Memory usage

The following causes a constant increase in the amount of memory used. Why?

ta!

' memory test
Strict
Graphics 640,480,0

Type test
	Field life
	Method die()
		life = life - 1
		If life = 0 Then test_list.remove(Self)
	End Method
End Type
Global test_list:TList = CreateList()

While Not KeyDown(key_escape)

	create_Test()
	
	kill_test()

	If KeyHit(key_1) Then Print MemAlloced()
	Flip
	Cls
Wend

End

' ### Create a test object
Function Create_test()
	
	Local NewTest:Test
	NewTest = New Test
	
	NewTest.life = 1
	
	test_List.AddLast( Newtest )

End Function

' ### Run the process that kills the test
Function kill_test()

	For Local ThisTest:test = EachIn test_list
		ThisTest.die()
	Next

End Function

Question about your code

The Newtest exists outside create_test because it is in the list right? So how can you remove it from the list when within one of its own methods? Cos then it shouldnt exist, but you are "in" it, so it needs to exist. no?

ok thats a fair enough point, but the following still does the same...

' memory test
Strict
Graphics 640,480,0

Type test
	Field life
End Type
Global test_list:TList = CreateList()

While Not KeyDown(key_escape)

	create_Test()
	
	kill_test()

	If KeyHit(key_1) Then Print MemAlloced()
	Flip
	Cls
Wend

End

' ### Create a test object
Function Create_test()
	
	Local NewTest:Test
	NewTest = New Test
	
	NewTest.life = 1
	
	test_List.AddLast( Newtest )

End Function

' ### Run the process that kills the test
Function kill_test()

	For Local ThisTest:test = EachIn test_list
		ThisTest.life = ThisTest.life-1
		If Thistest.life = 0 Then test_list.remove(ThisTest)
	Next

End Function

You're using memalloced so, I assume, a backlevel of Bmax so will need to use a flushmem() statement.
You should really install 1.18, upgrade to 1.20 and syncmods.
I ran a similar test at 1.20 and the memory usage settles down...

' memory test
Strict
Graphics 640,480,0

Type test
	Field life
	Method die()
		life = life - 1
		If life = 0 Then test_list.remove(Self)
	End Method
End Type
Global test_list:TList = CreateList()
Local high_mem:Int=0
While Not KeyDown(key_escape)

	create_Test()
	DrawText CountList(test_list),0,10
	
	kill_test()

	Local latest_mem:Int = GCMemAlloced()
	If latest_mem > high_mem high_mem = latest_mem
	DrawText high_mem , 0 , 0
	DrawText CountList(test_list),40,10
	Flip
	Cls
Wend

End

' ### Create a test object
Function Create_test()
	
	Local NewTest:Test
	NewTest = New Test
	
	NewTest.life = 1
	
	test_List.AddLast( Newtest )

End Function

' ### Run the process that kills the test
Function kill_test()

	For Local ThisTest:test = EachIn test_list
		ThisTest.die()
	Next

End Function

ahh perfik, thank you, yup flushmem sorted it out good and proper :)

i better upgrade too ;)