43d241c28d
- Add arena allocator for zero-allocation hot paths - Add thread pool for parallel operations - Add mmap utilities for memory-mapped I/O - Implement queue_index with heap-based priority queue - Implement dataset_hash with SIMD support (SHA-NI, ARMv8) - Add runtime SIMD detection for cross-platform correctness - Add comprehensive tests and benchmarks
40 lines
1 KiB
C++
40 lines
1 KiB
C++
#pragma once
|
|
#include <cstddef>
|
|
#include <cassert>
|
|
#include <cstdint>
|
|
|
|
namespace fetchml::common {
|
|
|
|
// Simple bump allocator for hot-path operations.
|
|
// NOT thread-safe - use one per thread.
|
|
class ArenaAllocator {
|
|
static constexpr size_t BUFFER_SIZE = 256 * 1024; // 256KB per thread
|
|
alignas(64) char buffer_[BUFFER_SIZE];
|
|
size_t offset_ = 0;
|
|
bool in_use_ = false;
|
|
|
|
public:
|
|
// Allocate size bytes with given alignment
|
|
void* allocate(size_t size, size_t align = 8) {
|
|
size_t aligned = (offset_ + align - 1) & ~(align - 1);
|
|
if (aligned + size > BUFFER_SIZE) {
|
|
return nullptr; // Arena exhausted
|
|
}
|
|
void* ptr = buffer_ + aligned;
|
|
offset_ = aligned + size;
|
|
return ptr;
|
|
}
|
|
|
|
void reset() { offset_ = 0; }
|
|
|
|
void begin() { in_use_ = true; reset(); }
|
|
void end() { in_use_ = false; }
|
|
bool in_use() const { return in_use_; }
|
|
};
|
|
|
|
// Thread-local arena access
|
|
ArenaAllocator* thread_local_arena();
|
|
void begin_arena_scope();
|
|
void end_arena_scope();
|
|
|
|
} // namespace fetchml::common
|