see post:Ozone hangs with timeline open when sample rate is set to Max
I have similar problem,

1, create a simple test project using IAR or Keil (othe compilers surport both C and C++ should have the same problem)
2, define a variable named 'a' for example in the project, compile the project using C++ compiler(a option of IAR/Keil)
3, add 'a' to timeline window of ozone, and set sample rate to MAX
4, run the program to observe 'a'
5, ozone hangs after step 4, but if compile the project using C compiler ozone works smoothly.

SWD is running at 20MHz
ver of ozone is 3.36, early versions have the same problem.
tools is jlink ultra v4

I have reproduced the problem with IAR and Keil, Cortex-M0/M3


I agree with grb212: the timeline was re-parsing the singleton-reference every sample, causing the delay.

Hi AlexD:

steps to reproduce the issue:
1,downlaod the 3 files attached, and unzip
2,put the following 2 files to C:/
OzoneStuck-C.axf
OzoneStuck-C++.axf
3,open OzoneStuck-C++.jdebug using Ozone, download and run, Ozone will hang for seconds.
4,open OzoneStuck-C.jdebug, download and run, Ozone should run smoothly.

tools and conditions:
any stm32f103 eval board should be ok;
jlink ultra v4, ozone v3.36
SWD 20MHz, timeline window sample rate is max;
OzoneStuck_Keil_Proj.zip is the keil project that generates OzoneStuck-C++.axf and OzoneStuck-C.axf
(to switch between c and c++: open keil project, and right click main.c -> options for 'main.c' -> file type:c/c++ source file)


OzoneStuck_Keil_Proj.zip
OzoneStuck.zip
OzoneStuck-C.zip

Hi
Glad to help.
Thanks for your team work.