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bugfix(pathfinder): Prevent infinite loop within PathfindCell::putOnSortedOpenList() #1965

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Merged
xezon merged 1 commit into from
Dec 10, 2025
+48 −29
Merged

bugfix(pathfinder): Prevent infinite loop within PathfindCell::putOnSortedOpenList() #1965

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38 changes: 24 additions & 14 deletions Generals/Code/GameEngine/Source/GameLogic/AI/AIPathfind.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -92,6 +92,13 @@ inline Int IABS(Int x) { if (x>=0) return x; return -x;};
//-----------------------------------------------------------------------------------
static Int frameToShowObstacles;

constexpr const UnsignedInt MAX_CELL_COUNT = 500;
constexpr const UnsignedInt MAX_ADJUSTMENT_CELL_COUNT = 400;
constexpr const UnsignedInt MAX_SAFE_PATH_CELL_COUNT = 2000;

constexpr const UnsignedInt PATHFIND_CELLS_PER_FRAME = 5000; // Number of cells we will search pathfinding per frame.
constexpr const UnsignedInt CELL_INFOS_TO_ALLOCATE = 30000;

//-----------------------------------------------------------------------------------
PathNode::PathNode() :
m_nextOpti(0),
Expand Down Expand Up @@ -1077,8 +1084,6 @@ Real Path::computeFlightDistToGoal( const Coord3D *pos, Coord3D& goalPos )
}
//-----------------------------------------------------------------------------------

enum { PATHFIND_CELLS_PER_FRAME=5000}; // Number of cells we will search pathfinding per frame.
enum {CELL_INFOS_TO_ALLOCATE = 30000};
PathfindCellInfo *PathfindCellInfo::s_infoArray = NULL;
PathfindCellInfo *PathfindCellInfo::s_firstFree = NULL;

Expand Down Expand Up @@ -1547,8 +1552,18 @@ PathfindCell *PathfindCell::putOnSortedOpenList( PathfindCell *list )
{
// insertion sort
PathfindCell *c, *lastCell = NULL;
for( c = list; c; c = c->getNextOpen() )
#if RETAIL_COMPATIBLE_PATHFINDING
// TheSuperHackers @bugfix In the retail compatible pathfinding, on rare ocassions, we get stuck in an infinite loop
// External code should pickup on the bad behaviour and cleanup properly, but we need to explicitly break out here
// The fixed pathfinding does not have this issue due to the proper cleanup of pathfindCells and their pathfindCellInfos
UnsignedInt cellCount = 0;
for (c = list; c && cellCount < PATHFIND_CELLS_PER_FRAME; c = c->getNextOpen())
{
cellCount++;
#else
for (c = list; c; c = c->getNextOpen())
{
#endif
if (c->m_info->m_totalCost > m_info->m_totalCost)
break;

Expand Down Expand Up @@ -4715,8 +4730,7 @@ Bool Pathfinder::adjustToLandingDestination(Object *obj, Coord3D *dest)
}
worldToCell( &adjustDest, &cell );

enum {MAX_CELLS_TO_TRY=400};
Int limit = MAX_CELLS_TO_TRY;
Int limit = MAX_ADJUSTMENT_CELL_COUNT;
Int i, j;
i = cell.x;
j = cell.y;
Expand Down Expand Up @@ -4793,8 +4807,7 @@ Bool Pathfinder::adjustDestination(Object *obj, const LocomotorSet& locomotorSet
layer = TheTerrainLogic->getLayerForDestination(groupDest);
}

enum {MAX_CELLS_TO_TRY=400};
Int limit = MAX_CELLS_TO_TRY;
Int limit = MAX_ADJUSTMENT_CELL_COUNT;
Int i, j;
i = cell.x;
j = cell.y;
Expand Down Expand Up @@ -4877,8 +4890,8 @@ Bool Pathfinder::adjustTargetDestination(const Object *obj, const Object *target
if (worldToCell( &adjustDest, &cell )) {
return false; // outside of bounds.
}
enum {MAX_CELLS_TO_TRY=400};
Int limit = MAX_CELLS_TO_TRY;

Int limit = MAX_ADJUSTMENT_CELL_COUNT;
Int i, j;
i = cell.x;
j = cell.y;
Expand Down Expand Up @@ -5001,8 +5014,7 @@ Bool Pathfinder::adjustToPossibleDestination(Object *obj, const LocomotorSet& lo
}
}

enum {MAX_CELLS_TO_TRY=400};
Int limit = MAX_CELLS_TO_TRY;
Int limit = MAX_ADJUSTMENT_CELL_COUNT;
Int i, j;
i = goalCellNdx.x;
j = goalCellNdx.y;
Expand Down Expand Up @@ -7511,7 +7523,6 @@ Bool Pathfinder::pathDestination( Object *obj, const LocomotorSet& locomotorSet
if (!obj) return false;

Int cellCount = 0;
#define MAX_CELL_COUNT 500

Coord3D adjustTo = *groupDest;
Coord3D *to = &adjustTo;
Expand Down Expand Up @@ -7806,7 +7817,6 @@ Int Pathfinder::checkPathCost(Object *obj, const LocomotorSet& locomotorSet, con
if (!obj) return MAX_COST;

Int cellCount = 0;
#define MAX_CELL_COUNT 500

Coord3D adjustTo = *rawTo;
Coord3D *to = &adjustTo;
Expand Down Expand Up @@ -10328,7 +10338,7 @@ Path *Pathfinder::findSafePath( const Object *obj, const LocomotorSet& locomotor
// Int startTimeMS = ::GetTickCount();
#endif

const Int MAX_CELLS = 2000; // this is a rather expensive operation, so limit the search.
const Int MAX_CELLS = MAX_SAFE_PATH_CELL_COUNT; // this is a rather expensive operation, so limit the search.

