Add extension and agent for dumping internal jvmti plugin data.

When debugging openjdkjvmti plugin issues it can be useful to dump
internal state somewhere it can be examined. This adds a new extension
method that will let agents get a view of the deopt state of the
plugin and an agent that prints this information to LOG(INFO) on
SIGQUIT.

Test: ./test.py --host
Change-Id: Ia265a5bcca31a2df5ac930ddc2ecffb57d3db911

1 files changed, 15 insertions, 0 deletions

diff --git a/openjdkjvmti/ti_extension.cc b/openjdkjvmti/ti_extension.cc
index 5d398844b2..f12cb0a380 100644
--- a/openjdkjvmti/ti_extension.cc
+++ b/openjdkjvmti/ti_extension.cc
@@ -38,6 +38,7 @@
 #include "ti_allocator.h"
 #include "ti_class.h"
 #include "ti_ddms.h"
+#include "ti_dump.h"
 #include "ti_heap.h"
 #include "ti_logging.h"
 #include "ti_monitor.h"
@@ -312,6 +313,20 @@ jvmtiError ExtensionUtil::GetExtensionFunctions(jvmtiEnv* env,
     return error;
   }
 
+  // DumpInternalState
+  error = add_extension(
+      reinterpret_cast<jvmtiExtensionFunction>(DumpUtil::DumpInternalState),
+      "com.android.art.misc.get_plugin_internal_state",
+      "Gets internal state about the plugin and serializes it to the given msg. "
+      "There is no particular format to this message beyond being human readable.",
+      {
+          { "msg", JVMTI_KIND_ALLOC_BUF, JVMTI_TYPE_CCHAR, false },
+      },
+      { ERR(NULL_POINTER) });
+  if (error != ERR(NONE)) {
+    return error;
+  }
+
   // Copy into output buffer.
 
   *extension_count_ptr = ext_vector.size();