Reading crash dumps

[Gangrenous]

Is there any magic to reading a BT report? I am getting a random crash, only happens when no one is playing.

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#0  0x00007fff81b3a968 in ?? ()

I have the line of the dump, it is definitely code I have written but I am quickly running out of ideas. I have a mutex on the new vector, and a readlock on it.

Also, while I have C++ coders attention. If I am already iterating a collection, and want to iterate it again, do I need two readlocks? I am thinking that I already have a lock on it, why lock twice? Such as if I was iterating the spawn_list and want to iterate it again, comparing spawn against spawn. Something like that anyway. Of course that is very intensive so I am already only getting the spawns in the immediate area, otherwise you can really compound the number of loops.

And one more. I have always been unclear on this one. Take a line like this one, where you check against the existence of an object.

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if (assist && assist->IsNPC() && assist->EngagedInCombat() == false){

Is the entire line read in and checked? I am just curious if that could cause a null to crash the line? Does that need to be embedded like this?

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if (assist)
    if (assist->IsNPC() && assist->EngagedInCombat() == false){

Reading this, I guess I am correct, the entire line would not be evaluated?

[Jabantiz]

The hex is the memory address the program crashed at I believe. I never really used Linux so I am not the best at debugging it, I mainly go by the couple of lines before that tell you the function and general area that caused the crash.

If you are looping through a list and within that loop you loop through it again then you only need the 1 read lock assuming you aren't modifying the list.

That if statement is read left to right, as soon as it hits a false it won't bother checking the rest and skip to the else or out of the if. So if for some reason assist is null then it won't even bother to check assist->IsNPC() and therefore avoid the null pointer crash.

[Gangrenous]

IsNPC() is where it is crashing. I am able to reproduce the problem so I can get it fixed now. I will let you know