Hi,

I have a huge program in c++ using lots of pointers. I have been working on it for few months now. Since about few days I am getting this error:

*** glibc detected *** double free or corruption (out): 0x08065060 ***

when I delete a memory allocated using "new". This error comes the first time I try to delete. I have been trying to find the problem, but I am kind of given up now. As for as I think, there is no overwriting/overflowing taking place.

Can someone help me with ideas as to what may be causing this problem?

Thanks.

Abhi.

Two possibilities come to mind.

1. You are actually deleting the same thing twice, though you think it is just once.
2. You are deleting something that was not allocated via calling operator new.

Without some more specific info or some code, I don't have much to add.

Matthew

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Thanks for reply. But none of the two possibilities are happening.

I have a tree structure, and I create new nodes in the tree using "new" with the structure for the node. The 'first' time I try to delete one node, I get that error. Using GDB, I tried to locate something but everything seems fine. Just before deleting the node, I perform some modifications to other nodes (reassign some variables), and then isolate the node I want to delete and call "delete" to free the memory. In GDB, I can clearly see that the node to be deleted is working fine, and everything exists. I do not delete anything before this (this is the first delete operation called).

I am not able to put some code here due to huge size of it, and isolating few things might be difficult (and may not include the code having the problem). If you have any other ideas, do tell me.

Thanks again.

Abhi.

Search for this string in google:

"double free or corruption (out):"

This problem seems to be common and varies by platform (or distribution).
(there are over 15 million hits without the quotes, but < 900 hits with the quotes)

Maybe one of the hits can be helpful for you, by further narrowing the results with your version/distribution.

Please let us know what you discover.

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Ofcourse I searched a lot in google before posting this problem here. Unfortunately I did not find any link that was useful to me.

hi asarje,

i had the same problem in the software i am currently working on. I managed to solve it by deleting all files from my working directory except *.cpp *.h and Makefile. When i recompiled everything from the beginning, the runtime error you specified disappeared.

So i guess something was not up2date in my previously compiled .o files, though i am not an expert at all. Maybe we should fix something in our Makefiles.

Hope i could help you,
prahlad