android - SIGSEGV error with QtThread on deleting QSGNode -

i working on qt app runs on android & ios.

scenario: calling delete on pointer causes app crash gives me following error on android.

fatal signal 11 (sigsegv), code 1, fault addr 0x3c in tid 7134 (qtthread) 

this caused due delete call in updatepaintnode of qquickitem derived class.

// updatepaintnode logic relevant question qsgnode * myqquickitem::updatepaintnode(qsgnode * oldnode, updatepaintnodedata * updatepaintnodedata) {    q_unused(oldnode)   q_unused(updatepaintnodedata)    if(class_mem_node != q_nullptr) {     delete class_mem_node;    // crash occurs   }    class_mem_node = new qsgnode;    // execute drawing logic    return class_mem_node; } 

problem:
window of application dependent on myqquickitem::updatepaintnode execute on android call delete class_mem_node causes crash fatal signal error. interestingly, issue only happens on android, not on ios or osx.

question:
wrong in logic in updatepaintnode ? thread synchronisation issue?

is there way can check whether qsgnode in use & return out?

when return class_mem_node; don't have ownership of class_mem_node more.

the implementation may delete node when becomes not useful. passes nullptr oldnode on next call updatepaintnode().

don't store class_mem_node, use oldnode.