+++ /dev/null
-/* Copyright (c) 2007-2023. 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. */
-
-#include "src/mc/sosp/Region.hpp"
-#include "src/mc/mc_config.hpp"
-#include "src/mc/mc_forward.hpp"
-#include "src/mc/sosp/RemoteProcessMemory.hpp"
-
-#include <cstdlib>
-#include <sys/mman.h>
-#ifdef __FreeBSD__
-#define MAP_POPULATE MAP_PREFAULT_READ
-#endif
-
-namespace simgrid::mc {
-
-Region::Region(PageStore& store, const RemoteProcessMemory& memory, RegionType region_type, void* start_addr,
- size_t size)
- : region_type_(region_type), start_addr_(start_addr), size_(size)
-{
- xbt_assert((((uintptr_t)start_addr) & (xbt_pagesize - 1)) == 0, "Start address not at the beginning of a page");
-
- chunks_ = ChunkedData(store, memory, RemotePtr<void>(start_addr), mmu::chunk_count(size));
-}
-
-/** @brief Restore a region from a snapshot
- *
- * @param region Target region
- */
-void Region::restore(const RemoteProcessMemory& memory) const
-{
- xbt_assert(((start().address()) & (xbt_pagesize - 1)) == 0, "Not at the beginning of a page");
- xbt_assert(simgrid::mc::mmu::chunk_count(size()) == get_chunks().page_count());
-
- for (size_t i = 0; i != get_chunks().page_count(); ++i) {
- auto* target_page = (void*)simgrid::mc::mmu::join(i, (std::uintptr_t)(void*)start().address());
- const void* source_page = get_chunks().page(i);
- memory.write_bytes(source_page, xbt_pagesize, remote(target_page));
- }
-}
-
-static XBT_ALWAYS_INLINE void* mc_translate_address_region(uintptr_t addr, const simgrid::mc::Region* region)
-{
- auto [pageno, offset] = simgrid::mc::mmu::split(addr - region->start().address());
- void* snapshot_page = region->get_chunks().page(pageno);
- return (char*)snapshot_page + offset;
-}
-
-void* Region::read(void* target, const void* addr, std::size_t size) const
-{
- xbt_assert(contain(simgrid::mc::remote(addr)), "Trying to read out of the region boundary.");
-
- // Last byte of the region:
- const void* end_addr = (const char*)addr + size - 1;
- if (simgrid::mc::mmu::same_chunk((std::uintptr_t)addr, (std::uintptr_t)end_addr)) {
- // The memory is contained in a single page:
- return mc_translate_address_region((uintptr_t)addr, this);
- }
- // Otherwise, the memory spans several pages. Let's copy it all into the provided buffer
- xbt_assert(target != nullptr, "Missing destination buffer for fragmented memory access");
-
- // TODO, we assume the chunks are aligned to natural chunk boundaries.
- // We should remove this assumption.
-
- // Page of the last byte of the memory area:
- size_t page_end = simgrid::mc::mmu::split((std::uintptr_t)end_addr).first;
-
- void* dest = target; // iterator in the buffer to where we should copy next
-
- // Read each page:
- while (simgrid::mc::mmu::split((std::uintptr_t)addr).first != page_end) {
- const void* snapshot_addr = mc_translate_address_region((uintptr_t)addr, this);
- auto* next_page = (void*)simgrid::mc::mmu::join(simgrid::mc::mmu::split((std::uintptr_t)addr).first + 1, 0);
- size_t readable = (char*)next_page - (const char*)addr;
- memcpy(dest, snapshot_addr, readable);
- addr = (const char*)addr + readable;
- dest = (char*)dest + readable;
- size -= readable;
- }
-
- // Read the end:
- const void* snapshot_addr = mc_translate_address_region((uintptr_t)addr, this);
- memcpy(dest, snapshot_addr, size);
-
- return target;
-}
-
-} // namespace simgrid::mc
-
-/** Compare memory between snapshots (with known regions)
- *
- * @param addr1 Address in the first snapshot
- * @param region1 Region of the address in the first snapshot
- * @param addr2 Address in the second snapshot
- * @param region2 Region of the address in the second snapshot
- * @return same semantic as memcmp
- */
-int MC_snapshot_region_memcmp(const void* addr1, const simgrid::mc::Region* region1, const void* addr2,
- const simgrid::mc::Region* region2, size_t size)
-{
- // Using alloca() for large allocations may trigger stack overflow:
- // use malloc if the buffer is too big.
- bool stack_alloc = size < 64;
- void* buffer1a = stack_alloc ? alloca(size) : ::operator new(size);
- void* buffer2a = stack_alloc ? alloca(size) : ::operator new(size);
- const void* buffer1 = region1->read(buffer1a, addr1, size);
- const void* buffer2 = region2->read(buffer2a, addr2, size);
- int res;
- if (buffer1 == buffer2)
- res = 0;
- else
- res = memcmp(buffer1, buffer2, size);
- if (not stack_alloc) {
- ::operator delete(buffer1a);
- ::operator delete(buffer2a);
- }
- return res;
-}
