This still isn't a completely direct write - you're still creating an array in between which is then copied into shm, whereas struct.pack_into writes directly into the shared memory with no intermediate buffer. And unfortunately you can't do shm.buf[l_offset:r_offset].cast('Q')[:] = nums where nums is a plain Python iterable; it has to already be an array, so it still requires a copy. On 10/10/2021 16:57, Serhiy Storchaka wrote:
10.10.21 18:18, Facundo Batista пише:
You mean `array` from the `array` module? The only way I see using it is like the following:
shm = shared_memory.SharedMemory(create=True, size=total_size) a = array.array('Q', nums) shm.buf[l_offset:r_offset] = a.tobytes() But I don't like it because of the `tobytes` call, which will produce a huge bytearray only to insert it in the shared memory buffer.
That's why I liked `pack_into`, because it will write directly into the memory view.
Or I'm missing something? shm.buf[l_offset:r_offset].cast('Q')[:] = a
or
shm.buf[l_offset:r_offset] = memoryview(a).cast('B')
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