[GR-32291] Memory Leak on graal_isolatethread_t

[machaval]

Memory Leak detected on graal_isolatethread_t

I'm trying to build a SharedLibrary that allows to execute my language runtime from other languages like i this case GO. This function is going to be called multiple times, so I did a simulation to see how it behaves, memory, cpu. And I was seeing a small memory leak. What I did was very simple First

graal_isolatethread_t* thread;
    if (graal_create_isolate(NULL, NULL, &thread)) {
      return -1;
    }

Second do my stuff

runScript("myScript")

Third

 if (graal_tear_down_isolate(thread) != 0) {
       fprintf(stderr, "shutdown error\n");
       return 1;
     }

I put it inside a while true and I started to see that the memory usage of the process was growing, slowly but constantly.

So I commented the call to my code

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <graal_isolate.h>
#include <unistd.h>
int main(int argc, char** argv) {
//  compilation_result result;
//  char* expression = "attributes.headers.myParam";
//  printf("Expression is %p\n", expression);
  while(1){
    int i = 1;
    while (i < 4)
    {
        graal_isolatethread_t* thread;
        if (graal_create_isolate(NULL, NULL, &thread)) {
           return -1;
        }

        //
        // This frees all memory allocated by the GraalVM runtime
        //
          if (graal_tear_down_isolate(thread) != 0) {
             fprintf(stderr, "shutdown error\n");
             return 1;
          }
          printf("Thread is %p\n", thread);
          thread = NULL;
          i = i + 1;
       }
      sleep(1000000);
   }

    return 0;
}

I'm just using graal libraries.

And If I compile this script using clang and using mac leaks tool it shows

leaks Report Version: 4.0
Process 98105: 515 nodes malloced for 579 KB
Process 98105: 3 leaks for 864 total leaked bytes.

    3 (864 bytes) << TOTAL >>
      1 (288 bytes) ROOT LEAK: 0x7fe83fc04080 [288]
      1 (288 bytes) ROOT LEAK: 0x7fe83fc041a0 [288]
      1 (288 bytes) ROOT LEAK: 0x7fe84fd0a190 [288]

So as it can be seen after 3 loops 3 leaks are being detected.

Describe GraalVM and your environment:

• GraalVM version: 21.1.0**
• JDK major version: 11
• OS: macOS Catalina
• Architecture: 2,4 GHz 8-Core Intel Core i9

[oubidar-Abderrahim]

Thank you for reporting this issue, could you please provide the exact command you use to compile the above example? also, the version of clang you're using?

[machaval]

Hi Thanks for taking a look at the issue. I've created a project that showcase the issue. Just unzip the attached zip and inside there is a compile.sh (clang -I./src/main/c/ -L./src/main/c/ -ldw ./src/main/c/DataWeaveNative.c -o DataWeaveNative) that compiles the project.
native-leak.zip

Then what I do is executes leaks DataWeaveNative in another terminal while this process is running and it shows the leaks.

My current version of clang is

➜  native-leak clang --version
Apple clang version 11.0.3 (clang-1103.0.32.62)
Target: x86_64-apple-darwin19.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

[machaval]

@oubidar-Abderrahim Is this information good enough? Do you need more data to reproduce the issue?

[oubidar-Abderrahim]

Yes, I managed to reproduce the issue, thank you for the reproducer. This issue is tracked internally on GR-32291

[blacktooth]

Is this issue fixed?

[peter-hofer]

Unfortunately, this is not a single bug, but a number of issues mostly caused by native code of the JDK assuming that there is only ever going to be one isolate, so this is ongoing work.