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@ashokds
ashokds / NSZombieEnabled.md
Created October 24, 2017 20:38 — forked from JeOam/NSZombieEnabled.md
NSZombieEnabled

NSZombieEnabled is an environment variable which controls whether the Foundation runtime will use zombies. When zombies are enabled, a deallocated object's class is dynamically changed to be _NSZombie, and by default, the memory region is never marked as free, although this can be controlled separately(so, remember to disable NSZombieEnabled for Archived Release Build).

The end result is that, with zombies enabled, messages to deallocated objects will no longer behave strangely or crash in difficult-to-understand ways, but will instead log a message and die in a predictable and debugger-breakpointable way. This is the tool to use when trying to track down over-releases and premature releases.

Zombies will take effect for all Objective-C objects that are deallocated through normal means, including most Cocoa classes as well as user-created classes. On 10.4 and earlier, a rather important exception to this is most/all TollFreeBridged classes, as they are deallocated using CoreFoundation which NSZombieEnab

@maciekish
maciekish / resetXcode.sh
Created August 10, 2016 10:13
Reset Xcode. Clean, clear module cache, Derived Data and Xcode Caches. You can thank me later.
#!/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
@cabeca
cabeca / simulator_populator_xcode7
Last active April 16, 2020 09:18
This script removes and recreates all simulators in Xcode 7.
#!/usr/bin/env ruby
require 'JSON'
device_types = JSON.parse `xcrun simctl list -j devicetypes`
runtimes = JSON.parse `xcrun simctl list -j runtimes`
devices = JSON.parse `xcrun simctl list -j devices`
devices['devices'].each do |runtime, runtime_devices|
runtime_devices.each do |device|
@beny
beny / gist:8313959
Last active March 14, 2022 11:41
Xcode tips

Core Data

  • -com.apple.CoreData.SQLDebug 1-3 - print all SQL queries called by Core Data
    • -com.apple.CoreData.Logging.stderr 1-3 - needed alongside with the SQLDebug from iOS 10+ because of new logging system, more on that in changelog
  • -com.apple.CoreData.SyntaxtColoredLogging YES - probably syntax colored logging (not tried)
  • -com.apple.CoreData.SQLiteDebugSynchronous 1 - preference controls some aspects of the SQLite store. See the "Configuring a SQLite Store's Save Behavior" section of the Core Data Programming Guide for details
  • -com.apple.CoreData.SQLiteIntegrityCheck 1 - the SQLite store does extra integrity checking
  • -com.apple.CoreData.MigrationDebug 1 - Core Data will log information about exceptional cases as it migrates data
  • -com.apple.CoreData.ThreadingDebug - preference enables assertions to enforce Core Data's multi-threading policy. It is a number, where incre
@steipete
steipete / PSPDFUIKitMainThreadGuard.m
Last active May 27, 2024 12:11
This is a guard that tracks down UIKit access on threads other than main. This snippet is taken from the commercial iOS PDF framework http://pspdfkit.com, but relicensed under MIT. Works because a lot of calls internally call setNeedsDisplay or setNeedsLayout. Won't catch everything, but it's very lightweight and usually does the job.You might n…
// Taken from the commercial iOS PDF framework http://pspdfkit.com.
// Copyright (c) 2014 Peter Steinberger, PSPDFKit GmbH. All rights reserved.
// Licensed under MIT (http://opensource.org/licenses/MIT)
//
// You should only use this in debug builds. It doesn't use private API, but I wouldn't ship it.
// PLEASE DUPE rdar://27192338 (https://openradar.appspot.com/27192338) if you would like to see this in UIKit.
#import <objc/runtime.h>
#import <objc/message.h>
@dergachev
dergachev / GIF-Screencast-OSX.md
Last active June 3, 2024 09:24
OS X Screencast to animated GIF

OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Screencapture GIF

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

@erikreagan
erikreagan / mac-apps.md
Created August 4, 2012 19:18
Mac developer must-haves

Mac web developer apps

This gist's comment stream is a collection of webdev apps for OS X. Feel free to add links to apps you like, just make sure you add some context to what it does — either from the creator's website or your own thoughts.

— Erik

@masak
masak / explanation.md
Last active May 21, 2024 20:05
How is git commit sha1 formed

Ok, I geeked out, and this is probably more information than you need. But it completely answers the question. Sorry. ☺

Locally, I'm at this commit:

$ git show
commit d6cd1e2bd19e03a81132a23b2025920577f84e37
Author: jnthn <jnthn@jnthn.net>
Date:   Sun Apr 15 16:35:03 2012 +0200

When I added FIRST/NEXT/LAST, it was idiomatic but not quite so fast. This makes it faster. Another little bit of masak++'s program.