Magic-Mirror/llvm-capstone
1
0
Fork 0
mirror of https://github.com/capstone-engine/llvm-capstone.git synced 2025-01-31 14:15:12 +00:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity

[scudo] Use MemMap in Vector

Browse Source 
Reviewed By: Chia-hungDuan

Differential Revision: https://reviews.llvm.org/D159449
This commit is contained in:
Fabio D'Urso 2023-09-18 14:43:35 +02:00
parent 078651b6de
commit b3ca0f34cf
1 changed files with 32 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
compiler-rt/lib/scudo/standalone/vector.h
View File

@ -9,26 +9,20 @@
#ifndef SCUDO_VECTOR_H_
#define SCUDO_VECTOR_H_
#include "common.h"
#include "mem_map.h"
#include <string.h>
namespace scudo {
// A low-level vector based on map. May incur a significant memory overhead for
// small vectors. The current implementation supports only POD types.
// A low-level vector based on map. It stores the contents inline up to a fixed
// capacity, or in an external memory buffer if it grows bigger than that. May
// incur a significant memory overhead for small vectors. The current
// implementation supports only POD types.
//
// NOTE: This class is not meant to be used directly, use Vector<T> instead.
template <typename T> class VectorNoCtor {
public:
constexpr void init(uptr InitialCapacity = 0) {
Data = &LocalData[0];
CapacityBytes = sizeof(LocalData);
if (InitialCapacity > capacity())
reserve(InitialCapacity);
}
void destroy() {
if (Data != &LocalData[0])
unmap(Data, CapacityBytes, 0, &MapData);
}
T &operator[](uptr I) {
DCHECK_LT(I, Size);
return Data[I];
@ -78,24 +72,43 @@ public:
const T *end() const { return data() + size(); }
T *end() { return data() + size(); }
protected:
constexpr void init(uptr InitialCapacity = 0) {
Data = &LocalData[0];
CapacityBytes = sizeof(LocalData);
if (InitialCapacity > capacity())
reserve(InitialCapacity);
}
void destroy() {
if (Data != &LocalData[0])
ExternalBuffer.unmap(ExternalBuffer.getBase(),
ExternalBuffer.getCapacity());
}
private:
void reallocate(uptr NewCapacity) {
DCHECK_GT(NewCapacity, 0);
DCHECK_LE(Size, NewCapacity);
MemMapT NewExternalBuffer;
NewCapacity = roundUp(NewCapacity * sizeof(T), getPageSizeCached());
T *NewData = reinterpret_cast<T *>(
map(nullptr, NewCapacity, "scudo:vector", 0, &MapData));
memcpy(NewData, Data, Size * sizeof(T));
NewExternalBuffer.map(/*Addr=*/0U, NewCapacity, "scudo:vector");
T *NewExternalData = reinterpret_cast<T *>(NewExternalBuffer.getBase());
memcpy(NewExternalData, Data, Size * sizeof(T));
destroy();
Data = NewData;
Data = NewExternalData;
CapacityBytes = NewCapacity;
ExternalBuffer = NewExternalBuffer;
}
T *Data = nullptr;
T LocalData[256 / sizeof(T)] = {};
uptr CapacityBytes = 0;
uptr Size = 0;
[[no_unique_address]] MapPlatformData MapData = {};
T LocalData[256 / sizeof(T)] = {};
MemMapT ExternalBuffer;
};
template <typename T> class Vector : public VectorNoCtor<T> {