instruments-without-delay on Xcode 7

com.apple.instruments.deviceservice.plist

<?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>EnableTransactions</key>
	<true/>
	<key>EnvironmentVariables</key>
	<dict>
		<key>DYLD_INSERT_LIBRARIES</key>
		<string>/Users/lawrencelomax/src/instruments-without-delay/build/DTMobileISShim.dylib</string>
		<key>LIB_PATH</key>
		<string>/Users/lawrencelomax/src/instruments-without-delay/build</string>
	</dict>
	<key>JetsamProperties</key>
	<dict>
		<key>JetsamMemoryLimit</key>
		<integer>0</integer>
	</dict>
	<key>Label</key>
	<string>com.apple.instruments.deviceservice</string>
	<key>MachServices</key>
	<dict>
		<key>com.apple.instruments.deviceservice.lockdown</key>
		<true/>
		<key>com.apple.instruments.deviceservice.xpc</key>
		<true/>
	</dict>
	<key>POSIXSpawnType</key>
	<string>Adaptive</string>
	<key>Program</key>
	<string>/Developer/Library/PrivateFrameworks/DVTInstrumentsFoundation.framework/DTServiceHub</string>
</dict>
</plist>

Instructions.md

instruments-without-delay uses the DYLD_INSERT_LIBRARIES environment variable to shim from the instruments command line all the way down to ScriptAgentShim which is the iOS Simulator service responsible for interfacing UIAutomation JavaScript with the native UIAutomation.framework. It uses a stack of shims, starting at the instruments executable, going through Simulator.app. It is an essential part of ios-driver as it removes a pesky 200ms delay that drastically slows down the process of executing end-to-end tests. This is a fixed cost that would occur on every command.

Other than a few things being moved around and renamed in Xcode 7, there is the new issue of the codesigning of the Simulator app that triggers amfid whenever an unsigned image is loaded. This essentially means that we can't use DYLD_INSERT_LIBRARIES on the Simulator Process with SimShim

It is however, possible to inject these environment variables at the launchdaemon level. There is a plist for DTServiceHub at: /Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/Developer/Library/LaunchDaemons/com.apple.instruments.deviceservice.plist

It can be modified to inject the DTMobileISShim (see the attached plist). However, this is less than ideal as this requires modifying the Xcode binary.

@tarunchauhantft I did the following steps:
cd ~
git clone https://github.com/lawrencelomax/instruments-without-delay.git
cd instruments-without-delay/
git checkout xcode7-quirks
./build.sh

Next, you're going to want to edit the plist file at:
/Applications/Xcode-7.0.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/Developer/Library/LaunchDaemons/com.apple.instruments.deviceservice.plist
(I downloaded the library DTMobileISShim.dylib) and then added the path where it is found.
I restarted my MAC and i didn't notice any improvement in the performance.

Please can you give me the exact steps how you used it and noticed the difference in performance.

Thanks in advance

Hey, I am unable to run the build script with following errors, any ideas?

In file included from :1:
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator9.2.sdk/usr/include/sys/cdefs.h:707:2: error: Unsupported architecture

error Unsupported architecture

^
While building module 'Darwin' imported from /Users/xx/Documents/git_folder/instruments-without-delay/DTMobileISShim/DTMobileISShim/DTMobileISShim.m:17:
In file included from :3:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator9.2.sdk/usr/include/copyfile.h:36:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/7.0.2/include/stdint.h:63:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator9.2.sdk/usr/include/stdint.h:52:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator9.2.sdk/usr/include/sys/_types.h:33:
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator9.2.sdk/usr/include/machine/_types.h:34:2: error: architecture not supported

error architecture not supported

^
.... more

@ chrisjywu: I had the same issue and here is what I did: Open the build.sh file and add this: -destination 'platform=iOS Simulator,name=iPhone 6' to every xcodebuild command
This seems to be a bug of xcodebuild 7.2 and it is reported

Does this work for you on xcode 7.2? I added the destination code, ran successfully, plist file has the variables, but it doesn't remove the delay for ios 9.2.

@bthuan thanks, works for me now

It speeds up my test on the first run, but on subsequent runs the standard instruments delay seems to be implemented between commands thus slowing down my tests. What could be causing this? A process that may need killing to eliminate the delay second run onwards? Please help..

Hi. After successfully running the commands and making changes to the .plist file as mentioned above, if i try to run a test, the instrument crashes.

info: [debug] And launch timeouts (in ms): {"global":90000}
info: [debug] [INST] Waiting for device to boot...
info: [debug] [INSTSERVER] Instruments exited with code 253
info: [debug] Killall instruments
info: [debug] Instruments crashed on startup
info: [debug] Attempting to retry launching instruments, this is retry #3
info: [debug] Killall Simulator

Please assist

It worked! Had to change the folder permissions in order to edit the com.apple.instruments.deviceservice.plist file. Changed it back to Read Only.

@krutipandya do you have steps for removing the delay on instruments? I didnt really understand the thre
d here

@tarunchauhantft had you find the way to make IWD working on real device?