I am using Metal for rendering, and when calling the newCommandQueue interface of Metal, there is a certain probability that I will get a nil return value. However, when I call the MTLCreateSystemDefaultDevice interface, I can get a non-empty return value, which means my device supports Metal. I would like to ask what causes the newCommandQueue to return nil? Is there any way to avoid this situation? Thank you.
here is the code
if (self = [super init]) {
self.device = MTLCreateSystemDefaultDevice();
if (!self.device) {
return nil;
}
id<MTLLibrary> defaultLibrary = [self.device newLibraryWithSource:[self shaderSource] options:nil, error:nil];
if (!defaultLibrary) {
return nil;
}
command_queue = [self.device newCommandQueue];
if (!command_queue) {
return nil;
}
return self;
}