/** This runs in a separate thread */
static int fpathThreadFunc(void *)
{
wzMutexLock(fpathMutex);
while (!fpathQuit)
{
if (pathJobs.empty())
{
ASSERT(!waitingForResult, "Waiting for a result (id %u) that doesn't exist.", waitingForResultId);
wzMutexUnlock(fpathMutex);
wzSemaphoreWait(fpathSemaphore); // Go to sleep until needed.
wzMutexLock(fpathMutex);
continue;
}
// Copy the first job from the queue. Don't pop yet, since the main thread may want to set .deleted = true.
PATHJOB job = pathJobs.front();
wzMutexUnlock(fpathMutex);
// Execute path-finding for this job using our local temporaries
PATHRESULT result;
result.droidID = job.droidID;
memset(&result.sMove, 0, sizeof(result.sMove));
result.retval = FPR_FAILED;
result.originalDest = Vector2i(job.destX, job.destY);
// we need to lock BEFORE we fiddle with the data, or we get ugly data race conditions.
wzMutexLock(fpathMutex);
fpathExecute(&job, &result);
ASSERT(pathJobs.front().droidID == job.droidID, "Bug"); // The front of pathJobs may have .deleted set to true, but should not otherwise have been modified or deleted.
if (!pathJobs.front().deleted)
{
pathResults.push_back(result);
}
pathJobs.pop_front();
// Unblock the main thread, if it was waiting for this particular result.
if (waitingForResult && waitingForResultId == job.droidID)
{
waitingForResult = false;
objTrace(waitingForResultId, "These are the droids you are looking for.");
wzSemaphorePost(waitingForResultSemaphore);
}
}
wzMutexUnlock(fpathMutex);
return 0;
}
static FPATH_RETVAL fpathRoute(MOVE_CONTROL *psMove, unsigned id, int startX, int startY, int tX, int tY, PROPULSION_TYPE propulsionType,
DROID_TYPE droidType, FPATH_MOVETYPE moveType, int owner, bool acceptNearest, StructureBounds const &dstStructure)
{
objTrace(id, "called(*,id=%d,sx=%d,sy=%d,ex=%d,ey=%d,prop=%d,type=%d,move=%d,owner=%d)", id, startX, startY, tX, tY, (int)propulsionType, (int)droidType, (int)moveType, owner);
if (!worldOnMap(startX, startY) || !worldOnMap(tX, tY))
{
debug(LOG_ERROR, "Droid trying to find path to/from invalid location (%d %d) -> (%d %d).", startX, startY, tX, tY);
objTrace(id, "Invalid start/end.");
syncDebug("fpathRoute(..., %d, %d, %d, %d, %d, %d, %d, %d, %d) = FPR_FAILED", id, startX, startY, tX, tY, propulsionType, droidType, moveType, owner);
return FPR_FAILED;
}
// don't have to do anything if already there
if (startX == tX && startY == tY)
{
// return failed to stop them moving anywhere
objTrace(id, "Tried to move nowhere");
syncDebug("fpathRoute(..., %d, %d, %d, %d, %d, %d, %d, %d, %d) = FPR_FAILED", id, startX, startY, tX, tY, propulsionType, droidType, moveType, owner);
return FPR_FAILED;
}
// Check if waiting for a result
while (psMove->Status == MOVEWAITROUTE)
{
objTrace(id, "Checking if we have a path yet");
auto const &I = pathResults.find(id);
ASSERT(I != pathResults.end(), "Missing path result promise");
PATHRESULT result = I->second.get();
ASSERT(result.retval != FPR_OK || result.sMove.asPath, "Ok result but no path in list");
// Copy over select fields - preserve others
psMove->destination = result.sMove.destination;
psMove->numPoints = result.sMove.numPoints;
bool correctDestination = tX == result.originalDest.x && tY == result.originalDest.y;
psMove->pathIndex = 0;
psMove->Status = MOVENAVIGATE;
free(psMove->asPath);
psMove->asPath = result.sMove.asPath;
FPATH_RETVAL retval = result.retval;
ASSERT(retval != FPR_OK || psMove->asPath, "Ok result but no path after copy");
ASSERT(retval != FPR_OK || psMove->numPoints > 0, "Ok result but path empty after copy");
// Remove it from the result list
pathResults.erase(id);
objTrace(id, "Got a path to (%d, %d)! Length=%d Retval=%d", psMove->destination.x, psMove->destination.y, psMove->numPoints, (int)retval);
syncDebug("fpathRoute(..., %d, %d, %d, %d, %d, %d, %d, %d, %d) = %d, path[%d] = %08X->(%d, %d)", id, startX, startY, tX, tY, propulsionType, droidType, moveType, owner, retval, psMove->numPoints, ~crcSumVector2i(0, psMove->asPath, psMove->numPoints), psMove->destination.x, psMove->destination.y);
if (!correctDestination)
{
goto queuePathfinding; // Seems we got the result of an old pathfinding job for this droid, so need to pathfind again.
}
return retval;
}
queuePathfinding:
// We were not waiting for a result, and found no trivial path, so create new job and start waiting
PATHJOB job;
job.origX = startX;
job.origY = startY;
job.droidID = id;
job.destX = tX;
job.destY = tY;
job.dstStructure = dstStructure;
job.droidType = droidType;
job.propulsion = propulsionType;
job.moveType = moveType;
job.owner = owner;
job.acceptNearest = acceptNearest;
job.deleted = false;
fpathSetBlockingMap(&job);
debug(LOG_NEVER, "starting new job for droid %d 0x%x", id, id);
// Clear any results or jobs waiting already. It is a vital assumption that there is only one
// job or result for each droid in the system at any time.
fpathRemoveDroidData(id);
packagedPathJob task([job]() { return fpathExecute(job); });
pathResults[id] = task.get_future();
// Add to end of list
wzMutexLock(fpathMutex);
bool isFirstJob = pathJobs.empty();
pathJobs.push_back(std::move(task));
wzMutexUnlock(fpathMutex);
if (isFirstJob)
{
wzSemaphorePost(fpathSemaphore); // Wake up processing thread.
}
objTrace(id, "Queued up a path-finding request to (%d, %d), at least %d items earlier in queue", tX, tY, isFirstJob);
syncDebug("fpathRoute(..., %d, %d, %d, %d, %d, %d, %d, %d, %d) = FPR_WAIT", id, startX, startY, tX, tY, propulsionType, droidType, moveType, owner);
return FPR_WAIT; // wait while polling result queue
}
