primitive scheduler algorithms

alg_earliestdeadlinefirst.c

#include "algorithms.h"
#include "dispatcher.h"

HANDLE Algorithm_EarliestDeadlineFirst(PLIST_ENTRY TaskList, ULONG Clock) {

	PLIST_ENTRY ListEntry, Candidate;
	HANDLE CandidateThreadHandle, ListEntryThreadHandle;
	PDISPATCHER_TASK ListEntryTask;
	PEDF_TASKINFO ListEntryTaskInfo, CandidateTaskInfo;

	// just to be sure
	Candidate = NULL;
	CandidateThreadHandle = NULL;

	for(ListEntry = TaskList->Flink; ListEntry != TaskList; ListEntry = ListEntry->Flink)
	{
		ListEntryTask = (PDISPATCHER_TASK) CONTAINING_RECORD(ListEntry, DISPATCHER_TASK, Link);
		ListEntryTaskInfo = ListEntryTask->TaskInfo;
		ListEntryThreadHandle = ListEntryTask->ThreadHandle;
		if( (ListEntryTaskInfo->NextDeadLine > Clock) && (ListEntryTaskInfo->StartTime <= Clock) &&
			(!Candidate || CandidateTaskInfo->NextDeadLine >= ListEntryTaskInfo->NextDeadLine) )
		{
			Candidate             = ListEntry;
			CandidateTaskInfo     = ListEntryTaskInfo;
			CandidateThreadHandle = ListEntryThreadHandle;
		}
	}

	return CandidateThreadHandle;
}

alg_roundrobin.c

#include "algorithms.h"
#include "dispatcher.h"

HANDLE Algorithm_RoundRobin(PLIST_ENTRY TaskList, ULONG Clock) {

	PLIST_ENTRY ListEntry;
	HANDLE CandidateThreadHandle;
	PDISPATCHER_TASK ListEntryTask;
	PEDF_TASKINFO ListEntryTaskInfo;

	// just to be sure
	CandidateThreadHandle = NULL;

	for(ListEntry = TaskList->Flink; ListEntry != TaskList; ListEntry = ListEntry->Flink)
	{
		ListEntryTask = (PDISPATCHER_TASK) CONTAINING_RECORD(ListEntry, DISPATCHER_TASK, Link);
		ListEntryTaskInfo = ListEntryTask->TaskInfo;
		if((ListEntryTaskInfo->NextDeadLine > Clock) && (ListEntryTaskInfo->StartTime <= Clock)) {
			CandidateThreadHandle = ListEntryTask->ThreadHandle;
			RemoveEntryList(ListEntry);
			InsertTailList(TaskList, ListEntry);
			break;
		}
	}

	return CandidateThreadHandle;
}