Hi! Threads in Pharo have always been mysterious for me. If I doit the following: [ true ] whileTrue Can other thread interrupt this? Say in other words, can the following piece of code may suffer from a concurrent problem in Pharo anOrderedCollection add: 42 My current understanding about thread is that there is a scheduling that may occurs each time we enter the VM (e.g., primitive call, instantiating an object, throwing an exception). So, the code "anOrderedCollection add: 42â will _never_ suffer from concurrent call because adding 42 to a collection does not enter the VM. Does this make sense? What is the current status of this? Thanks to you all Alexandre -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.