TeensyThreads Yield broken for 4.x?

[vjmuzik]

Possibly first mentioned here.
Using Teensyduino 1.54 and Teensy 4.1(though it should be the same for any 4.x)
TeensyThreads Yield does not seem to be working correctly, I started trying to use it on a project and I noticed that I wasn't getting the results I would expect so I did a minimal example that should just increment a value every millisecond and then print that value every second in the main loop. I would expect this value to be at or around 1000 by the time it gets printed, but this is not the case, I also ran the Tests sketch from TeensyThreads and get much of the same results as what AcidZero got in the other thread, besides the addition of Test delay yield failing.

Results from Minimum Sketch:

Loop: 119937000    Thread: 91     
Loop: 119936999    Thread: 91     
Loop: 119936993    Thread: 91     
Loop: 119936998    Thread: 91

Here's the minimum Sketch that does not give the correct results(you can also replace threads.delay(1) with threads.yield() and see that it outputs the same exact results):

#include <TeensyThreads.h>

volatile uint32_t threadLooped = 0;
volatile uint32_t thread_poll_id = 0;
void thread_poll() {
  while(1) {
      threadLooped++;
      threads.delay(1);
//      threads.yield();
  }
}

void setup() {
  while(!Serial);
  if(CrashReport){
    Serial.println(CrashReport);
  }

  thread_poll_id = threads.addThread(thread_poll);
}

elapsedMillis seconds = 0;
volatile uint32_t loopCounter = 0;

void loop() {
  while(1){
    loopCounter++;
    if(seconds >= 1000){
      seconds -= 1000;
      
      Serial.printf("Loop: %d    Thread: %d     \n", loopCounter, threadLooped);
  
      loopCounter = 0;
      threadLooped = 0;
    }
  }
}

My results from TeensyThread Tests sketch:

CPU speed consistency ***FAIL***
Test thread start OK
Test thread run state OK
Test thread return OK
Test thread speed ***FAIL***
Speed no threads: 85705208
Speed 1 thread: 60613234
Ratio: 0.71
Test set time slice OK
Speed default ticks: 60613248
Speed 200 ticks: 114710017
Expected: 115453808.00
Ratio with expected: 0.99
Test delay yield ***FAIL***
Yield wait ratio: 1.40
Test thread end state OK
Test thread reinitialize OK
Test stack usage OK
Test thread suspend OK
Test thread restart OK
Test thread stop OK
Test thread start OK
Test thread wait OK
Test thread wait time OK
Test thread kill OK
Test std::thread scope OK
Test basic lock OK
Test basic unlock OK
Test mutex lock state OK
Test mutex lock thread OK
Test mutex unlock OK
Test fast locks OK
24587500 25000000 21827474
Test std::mutex lock OK
Test std::mutex unlock OK
Test Grab init OK
Test Grab set OK
Test Grab lock OK
Test thread stack overflow OK
Test infinite loop (will not end)
0: 0 sec 75204080 587109984 17591694
1: 5 sec 75204080 836691035 17591694
2: 10 sec 75204080 1087371562 17591694
3: 15 sec 75204080 1336952613 17591694
4: 20 sec 75204080 1587633140 17591694
5: 25 sec 75204080 1837214191 17591694
6: 30 sec 75204080 2087894718 17591694
7: 35 sec 75204080 -1957491527 17591694
8: 40 sec 75204080 -1706811000 17591694
9: 45 sec 75204080 -1457229949 17591694
10: 50 sec 75204080 -1206549422 17591694
11: 55 sec 75204080 -956968371 17591694
12: 60 sec 75204080 -706287844 17591694

 

[vjmuzik]

I now see that in my example sketch I had to do threads.setSliceMicros(10); in order to have such a short threads.delay, though I am curious on why Test delay yield failed in the TeensyThreads Tests sketch, that lead me to believe there was nothing wrong on my part.

You can disregard this thread.