Red Hat Enterprise Linux4 *** glibcdetected *** doublefree

Red Hat Enterprise doub4 *** glibcdetected *** doublefree -- Linux general technology-Linux programming and kernel information. For more information, see the following. Q: When executing a program, the following error occurs:
* ** Glibc detected ** double free or duplicate uption: 0x0937d008 ***
Why?

A: Set the MALLOC_CHECK _ environment variable and run the program again. The error message disappears.
MALLOC_CHECK _ = 0./myprogram

Glibc provided by Red Hat Enterprise Linux 4 can perform additional internal data health checks to detect and protect data corruption as early as possible. By default, when corrupted data is found, similar error messages are displayed on the standard error output (if stderr is not enabled, will be recorded in syslog ):

* ** Glibc detected ** double free or duplicate uption: 0x0937d008 ***

By default, programs that generate this error will also be aborted. However, this (and whether error messages are generated) can be controlled using the environment variable MALLOC_CHECK. The following settings are supported:

0-no error message is generated or this program is not aborted
1-generate error message, but do not stop this program
2-no error message is generated, but the program is aborted.
3-generate an error message and abort the program

Remarks
If MALLOC_CHECK _ is set to a value other than 0, this causes glibc to perform more checks and may affect the system performance.