Category Archives: Programming

Determinism Bugs, Part Two, Kernel32.dll

Posted on January 6, 2022 by brucedawson

It was literally the day after I cracked the __FILE__ determinism bug that I hit a completely different build determinism issue. I was asked to investigate why the Chrome build number reported for Chrome crashes on Windows 11 was lagging … Continue reading →

Posted in Bugs, Chromium, Computers and Internet, Investigative Reporting, Programming, Symbols | Tagged , , | 17 Comments

Two Deterministic Build Bugs

Posted on January 4, 2022 by brucedawson

‘Twas the week before Christmas and I ran across a deterministic-build bug. And then another one. One was in Chromium, and the other was in Microsoft Windows. It seemed like a weird coincidence so I thought I’d write about both … Continue reading →

Posted in Bugs, Chromium, Computers and Internet, Debugging, Programming | Tagged , , | 14 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

GDI leaks and the importance of luck

Posted on May 10, 2020 by brucedawson

In May 2019 I was asked to look at a potentially serious Chrome bug. I initially misdiagnosed it as unimportant, thus wasting two valuable weeks, and when I rejoined the investigation it was the number one browser-process crash in Chrome’s … Continue reading →

Posted in Bugs, Chromium, Debugging, Programming | Tagged | 25 Comments

Big Project Build Times–Chromium

Posted on March 30, 2020 by brucedawson

A twitter discussion on build times and source-file sizes got me interested in doing some analysis of Chromium build times. I had some ideas about what I would find (lots of small source files causing much of the build time) … Continue reading →

Posted in Chromium, Performance, Programming | Tagged , | 23 Comments

Creating a Public Symbol Server, Easily

Posted on March 14, 2020 by brucedawson

I’ve been a big fan of symbol servers for years. They are a part of the Microsoft/Windows ecosystem that is far better than anything I have seen for other operating systems. With Microsoft’s and Chrome’s symbol servers configured I can … Continue reading →

Posted in Debugging, Programming, Symbols, uiforetw | Tagged | 15 Comments

O(n^2), again, now in WMI

Posted on December 8, 2019 by brucedawson

I recently hit some multi-minute delays on my workstation. After investigating I found that the problem was due to a lock being held for five minutes, and during that time the lock-holder was mostly just spinning in a nine-instruction loop. … Continue reading →

Posted in Investigative Reporting, Programming, Quadratic, Rants, uiforetw, xperf | Tagged , , , , | 23 Comments

Heap Snapshots–Tracing All Heap Allocations

Posted on October 27, 2019 by brucedawson

I’ve recently started using heap snapshots on Windows to track heap allocations. I was able to use heap snapshots to record call stacks for all outstanding allocations in Chrome’s browser process over a full two weeks, letting me account for … Continue reading →

Posted in Documentation, Performance, Programming, uiforetw, xperf | Tagged , | 22 Comments

63 Cores Blocked by Seven Instructions

Posted on October 20, 2019 by brucedawson

I seem to have a habit of writing about super powerful machines whose many cores are laid low by misuse of locks. So. Yeah. It’s that again. But this one seems particularly impressive. I mean, how often do you have … Continue reading →

Posted in Investigative Reporting, Performance, Programming, Quadratic, uiforetw, xperf | Tagged , , | 12 Comments

When Your Profiler Lies

Posted on December 9, 2018 by brucedawson

Last week I wrote about the performance consequences of inadvertently loading gdi32.dll into processes that are created and destroyed at very high rates. This week I want to share some techniques for digging deeper into this behavior, and the odd … Continue reading →

Posted in Investigative Reporting, Performance, Programming, uiforetw, xperf | Tagged , , | 12 Comments