//===-- Memory.cpp ----------------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lldb/Target/Memory.h"
// C Includes
#include <inttypes.h>
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Core/RangeMap.h"
#include "lldb/Core/State.h"
#include "lldb/Target/Process.h"
#include "lldb/Utility/DataBufferHeap.h"
#include "lldb/Utility/Log.h"
using namespace lldb;
using namespace lldb_private;
//----------------------------------------------------------------------
// MemoryCache constructor
//----------------------------------------------------------------------
MemoryCache::MemoryCache(Process &process)
: m_mutex(), m_L1_cache(), m_L2_cache(), m_invalid_ranges(),
m_process(process),
m_L2_cache_line_byte_size(process.GetMemoryCacheLineSize()) {}
//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
MemoryCache::~MemoryCache() {}
void MemoryCache::Clear(bool clear_invalid_ranges) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
m_L1_cache.clear();
m_L2_cache.clear();
if (clear_invalid_ranges)
m_invalid_ranges.Clear();
m_L2_cache_line_byte_size = m_process.GetMemoryCacheLineSize();
}
void MemoryCache::AddL1CacheData(lldb::addr_t addr, const void *src,
size_t src_len) {
AddL1CacheData(
addr, DataBufferSP(new DataBufferHeap(DataBufferHeap(src, src_len))));
}
void MemoryCache::AddL1CacheData(lldb::addr_t addr,
const DataBufferSP &data_buffer_sp) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
m_L1_cache[addr] = data_buffer_sp;
}
void MemoryCache::Flush(addr_t addr, size_t size) {
if (size == 0)
return;
std::lock_guard<std::recursive_mutex> guard(m_mutex);
// Erase any blocks from the L1 cache that intersect with the flush range
if (!m_L1_cache.empty()) {
AddrRange flush_range(addr, size);
BlockMap::iterator pos = m_L1_cache.upper_bound(addr);
if (pos != m_L1_cache.begin()) {
--pos;
}
while (pos != m_L1_cache.end()) {
AddrRange chunk_range(pos->first, pos->second->GetByteSize());
if (!chunk_range.DoesIntersect(flush_range))
break;
pos = m_L1_cache.erase(pos);
}
}
if (!m_L2_cache.empty()) {
const uint32_t cache_line_byte_size = m_L2_cache_line_byte_size;
const addr_t end_addr = (addr + size - 1);
const addr_t first_cache_line_addr = addr - (addr % cache_line_byte_size);
const addr_t last_cache_line_addr =
end_addr - (end_addr % cache_line_byte_size);
// Watch for overflow where size will cause us to go off the end of the
// 64 bit address space
uint32_t num_cache_lines;
if (last_cache_line_addr >= first_cache_line_addr)
num_cache_lines = ((last_cache_line_addr - first_cache_line_addr) /
cache_line_byte_size) +
1;
else
num_cache_lines =
(UINT64_MAX - first_cache_line_addr + 1) / cache_line_byte_size;
uint32_t cache_idx = 0;
for (addr_t curr_addr = first_cache_line_addr; cache_idx < num_cache_lines;
curr_addr += cache_line_byte_size, ++cache_idx) {
BlockMap::iterator pos = m_L2_cache.find(curr_addr);
if (pos != m_L2_cache.end())
m_L2_cache.erase(pos);
}
}
}
void MemoryCache::AddInvalidRange(lldb::addr_t base_addr,
lldb::addr_t byte_size) {
if (byte_size > 0) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
InvalidRanges::Entry range(base_addr, byte_size);
m_invalid_ranges.Append(range);
m_invalid_ranges.Sort();
}
}
bool MemoryCache::RemoveInvalidRange(lldb::addr_t base_addr,
lldb::addr_t byte_size) {
if (byte_size > 0) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
const uint32_t idx = m_invalid_ranges.FindEntryIndexThatContains(base_addr);
if (idx != UINT32_MAX) {
const InvalidRanges::Entry *entry = m_invalid_ranges.GetEntryAtIndex(idx);
if (entry->GetRangeBase() == base_addr &&
entry->GetByteSize() == byte_size)
return m_invalid_ranges.RemoveEntrtAtIndex(idx);
}
}
return false;
}
size_t MemoryCache::Read(addr_t addr, void *dst, size_t dst_len, Error &error) {
size_t bytes_left = dst_len;
// Check the L1 cache for a range that contain the entire memory read.
// If we find a range in the L1 cache that does, we use it. Else we fall
// back to reading memory in m_L2_cache_line_byte_size byte sized chunks.
