better logging for CrtResource refCount tracking

Author: sbSteveK

src/main/java/software/amazon/awssdk/crt/CrtResource.java

@@ -124,14 +124,15 @@ public CrtResource() {
      * @param resource The resource to add a reference to
      */
     public void addReferenceTo(CrtResource resource) {
+        if (debugNativeObjects) {
+            Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, 
+                String.format("%s(%d) is adding a reference to %s(%d)", 
+                this.getClass().getCanonicalName(), id, resource.getClass().getCanonicalName(), resource.id));
+        }
         resource.addRef();
         synchronized(this) {
             referencedResources.add(resource);
         }
-
-        if (debugNativeObjects) {
-            Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, String.format("Instance of class %s(%d) is adding a reference to instance of class %s(%d)", this.getClass().getCanonicalName(), id, resource.getClass().getCanonicalName(), resource.id));
-        }
     }
 
     /**
@@ -146,9 +147,13 @@ public void removeReferenceTo(CrtResource resource) {
 
         if (debugNativeObjects) {
             if (removed) {
-                Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, String.format("Instance of class %s(%d) is removing a reference to instance of class %s(%d)", this.getClass().getCanonicalName(), id, resource.getClass().getCanonicalName(), resource.id));
+                Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, 
+                    String.format("%s(%d) is removing a reference to %s(%d)", 
+                    this.getClass().getCanonicalName(), id, resource.getClass().getCanonicalName(), resource.id));
             } else {
-                Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, String.format("Instance of class %s(%d) erroneously tried to remove a reference to instance of class %s(%d) that it was not referencing", this.getClass().getCanonicalName(), id, resource.getClass().getCanonicalName(), resource.id));
+                Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, 
+                String.format("%s(%d) erroneously tried to remove a reference to %s(%d) that it was not referencing", 
+                this.getClass().getCanonicalName(), id, resource.getClass().getCanonicalName(), resource.id));
             }
         }
 
@@ -209,7 +214,8 @@ protected void acquireNativeHandle(long handle) {
      */
     private void release() {
         if (debugNativeObjects) {
-            Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, String.format("Releasing class %s(%d)", this.getClass().getCanonicalName(), id));
+            Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, 
+                String.format("Releasing class %s(%d)", this.getClass().getCanonicalName(), id));
 
             synchronized(CrtResource.class) {
                 CRT_RESOURCES.remove(id);
@@ -237,7 +243,25 @@ public long getNativeHandle() {
      * Increments the reference count to this resource.
      */
     public void addRef() {
-        refCount.incrementAndGet();
+        int updatedRefs = refCount.incrementAndGet();
+        if (debugNativeObjects) {
+           Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, 
+            String.format("%s(%d) is adding a reference. refCount is now %d", 
+            this.getClass().getCanonicalName(), id, updatedRefs));
+        }
+    }
+
+    /**
+     * Increments the reference count to this resource with a description.
+     * @param desc Descrption string of why the reference is being incremented.
+     */
+    public void addRef(String desc) {
+       int updatedRefs = refCount.incrementAndGet();
+       if (debugNativeObjects) {
+           Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, 
+            String.format("%s(%d) is adding a reference for: (%s). RefCount is now %d", 
+            this.getClass().getCanonicalName(), id, desc, updatedRefs));
+       }
     }
 
     /**
@@ -274,7 +298,11 @@ public boolean isNull() {
 
     @Override
     public void close() {
-        decRef();
+        decRef("close() called");
+    }
+
+    public void close(String desc) {
+        decRef(desc);
     }
 
     /**
@@ -286,12 +314,37 @@ public void decRef(CrtResource decRefInstigator) {
         int remainingRefs = refCount.decrementAndGet();
 
         if (debugNativeObjects) {
-            if (decRefInstigator != null) {
-                Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, String.format(
-                    "DecRef instance of class %s(%d) called by %s(%d). %d remaining refs", this.getClass().getCanonicalName(), id, 
-                    decRefInstigator.getClass().getCanonicalName(), decRefInstigator.id, remainingRefs));
+            Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, String.format(
+                "DecRef of %s(%d) called by %s(%d). %d remaining refs", this.getClass().getCanonicalName(), id, 
+                decRefInstigator.getClass().getCanonicalName(), decRefInstigator.id, remainingRefs));
+        }
+
+        if (remainingRefs != 0) {
+            return;
+        }
+
+        release();
+
+        if (canReleaseReferencesImmediately()) {
+            releaseReferences();
+        }
+    }
+
+    /**
+     * Decrements the reference count to this resource with a description.
+     * @param desc Descrption string of why the reference is being decremented.
+     */
+    public void decRef(String desc) {
+        int remainingRefs = refCount.decrementAndGet();
+
+        if (debugNativeObjects) {
+            if (desc != null) {
+                Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, 
+                    String.format("DecRef on %s(%d) for: (%s). %d remaining refs", 
+                    this.getClass().getCanonicalName(), id, desc, remainingRefs));
             } else {
-                Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, String.format("DecRef instance of class %s(%d) via self.close(). %d remaining refs", 
+                Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource,
+                    String.format("Defref on %s(%d). %d remaining refs",
                     this.getClass().getCanonicalName(), id, remainingRefs));
             }
         }
@@ -306,11 +359,12 @@ public void decRef(CrtResource decRefInstigator) {
             releaseReferences();
         }
     }
+
     /**
      * Decrements the reference count to this resource.
      */
     public void decRef() {        
-        decRef(null);
+        decRef((String)null);
     }
 
     /**
@@ -320,7 +374,9 @@ public void decRef() {
      */
     protected void releaseReferences() {
         if (debugNativeObjects) {
-            Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, String.format("Instance of class %s(%d) closing all referenced objects", this.getClass().getCanonicalName(), id));
+            Log.log(ResourceLogLevel, Log.LogSubject.JavaCrtResource, 
+            String.format("%s(%d) closing all referenced objects", 
+            this.getClass().getCanonicalName(), id));
         }
 
         synchronized(this) {