fixes exec queue add and pop

[AdoAdoAdo]

Reasoning behind the pull request

Proposed changes

Testing procedure

Pre-requisites

Based on the Contributing Guidelines the PR author and the reviewers must check the following requirements are met:

• was the PR targeted to the correct branch?
• if this is a larger feature that probably needs more than one PR, is there a feat branch created?
• if this is a feat branch merging, do all satellite projects have a proper tag inside go.mod?

[Copilot]

Pull request overview

This PR fixes issues with the execution queue's Add and Pop operations, addressing concurrency problems and improving error handling in the async execution system.

Key Changes

• Fixed the Pop() method condition from > 1 to >= 1 to correctly handle single-item queues
• Updated AddOrReplace notification logic to only notify when the first item is added to an empty queue
• Added ValidateQueueIntegrity() method for periodic queue health checks
• Improved error handling with proper error propagation and retry logic with exponential backoff
• Enhanced error handling in baseSync.go using errors.Is() instead of direct comparison

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
process/asyncExecution/queue/blocksQueue.go	Fixed Pop() condition bug, restructured notification logic, added ValidateQueueIntegrity() method, and enhanced logging
process/asyncExecution/headersExecutor.go	Added retry mechanism with max attempts and exponential backoff, periodic validation ticker, nil checks for headers/bodies, and fixed error propagation
process/sync/baseSync.go	Updated error comparison to use errors.Is() and ensured deferred error handling works correctly
process/asyncExecution/queue/errors.go	Removed unused ErrMissingHeaderNonce and added ErrQueueIntegrityViolation
process/asyncExecution/errors.go	Added new error types for nil handlers and execution results
process/interface.go	Added ValidateQueueIntegrity() to BlocksQueue interface
process/asyncExecution/interface.go	Added ValidateQueueIntegrity() to BlocksQueue interface
testscommon/processMocks/blocksQueueMock.go	Added ValidateQueueIntegrityCalled field and method to mock
process/asyncExecution/queue/blocksQueue_test.go	Added comprehensive test coverage for ValidateQueueIntegrity() and concurrent operations
process/asyncExecution/headersExecutor_test.go	Fixed test expectations to properly validate error propagation

Comments suppressed due to low confidence (1)

process/asyncExecution/headersExecutor.go:143

• This select statement with a default case creates a busy-wait loop when the validation ticker doesn't fire. The default case will be executed continuously, causing high CPU usage even when the queue is empty and Pop() is blocking. Consider removing the default case or adding a small sleep in the default branch to avoid busy-waiting. The ticker and Pop() blocking should provide sufficient responsiveness without the default case.

		select {
		case <-ctx.Done():
			return
		case <-validationTicker.C:
			// Periodic queue validation
			err := he.blocksQueue.ValidateQueueIntegrity()
			if err != nil {
				log.Error("headersExecutor.start: queue integrity validation failed", "err", err)
			}
		default:
			he.mutPaused.RLock()
			isPaused := he.isPaused
			he.mutPaused.RUnlock()

			if isPaused {
				time.Sleep(timeToSleep)
				continue
			}

			// blocking operation
			headerBodyPair, ok := he.blocksQueue.Pop()
			if !ok {
				log.Debug("headersExecutor.start: not ok fetching from queue")
				// close event
				return
			}

			if check.IfNil(headerBodyPair.Header) || check.IfNil(headerBodyPair.Body) {
				log.Debug("headersExecutor.start: popped nil header or body, continuing...")
				continue
			}

			err := he.process(headerBodyPair)
			if err != nil {
				he.handleProcessError(ctx, headerBodyPair)
			}
		}

---

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[sstanculeanu]

Suggested change

	"hash", pair.Header.GetPrevHash(),
	"prevHash", pair.Header.GetPrevHash(),

[AdoAdoAdo]

done

[ssd04]

don't think its really needed, there are already some nil checks before process call

[AdoAdoAdo]

removed

[Copilot]

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated 7 comments.

---

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The base branch was changed.

[codecov]

Codecov Report

❌ Patch coverage is 74.57627% with 30 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.68%. Comparing base (09a3fcc) to head (0b6f2f8).
⚠️ Report is 22 commits behind head on feat/supernova-async-exec.

Files with missing lines	Patch %	Lines
process/asyncExecution/headersExecutor.go	60.60%	11 Missing and 2 partials ⚠️
epochStart/metachain/epochStartData.go	58.33%	5 Missing ⚠️
update/common.go	0.00%	4 Missing ⚠️
process/block/preprocess/transactions.go	50.00%	2 Missing and 1 partial ⚠️
consensus/spos/worker.go	66.66%	1 Missing and 1 partial ⚠️
epochStart/metachain/trigger.go	80.00%	1 Missing ⚠️
process/asyncExecution/queue/blocksQueue.go	97.50%	1 Missing ⚠️
storage/pruning/pruningStorer.go	50.00%	1 Missing ⚠️

Additional details and impacted files

@@                    Coverage Diff                     @@
##           feat/supernova-async-exec    #7591   +/-   ##
==========================================================
  Coverage                      77.68%   77.68%           
==========================================================
  Files                            876      876           
  Lines                         121033   121120   +87     
==========================================================
+ Hits                           94029    94097   +68     
- Misses                         20796    20816   +20     
+ Partials                        6208     6207    -1     

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