// The L1 cache contains chunks of memory that are not required to be
// m_L2_cache_line_byte_size bytes in size, so we don't try anything
// tricky when reading from them (no partial reads from the L1 cache).
std::lock_guard<std::recursive_mutex> guard(m_mutex);
if (!m_L1_cache.empty()) {
AddrRange read_range(addr, dst_len);
BlockMap::iterator pos = m_L1_cache.upper_bound(addr);
if (pos != m_L1_cache.begin()) {
--pos;
}
AddrRange chunk_range(pos->first, pos->second->GetByteSize());
if (chunk_range.Contains(read_range)) {
memcpy(dst, pos->second->GetBytes() + addr - chunk_range.GetRangeBase(),
dst_len);
return dst_len;
}
}
// If this memory read request is larger than the cache line size, then
// we (1) try to read as much of it at once as possible, and (2) don't
// add the data to the memory cache. We don't want to split a big read
// up into more separate reads than necessary, and with a large memory read
// request, it is unlikely that the caller function will ask for the next
// 4 bytes after the large memory read - so there's little benefit to saving
// it in the cache.
if (dst && dst_len > m_L2_cache_line_byte_size) {
size_t bytes_read =
m_process.ReadMemoryFromInferior(addr, dst, dst_len, error);
// Add this non block sized range to the L1 cache if we actually read
// anything
if (bytes_read > 0)
AddL1CacheData(addr, dst, bytes_read);
return bytes_read;
}
if (dst && bytes_left > 0) {
const uint32_t cache_line_byte_size = m_L2_cache_line_byte_size;
uint8_t *dst_buf = (uint8_t *)dst;
addr_t curr_addr = addr - (addr % cache_line_byte_size);
addr_t cache_offset = addr - curr_addr;
while (bytes_left > 0) {
if (m_invalid_ranges.FindEntryThatContains(curr_addr)) {
error.SetErrorStringWithFormat("memory read failed for 0x%" PRIx64,
curr_addr);
return dst_len - bytes_left;
}
BlockMap::const_iterator pos = m_L2_cache.find(curr_addr);
BlockMap::const_iterator end = m_L2_cache.end();
if (pos != end) {
size_t curr_read_size = cache_line_byte_size - cache_offset;
if (curr_read_size > bytes_left)
curr_read_size = bytes_left;
memcpy(dst_buf + dst_len - bytes_left,
pos->second->GetBytes() + cache_offset, curr_read_size);
bytes_left -= curr_read_size;
curr_addr += curr_read_size + cache_offset;
cache_offset = 0;
if (bytes_left > 0) {
// Get sequential cache page hits
for (++pos; (pos != end) && (bytes_left > 0); ++pos) {
assert((curr_addr % cache_line_byte_size) == 0);
if (pos->first != curr_addr)
break;
curr_read_size = pos->second->GetByteSize();
if (curr_read_size > bytes_left)
curr_read_size = bytes_left;
memcpy(dst_buf + dst_len - bytes_left, pos->second->GetBytes(),
curr_read_size);
bytes_left -= curr_read_size;
curr_addr += curr_read_size;
// We have a cache page that succeeded to read some bytes
// but not an entire page. If this happens, we must cap
// off how much data we are able to read...
if (pos->second->GetByteSize() != cache_line_byte_size)
return dst_len - bytes_left;
}
}
}
// We need to read from the process
if (bytes_left > 0) {
assert((curr_addr % cache_line_byte_size) == 0);
std::unique_ptr<DataBufferHeap> data_buffer_heap_ap(
new DataBufferHeap(cache_line_byte_size, 0));
size_t process_bytes_read = m_process.ReadMemoryFromInferior(
curr_addr, data_buffer_heap_ap->GetBytes(),
data_buffer_heap_ap->GetByteSize(), error);
if (process_bytes_read == 0)
return dst_len - bytes_left;
if (process_bytes_read != cache_line_byte_size)
data_buffer_heap_ap->SetByteSize(process_bytes_read);
m_L2_cache[curr_addr] = DataBufferSP(data_buffer_heap_ap.release());
// We have read data and put it into the cache, continue through the
// loop again to get the data out of the cache...
}
}
}
return dst_len - bytes_left;
}
AllocatedBlock::AllocatedBlock(lldb::addr_t addr, uint32_t byte_size,
uint32_t permissions, uint32_t chunk_size)
: m_range(addr, byte_size), m_permissions(permissions),
m_chunk_size(chunk_size)
{
// The entire address range is free to start with.
m_free_blocks.Append(m_range);
assert(byte_size > chunk_size);
}
AllocatedBlock::~AllocatedBlock() {}
lldb::addr_t AllocatedBlock::ReserveBlock(uint32_t size) {
// We must return something valid for zero bytes.
if (size == 0)
size = 1;
Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
const size_t free_count = m_free_blocks.GetSize();
for (size_t i=0; i<free_count; ++i)
{
auto &free_block = m_free_blocks.GetEntryRef(i);
const lldb::addr_t range_size = free_block.GetByteSize();
if (range_size >= size)
{
// We found a free block that is big enough for our data. Figure out how
// many chunks we will need and calculate the resulting block size we will
// reserve.
addr_t addr = free_block.GetRangeBase();
size_t num_chunks = CalculateChunksNeededForSize(size);
lldb::addr_t block_size = num_chunks * m_chunk_size;
lldb::addr_t bytes_left = range_size - block_size;
if (bytes_left == 0)
{
// The newly allocated block will take all of the bytes in this
// available block, so we can just add it to the allocated ranges and
// remove the range from the free ranges.
m_reserved_blocks.Insert(free_block, false);
m_free_blocks.RemoveEntryAtIndex(i);
}
else
{
// Make the new allocated range and add it to the allocated ranges.
