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ThrustAllocator.cuh
/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD+Patents license found in the
* LICENSE file in the root directory of this source tree.
*/
#pragma once
#include <cuda.h>
#include <unordered_set>
namespace faiss { namespace gpu {
/// Allocator for Thrust that comes out of a specified memory space
class GpuResourcesThrustAllocator {
public:
typedef char value_type;
GpuResourcesThrustAllocator(void* mem, size_t size)
: start_((char*) mem),
cur_((char*) mem),
end_((char*) mem + size) {
}
~GpuResourcesThrustAllocator() {
}
char* allocate(std::ptrdiff_t size) {
if (size <= (end_ - cur_)) {
char* p = cur_;
cur_ += size;
FAISS_ASSERT(cur_ <= end_);
return p;
} else {
char* p = nullptr;
CUDA_VERIFY(cudaMalloc(&p, size));
mallocAllocs_.insert(p);
return p;
}
}
void deallocate(char* p, size_t size) {
// Allocations could be returned out-of-order; ignore those we
// didn't cudaMalloc
auto it = mallocAllocs_.find(p);
if (it != mallocAllocs_.end()) {
CUDA_VERIFY(cudaFree(p));
mallocAllocs_.erase(it);
}
}
private:
char* start_;
char* cur_;
char* end_;
std::unordered_set<char*> mallocAllocs_;
};
} } // namespace
faiss::gpu::GpuResourcesThrustAllocator
Allocator for Thrust that comes out of a specified memory space.
Definition: ThrustAllocator.cuh:18