-BumpPtrAllocator::BumpPtrAllocator(size_t size, size_t threshold,
- SlabAllocator &allocator)
- : SlabSize(size), SizeThreshold(threshold), Allocator(allocator),
- CurSlab(0), BytesAllocated(0) {
- StartNewSlab();
-}
-
-BumpPtrAllocator::~BumpPtrAllocator() {
- DeallocateSlabs(CurSlab);
-}
-
-/// AlignPtr - Align Ptr to Alignment bytes, rounding up. Alignment should
-/// be a power of two. This method rounds up, so AlignPtr(7, 4) == 8 and
-/// AlignPtr(8, 4) == 8.
-char *BumpPtrAllocator::AlignPtr(char *Ptr, size_t Alignment) {
- assert(Alignment && (Alignment & (Alignment - 1)) == 0 &&
- "Alignment is not a power of two!");
-
- // Do the alignment.
- return (char*)(((uintptr_t)Ptr + Alignment - 1) &
- ~(uintptr_t)(Alignment - 1));
-}
-
-/// StartNewSlab - Allocate a new slab and move the bump pointers over into
-/// the new slab. Modifies CurPtr and End.
-void BumpPtrAllocator::StartNewSlab() {
- MemSlab *NewSlab = Allocator.Allocate(SlabSize);
- NewSlab->NextPtr = CurSlab;
- CurSlab = NewSlab;
- CurPtr = (char*)(CurSlab + 1);
- End = CurPtr + CurSlab->Size;
-}
-
-/// DeallocateSlabs - Deallocate all memory slabs after and including this
-/// one.
-void BumpPtrAllocator::DeallocateSlabs(MemSlab *Slab) {
- while (Slab) {
- MemSlab *NextSlab = Slab->NextPtr;
-#ifndef NDEBUG
- // Poison the memory so stale pointers crash sooner. Note we must
- // preserve the Size and NextPtr fields at the beginning.
- memset(Slab + 1, 0xCD, Slab->Size - sizeof(MemSlab));
-#endif
- Allocator.Deallocate(Slab);
- Slab = NextSlab;
- }
-}
-
-/// Reset - Deallocate all but the current slab and reset the current pointer
-/// to the beginning of it, freeing all memory allocated so far.
-void BumpPtrAllocator::Reset() {
- DeallocateSlabs(CurSlab->NextPtr);
- CurSlab->NextPtr = 0;
- CurPtr = (char*)(CurSlab + 1);
- End = CurPtr + CurSlab->Size;
-}
-
-/// Allocate - Allocate space at the specified alignment.
-///
-void *BumpPtrAllocator::Allocate(size_t Size, size_t Alignment) {
- // Keep track of how many bytes we've allocated.
- BytesAllocated += Size;
-
- // 0-byte alignment means 1-byte alignment.
- if (Alignment == 0) Alignment = 1;