Timelines & Triggers - Learn SpriteBuilder for iOS Game Development - page 167

Avoiding the “Physics Space Locked” Error
Wait, did I just say “crash”? Unfortunately so:

Aborting due to Chipmunk error: You cannot manually reindex
objects while the space is locked. Wait until the current
query or step is complete.
Failed condition: !space->locked

This error is representative of a known issue with most physics engines: during collision
events, you can't modify certain aspects of the physics world (known as space in Chip-
munk). In this instance, playing the animation will change the node's rotation, and thus
the rotation of the node's physics body. Chipmunk doesn't like this because the physics
world (space) is locked , meaning the bodies in it are currently processed and need to be in
a coherent state where only the physics engine itself is allowed to make changes.

Consider where playing the animation came from: a Trigger instance sent the
didTriggerWithNode: message, which in turn had its triggerActivatedBy:
method run by the GameScene.m collision callback method ccPhysicsColli-
sionBegin:player:trigger .

Fortunately, there's a quick and simple fix for such issues. It's so simple you can try this
whenever you merely suspect such a u can't touch this issue. I'm terribly sorry about the
earworm.
Update the didTriggerWithNode: method in
PlayTimelineWhenTriggered.m as shown in Listing 5-17 .

Listing 5-17 . Fixing the Chipmunk space locked error

[self scheduleBlock:^(CCTimer *timer) {
[self.animationManager
runAnimationsForSequenceNamed:_timelineName];
} delay:0.0];

Scheduling a block with a 0 delay defers executing the contents of the block until the next
time the Cocos2D scheduler runs scheduled blocks. At the latest, this will run in the next
frame.