X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/2434cd24de2d531a46c3b7089f490ddce659c566..c59c82ee01d89d9d0607bf526df5449bcf161472:/src/mc/sosp/PageStore.cpp diff --git a/src/mc/sosp/PageStore.cpp b/src/mc/sosp/PageStore.cpp index ce53075221..e2c46f400d 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) 2015-2023. 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. */ @@ -12,53 +12,36 @@ #include "xbt/log.h" #include "xbt/sysdep.h" -#ifdef SG_HAVE_CPP14 -#include "src/include/xxhash.hpp" -#endif +#include "src/3rd-party/xxhash.hpp" #include "src/mc/mc_mmu.hpp" #include "src/mc/sosp/PageStore.hpp" #include // memcpy, memcmp #include -XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_page_snapshot, mc, "Logging specific to mc_page_snapshot"); - -namespace simgrid { -namespace mc { +namespace simgrid::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 = ::mmap(nullptr, size << xbt_pagebits, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, -1, 0); - if (memory == MAP_FAILED) - xbt_die("Could not mmap initial snapshot pages."); + xbt_assert(memory != MAP_FAILED, "Could not mmap initial snapshot pages."); this->top_index_ = 0; this->memory_ = memory; @@ -80,24 +63,23 @@ void PageStore::resize(std::size_t size) // virtual memory address if necessary: #if HAVE_MREMAP new_memory = mremap(this->memory_, old_bytesize, new_bytesize, MREMAP_MAYMOVE); - if (new_memory == MAP_FAILED) - xbt_die("Could not mremap snapshot pages."); + xbt_assert(new_memory != MAP_FAILED, "Could not mremap snapshot pages."); #else if (new_bytesize > old_bytesize) { // Grow: first try to add new space after current map new_memory = mmap((char*)this->memory_ + old_bytesize, new_bytesize - old_bytesize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, -1, 0); - if (new_memory == MAP_FAILED) - xbt_die("Could not mremap snapshot pages."); + xbt_assert(new_memory != MAP_FAILED, "Could not mremap snapshot pages."); // Check if expanding worked - if (new_memory != (char*)this->memory_ + old_bytesize) { + if (new_memory == (char*)this->memory_ + old_bytesize) { + new_memory = this->memory_; + } else { // New memory segment could not be put at the end of this->memory_, - // so cancel this one and try to rellocate everything and copy data + // so cancel this one and try to relocate everything and copy data munmap(new_memory, new_bytesize - old_bytesize); new_memory = mmap(nullptr, new_bytesize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, -1, 0); - if (new_memory == MAP_FAILED) - xbt_die("Could not mremap snapshot pages."); + xbt_assert(new_memory != MAP_FAILED, "Could not mremap snapshot pages."); memcpy(new_memory, this->memory_, old_bytesize); munmap(this->memory_, old_bytesize); } @@ -120,7 +102,6 @@ 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: @@ -128,9 +109,7 @@ 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(); @@ -147,7 +126,7 @@ 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"); @@ -162,7 +141,6 @@ 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; @@ -172,12 +150,11 @@ 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]++; return pageno; } -} // namespace mc -} // namespace simgrid +} // namespace simgrid::mc