Range<lldb::addr_t, uint32_t> reserved_block(free_block);
reserved_block.SetByteSize(block_size);
// Insert the reserved range and don't combine it with other blocks
// in the reserved blocks list.
m_reserved_blocks.Insert(reserved_block, false);
// Adjust the free range in place since we won't change the sorted
// ordering of the m_free_blocks list.
free_block.SetRangeBase(reserved_block.GetRangeEnd());
free_block.SetByteSize(bytes_left);
}
LLDB_LOGV(log, "({0}) (size = {1} ({1:x})) => {2:x}", this, size, addr);
return addr;
}
}
LLDB_LOGV(log, "({0}) (size = {1} ({1:x})) => {2:x}", this, size,
LLDB_INVALID_ADDRESS);
return LLDB_INVALID_ADDRESS;
}
bool AllocatedBlock::FreeBlock(addr_t addr) {
bool success = false;
auto entry_idx = m_reserved_blocks.FindEntryIndexThatContains(addr);
if (entry_idx != UINT32_MAX)
{
m_free_blocks.Insert(m_reserved_blocks.GetEntryRef(entry_idx), true);
m_reserved_blocks.RemoveEntryAtIndex(entry_idx);
success = true;
}
Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
LLDB_LOGV(log, "({0}) (addr = {1:x}) => {2}", this, addr, success);
return success;
}
AllocatedMemoryCache::AllocatedMemoryCache(Process &process)
: m_process(process), m_mutex(), m_memory_map() {}
AllocatedMemoryCache::~AllocatedMemoryCache() {}
void AllocatedMemoryCache::Clear() {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
if (m_process.IsAlive()) {
PermissionsToBlockMap::iterator pos, end = m_memory_map.end();
for (pos = m_memory_map.begin(); pos != end; ++pos)
m_process.DoDeallocateMemory(pos->second->GetBaseAddress());
}
m_memory_map.clear();
}
AllocatedMemoryCache::AllocatedBlockSP
AllocatedMemoryCache::AllocatePage(uint32_t byte_size, uint32_t permissions,
uint32_t chunk_size, Error &error) {
AllocatedBlockSP block_sp;
const size_t page_size = 4096;
const size_t num_pages = (byte_size + page_size - 1) / page_size;
const size_t page_byte_size = num_pages * page_size;
addr_t addr = m_process.DoAllocateMemory(page_byte_size, permissions, error);
Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
if (log) {
log->Printf("Process::DoAllocateMemory (byte_size = 0x%8.8" PRIx32
", permissions = %s) => 0x%16.16" PRIx64,
(uint32_t)page_byte_size, GetPermissionsAsCString(permissions),
(uint64_t)addr);
}
if (addr != LLDB_INVALID_ADDRESS) {
block_sp.reset(
new AllocatedBlock(addr, page_byte_size, permissions, chunk_size));
m_memory_map.insert(std::make_pair(permissions, block_sp));
}
return block_sp;
}
lldb::addr_t AllocatedMemoryCache::AllocateMemory(size_t byte_size,
uint32_t permissions,
Error &error) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
addr_t addr = LLDB_INVALID_ADDRESS;
std::pair<PermissionsToBlockMap::iterator, PermissionsToBlockMap::iterator>
range = m_memory_map.equal_range(permissions);
for (PermissionsToBlockMap::iterator pos = range.first; pos != range.second;
++pos) {
addr = (*pos).second->ReserveBlock(byte_size);
if (addr != LLDB_INVALID_ADDRESS)
break;
}
if (addr == LLDB_INVALID_ADDRESS) {
AllocatedBlockSP block_sp(AllocatePage(byte_size, permissions, 16, error));
if (block_sp)
addr = block_sp->ReserveBlock(byte_size);
}
Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
if (log)
log->Printf(
"AllocatedMemoryCache::AllocateMemory (byte_size = 0x%8.8" PRIx32
", permissions = %s) => 0x%16.16" PRIx64,
(uint32_t)byte_size, GetPermissionsAsCString(permissions),
(uint64_t)addr);
return addr;
}
bool AllocatedMemoryCache::DeallocateMemory(lldb::addr_t addr) {
std::lock_guard<std::recursive_mutex> guard(m_mutex);
PermissionsToBlockMap::iterator pos, end = m_memory_map.end();
bool success = false;
for (pos = m_memory_map.begin(); pos != end; ++pos) {
if (pos->second->Contains(addr)) {
success = pos->second->FreeBlock(addr);
break;
}
}
Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
if (log)
log->Printf("AllocatedMemoryCache::DeallocateMemory (addr = 0x%16.16" PRIx64
") => %i",
(uint64_t)addr, success);
return success;
}