Bool centerInCell;
Int radius;
Expand Down
39 changes: 24 additions & 15 deletions GeneralsMD/Code/GameEngine/Source/GameLogic/AI/AIPathfind.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -106,7 +106,13 @@ inline Int IABS(Int x) { if (x>=0) return x; return -x;};
static Int frameToShowObstacles;


static UnsignedInt ZONE_UPDATE_FREQUENCY = 300;
constexpr const UnsignedInt ZONE_UPDATE_FREQUENCY = 300;
constexpr const UnsignedInt MAX_CELL_COUNT = 500;
constexpr const UnsignedInt MAX_ADJUSTMENT_CELL_COUNT = 400;
constexpr const UnsignedInt MAX_SAFE_PATH_CELL_COUNT = 2000;

constexpr const UnsignedInt PATHFIND_CELLS_PER_FRAME = 5000; // Number of cells we will search pathfinding per frame.
constexpr const UnsignedInt CELL_INFOS_TO_ALLOCATE = 30000;

//-----------------------------------------------------------------------------------
PathNode::PathNode() :
Expand Down Expand Up @@ -1093,8 +1099,6 @@ Real Path::computeFlightDistToGoal( const Coord3D *pos, Coord3D& goalPos )
}
//-----------------------------------------------------------------------------------

enum { PATHFIND_CELLS_PER_FRAME=5000}; // Number of cells we will search pathfinding per frame.
enum {CELL_INFOS_TO_ALLOCATE = 30000};
PathfindCellInfo *PathfindCellInfo::s_infoArray = NULL;
PathfindCellInfo *PathfindCellInfo::s_firstFree = NULL;

Expand Down Expand Up @@ -1565,8 +1569,18 @@ PathfindCell *PathfindCell::putOnSortedOpenList( PathfindCell *list )
{
// insertion sort
PathfindCell *c, *lastCell = NULL;
for( c = list; c; c = c->getNextOpen() )
#if RETAIL_COMPATIBLE_PATHFINDING
// TheSuperHackers @bugfix In the retail compatible pathfinding, on rare ocassions, we get stuck in an infinite loop
// External code should pickup on the bad behaviour and cleanup properly, but we need to explicitly break out here
// The fixed pathfinding does not have this issue due to the proper cleanup of pathfindCells and their pathfindCellInfos
UnsignedInt cellCount = 0;
for (c = list; c && cellCount < PATHFIND_CELLS_PER_FRAME; c = c->getNextOpen())
{
cellCount++;
#else
for (c = list; c; c = c->getNextOpen())
{
#endif
if (c->m_info->m_totalCost > m_info->m_totalCost)
break;

Expand Down Expand Up @@ -4998,8 +5012,7 @@ Bool Pathfinder::adjustToLandingDestination(Object *obj, Coord3D *dest)
}
worldToCell( &adjustDest, &cell );

enum {MAX_CELLS_TO_TRY=400};
Int limit = MAX_CELLS_TO_TRY;
Int limit = MAX_ADJUSTMENT_CELL_COUNT;
Int i, j;
i = cell.x;
j = cell.y;
Expand Down Expand Up @@ -5076,8 +5089,7 @@ Bool Pathfinder::adjustDestination(Object *obj, const LocomotorSet& locomotorSet
layer = TheTerrainLogic->getLayerForDestination(groupDest);
}

enum {MAX_CELLS_TO_TRY=400};
Int limit = MAX_CELLS_TO_TRY;
Int limit = MAX_ADJUSTMENT_CELL_COUNT;
Int i, j;
i = cell.x;
j = cell.y;
Expand Down Expand Up @@ -5160,8 +5172,8 @@ Bool Pathfinder::adjustTargetDestination(const Object *obj, const Object *target
if (worldToCell( &adjustDest, &cell )) {
return false; // outside of bounds.
}
enum {MAX_CELLS_TO_TRY=400};
Int limit = MAX_CELLS_TO_TRY;

Int limit = MAX_ADJUSTMENT_CELL_COUNT;
Int i, j;
i = cell.x;
j = cell.y;
Expand Down Expand Up @@ -5284,8 +5296,7 @@ Bool Pathfinder::adjustToPossibleDestination(Object *obj, const LocomotorSet& lo
}
}

enum {MAX_CELLS_TO_TRY=400};
Int limit = MAX_CELLS_TO_TRY;
Int limit = MAX_ADJUSTMENT_CELL_COUNT;
Int i, j;
i = goalCellNdx.x;
j = goalCellNdx.y;
Expand Down Expand Up @@ -7910,7 +7921,6 @@ Bool Pathfinder::pathDestination( Object *obj, const LocomotorSet& locomotorSet
if (!obj) return false;

Int cellCount = 0;
#define MAX_CELL_COUNT 500

Coord3D adjustTo = *groupDest;
Coord3D *to = &adjustTo;
Expand Down Expand Up @@ -8205,7 +8215,6 @@ Int Pathfinder::checkPathCost(Object *obj, const LocomotorSet& locomotorSet, con
if (!obj) return MAX_COST;

Int cellCount = 0;
#define MAX_CELL_COUNT 500

Coord3D adjustTo = *rawTo;
Coord3D *to = &adjustTo;
Expand Down Expand Up @@ -10805,7 +10814,7 @@ Path *Pathfinder::findSafePath( const Object *obj, const LocomotorSet& locomotor
// Int startTimeMS = ::GetTickCount();
#endif

const Int MAX_CELLS = 2000; // this is a rather expensive operation, so limit the search.
const Int MAX_CELLS = MAX_SAFE_PATH_CELL_COUNT; // this is a rather expensive operation, so limit the search.

Bool centerInCell;
Int radius;
Expand Down
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