Implement OpenVX streaming extension

[simonCatBot]

Summary

This PR implements the OpenVX streaming extension (vxEnableGraphStreaming, vxStartGraphStreaming, vxStopGraphStreaming) on top of the existing pipelining work in the openvx_1.3.2 branch. It is modelled on the rustVX reference implementation and makes the GraphStreaming conformance tests pass.

What changed

• sample/include/vx_internal.h

  • Adds streaming state fields to vx_kernel_t, vx_node_t and vx_graph_t.
  • Includes vx_khr_pipelining.h when either pipelining or streaming is enabled.

• sample/framework/vx_kernel.c

  • Defaults pipeup_output_depth / pipeup_input_depth to 1.
  • Handles VX_KERNEL_PIPEUP_OUTPUT_DEPTH and VX_KERNEL_PIPEUP_INPUT_DEPTH in query/set attribute.
  • Relaxes vxAddUserKernel so a NULL validate callback is accepted (required by the streaming conformance tests).

• sample/framework/vx_node.c

  • Initializes per-node execution_count and node_state.
  • Adds VX_NODE_STATE query support.

• sample/framework/vx_graph.c

  • Sets VX_NODE_STATE to PIPEUP/STEADY before each execution and increments execution_count afterwards.
  • For non-streaming vxProcessGraph, runs internal pipeup warm-up iterations until all nodes reach steady state, then executes one steady iteration, matching rustVX.
  • Skips downstream nodes whose producer is still in PIPEUP so only steady outputs are consumed.
  • Guards validate_input / validate_output calls during verification so user kernels without validators don't crash.
  • Derives scalar meta type from the actual output object when no output validator is provided.
  • Stops the streaming worker thread when the graph is destroyed.

• sample/framework/vx_graph_stream.c

  • Implements vxEnableGraphStreaming, vxStartGraphStreaming and vxStopGraphStreaming with a background worker thread.

Verification

• GraphStreaming.*: 24/24 tests pass.
• Pipelining fast tests and baseline smoke/graph tests pass locally (the single unrelated Graph.VirtualArray failure is due to missing test-data images in the local environment).

Notes

The implementation intentionally keeps streaming and pipelining orthogonal: streaming builds on the same per-node pipeup-state machinery but does not require the pipelining schedule-mode APIs to be used.

[CLAassistant]

All committers have signed the CLA.

[Copilot]

Pull request overview

Note

Copilot couldn't run its full agentic review because no GitHub Actions runner was available. Make sure your repository has a runner available to run Copilot's review, or add a copilot-setup-steps.yml file specifying one with the runs-on attribute. See the docs for more details.

Implements the OpenVX graph streaming extension by adding per-node pipeup/steady state tracking and a background worker thread to run vxProcessGraph repeatedly, aligning behavior with the GraphStreaming conformance expectations.

Changes:

• Added streaming state fields to internal kernel/node/graph structures and enabled pipelining header inclusion when streaming is enabled.
• Implemented vxEnableGraphStreaming, vxStartGraphStreaming, and vxStopGraphStreaming using a worker thread.
• Updated graph execution to support pipeup warm-up/steady iteration behavior and to tolerate user kernels without validators.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
sample/include/vx_internal.h	Adds streaming-related fields to internal structs and includes pipelining headers when streaming is enabled.
sample/framework/vx_kernel.c	Initializes pipeup depths, adds kernel attribute query/set hooks, and relaxes user-kernel validation requirements.
sample/framework/vx_node.c	Initializes and exposes per-node streaming state via VX_NODE_STATE.
sample/framework/vx_graph_stream.c	Adds streaming APIs and a background worker thread that repeatedly processes the graph.
sample/framework/vx_graph.c	Stops streaming on graph destruction, guards validator calls, derives scalar meta type when needed, and adds pipeup/steady execution logic.

Comments suppressed due to low confidence (1)

sample/framework/vx_kernel.c:1

• addkernel previously accepted an explicit valid_rect_reset argument, but now forces valid_rect_reset solely based on is_user_kernel. That changes semantics: user kernels can no longer opt out of valid_rect_reset, and non-user kernels can no longer opt in (if they previously could) via this call path. Suggestion (mandatory): restore a separate valid_rect_reset parameter (or otherwise preserve the previous behavior) while keeping the relaxed validator requirement for user kernels; also consider adding parentheses around the validator check to avoid precedence ambiguity in future edits.

