Show task performance

[archbirdplus]

Notes:

• Are the categories properly assigned?
• Rename TaskType to TaskClass?
• Which time units to use?
• Numbers fluctuate a lot -> Add an average of x frames into the frame time graph. #438
• "Wouldn't this make adding new tasks more difficult?" -> just put .misc if the task doesn't take a significant amount of time
• Mesh generation is insanely slow -> Avoid meshing for uniform chunks. #444

[archbirdplus]

Looks like my "meshgen" was just more lighting under the hood. Updated to reflect that.

[IntegratedQuantum]

It crashes with division by zero error when I try it:

thread 6678 panic: division by zero
/home/mint/Downloads/Cubyz/src/gui/windows/debug.zig:52:97: 0x1330e34 in render (Cubyzig)
   draw.print("    " ++ name ++ " time: {} ms ({} µs/task)", .{@divFloor(perf.utime[i], 1000), @divFloor(perf.utime[i], perf.tasks[i])}, 0, y, 8, .left);
                                                                                                ^

[archbirdplus]

Is my divFloor different from yours?

[IntegratedQuantum]

I don't know. Maybe you didn't test it in debug mode?

[archbirdplus]

Building in debug mode takes extra steps because zig ld crashes.

[archbirdplus]

Does it crash in release mode?

[IntegratedQuantum]

Building in debug mode takes extra steps because zig ld crashes.

Could you send me the issue link? Then we can add it to #308

[IntegratedQuantum]

It also crashes in release, looking at gdb it seems to be the same issue:

Thread 1 "Cubyzig" received signal SIGFPE, Arithmetic exception.
0x000000000110878c in windows.debug.render () at /home/mint/Downloads/Cubyz/src/gui/windows/debug.zig:52
52				draw.print("    " ++ name ++ " time: {} ms ({} µs/task)", .{@divFloor(perf.utime[i], 1000), @divFloor(perf.utime[i], perf.tasks[i])}, 0, y, 8, .left);

[archbirdplus]

Resolved both complaints.
Zig issue: ziglang/zig#17424

[IntegratedQuantum]

It's really hard to read anything here. The numbers seem to get reset every frame:

video-2024-06-06_08.17.52.mp4

[archbirdplus]

In my defense, it is quite legible at 10 fps.

[IntegratedQuantum]

A couple of ideas how to improve it. Also zig reported a memory leak:

memory address 0x7fa9aed53040 leaked: 
/home/mint/Downloads/Cubyz/src/utils.zig:627:31: 0x13250c2 in create__anon_13927 (Cubyzig)
  return self.allocator.create(T) catch unreachable;
                              ^
/home/mint/Downloads/Cubyz/src/utils.zig:1040:35: 0x13152e5 in init (Cubyzig)
   .performance = allocator.create(Performance),
                                  ^
/home/mint/Downloads/Cubyz/src/main.zig:356:36: 0x1313028 in main (Cubyzig)
 threadPool = utils.ThreadPool.init(globalAllocator, @max(1, (std.Thread.getCpuCount() catch 4) -| 1));
                                   ^
/home/mint/Cubyz/compiler/zig/lib/std/start.zig:501:22: 0x1312b49 in main (Cubyzig)
            root.main();
                     ^

[IntegratedQuantum]

This PR has been stale for 4 months now. Do you still intend to finish this?
I think this would still be a useful addition for profiling things more quickly.

[archbirdplus]

Didn't realize it was this old already. Sure, I'll finish it up.

[archbirdplus]

There are actually some controversial changes here.
I added a global frameCount to only update the performance on screen every 10 frames.
I'm also not very experienced with atomics, and I don't think my readAndReset is particularly sound. Maybe I should read the whole struct atomically by packing it with @Vectors? Maybe I should have an array of {count, utime} tuples instead?

[IntegratedQuantum]

I'm also not very experienced with atomics, and I don't think my readAndReset is particularly sound. Maybe I should read the whole struct atomically by packing it with @vectors? Maybe I should have an array of {count, utime} tuples instead?

Yeah, your atomics are definitely incorrect here.

Sadly bigger atomics don't seem to work very well, see ziglang/zig#14235 (although it might be worth checking if this still happens)
The solution in this case would probably just be to use a Mutex instead of atomics.

Or I guess just don't reset the values.

[IntegratedQuantum]

When I run this I get a memory leak:

memory address 0x756fcc252040 leaked: 
/home/mint/Downloads/archbirdplus/src/utils.zig:627:31: 0x13ab6a2 in create__anon_15345 (Cubyzig)
  return self.allocator.create(T) catch unreachable;
                              ^
/home/mint/Downloads/archbirdplus/src/utils.zig:1058:33: 0x13499d6 in init (Cubyzig)
   const self = allocator.create(Performance);
                                ^
/home/mint/Downloads/archbirdplus/src/utils.zig:1083:35: 0x1332672 in init (Cubyzig)
   .performance = Performance.init(allocator),
                                  ^
/home/mint/Downloads/archbirdplus/src/main.zig:519:36: 0x132c8e2 in main (Cubyzig)
 threadPool = utils.ThreadPool.init(globalAllocator, settings.cpuThreads orelse @max(1, (std.Thread.getCpuCount() catch 4) -| 1));
                                   ^
/home/mint/Cubyz/compiler/zig/lib/std/start.zig:608:22: 0x132bfa9 in main (Cubyzig)
            root.main();
                     ^

Memory leak

[IntegratedQuantum]

Everything looks good now, thanks for finishing this.
I think this will be quite useful for quick profiling and detecting some of the random performance regressions on zig updates.