Embree ASAN issues with Emscripten

[jjcasmar]

I am using Embree in Emscripten and I use ASAN to catch leaks in my testing code.

Recently, I found a leak in the way I was using Embree and I solve. However, that fix works in x86_64 but not in wasm, where I get the following error:

==42==ERROR: AddressSanitizer failed to deallocate 0xb09000 (11571200) bytes at address 0x20fb0000
==42==ERROR: AddressSanitizer failed to deallocate 0xb09000 (11571200) bytes at address 0x20490000
AddressSanitizer: CHECK failed: sanitizer_posix.cpp:61 "(("unable to unmap" && 0)) != (0)" (0x0, 0x0) (tid=533069872)
AddressSanitizer: CHECK failed: sanitizer_posix.cpp:61 "(("unable to unmap" && 0)) != (0)" (0x0, 0x0) (tid=528744496)
    <empty stack>

I have been able to reproduce the issue with this simple code

#include <gtest/gtest.h>

#include <embree3/rtcore.h>

TEST(Basic, embree)
{
    auto rtcDevice{rtcNewDevice("")};
    auto rtcScene{rtcNewScene(rtcDevice)};

    rtcCommitScene(rtcScene);

    rtcReleaseDevice(rtcDevice);
    rtcReleaseScene(rtcScene);
}

If I remove the rtcRelease at the end, I get a memory leak error. However, if I add them, I get the already mentioned error. It doesn't matter the order in which I try to destroy the objects, I get the same error.

[jjcasmar]

I have been doing some testing and the error only happens if I set more than one thread for the device. Is multithreading not allowed in embree running in emscripten?

[svenwoop]

Embree does not officially support emscripten, we just enabled compiling with it. I would expect multithreading to work though. The simple example above should also not do much multi-threading, it just builds an empty scene.

[jjcasmar]

Even for this simple test code, it still fails with an ASAN error when I use something else than 1 thread for the RTCDevice. If you are interested, I can try to provide a stracktrace, but I totally undersstand if you prefer to close the issue, as Emscripten is not a supported platform.

[svenwoop]

We would be happy to accept a pull request in case you could localize the issue. I will close the issue for now, please re-open if you know some workaround for the issue.