Improve retry handling when saving FileStoreAttributes fails

- fix handling of interrupts in FileStoreAttributes#saveToConfig
- increase retry wait time to 100ms
- don't wait after last retry
- dont retry if failure is caused by another exception than
LockFailedException

Change-Id: I108c012717d2bcce71f2c6cb9cf0879de704ebc2
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties

@@ -430,6 +430,7 @@ localRefIsMissingObjects=Local ref {0} is missing object(s).
 localRepository=local repository
 lockCountMustBeGreaterOrEqual1=lockCount must be >= 1
 lockError=lock error: {0}
+lockFailedRetry=locking {0} failed after {1} retries
 lockOnNotClosed=Lock on {0} not closed.
 lockOnNotHeld=Lock on {0} not held.
 malformedpersonIdentString=Malformed PersonIdent string (no < was found): {0}

org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java

@@ -491,6 +491,7 @@ public class JGitText extends TranslationBundle {
 	/***/ public String localRepository;
 	/***/ public String lockCountMustBeGreaterOrEqual1;
 	/***/ public String lockError;
+	/***/ public String lockFailedRetry;
 	/***/ public String lockOnNotClosed;
 	/***/ public String lockOnNotHeld;
 	/***/ public String malformedpersonIdentString;

org.eclipse.jgit/src/org/eclipse/jgit/util/FS.java

@@ -580,20 +580,30 @@ public abstract class FS {
 				} catch (LockFailedException e) {
 					// race with another thread, wait a bit and try again
 					try {
-						LOG.warn(MessageFormat.format(JGitText.get().cannotLock,
-								userConfig));
 						retries++;
-						Thread.sleep(20);
+						if (retries < max_retries) {
+							Thread.sleep(100);
+							LOG.debug("locking {} failed, retries {}/{}", //$NON-NLS-1$
+									userConfig, Integer.valueOf(retries),
+									Integer.valueOf(max_retries));
+						} else {
+							LOG.warn(MessageFormat.format(
+									JGitText.get().lockFailedRetry, userConfig,
+									Integer.valueOf(retries)));
+						}
 					} catch (InterruptedException e1) {
-						Thread.interrupted();
+						Thread.currentThread().interrupt();
+						break;
 					}
 				} catch (IOException e) {
 					LOG.error(MessageFormat.format(
 							JGitText.get().cannotSaveConfig, userConfig), e);
+					break;
 				} catch (ConfigInvalidException e) {
 					LOG.error(MessageFormat.format(
 							JGitText.get().repositoryConfigFileInvalid,
 							userConfig, e.getMessage()));
+					break;
 				}
 			}
 		}