<AWT Dev> [7u] Review request for 8005607: Recursion in J2DXErrHandler() Causes a Stack Overflow on Linux

[Anthony Petrov]

Hi Anton,

The updated fix looks fine to me. Thank you.

Just a minor suggestion: could you please add a comment just before the 
line 441 at GLXSurfaceData.c to state that this particular XSync() call 
is performed w/o an AWTLock? No need to resend a new webrev for this change.

--
best regards,
Anthony

On 07/10/2013 07:16 PM, Anton Litvinov wrote:
> Hello Anthony,
>
> Thank you for review of this fix and for these remarks. I think that it
> is better to make macros return values, then to rename them to STORE_*,
> because it will reduce the number of parameters of the macros and make
> them clear. Yes, sure, I can file a separate bug for changing of JDK 8
> code related to the fix to make it equal to the fix for JDK 7, but only
> after the final version of the fix for JDK 7 is deduced and integrated
> into jdk7u-dev repository. Could you please review the second version of
> the fix with corrections which should follow your remarks.
>
> Webrev: http://cr.openjdk.java.net/~alitvinov/8005607/jdk7/webrev.01
>
> The following changes were added to the fix:
>
> 1. The macros GET_HANDLER_ERROR_OCCURRED_FLAG, GET_XERROR_CODE from the
> file "awt_util.h" were changed to expressions to return values. The
> places, from which the macros are called, were edited.
>
>      "awt_util.h": 119         errorOccurredFlag =
> GET_HANDLER_ERROR_OCCURRED_FLAG(env, handlerRef);
>      "GLXSurfaceData.c": 443     errorOccurredFlag =
> GET_HANDLER_ERROR_OCCURRED_FLAG(env, errorHandlerRef);
>      "awt_xembed_server.c": 659     xerror_code = GET_XERROR_CODE(env,
> savedError);
>      "awt_wm.c": 1053     xerror_code = GET_XERROR_CODE(env, savedError);
>                              2743     xerror_code = GET_XERROR_CODE(env,
> savedError);
>
> 2. The tags <code>...</code> were changed for {@code ...} in all java
> comments which were added by the fix. The edited files are
> "XErrorHandler.java" and "XErrorHandlerUtil.java".
>
> 3. The comment related to XSync() method call in the method
> "sun.awt.X11.XErrorHandlerUtil.RESTORE_XERROR_HANDLER(boolean doXSync)"
> was moved in the body of "if (doXSync)" statement.
>
> Also jdk7u-dev repository with this fix was successfully compiled for
> all architectures on Linux OS and Oracle Solaris OS. And the fix was
> verified for the bug JDK-8005607 and JDK-8015730 in my local environment.
>
> Thank you,
> Anton
>
> On 7/9/2013 5:50 PM, Anthony Petrov wrote:
>> Hi Anton,
>>
>> The word "get" usually implies that a method returns some value. The
>> GET_HANDLER_ERROR_OCCURRED_FLAG/GET_XERROR_CODE macros that you
>> introduce actually store a value in a variable. So perhaps they might
>> be renamed to STORE_* then? Alternatively, you could use the ?:
>> operator and actually make the macros "return" a value. E.g.:
>>
>> ((h) ? J_C(...) : JNI_FALSE)
>>
>> or
>>
>> ((sE = J_GSFBN()) ? J_CMBN() : Success )
>>
>> You could even try to avoid passing the savedError arg (if it's
>> unneeded in caller code) with the following macro:
>>
>> ({jobject sE = ...; (sE ? J_C() : Success);})
>>
>> (not sure if this compiles on Solaris with old C compilers though).
>>
>> Also, the G_X_C initializes the value with Success, but G_H_E_O_F
>> doesn't do that. Which means that if handlerRef is NULL for some
>> reason, the value stored in the variable errorOccirredFlag might be
>> undefined. So, if we choose the STORE_ alternative, should we use a
>> similar pattern for both macros in this regard, or there's a reason to
>> not do that?
>>
>> I suggest to replace legacy <code>...</code> in javadocs in
>> XErrorHandlerUtil.java with the modern variant {@code ... }. (And I'd
>> appreciate if you could file a separate bug and port this change to
>> jdk8 as well).
>>
>>>  112         // Wait until all requests are processed by the X server
>>>  113         // and only then uninstall the error handler.
>>>  114         if (doXSync) {
>>>  115             XSync();
>>
>> The comment applies to the XSync() call itself, so it's worth moving
>> it inside the if(){} block.
>>
>> --
>> best regards,
>> Anthony
>>
>> On 07/09/2013 01:30 PM, Anton Litvinov wrote:
>>> Hello Artem and Anthony,
>>>
>>> Could you please review this backport of the fix, which was approved by
>>> you for JDK 8, from JDK 8 to JDK 7.
>>>
>>> Bug: http://bugs.sun.com/view_bug.do?bug_id=8005607
>>> Webrev: http://cr.openjdk.java.net/~alitvinov/8005607/jdk7/webrev.00
>>> JDK 8 webrev: http://cr.openjdk.java.net/~alitvinov/8005607/webrev.05
>>>
>>> This fix is identical to the original fix for JDK 8 with the exception
>>> of the following places:
>>>
>>> 1) The new macro "GET_XERROR_CODE" was added in the file
>>> "src/solaris/native/sun/awt/awt_util.h". This macro allows native code
>>> to get "error_code" value of a saved XErrorEvent object from the global
>>> toolkit error handler in Java code. This variable is used in functions
>>> defined in the files "awt_wm.c", "awt_xembed_server.c".
>>>
>>> 138 #define GET_XERROR_CODE(env, savedError, errorCode) do {
>>>
>>> 2) The following 3 native XError handlers were substituted for the
>>> corresponding Java synthetic analogs in the files
>>> "src/solaris/native/sun/awt/awt_wm.c",
>>> "src/solaris/native/sun/awt/awt_xembed_server.c".
>>>
>>> a. xerror_ignore_bad_window(Display *dpy, XErrorEvent *err) --> Existing
>>> "sun.awt.X11.XErrorHandler.IgnoreBadWindowHandler"
>>>
>>> b. xerror_verify_change_property(Display *dpy, XErrorEvent *err) -->
>>> Existing "sun.awt.X11.XErrorHandler.VerifyChangePropertyHandler"
>>>
>>> c. xerror_detect_wm(Display *dpy, XErrorEvent *err) --> Created
>>> "sun.awt.X11.XErrorHandler.XChangeWindowAttributesHandler"
>>>
>>> 3) The fix for JDK-8015730, which is the regression of the fix for
>>> JDK-8005607 discovered in JDK 8, was ported to JDK 7 as part of this
>>> backport fix without any changes.
>>>
>>> The fix was tested by means of a manual testcase attached to the bug's
>>> record in JBS both on Linux OS and on Oracle Solaris OS.
>>>
>>> Thank you,
>>> Anton
>>>
>