[STR-3161] Servlet not injected into newly created action in higly concurrent env

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.3.8
• Fix Version/s: 1.3.10, 1.4.0
• Component/s: Core
• Environment: win xp, jvm 1.5.0_12
• Assignee: Niall Pemberton
• Reporter: Bartek Wasko
• Created: 28/Jul/08 09:16
• Updated: 31/Jul/08 13:00
• Resolved: 28/Jul/08 13:28

Description

In struts 1.3.8 we encountered such an issue

getServlet() invoked from action code returns null.

After quick investigation I found a bit susspicious place in the
RequestProcessor#processActionCreate code.
The synchronized block seems to be a bit risky in highly concurrent environment because it does not cover also the code injecting servlet into freshly created action:

if (instance.getServlet() == null) {
instance.setServlet(this.servlet);
}

After I had extended synchronisation to above code fragment, it seems, our nullpointer vanished.