X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/ca82f90e6d610b6bb3b038cd9ee48d378cc8a909..39c935d6d5ee86d153f6f7e6a10d723ae7c57f6f:/src/mc/sosp/PageStore.cpp diff --git a/src/mc/sosp/PageStore.cpp b/src/mc/sosp/PageStore.cpp index e11d6532b4..58fe2436c8 100644 --- a/src/mc/sosp/PageStore.cpp +++ b/src/mc/sosp/PageStore.cpp @@ -1,4 +1,4 @@ -/* Copyright (c) 2015-2019. The SimGrid Team. All rights reserved. */ +/* Copyright (c) 2015-2021. 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. */ @@ -12,9 +12,7 @@ #include "xbt/log.h" #include "xbt/sysdep.h" -#ifdef SG_HAVE_CPP14 #include "src/include/xxhash.hpp" -#endif #include "src/mc/mc_mmu.hpp" #include "src/mc/sosp/PageStore.hpp" @@ -26,31 +24,20 @@ namespace mc { /** @brief Compute a hash for the given memory page * - * The page is used before inserting the page in the page store - * in order to find duplicate of this page in the page store. + * The page is used before inserting the page in the page store in order to find duplicate of this page in the page + * store. * * @param data Memory page * @return hash off the page */ static XBT_ALWAYS_INLINE PageStore::hash_type mc_hash_page(const void* data) { -#ifdef SG_HAVE_CPP14 return xxh::xxhash<64>(data, xbt_pagesize); -#else - const std::uint64_t* values = (const uint64_t*)data; - std::size_t n = xbt_pagesize / sizeof(uint64_t); - - // This djb2: - std::uint64_t hash = 5381; - for (std::size_t i = 0; i != n; ++i) - hash = ((hash << 5) + hash) + values[i]; - return hash; -#endif } // ***** snapshot_page_manager -PageStore::PageStore(std::size_t size) : memory_(nullptr), capacity_(size), top_index_(0) +PageStore::PageStore(std::size_t size) : capacity_(size) { // Using mmap in order to be able to expand the region by relocating it somewhere else in the virtual memory space: void* memory = @@ -118,7 +105,6 @@ void PageStore::resize(std::size_t size) std::size_t PageStore::alloc_page() { if (this->free_pages_.empty()) { - // Expand the region: if (this->top_index_ == this->capacity_) // All the pages are allocated, we need add more pages: @@ -126,9 +112,7 @@ std::size_t PageStore::alloc_page() // Use a page from the top: return this->top_index_++; - } else { - // Use a page from free_pages_ (inside of the region): size_t res = this->free_pages_[this->free_pages_.size() - 1]; this->free_pages_.pop_back(); @@ -145,7 +129,7 @@ void PageStore::remove_page(std::size_t pageno) } /** Store a page in memory */ -std::size_t PageStore::store_page(void* page) +std::size_t PageStore::store_page(const void* page) { xbt_assert(top_index_ <= this->capacity_, "top_index is not consistent"); @@ -160,7 +144,6 @@ std::size_t PageStore::store_page(void* page) for (size_t const& pageno : page_set) { const void* snapshot_page = this->get_page(pageno); if (memcmp(page, snapshot_page, xbt_pagesize) == 0) { - // If a page with the same content is already in the page store it's reused and its refcount is incremented. page_counts_[pageno]++; return pageno; @@ -170,7 +153,7 @@ std::size_t PageStore::store_page(void* page) // Otherwise, a new page is allocated in the page store and the content of the page is `memcpy()`-ed to this new page. std::size_t pageno = alloc_page(); xbt_assert(this->page_counts_[pageno] == 0, "Allocated page is already used"); - void* snapshot_page = (void*)this->get_page(pageno); + void* snapshot_page = this->get_page(pageno); memcpy(snapshot_page, page, xbt_pagesize); page_set.insert(pageno); page_counts_[pageno]++;