/*

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[simonCatBot]

Thanks for the review. I've pushed an update (0b944d6) that addresses the mandatory items:

1. valid_rect_reset semantics (sample/framework/vx_kernel.c)

   • Restored the separate valid_rect_reset parameter in addkernel. vxAddKernel now passes is_user_kernel=vx_false_e, valid_rect_reset=vx_false_e; vxAddUserKernel passes is_user_kernel=vx_true_e, valid_rect_reset=vx_true_e. The relaxed validator requirement for user kernels is preserved.

2. SMP execution_count counting (sample/framework/vx_graph.c)

   • Introduced numWork to count only work-items that are actually scheduled. The threadpool is now issued with numWork, the action scan loops over numWork, and execution_count is incremented only for nodes stored in those work-items. Skipped nodes no longer advance toward steady state.

3. NULL guards in helpers (sample/framework/vx_graph.c)

   • Added node == NULL and kernel == NULL guards in ownAnyNodeInPipeup and ownIsPredecessorInPipeup.

4. Race-free streaming stop synchronization (sample/framework/vx_graph_stream.c, sample/include/vx_internal.h, sample/framework/vx_graph.c)

   • Replaced the polled streaming_stop/streaming_thread_running flags with a vx_internal_event_t streaming_stop_event. vxStartGraphStreaming initializes it, the worker blocks on ownWaitEvent(..., 1) between graph executions, and vxStopGraphStreaming signals the event and joins the thread. Graph destruction also signals and cleans up the event.

5. Busy-wait in worker (moderate)

   • Addressed by the same event change: the worker now blocks on the event instead of sleeping in a tight loop.

Re-verification:

• GraphStreaming.* conformance: 24/24 passed.
• Broader graph/pipelining smoke tests still pass; the only unrelated failure is Graph.VirtualArray due to missing optflow_00.bmp test data in the local environment.

Note: the CLA assistant flag is because the original commit author email (simon@openclaw.local) wasn't linked to the GitHub account. The commit author has been amended to simonCatBot@users.noreply.github.com; the CLA check may need a recheck.

[simonCatBot]

Updated README and CI in b755540:

• README.md

  • Added Pipelining and Streaming to the list of supported extensions.
  • Updated the extension-status note: Pipelining and Streaming are functional; Event Queue remains a stub.
  • Updated Mode 7/8 conformance notes so Streaming is expected to pass.
  • Updated the CI/CD section to say the Streaming job is required (no longer warning-only).

• BUILD_DEFINES

  • Added notes that OPENVX_USE_PIPELINING and OPENVX_USE_STREAMING are functional implementations.

• .github/workflows/ci.yml

  • Removed continue-on-error: true from the Streaming job and all other conformance test jobs (graph, data objects, user kernels, import/export, neural networks, NNEF import, and every Vision functional group) so the full suite is required to pass.
  • Renamed the Streaming job and removed the warning-only ::warning echo.

Note: the neural-networks job already excludes the TensorNetworks.AlexNetTestNetwork test because the weights are not shipped, so it no longer needs to be allowed to fail.

[simonCatBot]

Enabled Git LFS and removed the remaining test exception in cbd7629:

• .github/workflows/ci.yml

  • Added lfs: true to actions/checkout@v4 in both build jobs so the large CTS test data files are pulled.
  • Installed git-lfs in the runner and added a quick git lfs ls-files verification step.
  • Removed the TensorNetworks.AlexNetTestNetwork exclusion from the Neural Networks job — its weights are now available via LFS, so all NN tests are expected to pass.
  • Raised the neural-networks timeout to 1200s to account for the additional AlexNet test.

• README.md

  • Added a note under the conformance setup section that cts/test_data/ is managed with Git LFS and must be pulled before running the suite.

[simonCatBot]

Updated the cts submodule to the latest openvx_1.3.2 tip in 14940af:

• Bumped KhronosGroup/OpenVX-cts from c550b2c to 2d672f7.
• Picks up recent changes including stale-output detection for Laplacian pyramid / reconstruct tests and Git LFS documentation.
• Rebuilt the CTS locally and re-ran GraphStreaming.*: 24/24 passed.

The CI workflow already has lfs: true and the full conformance suite is required to pass, so the new CTS revision will be validated there.