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Recently I was debugging a NullPointerException in Spark. The stacktrace was indicating this: After some digging I found out that the following query causes the problem: If I commented out the line with the comment the NPE was no longer there. Also, when I replaced either df2(“ref”) or df1(“ref”) with lit(“ref”) it was not crashing … Continue reading Spark and NullPointerException in UTF8String.contains
Recently I was debugging a case of NoSuchMethodError when using the Google Guava library. Conceptually my code was doing the following: In runtime I was using library in version 19 and I was getting the following error: I decompiled the code and got something similar to this If you look closely you can see that … Continue reading Source compatibility issue with Google Guava library
This is the ninth part of the .NET Inside Out series. For your convenience you can find other parts in the table of contents in Part 1 – Virtual and non-virtual calls in C# We know how to generate delegate from a byte array. Last time we did it by modifying some code using jumps … Continue reading .NET Inside Out Part 9 — Generating Func from a bunch of bytes in C# revisited
This is the fourth part of the WRK series. For your convenience you can find other parts in the table of contents in Part 1 — Compiling and debugging To create a new module, you need to prepare some directories and a make file. First, create the following structure in base\ntos Next, in module\BUILD\ put … Continue reading Windows Research Kernel Part 4 — New module
This is the third part of the WRK series. For your convenience you can find other parts in the table of contents in Part 1 — Compiling and debugging Today we are going to write a very simple hello world in the kernel space. Let’s go. Kernel First, we need to add new syscall to … Continue reading Windows Research Kernel Part 3 — Syscall