The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).
My take-aways are:
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You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.
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Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse
# Bash best practices and style-guide | |
Just simple methods to keep the code clean. | |
Inspired by [progrium/bashstyle](https://github.com/progrium/bashstyle) and [Kfir Lavi post](http://www.kfirlavi.com/blog/2012/11/14/defensive-bash-programming/). | |
## Quick big rules | |
* All code goes in a function | |
* Always double quote variables |
#!/bin/bash | |
killall Xcode | |
xcrun -k | |
xcodebuild -alltargets clean | |
rm -rf "$(getconf DARWIN_USER_CACHE_DIR)/org.llvm.clang/ModuleCache" | |
rm -rf "$(getconf DARWIN_USER_CACHE_DIR)/org.llvm.clang.$(whoami)/ModuleCache" | |
rm -rf ~/Library/Developer/Xcode/DerivedData/* | |
rm -rf ~/Library/Caches/com.apple.dt.Xcode/* | |
open /Applications/Xcode.app |
<?xml version="1.0" encoding="UTF-8"?> | |
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> | |
<plist version="1.0"> | |
<dict> | |
<key>method</key> | |
<string>ad-hoc</string> | |
</dict> | |
</plist> |
LLDB comes with a great set of commands for powerful debugging.
Your starting point for anything. Type help
to get a list of all commands, plus any user installed ones. Type 'help
for more information on a command. Type help
to get help for a specific option in a command too.