Forums - How SNPE use ION buffers to avoid memory copy ?

Dear wei,

Thanks for your reply.

I tried three ways to use regiserIonBuffers, but none works.

1. use ioctl&mmap to alloc ION buffer beforehand, and assign the buffer to registerIonBuffers functions like:

    ioctl(ion_fd_, ION_IOC_ALLOC, &alloc_data);

   void* buffer=mmap(NULL, alloc_data.len, PROT_READ | PROT_WRITE, MAP_SHARED, alloc_data.fd, 0);

    UseMemoryMap map;

    map.add(name,buffer);

   snpe-> registerIonBuffers(map);

registerIonBuffers will return false from above pseudo code.

2. Do not alloc ION buffer in advance, and map add NULL like:

   UseMemoryMap map;

    map.add(name,NULL);

   snpe-> registerIonBuffers(map);

registerIonBuffers will also return false from above pseudo code.

3. Do not alloc ION buffer in advance, and map is empty like:

   UseMemoryMap map;

   snpe-> registerIonBuffers(map);

Nothing happened.

So, I just wonder whether shold I alloc ION buffer by myself or leave this work to SNPE. I want to use ION buffers because my app needs to transfer a huge data between CPU and DSP memories, alloc a ION shared buffer between them to avoid memcpy is a good choice, but I have no way to make SNPE know I alreadly alloc an ION buffer and just use it. Can you give me a tiny sample code?

Sincely,

guangchao