1_callback_hostfunc

Description

This sample demonstrates dispatching a Host-side function on a Stream. This Host-side function is called after currently dispatched tasks complete, and blocks subsequently added tasks.

Product Support

This sample has the following support status on the following products:

Product	Supported
Atlas A3 training series products/Atlas A3 inference series products	Yes
Atlas A2 training series products/Atlas A2 inference series products	Yes

Build and Run

For environment installation details and running details, see README in the example directory.

Run steps:

# Replace ${install_root} with CANN installation root directory, default installation at /usr/local/Ascend
source ${install_root}/cann/set_env.sh

# Automatically identify SOC_VERSION and ASCENDC_CMAKE_DIR.
source ${git_clone_path}/example/set_sample_env.sh

# Build and run
bash run.sh

CANN RUNTIME API

Key features and interfaces in this sample:

• Initialization
  • Call aclInit interface to initialize AscendCL configuration.
  • Call aclFinalize interface to deinitialize AscendCL.
• Device Management
  • Call aclrtSetDevice interface to specify Device for computation.
  • Call aclrtResetDeviceForce interface to forcibly reset current computation Device and reclaim Device resources.
• Context Management
  • Call aclrtCreateContext interface to create Context.
  • Call aclrtDestroyContext interface to destroy Context.
• Stream Management
  • Call aclrtCreateStream interface to create Stream.
  • Call aclrtSynchronizeStream interface to block waiting for Stream task completion.
  • Call aclrtSetStreamFailureMode interface to set Stream task execution error handling, defaults to continue on error, can be set to stop on error.
  • Call aclrtDestroyStreamForce interface to forcibly destroy Stream, discarding all tasks.
• Callback Control
  • Call aclrtLaunchHostFunc interface to directly trigger callback, without explicit thread creation.
• Memory Management
  • Call aclrtMalloc interface to allocate Device memory.
  • Call aclrtFree interface to release Device memory.
• Data Transfer
  • Call aclrtMemcpy interface to implement data transfer by memory copy.

Sample Output

[INFO]  Hostfunc callback!!!
[INFO]  After assigning the task through the created stream, the current result is: ...
[INFO]  Resource cleanup completed.

Known Issues

None