Hi,
I expect it would be a good & safe thing to do, to check for NULL.
But I don't know if all of these reports you have are down to that.
Did you get stack traces for all of them ?
We also have open bugs like
https://bugs.openjdk.java.net/browse/JDK-8146329
https://bugs.openjdk.java.net/browse/JDK-8133783
which look different.
-phil.
On 10/10/2018 10:56 AM, Bill York wrote:
Thanks for the response Phil, here’s what I know.
Reports show:
* Mac OS – many versions 10.10 through 17.7
* Java - 8 u144-b01 (48 reports), 8 u152-b16 (12 reports) 8
u152-release-1136-b5 – JetBrains (1 report)
Comments say:
* Screen change event. I am using the jetbrains JRE, as you can see
in the stack trace.
* I am on a mac and product crashes very often when I put my
computer to sleep.
* Woke up computer after connecting to two external monitors.
I’ve annotated the function names with links to code I found on the
OpenJDK site and the Apple site.
As an experiment, I created a simple X-Code project to examine how
CFSTringCompare behaves when passed NULL. It does throw an
EXC_BAD_ACCESS as is shown in the below stack trace. My example code
is at the end of this message.
Stack trace shows:
[ 7] 0x00006000001c5848 <unknown-module>+00000000
[ 8] 0x00007fff3cc4e678
/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+00140920CFStringCompare
<https://developer.apple.com/documentation/corefoundation/1542911-cfstringcompare?language=objc>+00000024
[ 9] 0x00000001351a80f7
java/jre/maci64/jre/lib/libawt_lwawt.dylib+00119031
getBPPFromModeString
<http://hg.openjdk.java.net/jdk8/jdk8/jdk/file/687fd7c7986d/src/macosx/native/sun/awt/CGraphicsDevice.m>+00000032
(see line 32)
[ 10] 0x00000001351a819f
java/jre/maci64/jre/lib/libawt_lwawt.dylib+00119199
createJavaDisplayMode
<http://hg.openjdk.java.net/jdk8/jdk8/jdk/file/687fd7c7986d/src/macosx/native/sun/awt/CGraphicsDevice.m>+00000053
(see line 130)
[ 11] 0x00000001351a841e
java/jre/maci64/jre/lib/libawt_lwawt.dylib+00119838
Java_sun_awt_CGraphicsDevice_nativeGetDisplayMode
<http://hg.openjdk.java.net/jdk8/jdk8/jdk/file/687fd7c7986d/src/macosx/native/sun/awt/CGraphicsDevice.m>+00000031
(see line 267)
Example code:
#import <Foundation/Foundation.h>
static int getBPPFromModeString(CFStringRef mode)
{
if((CFStringCompare(mode, CFSTR(kIO30BitDirectPixels),
kCFCompareCaseInsensitive) == kCFCompareEqualTo)) {
// This is a strange mode, where we using 10 bits per RGB component
and pack it into 32 bits
// Java is not ready to work with this mode but we have to specify it
as supported
return 30;
}
elseif(CFStringCompare(mode, CFSTR(IO32BitDirectPixels),
kCFCompareCaseInsensitive) == kCFCompareEqualTo) {
return 32;
}
elseif(CFStringCompare(mode, CFSTR(IO16BitDirectPixels),
kCFCompareCaseInsensitive) == kCFCompareEqualTo) {
return 16;
}
elseif(CFStringCompare(mode, CFSTR(IO8BitIndexedPixels),
kCFCompareCaseInsensitive) == kCFCompareEqualTo) {
return 8;
}
return0;
}
int main(int argc, const char * argv[]) {
@autoreleasepool{
// insert code here...
CFStringRef mode;
getBPPFromModeString(mode);
NSLog(@"Hello, World!");
}
return0;
}
*From: *Philip Race <philip.r...@oracle.com>
*Organization: *Oracle Corporation
*Date: *Wednesday, October 10, 2018 at 12:03 PM
*To: *Bill York <bill.y...@mathworks.com>
*Cc: *"2d-dev@openjdk.java.net" <2d-dev@openjdk.java.net>
*Subject: *Re: [OpenJDK 2D-Dev] Crash in CGraphicsDevice.m
The code you suspect has nothing to do with the webrev you list.
It was introduced in fixing
https://bugs.openjdk.java.net/browse/JDK-7124247
<https://bugs.openjdk.java.net/browse/JDK-7124247>
So has been there since JDK 8 GA. Not recent .. perhaps you can tell us
more about your users JDK versions and what is the earliest that
reproduces this crash ?
-phil.
On 10/10/18, 8:45 AM, Bill York wrote:
2d-dev folks,
I work on a product called MATLAB and we have about 60 reports
from customers on Mac related to a crash in CGraphicsDevice.m
Please let me know if this is the right way to report a crash and
discuss getting it resolved.
Here are the details:
CGraphicsDevice.m is a native file in support of Java drawing and
gets called from Java_sun_awt_CGraphicsDevice_nativeGetDisplayMode
While I can’t reproduce the problem, it looks like the display
pointer is becoming invalid for a time when the user’s laptop
opens or closes.
Looking at this source code:
http://cr.openjdk.java.net/~serb/8000629/webrev.08/src/macosx/native/sun/awt/CGraphicsDevice.m.html
<http://cr.openjdk.java.net/%7Eserb/8000629/webrev.08/src/macosx/native/sun/awt/CGraphicsDevice.m.html>
I see a direct call to CFStringCompare without a check for a NULL
CFStringRef.
* (CFStringCompare(mode, CFSTR(kIO30BitDirectPixels),
kCFCompareCaseInsensitive) == kCFCompareEqualTo)
I believe if this code returned 0, the crash would not occur
though there may be some other cleanup in the surrounding call frames.
Bill
