SDL2从OSX上的不同线程创建纹理

我正在尝试在用于加载屏幕的单独线程中加载SDL2程序的纹理。我的代码看起来像这样

int batchLoad(void *ptr) {
loop through resources
    SDL_LockMutex(renderMutex);

        SDL_Texture *texture = NULL;

    SDL_Surface *surface = IMG_Load(("../resources/" + fileName).c_str());
    if (surface) {
    texture = SDL_CreateTextureFromSurface(renderer, surface);
    SDL_FreeSurface(surface);
    }
    SDL_UnlockMutex(renderMutex);

        // store texture

return 0;
}

void LoadingScreen::loadResources() {
// do some stuff

renderMutex = SDL_CreateMutex();

ScreenMap screenMap;
    // init with data
    SDL_Thread* load = SDL_CreateThread(batchLoad, "batchLoad", &screenMap);

while loading {
    // do work

    SDL_LockMutex(renderMutex);

    SDL_RenderClear(renderer);
    SDL_RenderCopy(renderer, white, NULL, NULL);

    // draw stuff

    SDL_RenderPresent(renderer);
    SDL_UnlockMutex(renderMutex);
}

SDL_WaitThread(load, NULL);
SDL_DestroyMutex(renderMutex);
SDL_DestroyMutex(satMutex);

在Windows上，这工作得很好，但是在OSX上，CreateTextureFromSurface调用出现错误。它使用空指针错误进行段错误处理。这是osx问题报告。

Thread 10 Crashed:: batchLoad
0   libGL.dylib                     0x00007fff885ead32 glGenTextures + 18

Thread 10 crashed with X86 Thread State (64-bit):
rax: 0x0000000000000000  rbx: 0x00007ff913c37ad0  rcx: 0x0000000000000001  rdx: 0x00007ff913c37b50
rdi: 0x0000000000000001  rsi: 0x00007ff913c37b50  rbp: 0x00000001157ae4d0  rsp: 0x00000001157ae4d0
r8: 0x0000000000000004   r9: 0x00007ff913c00000  r10: 0x0000000023f4e094  r11: 0x000000000abea012
r12: 0x00007ff913d1e3b0  r13: 0x00007ff913d1e3b0  r14: 0x000000000000001a  r15: 0x0000000000000022
rip: 0x00007fff885ead32  rfl: 0x0000000000010246  cr2: 0x0000000000000000

和lldb

* thread #9: tid = 0xee08, 0x00007fff885ead32 libGL.dylib`glGenTextures + 18, name = 'batchLoad', stop reason = EXC_BAD_ACCESS (code=1, address=0x0)
frame #0: 0x00007fff885ead32 libGL.dylib`glGenTextures + 18
libGL.dylib`glGenTextures + 18:
-> 0x7fff885ead32:  movq   (%rax), %rdi
   0x7fff885ead35:  movq   0x318(%rax), %rax
   0x7fff885ead3c:  movl   %ecx, %esi
   0x7fff885ead3e:  popq   %rbp

当我注释掉所有线程内容并正常调用批处理加载时，没有错误，因此我认为必须存在一些并发问题。但是我对所有的渲染器调用都使用了互斥锁，所以我不确定可能是什么问题。然后我也不知道为什么它在Windows上可以正常工作，但在OSX上却不能正常工作