8209889: RedefineStress tests crash

Create CompileTaskWrapper before potential safepoint

Reviewed-by: mdoerr, dlong

src/hotspot/share/compiler/compileBroker.cpp

@@ -1781,30 +1781,31 @@ void CompileBroker::compiler_thread_loop() {
           return; // Stop this thread.
         }
       }
-      continue;
-    }
+    } else {
+      // Assign the task to the current thread.  Mark this compilation
+      // thread as active for the profiler.
+      // CompileTaskWrapper also keeps the Method* from being deallocated if redefinition
+      // occurs after fetching the compile task off the queue.
+      CompileTaskWrapper ctw(task);
+      nmethodLocker result_handle;  // (handle for the nmethod produced by this task)
+      task->set_code_handle(&result_handle);
+      methodHandle method(thread, task->method());
 
-    if (UseDynamicNumberOfCompilerThreads) {
-      possibly_add_compiler_threads();
-    }
+      // Never compile a method if breakpoints are present in it
+      if (method()->number_of_breakpoints() == 0) {
+        // Compile the method.
+        if ((UseCompiler || AlwaysCompileLoopMethods) && CompileBroker::should_compile_new_jobs()) {
+          invoke_compiler_on_method(task);
+          thread->start_idle_timer();
+        } else {
+          // After compilation is disabled, remove remaining methods from queue
+          method->clear_queued_for_compilation();
+          task->set_failure_reason("compilation is disabled");
+        }
+      }
 
-    // Assign the task to the current thread.  Mark this compilation
-    // thread as active for the profiler.
-    CompileTaskWrapper ctw(task);
-    nmethodLocker result_handle;  // (handle for the nmethod produced by this task)
-    task->set_code_handle(&result_handle);
-    methodHandle method(thread, task->method());
-
-    // Never compile a method if breakpoints are present in it
-    if (method()->number_of_breakpoints() == 0) {
-      // Compile the method.
-      if ((UseCompiler || AlwaysCompileLoopMethods) && CompileBroker::should_compile_new_jobs()) {
-        invoke_compiler_on_method(task);
-        thread->start_idle_timer();
-      } else {
-        // After compilation is disabled, remove remaining methods from queue
-        method->clear_queued_for_compilation();
-        task->set_failure_reason("compilation is disabled");
+      if (UseDynamicNumberOfCompilerThreads) {
+        possibly_add_compiler_threads();
       }
     }
   }