#include <cstddef> /* std::size_t */
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_snapshot, mc, "Taking and restoring snapshots");
-
-/** @brief Read memory from a snapshot region broken across fragmented pages
- *
- * @param addr Process (non-snapshot) address of the data
- * @param region Snapshot memory region where the data is located
- * @param target Buffer to store the value
- * @param size Size of the data to read in bytes
- * @return Pointer where the data is located (target buffer of original location)
- */
-const void* MC_region_read_fragmented(simgrid::mc::Region* region, void* target, const void* addr, size_t size)
-{
- // Last byte of the memory area:
- void* end = (char*)addr + size - 1;
-
- // 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).first;
-
- void* dest = target;
-
- if (dest == nullptr)
- xbt_die("Missing destination buffer for fragmented memory access");
-
- // Read each page:
- while (simgrid::mc::mmu::split((std::uintptr_t)addr).first != page_end) {
- void* snapshot_addr = mc_translate_address_region((uintptr_t)addr, region);
- void* next_page = (void*)simgrid::mc::mmu::join(simgrid::mc::mmu::split((std::uintptr_t)addr).first + 1, 0);
- size_t readable = (char*)next_page - (char*)addr;
- memcpy(dest, snapshot_addr, readable);
- addr = (char*)addr + readable;
- dest = (char*)dest + readable;
- size -= readable;
- }
-
- // Read the end:
- void* snapshot_addr = mc_translate_address_region((uintptr_t)addr, region);
- memcpy(dest, snapshot_addr, size);
-
- return target;
-}
-
-/** 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, simgrid::mc::Region* region1, const void* addr2,
- 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 = MC_region_read(region1, buffer1a, addr1, size);
- const void* buffer2 = MC_region_read(region2, 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;
-}
-
namespace simgrid {
namespace mc {
/************************************* Take Snapshot ************************************/
{
Region* region = this->get_region((void*)address.address());
if (region) {
- const void* res = MC_region_read(region, buffer, (void*)address.address(), size);
+ const void* res = region->read(buffer, (void*)address.address(), size);
if (buffer == res || options & ReadOptions::lazy())
return res;
else {
