Improve "waiting on"/"waiting to lock" SIGQUIT dump info.

In particular, when we're waiting on a Class, say which class:

  I(16573)   - waiting on <0xf5ed54f8> (java.lang.Class<java.lang.ref.ReferenceQueue>)

versus:

  I(16573)   - waiting on <0xf5feda38> (a java.util.LinkedList)

Bug: http://code.google.com/p/android/issues/detail?id=17349
Change-Id: I844d02c008b1499adb02995ff3da25ba8cad0e0a

1 files changed, 3 insertions, 4 deletions

diff --git a/vm/Sync.cpp b/vm/Sync.cpp
index 8257f80d4..09b12e423 100644
--- a/vm/Sync.cpp
+++ b/vm/Sync.cpp
@@ -271,7 +271,7 @@ static void logContentionEvent(Thread *self, u4 waitMs, u4 samplePercent,
     u4 relativePc;
     char eventBuffer[174];
     const char *fileName;
-    char procName[33], *selfName;
+    char procName[33];
     char *cp;
     size_t len;
     int fd;
@@ -299,9 +299,8 @@ static void logContentionEvent(Thread *self, u4 waitMs, u4 samplePercent,
     cp = logWriteInt(cp, isSensitive);
 
     /* Emit self thread name string, <= 37 bytes. */
-    selfName = dvmGetThreadName(self);
-    cp = logWriteString(cp, selfName, strlen(selfName));
-    free(selfName);
+    std::string selfName = dvmGetThreadName(self);
+    cp = logWriteString(cp, selfName.c_str(), selfName.size());
 
     /* Emit the wait time, 5 bytes. */
     cp = logWriteInt(cp, waitMs);