Allocation Question for Linux

[barisyild]

I think there is a memory leak in haxe's garbage collector, as seen in the example below, the final memory offset must be 0 for the test to pass.

If you define clear_all_allocation you will see that the test always passes, I think the garbage collector has a leak because the required behavior is that there is no memory allocation.

Only for Linux

Reproduce Code:

package;
import haxe.atomic.AtomicInt;
import sys.thread.FixedThreadPool;

#if linux
@:cppFileCode("
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
")
#end

class AllocationTest {
    private static var completedCount:AtomicInt = new AtomicInt(0);
    private static var maxThreadCount:Int = 3;
    private static var workCount:Int = 100;
    private static var threadPool:FixedThreadPool;

    public static function main() {
        threadPool = new FixedThreadPool(maxThreadCount);
        run(true);
    }

    public static function run(firstRun:Bool):Void {

        completedCount = new AtomicInt(0);

        var endMemory:Float;
        var finalAllocation:Float;
        var startMemory:Float;

        // Clear garbage to get actual memory usage
        #if !clear_all_allocation
        cpp.vm.Gc.compact();
        #end
        startMemory = getMemoryUsage();

        for(i in 0...workCount) {
            createThread();
        }

        while (completedCount.load() < workCount) {
            Sys.sleep(0.01);
        }

        if(!firstRun) {
            // Clear garbage to get actual memory usage
            #if !clear_all_allocation
            cpp.vm.Gc.compact();
            #end
            endMemory = getMemoryUsage();

            finalAllocation = endMemory - startMemory;
            if(finalAllocation != 0) {
                trace("Allocation: " + finalAllocation);
                trace("Allocation Test Failed!");
                return;
            }

            trace("Allocation Test Success!");
        }

        run(false);
    }

    public static function createThread() {
        threadPool.run(() -> {
            #if clear_all_allocation
            cpp.vm.Gc.compact();
            #end

            haxe.io.Bytes.alloc(1024 * 50);
            completedCount.add(1);
        });
    }

    #if linux
    private static function getMemoryUsage():Int
    {
        untyped __cpp__('FILE *fp;
    char line[256];
    long memory = 0;

    // Open the /proc/self/status file
    fp = fopen("/proc/self/status", "r");
    if (fp == NULL) {
        perror("fopen");
        return -1;
    }

    // Read each line and look for the VmRSS field
    while (fgets(line, sizeof(line), fp)) {
        if (strncmp(line, "VmRSS:", 6) == 0) {
            // VmRSS is in kilobytes, so we convert it to a long
            sscanf(line, "VmRSS: %ld kB", &memory);
            break;
        }
    }

    fclose(fp);
    return memory * 1024;');

        return -1;
    }
    #end
}

Definitions:

-D HXCPP_VERBOSE
-D HXCPP_STACK_LINE
-D HXCPP_STACK_TRACE
-D HXCPP_CHECK_POINTER
-D HXCPP_CPP11
-D HXCPP_GC_MOVING

[dja-in-space]

Hello, @hughsando! Any comment on this issue?

[barisyild]

Hello, @hughsando! Any comment on this issue?

Can you try to repro?

It needs to be verified again by a anothet dev because it's been so long since I created the issue.

[dja-in-space]

@barisyild, @hughsando My test result with linux 6.12, haxe 4.3.7, hxcpp 4.3.2:

1. without flag clear_all_allocation - endless output of "Allocation Test Success!"
2. with flag clear_all_allocation - every running has different results. E.g.

./Main
src/Main.hx:60: Allocation Test Success!
src/Main.hx:60: Allocation Test Success!
src/Main.hx:60: Allocation Test Success!
src/Main.hx:60: Allocation Test Success!
src/Main.hx:55: Allocation: 53248
src/Main.hx:56: Allocation Test Failed!

./Main
src/Main.hx:55: Allocation: 98304
src/Main.hx:56: Allocation Test Failed!

[dja-in-space]

@barisyild UPD: With git version (tag v4.3.98) of hxcpp I have "Allocation Test Success!" in both cases. @hughsando We need fresh hxcpp version in haxelib:).