fun chooseThread()

in src/jvm/main/org/jetbrains/kotlinx/lincheck/strategy/managed/modelchecking/ModelCheckingStrategy.kt [358:396]
39 lines of code
9 McCabe index (conditional complexity)

        fun chooseThread(iThread: Int): Int {
            val availableThreads = availableThreads(iThread)
            val nextThread = if (currentInterleavingPosition < threadSwitchChoices.size) {
                // Use the predefined choice.
                val nextThread = threadSwitchChoices[currentInterleavingPosition++]
                // Update current node.
                if (shouldMoveCurrentNode && !loopDetector.replayModeEnabled) {
                    currentInterleavingNode = currentInterleavingNode
                        .getChildNode(executionPosition)!!
                        .getChildNode(nextThread)!!
                        as SwitchChoosingNode
                    // we reached the next `SwitchChoosingNode` node, so mark it as initialized
                    currentInterleavingNode.initialize()
                }
                check(nextThread in availableThreads) {
                    """
                        Trying to switch the execution to thread $nextThread,
                        but only the following threads are eligible to switch: $availableThreads
                    """.trimIndent()
                }
                nextThread
            } else {
                // There is no predefined choice.
                // This can happen if there were forced thread switches after the last predefined one
                // (e.g., thread end, coroutine suspension, acquiring an already acquired lock or monitor.wait).
                // We use a deterministic random here to choose the next thread.
                // end of tracked execution positions, so tell strategy not to generate switch points any further
                shouldAddNewSwitchPoints = false
                // in case no switchable thread available we return -1, this way
                // the strategy will either report an error or stay on the calling
                // thread if the switch was not mandatory
                if (availableThreads.isEmpty()) -1
                else availableThreads.random(interleavingFinishingRandom)
            }
            if (currentInterleavingPosition == threadSwitchChoices.size) {
                shouldMoveCurrentNode = false
            }
            return nextThread
        }