Can I remove an element from a global associative array from within a class destructor?

realhet real_het at hotmail.com
Fri Aug 2 23:13:10 UTC 2019


Hi,

I tried to make some resource statistict for my OpenGL Buffer 
objects:


//here are the things that hold the statistics.
private __gshared{ size_t[int] textureSizeMap, bufferSizeMap; }

struct GLCounters{
   int programs, shaders, textures, buffers;
   size_t textureSize, bufferSize;
}
__gshared GLCounters glCounters;

...

//And this is the buffer creation.
int genBuffer(size_t size){
   int res; glGenBuffers (1, &res); glChk;
   glCounters.buffers ++;
   glCounters.bufferSize  += size;
   bufferSizeMap [res] = size;
   writefln("buffer allocated %d %d", res, size);
   return res;
}

//Finally, this is the deallocation. If it is called from the GC 
(when it destroys a class), it has a big chance to throw an 
Invalid Memory Operation exception.

void deleteBuffer (int handle){
   if(!handle) return;
   glDeleteBuffers (1, &handle); glChk;
   glCounters.buffers --;
   glCounters.bufferSize  -= bufferSizeMap [handle];
   writefln("buffer deallocated %d %d", handle, bufferSizeMap 
[handle]);
   bufferSizeMap.remove(handle); <- this is the problematic part.
}

--------------------------------------------
Today I read the documentation about structs, unions and classes, 
but I haven't find any restrictions for the ~this() destructors.

Is there some extra rules regarding the GC and what I must not do 
in the destructors?

I think the destructor always called in the same thread where the 
instance was created. This can't be the case.
But what I can guess is: The GC makes a collection and calls my 
destructor and inside I do something and the GC calls a 
collection again recursively. But it seems a bit crazy, so I 
think it's not the case :D

Please help me solve this!

*I'm using LDC 1.6.0 Win64




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