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https://issues.apache.org/jira/browse/ARROW-2447?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16789651#comment-16789651
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Wes McKinney commented on ARROW-2447:
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It _is_ attached, but not by a shared_ptr
https://github.com/apache/arrow/blob/8b65bf845a2bc9ad071451c6924a9c33e29a4e9f/cpp/src/arrow/buffer.cc#L99
One possibility is to use shared_ptr. There are probably other possibilities to
extend the life of allocated memory; probably some microbenchmarks should be
implemented to evaluate whatever strategy is employed
> [C++] Create a device abstraction
> ---------------------------------
>
> Key: ARROW-2447
> URL: https://issues.apache.org/jira/browse/ARROW-2447
> Project: Apache Arrow
> Issue Type: Improvement
> Components: C++, GPU
> Affects Versions: 0.9.0
> Reporter: Antoine Pitrou
> Assignee: Pearu Peterson
> Priority: Major
> Fix For: 0.14.0
>
>
> Right now, a plain Buffer doesn't carry information about where it actually
> lies. That information also cannot be passed around, so you get APIs like
> {{PlasmaClient}} which take or return device number integers, and have
> implementations which hardcode operations on CUDA buffers. Also, unsuspecting
> receivers of a {{Buffer}} pointer may try to act on the underlying memory
> without knowing whether it's CPU-reachable or not.
> Here is a sketch for a proposed Device abstraction:
> {code}
> class Device {
> enum DeviceKind { KIND_CPU, KIND_CUDA };
> virtual DeviceKind kind() const;
> //MemoryPool* default_memory_pool() const;
> //std::shared_ptr<Buffer> Allocate(...);
> };
> class CpuDevice : public Device {};
> class CudaDevice : public Device {
> int device_num() const;
> };
> class Buffer {
> virtual DeviceKind device_kind() const;
> virtual std::shared_ptr<Device> device() const;
> virtual bool on_cpu() const {
> return true;
> }
> const uint8_t* cpu_data() const {
> return on_cpu() ? data() : nullptr;
> }
> uint8_t* cpu_mutable_data() {
> return on_cpu() ? mutable_data() : nullptr;
> }
> virtual CopyToCpu(std::shared_ptr<Buffer> dest) const;
> virtual CopyFromCpu(std::shared_ptr<Buffer> src);
> };
> class CudaBuffer : public Buffer {
> virtual bool on_cpu() const {
> return false;
> }
> };
> CopyBuffer(std::shared_ptr<Buffer> dest, const std::shared_ptr<Buffer> src);
> {code}
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