Re: RFR: 8039173 Propagate errors from Diagnostic Commands as exceptions in the attach framework

[Ivan Gerasimov]

Thank you Staffan for fixing them!

But I'm afraid that now the function will never add ellipsis to the 
message, even if it gets truncated.

Sincerely yours,
Ivan

On 04.04.2014 15:47, Staffan Larsen wrote:
Thanks for finding these bugs, Ivan!

I have updated the webrev at: 
http://cr.openjdk.java.net/~sla/8039173/webrev.01/, and I have also included 
the diff below.

The updated webrev also has some changes in the javadoc for VirtualMachine to 
clarify that some methods can now throw AttachOperationFailedException.

Thanks,
/Staffan


diff --git a/src/share/classes/sun/tools/attach/HotSpotVirtualMachine.java 
b/src/share/classes/sun/tools/attach/HotSpotVirtualMachine.java
--- a/src/share/classes/sun/tools/attach/HotSpotVirtualMachine.java
+++ b/src/share/classes/sun/tools/attach/HotSpotVirtualMachine.java
@@ -266,18 +266,21 @@
       */
      String getErrorMessage(InputStream sis, int maxlen) throws IOException {
          byte b[] = new byte[maxlen];
-        int n, off = 0, len = b.length;
+        int n, off = 0, len = maxlen;
          do {
              n = sis.read(b, off, len);
+            if (n == -1) {
+                break;
+            }
              off += n;
              len -= n;
-        } while (n >= 0 && off < b.length);
+        } while (off < maxlen);

          String message = null;
          if (off > 0) {
              message = new String(b, 0, off, "UTF-8");
          }
-        if (off == b.length && message != null) {
+        if (off > b.length && message != null) {
              message += " ...";
          }
          return message;


On 4 apr 2014, at 11:18, Ivan Gerasimov <ivan.gerasi...@oracle.com> wrote:

Hi Staffan!

I think there is a couple of minor bugs in getErrorMessage(InputStream sis, int 
maxlen).

1) If maxlen is exactly the size of the message to read, the function will add 
an ellipsis, even though the message isn't truncated,
2) If maxlen is greater than needed, then sis.read(b, off, len) at the line 
#271 will eventually return -1, and it will cause the message to lose its last 
character.

Sincerely yours,
Ivan