Author Archives: brucedawson

About brucedawson

I'm a programmer, working for Google, focusing on optimization and reliability. Nothing's more fun than making code run 10x as fast. Unless it's eliminating large numbers of bugs. I also unicycle. And play (ice) hockey. And sled hockey. And juggle. And worry about whether this blog should have been called randomutf-8. 2010s in review tells more: https://twitter.com/BruceDawson0xB/status/1212101533015298048

Finding Windows HANDLE leaks, in Chromium and others

Posted on July 25, 2021 by brucedawson

Three years ago I found a 32 GB memory leak caused by CcmExec.exe failing to close process handles. That bug is fixed, but ever since then I have had the handles column in  Windows Task Manager enabled, just in case … Continue reading →

Posted in Bugs, Code Reliability, Investigative Reporting, uiforetw, xperf | Tagged , | 12 Comments

Arranging Invisible Icons in Quadratic Time

Posted on February 16, 2021 by brucedawson

Near the end of January I was pointed to a twitter thread where a Windows user with a powerful machine was hitting random hangs in explorer. Lots of unscientific theories were being proposed. I don’t generally do random analysis of … Continue reading →

Posted in Investigative Reporting, Performance, Programming, Quadratic, Rants, Symbols | Tagged , | 18 Comments

Windows Timer Resolution: The Great Rule Change

Posted on January 29, 2021 by brucedawson

The behavior of the Windows scheduler changed significantly in Windows 10 2004 (aka, the April 2020 version of Windows), in a way that will break a few applications, and there appears to have been no announcement, and the documentation has … Continue reading →

Posted in Uncategorized | Tagged , | 1 Comment

Ditching WhatsApp

Posted on January 29, 2021 by brucedawson

WhatsApp has served me well as a communications medium for my family, but I was never thrilled with its ownership by Facebook, and the recently announced privacy changes made it necessary for me to move on.

Posted in Computers and Internet, Security | Tagged , , | 9 Comments

ARM and Lock-Free Programming

Posted on November 29, 2020 by brucedawson

I was inspired by the release of Apple’s M1 ARM processor to tweet about the perils of lock-free programming which led to some robust discussion. The discussion went pretty well given the inanity of trying to discuss something as complicated … Continue reading →

Posted in Uncategorized | 6 Comments

Floating Point in the Browser, Part 3: When x+y=x (y != 0)

Posted on October 18, 2020 by brucedawson

A few years ago I did a lot of thinking and writing about floating-point math. It was good fun, and I learned a lot in the process, but sometimes I go a long time without actually using that hard-earned knowledge. … Continue reading →

Posted in Chromium, Computers and Internet, Floating Point | Tagged , | 5 Comments

Floating Point in the Browser, Part 2: Bad Epsilon

Posted on October 11, 2020 by brucedawson

A few years ago I did a lot of thinking and writing about floating-point math. It was good fun, and I learned a lot in the process, but sometimes I go a long time without actually using that hard-earned knowledge. … Continue reading →

Posted in Chromium, Computers and Internet, Floating Point | Tagged , | 2 Comments

Windows Timer Resolution: The Great Rule Change

Posted on October 4, 2020 by brucedawson

The behavior of the Windows scheduler changed significantly in Windows 10 2004 (aka, the April 2020 version of Windows), in a way that will break a few applications, and there appears to have been no announcement, and the documentation has … Continue reading →

Posted in Environment, Investigative Reporting, Performance, Rants | Tagged , | 58 Comments

Floating Point in the Browser, Part 1: Impossible Expectations

Posted on September 27, 2020 by brucedawson

A few years ago I did a lot of thinking and writing about floating-point math. It was good fun, and I learned a lot in the process, but sometimes I go a long time without actually using that hard-earned knowledge. … Continue reading →

Posted in Chromium, Computers and Internet, Floating Point | Tagged , | 25 Comments

The Easy Ones – Three Bugs Hiding in the Open

Posted on August 30, 2020 by brucedawson

I write a lot about investigations into tricky bugs – CPU defects, kernel bugs, transient 4-GB memory allocations – but most bugs are not that esoteric. Sometimes tracking down a bug is as simple as paying attention to server dashboards, … Continue reading →

Posted in Bugs, Code analysis, Code Reliability, Debugging, Floating Point, Linux, Performance | Tagged | 23 Comments