Message

Reply | Reply all

Date Prev | Date Next | Thread Prev | Thread Next Date Index | Thread Index

From: cvs at opencores.org<cvs@o...>
Date: Fri Jan 18 23:45:10 CET 2008
Subject: [cvs-checkins] MODIFIED: jop ...
Date: 00/08/01 18:23:45

Modified: jop/java/target/src/common/com/jopdesign/sys GC.java
Log:
- Changed some final constants to be also public.

- Added one method to check if a handle is valid or not.




Revision Changes Path
1.51 jop/java/target/src/common/com/jopdesign/sys/GC.java

http://www.opencores.org/cvsweb.shtml/jop/java/target/src/common/com/jopdesign/sys/GC.java.diff?r1=1.50&r2=1.51

(In the diff below, changes in quantity of whitespace are not shown.)

Index: GC.java
===================================================================
RCS file: /cvsroot/paulo/jop/java/target/src/common/com/jopdesign/sys/GC.java,v
retrieving revision 1.50
retrieving revision 1.51
diff -u -b -r1.50 -r1.51
--- GC.java 18 Jan 2008 11:08:46 -0000 1.50
+++ GC.java 18 Jan 2008 22:45:10 -0000 1.51
@@ -57,9 +57,9 @@
* !!! be carefule when changing the handle structure, it's
* used in System.arraycopy() and probably in jvm.asm!!!
*/
- static final int OFF_PTR = 0;
- static final int OFF_MTAB_ALEN = 1;
- static final int OFF_SIZE = 2;
+ public static final int OFF_PTR = 0;
+ public static final int OFF_MTAB_ALEN = 1;
+ public static final int OFF_SIZE = 2;
public static final int OFF_TYPE = 3;

// size != array length (think about long/double)
@@ -68,8 +68,8 @@
// our addition:
// 1 reference
// 0 a plain object
- static final int IS_OBJ = 0;
- static final int IS_REFARR = 1;
+ public static final int IS_OBJ = 0;
+ public static final int IS_REFARR = 1;

/**
* Free and Use list.
@@ -630,6 +630,56 @@
return semi_size*4;
}

+ /**
+ * Check if a given value is a valid handle.
+ *
+ * This method traverse the list of handles (in use) to check
+ * if the handle provided belong to the list.
+ *
+ * It does *not* check the free handle list.
+ *
+ * One detail: the result may state that a handle to a
+ * (still unknown garbage) object is valid, in case
+ * the object is not reachable but still present
+ * on the use list.
+ * This happens in case the object becomes unreachable
+ * during execution, but GC has not reclaimed it yet.
+ * Anyway, it's still a valid object handle.
+ *
+ * @param handle the value to be checked.
+ * @return
+ */
+ public static final boolean isValidObjectHandle(int handle)
+ {
+ boolean isValid;
+ int handlePointer;
+
+ // assume it's not valid and try to show otherwise
+ isValid = false;
+
+ // synchronize on the GC lock
+ synchronized (mutex) {
+ // start on the first element of the list
+ handlePointer = useList;
+
+ // traverse the list until the element is found or the list is over
+ while(handlePointer != 0)
+ {
+ if(handle == handlePointer)
+ {
+ // found it! hence, it's a valid handle. Stop the search.
+ isValid = true;
+ break;
+ }
+
+ // not found yet. Let's go to the next element and try again.
+ handlePointer = Native.rdMem(handlePointer+OFF_NEXT);
+ }
+ }
+
+ return isValid;
+ } + /************************************************************************************************/