Trace slows app launch time when using Xcode SPM

[mackoj]

Your environment:

• Xcode version: 12.5.1
• Trace SDK version: 1.7.36
• Installation method: SPM
• iOS Version: 14.7.1
• test device: iPhone 12

Steps to reproduce:

I did notice a slowdown of our app since I added the Trace SDK.

I used DYLD_PRINT_STATISTICS(App Launch Time: 7 tips to increase performance) in order to print information about the app start.

The name of our app binary is Sambot.

The difference is huge between when I have the Trace SDK in the app and when I don't have it.

with Trace SDK

Total pre-main time: 461.11 milliseconds (100.0%)
         dylib loading time: 148.26 milliseconds (32.1%)
        rebase/binding time:  90.55 milliseconds (19.6%)
            ObjC setup time:   3.49 milliseconds (0.7%)
           initializer time: 218.80 milliseconds (47.4%)
           slowest intializers :
    libMainThreadChecker.dylib :  16.93 milliseconds (3.6%)
                        Sambot : 374.92 milliseconds (81.3%)

without Trace SDK

Total pre-main time: 286.37 milliseconds (100.0%)
         dylib loading time: 158.84 milliseconds (55.4%)
        rebase/binding time:  30.61 milliseconds (10.6%)
            ObjC setup time:  11.49 milliseconds (4.0%)
           initializer time:  85.41 milliseconds (29.8%)
           slowest intializers :
             libSystem.B.dylib :  12.93 milliseconds (4.5%)
   libBacktraceRecording.dylib :   9.03 milliseconds (3.1%)
    libMainThreadChecker.dylib :  36.37 milliseconds (12.7%)
                        Sambot :  21.25 milliseconds (7.4%)

env	name	time(ms)
with Trace SDK	pre-main	461.11
with Trace SDK	dylib loading	148.26
with Trace SDK	rebase/binding	90.55
with Trace SDK	ObjC setup	3.49
with Trace SDK	initializer	218.80
with Trace SDK	libMainThreadChecker.dylib	16.93
with Trace SDK	Sambot	374.92
without Trace SDK	pre-main	286.37
without Trace SDK	dylib loading	158.84
without Trace SDK	rebase/binding	30.61
without Trace SDK	ObjC setup	11.49
without Trace SDK	initializer	85.41
without Trace SDK	libSystem.B.dylib	12.93
without Trace SDK	libBacktraceRecording.dylib	9.03
without Trace SDK	libMainThreadChecker.dylib	36.37
without Trace SDK	Sambot	21.25

Can you improve it ?

[shams-ahmed]

@mackoj I'm aware SPM is slower than other integration such as Cocoapods. This is mainly due to how we structured the SDK, internal dependencies layout, and some limitations on the SPM side.

However, with the recent changes, I'm sure we can concatenate some of the dependencies together that should improve the overall launch time. I've added this to our backlog