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class EXAMPLE6
-- Compilation:
-- compile_to_jvm example6
-- Execution:
-- java example6
-- This example demonstrates how to set Java field attributes of Eiffel
-- class attributes, how to declare a method synchronized, and how to
-- construct a synchronized block.
creation make
feature
make is
do
field_attributes
synchronized_test
monitor_test
end
feature
field_attributes is
-- have to look at dump of classfile to verify that
-- var1 is public
-- var2 is public and transient
-- var3 is public and volatile
-- var4 is public and transient and volatile
-- Note: The field_is_transient and field_is_volatile procedure calls
-- must be in a routine in the Eiffel class that will not be optimized
-- out at compile time. The best place to put them is in a creation
-- procedure that you know will be called at runtime.
do
field_is_transient( "var2" )
field_is_volatile( "var3" )
field_is_transient( "var4" )
field_is_volatile( "var4" )
var1 := 1
var2 := 1
var3 := 1
var4 := 1
end
feature
var1: INTEGER
var2: INTEGER
var3: INTEGER
var4: INTEGER
feature
synchronized_test is
-- have to look at dump of classfile to verify that this method is synchronized
-- Note: The routine_is_synchronized procedure call must be within the Eiffel routine
-- to be declared synchronized. It generates no code.
local
i: INTEGER
do
routine_is_synchronized
i := 1
end
monitor_test is
-- have to look at dump of classfile to verify that this Eifel routine has
-- monitorenter and monitorexit calls ( in Java, this would be a
-- synchronized block )
-- the user is responsible for ensuring that each monitorenter is matched
-- by a correspondng monitorexit on the same object
local
i: INTEGER
do
i := 0
-- start of synchronized block
monitor_enter( Current.to_pointer )
i := 1
monitor_exit( Current.to_pointer )
-- end of synchronized block
i := 2
end
feature -- externals
field_is_transient( s: STRING ) is
external "Java transient"
end
field_is_volatile( s: STRING ) is
external "Java volatile"
end
routine_is_synchronized is
external "Java synchronized"
end
monitor_enter( p: POINTER ) is
external "Java monitorenter"
end
monitor_exit( p: POINTER ) is
external "Java monitorexit"
end
end -- class EXAMPLE6
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