hw' they contain the whole kernel
* object in addition. Thus we use the given allocator directly.
*/
class Cpu_thread_allocator : public Allocator
{
private:
/*
* Noncopyable
*/
Cpu_thread_allocator(Cpu_thread_allocator const &);
Cpu_thread_allocator &operator = (Cpu_thread_allocator const &);
Allocator &_alloc;
public:
/**
* Constructor
*
* \param alloc allocator backend
*/
Cpu_thread_allocator(Allocator &alloc) : _alloc(alloc) { }
/*************************
** Allocator interface **
*************************/
bool alloc(size_t size, void **out_addr) override {
return _alloc.alloc(size, out_addr); }
void free(void *addr, size_t size) override {
_alloc.free(addr, size); }
size_t consumed() const override { ASSERT_NEVER_CALLED; }
size_t overhead(size_t) const override { ASSERT_NEVER_CALLED; }
bool need_size_for_free() const override {
return _alloc.need_size_for_free(); }
};
}
#endif /* _CORE__CPU_THREAD_ALLOCATOR_H_ */