When i profile using system trace instrument. There is always three lines for every thread. So what does the red and blue line mean?
System calls are the red capsules, virtual memory faults appear as the blue capsules. The grey bar with the annotations "Blocked" and "Running" represents the thread state.
There's a WWDC session that explains https://developer.apple.com/videos/play/wwdc2016/411
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First of all let me say that I confirmed that this behavior only happens on iOS 16, and does not happen on the previous iOS versions.
In short, the app uses Apple Vision Framework to track face rectangles in the camera input and show that in camera output with view overlays over those found faces.
The correct behavior of the apps is as follows:
camera output is shown on the screen
frames from camera input is constantly checked whether it contains faces
if the face is found it's being overlaid by a circular view, and it's also being tracked (if you move the camera to the left, the view overlay will move to the left as well and the app will know it's the same face and won't draw another circle)
The breaking behaviour is as follows:
the same
the same
if the face is found, at first it's being tracked correctly, but at some point if you bug it out (move the face close to the edges) it will stop recognizing that it's the same face and it will constantly register (even the same face) as another one popping in the screen, and that results in constant jittery overlap of the circular overlay view, and ultimately to the error:
Exceeded maximum allowed number of Trackers for a tracker type:
VNObjectTrackerRevision2Type
Also, there's one more thing which I noticed after updating my Xcodde:
Thread Performance Checker: -[AVCaptureSession startRunning] should be called from background thread. Calling it on the main thread can lead to UI unresponsiveness
I did put those methods in background thread, but no avail, the issue only worsened from that point on.
Does anyone know what could've changed in the iOS 16 version that would impact this behaviour? Is it more likely a thread related issue, camera input related issue, VN framework related issue, or something else?
How would you go about detecting where the problem is? (I spent 2 days logging the face tracking but I've found no logical issue).
I tried to find a legend for these graphics and colors, but I couldn't find anything that was certainly referring to this instrument. Does anyone know? Specifically, the blue and red telephones, the red lollipop and the black line with red stripes. What do they all mean?
It appears to me that the red and blue telephone icons are kernel event messages, and the other icon is a red alarm bell which indicates kernel interrupts. If you click on those icons you will see a popup with specific details.
I checked in my project and the red telephones always corresponded to BSC_* events while blue telephones corresponded to MSC_* events.
The events list for the XNU/MacOS kernel are listed here:
https://github.com/opensource-apple/xnu/blob/10.10/bsd/kern/trace.codes
I don't know what BSC means vs. MSC (maybe someone else can answer that?) but it appears to me that MSC is a generic low level event message trap such as MSC_mach_msg_trap, while BSC is more specific high level events such as BSC_gettimeofday.
In this project i using ARC
what is meaning of the red color and yellow and is it memory leak ?
The line of code highlighted red in your screenshot is red because a high percentage of the memory allocated in the method actCallTaxi: is allocated in the highlighted line, 94% of the allocated memory. If you find actCallTaxi: is allocating too much memory, Instruments is alerting you to the source of the high memory allocation by highlighting the line of code red.
The line of code highlighted yellow is yellow because a smaller percentage of memory allocated in actCallTaxi: is allocated in the yellow line. Instruments uses color coding to show the severity of possible problems in your code, with red being more severe than yellow.
The graph for the Leaks instrument isn't showing any leaks so you most likely don't have a problem with memory leaks.
I've just had my Red Pitaya running for two nights now, but I've already noticed that just having it booted up for a while makes the board quite hot. Is that normal or should I be cooling it?
This is normal and there is nothing to be worried about as long as your Red Pitaya is not placed in the environment that exceeds 30 degC, being covered or placed into enclosure. In such case the heatsink or small fan should be used for cooling.
For more details please read environmental conditions section inside hardware specifications.
Main wiki page
I have been tested my app with instruments allocations and get this picture:
Like graphic shows, my app work normally, but is it normally value in overall bytes? And I'm worry about "#Allocations (Net/Overall)", because it's color is red.What is it mean (red color)
Red is the total (Overall) allocations made and deallocated during all your App's runtime.
Purple (really thin bar over the red one) are the allocated and not yet deallocated objects.
I would say that you don't need to worry too much about it, specially for internal objects or Malloc, and focus indeed on higher level objects such as views and controllers.
Also if you click on the Allocations tool's i you can choose to ignore CF (Core Foundation) or Malloc allocations, which I often do as you don't normally deal directly/don't have control over those allocations.
Again as you improve your higher level objects allocations you'll be indirectly improving those underlying allocations as well.