kraken_engine/mimir
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Arena Allocator bug fixes
Some checks failed
CMake on multiple platforms / build (Release, cl, cl, windows-latest) (push) Has been cancelled
Details
CMake on multiple platforms / build (Release, clang, clang++, macos-latest) (push) Has been cancelled
Details
CMake on multiple platforms / build (Release, clang, clang++, ubuntu-latest) (push) Has been cancelled
Details
CMake on multiple platforms / build (Release, gcc, g++, ubuntu-latest) (push) Has been cancelled
Details

Browse Source
This commit is contained in:
Kearwood Gilbert
2026-08-15 02:52:22 -07:00
parent 7dd0eb961a
commit edc7669a5c
1 changed files with 11 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
src/arena.cpp
View File

@@ -61,8 +61,8 @@ struct ArenaControlBlock
static_assert(sizeof(ArenaControlBlock) < 4096); static_assert(sizeof(ArenaControlBlock) < 4096);
Arena::Arena(size_t minSize, size_t maxSize) Arena::Arena(size_t minSize, size_t maxSize)
: m_minSize(KRAKEN_MEM_ROUND_UP_PAGE(minSize)) : m_minSize(minSize)
, m_maxSize(KRAKEN_MEM_ROUND_UP_PAGE(maxSize)) , m_maxSize(maxSize)
, m_data(nullptr) , m_data(nullptr)
, m_usedSize(0) , m_usedSize(0)
, m_committedSize(0) , m_committedSize(0)
@@ -82,7 +82,7 @@ Arena::~Arena()
ReportWindowsLastError("VirtualAlloc"); ReportWindowsLastError("VirtualAlloc");
} }
#elif defined(__unix__) || defined(__APPLE__) || defined(ANDROID) #elif defined(__unix__) || defined(__APPLE__) || defined(ANDROID)
munmap(m_data, m_maxSize); munmap(m_data, KRAKEN_MEM_ROUND_UP_PAGE(m_maxSize));
#else #else
static_assert(false, "Not Implemented"); static_assert(false, "Not Implemented");
#endif #endif
@@ -95,13 +95,13 @@ std::byte* Arena::alloc(size_t size)
if (m_data == nullptr) { if (m_data == nullptr) {
#if defined(_WIN32) || defined(_WIN64) #if defined(_WIN32) || defined(_WIN64)
m_data = (std::byte*)VirtualAlloc(NULL, m_maxSize, MEM_RESERVE, PAGE_NOACCESS); m_data = (std::byte*)VirtualAlloc(NULL, KRAKEN_MEM_ROUND_UP_PAGE(m_maxSize), MEM_RESERVE, PAGE_NOACCESS);
if (m_data == nullptr) { if (m_data == nullptr) {
ReportWindowsLastError("VirtualAlloc"); ReportWindowsLastError("VirtualAlloc");
return nullptr; return nullptr;
} }
#elif defined(__unix__) || defined(__APPLE__) || defined(ANDROID) #elif defined(__unix__) || defined(__APPLE__) || defined(ANDROID)
m_data = (std::byte*)mmap(NULL, m_maxSize, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); m_data = (std::byte*)mmap(NULL, KRAKEN_MEM_ROUND_UP_PAGE(m_maxSize), PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (m_data == MAP_FAILED) { if (m_data == MAP_FAILED) {
return nullptr; return nullptr;
} }
@@ -110,7 +110,7 @@ std::byte* Arena::alloc(size_t size)
#endif #endif
} }
if (neededSize < m_committedSize) if (neededSize > m_committedSize)
{ {
size_t newSize = std::bit_ceil(neededSize) << 1; size_t newSize = std::bit_ceil(neededSize) << 1;
if (newSize < m_minSize) { if (newSize < m_minSize) {
@@ -131,10 +131,10 @@ std::byte* Arena::alloc(size_t size)
static_assert(false, "Not Implemented"); static_assert(false, "Not Implemented");
#endif #endif
m_committedSize = newSize; m_committedSize = newSize;
} // if (neededSize < m_committedSize) } // if (neededSize > m_committedSize)
std::byte* ret = m_data + m_usedSize; std::byte* ret = m_data + m_usedSize;
m_usedSize += neededSize; m_usedSize = neededSize;
return ret; return ret;
} }
@@ -172,6 +172,9 @@ void Arena::reset()
m_watermark[kWatermarkLen - 1] = m_usedSize; m_watermark[kWatermarkLen - 1] = m_usedSize;
size_t targetSize = std::bit_ceil(highWatermark) << 1; size_t targetSize = std::bit_ceil(highWatermark) << 1;
if (targetSize < m_minSize) {
targetSize = m_minSize;
}
size_t thresholdSize = targetSize << 1; // The threshold for shrinking is greater than the target to implement hysteresis size_t thresholdSize = targetSize << 1; // The threshold for shrinking is greater than the target to implement hysteresis
if (m_committedSize > thresholdSize) { if (m_committedSize > thresholdSize) {
size_t newSize = KRAKEN_MEM_ROUND_UP_PAGE(targetSize); size_t newSize = KRAKEN_MEM_ROUND_UP_PAGE(targetSize);