Mutlithreaded static function question

I want to know if a static function is thread safe.
Lets say I have two static functions in a class foo
public class foo
   // vars
   public static String stat = "";
   //bad - not threadsafe
   public static String bad( String test );
      stat = test +" is mine";
      return (stat);
   //maybegood
   public static String maybegood(String test );
      String local_string_in_static = test+" is mine";
      return local_string_in_static);
I am pretty sure that the first is not threadsafe, because the external variable stat can be altered by other threads. My question, is the function maybegood threadsafe because it uses a local string, or is the local string also psuedo-static because it is in a static funciton?
Thanks.

>
I am pretty sure that the first is not threadsafe,
because the external variable stat can be altered by
other threads. Correct.
My question, is the function maybegood
threadsafe because it uses a local string, or is the
local string also psuedo-static because it is in a
static funciton?It is a local string even though it appears in a static method. No different than if it was in a non-static method.
So it is safe.

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The synchronized statement often deals with an object (called monitor).
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So if a static function is declared as static, what is the function of
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Can you give me a simple expplanation?
regards,
George

Hence try and avoid synchronizing static methods.
Try and use non static method if you are doing
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Hi
I was wondering ,If I have multiple threads accessing a certain stateless static function,
do I have to worry about synchronization?
eg lets say my function is:
public static int addup(int a,int b,int c)
ans = a + b + c;
return ans;
}Will each thread create its own instance of this function on the stack or will they all use the same one
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If indeed there is no synch problem here then shouldn't any stateless function be declared as static?

Aharon wrote:
public static int addup(int a,int b,int c)
ans = a + b + c;
return ans;
If this does compile, it's not stateless. ;-)
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Can not call a static function with-in a instance of the object.

Another FYI.
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I used a set of "WHEN conditions" that called the same
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If I can call the static method from the "type object" without creating
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This doesn't seem appropriate,
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Sorry for the confusion. Here is the simplest example of what
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The anonymous block is a testing of the object type, which definition follows.
declare
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begin
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test.testcall( audit_info.t_EMPLOYER() );
end;
-- * ========================================== * --
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( seq_key integer
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, member procedure test_call(input_type varchar2)
instantiable
final;
create or replace type body audit_info
as
( id audit_info
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as
begin
return 'EMPLOYER';
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as
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WHEN t_EMPLOYER()
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WHEN ...
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The error occurs on the "WHEN t_EMPLOYER()" line. This code is only
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Problem with instantiation in static function

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Your class Edge is a member of the instance of the current class. You don't have an implicit instance of the current class (the "this" reference) in a static context, therefore you get the error.
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Can anyone explain this to me, please. It's a static section question.

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hi,
The static section shall be loaded before it's constructor is called. (i.e at the time of loading the class). Therefore making it available for any other objects to call.
hope this clarifies ur question
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Edited by: RohitRawat on Sep 9, 2009 7:45 AM

RohitRawat wrote:
Please tell me that why a static function can't be made abstract?
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I was wondering if using a static function would be slower than using a normal function, especially when the function is to be accessed by multiple threads since the same memory area is used each time the static function is accessed from any of the threads. Thus is it right if I say that static functions are not suitable for multiThreaded access ?

I was wondering if using a static function would be
slower than using a normal function,Static functions are linked at compile time, while normal functions have to be linked based on the runtime type of the object they are called on. This lookup means that static function invocations are likely to be faster.
especially when
the function is to be accessed by multiple threads
since the same memory area is used each time the
static function is accessed from any of the threads.If you are talking about the code segment, where the function definition is held, there is only a single copy of each "normal" function as well. The code segment is also read-only, so there are no issues with multiple threads reading and executing the same code at the same time.
There are the normal issues with multi-threaded access to variables in static functions that exist with normal functions.
Thus is it right if I say that static functions are
not suitable for multiThreaded access ?Static functions are no safer than non-static functions in terms of thread safety. On the other hand, it is no more dangerous having multiple threads calling a static function than having multiple threads calling a non-static function on the same object. Exactly the same thread safety techniques apply whether you are working in a static or a non-static context.
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Mutlithreaded static function question

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