In pharo seaside application on home button click all the data will get saved in a fuel file with some class name as Test.fl. If I call the same home page at a time in two instances, both are calling this below code to save Test.fl file with latest updates,
FLSerializer
serialize: self allObjects
toFileNamed: self name , '.fl'**
and getting exception:
CannotDeleteFileException: Could not delete the old version of file ...\Pharo3.0\Test.fl
And I have used Mutex to allow another instance to get executed after the first instance,
mutexBlock := Mutex new.
mutexBlock critical: [
FLSerializer
serialize: self allObjects
toFileNamed: self name , '.fl' ]
But still i am getting the same error
CannotDeleteFileException: Could not delete the old version of file
Please anybody help me on this to fix the error.
Your intuition is probably correct: two processes are trying to write (delete) the same file at the same time. Your Mutex approach will not work however because you create a new Mutex every time you execute that code. You have to store the Mutex in a class or instance variable (depending on how your code works) such that every process will use the same instance of the Mutex.
Your code would then look something like this:
MyClass class>>serializeProtect
^ SerializeProtect ifNil: [ SerializeProtect := Mutex new ]
self class serializeProtect critical: [
FLSerializer
serialize: self allObjects
toFileNamed: self name , '.fl' ]
Note: it is generally not safe to initialise a Mutex lazily. I'm simply doing it here for simplicities sake.