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  1. JDK
  2. JDK-4177987

java.lang.ref.SoftReference: OutOfMemoryError thrown before instances cleared

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: P3
    • Resolution: Not an Issue
    • Affects Version/s: 1.2.0
    • Fix Version/s: None
    • Component/s: core-libs
    • Subcomponent:
    • CPU:
      sparc
    • OS:
      solaris_2.5

      Description



      Name: akC45999 Date: 10/01/98



      Description of the class java.lang.ref.SoftReference reads:

        All soft references to softly-reachable objects are guaranteed to have
        been cleared before the virtual machine throws an OutOfMemoryError.


      However, the attached test shows that a soft reference might not be cleared
      before OutOfMemoryError is thrown:

      ------------------------- file SoftReference0101.java
      import java.io.PrintStream;
      import java.lang.ref.*;


      public class SoftReference0101 {

        public static int run(String argv[], PrintStream out) {
      SoftReference ref=new SoftReference(new Object());

      Object[] memWaste=null;
      int arrSize, arrSizeNext=100000;

      eatMem:
      for (;;) {
      arrSize=arrSizeNext;
      try {
      Object [] newMemWaste=new Object[arrSize];
      out.println("allocation of "+arrSize+": succeeded.");
      newMemWaste[0]=memWaste;
      memWaste=newMemWaste;
      if (ref.get()==null) break eatMem; // test passed
      arrSizeNext=arrSize*2;
      } catch (OutOfMemoryError e) {
      out.println("allocation of "+arrSize+": failed.");
      if (ref.get()==null) break eatMem; // test passed
      out.println("SoftReference.get()!=null");
      return 2;
      }
      }
      out.println("passed");
          return 0;
        }

        public static void main(String args[]) {
      run(args, System.out);
        }

      }

      ---------------------------------

      Running the test:

      novo64% java -fullversion
      java full version "JDK-1.2fcs-L"
      novo64% javac SoftReference0101.java
      novo64% java SoftReference0101
      allocation of 100000: succeeded.
      allocation of 200000: succeeded.
      allocation of 400000: succeeded.
      allocation of 800000: succeeded.
      allocation of 1600000: succeeded.
      allocation of 3200000: succeeded.
      allocation of 6400000: succeeded.
      allocation of 12800000: failed.
      SoftReference.get()!=null
      novo64%

      ======================================================================

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            Assignee:
            mr Mark Reinhold
            Reporter:
            rfqsunw Rfq Rfq (Inactive)
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