Function: set_device

aclError aclrtSetDevice(int32_t deviceId)

ret = acl.rt.set_device(device_id)

Sets the compute device in the calling thread. The call implicitly creates the default context.

For the Atlas 200/300/500 Inference Product, the default context contains two streams: one default stream and one stream for internal synchronization.

For the Atlas Training Series Product, the default context contains one default stream.

device_id: int, device ID.

After acl.rt.get_device_count is called to obtain the number of available devices, the value range of device ID is [0, Number of available devices – 1].

ret: int, error code.

• 0 indicates success.
• Other values indicate failure.

If acl.rt.set_device is called for multiple times in a process, acl.rt.reset_device does not need to be called to reset the device resources, because the device resources will be reset when the process exits. It is recommended that acl.rt.set_device and acl.rt.reset_device be used in pairs to reset the device resources that are no longer needed in a timely manner.

acl.rt.set_device can be called to specify the same device for computation in different processes or threads. In a multithreaded process, if acl.rt.set_device is called to specify the same compute device, they use the same default context.

For details about the API call sequence and example, see Runtime Resource Allocation and Deallocation and Synchronous Wait.