-/* Copyright (c) 2015-2019. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2015-2022. The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
#ifndef SIMGRID_MC_PAGESTORE_HPP
#define SIMGRID_MC_PAGESTORE_HPP
-#include <cstdint>
-#include <vector>
+#include "src/mc/mc_forward.hpp"
+#include "src/mc/mc_mmu.hpp"
#include <unordered_map>
#include <unordered_set>
-
-#include "src/mc/mc_forward.hpp"
-#include "src/mc/mc_mmu.hpp"
+#include <vector>
#ifndef XBT_ALWAYS_INLINE
#define XBT_ALWAYS_INLINE inline __attribute__((always_inline))
/** @brief Storage for snapshot memory pages
*
* The first (lower) layer of the per-page snapshot mechanism is a page store:
- * its responsibility is to store immutable sharable reference-counted memory
+ * its responsibility is to store immutable shareable reference-counted memory
* pages independently of the snapshotting logic. Snapshot management and
* representation is handled to an higher layer. READMORE
*
*
* We want to keep this memory region aligned on the memory pages (so
* that we might be able to create non-linear memory mappings on those
- * pages in the future) and be able to expand it without coyping the
+ * pages in the future) and be able to expand it without copying the
* data (there will be a lot of pages here): we will be able to
* efficiently expand the memory mapping using `mremap()`, moving it
* to another virtual address if necessary.
*/
class PageStore {
public: // Types
- typedef std::uint64_t hash_type;
+ using hash_type = std::uint64_t;
private:
// Types
// We are using a cheap hash to index a page.
// We should expect collision and we need to associate multiple page indices
// to the same hash.
- typedef std::unordered_set<std::size_t> page_set_type;
- typedef std::unordered_map<hash_type, page_set_type> pages_map_type;
+ using page_set_type = std::unordered_set<std::size_t>;
+ using pages_map_type = std::unordered_map<hash_type, page_set_type>;
// Fields:
/** First page */
* store.
*
* This will be the case if a page if soft clean: we know that is has not
- * changed since the previous cnapshot/restoration and we can avoid
+ * changed since the previous snapshot/restoration and we can avoid
* hashing the page, comparing byte-per-byte to candidates.
* */
void ref_page(size_t pageno);
/** @brief Store a page in the page store */
- std::size_t store_page(void* page);
+ std::size_t store_page(const void* page);
/** @brief Get a page from its page number
*
* @param pageno Number of the memory page in the store
* @return Start of the page
*/
- const void* get_page(std::size_t pageno) const;
+ void* get_page(std::size_t pageno) const;
// Debug/test methods
/** @brief Get the number of references for a page */
- std::size_t get_ref(std::size_t pageno);
+ std::size_t get_ref(std::size_t pageno) const;
/** @brief Get the number of used pages */
- std::size_t size();
+ std::size_t size() const;
/** @brief Get the capacity of the page store
*
* The capacity is expanded by a system call (mremap).
* */
- std::size_t capacity();
+ std::size_t capacity() const;
};
XBT_ALWAYS_INLINE void PageStore::unref_page(std::size_t pageno)
++this->page_counts_[pageno];
}
-XBT_ALWAYS_INLINE const void* PageStore::get_page(std::size_t pageno) const
+XBT_ALWAYS_INLINE void* PageStore::get_page(std::size_t pageno) const
{
return (void*)simgrid::mc::mmu::join(pageno, (std::uintptr_t)this->memory_);
}
-XBT_ALWAYS_INLINE std::size_t PageStore::get_ref(std::size_t pageno)
+XBT_ALWAYS_INLINE std::size_t PageStore::get_ref(std::size_t pageno) const
{
return this->page_counts_[pageno];
}
-XBT_ALWAYS_INLINE std::size_t PageStore::size()
+XBT_ALWAYS_INLINE std::size_t PageStore::size() const
{
return this->top_index_ - this->free_pages_.size();
}
-XBT_ALWAYS_INLINE std::size_t PageStore::capacity()
+XBT_ALWAYS_INLINE std::size_t PageStore::capacity() const
{
return this->capacity_;
}
