__MALLOC_LOCK(3)

NAME
2.25 `__malloc_lock', `__malloc_unlock'--lock malloc pool

SYNOPSIS
     #include <malloc.h>
     void __malloc_lock (struct _reent *REENT);
     void __malloc_unlock (struct _reent *REENT);

DESCRIPTION
The `malloc' family of routines call these functions when they need to lock the memory pool. The version of these routines supplied in the library use the lock API defined in sys/lock.h. If multiple threads of execution can call `malloc', or if `malloc' can be called reentrantly, then you need to define your own versions of these functions in order to safely lock the memory pool during a call. If you do not, the memory pool may become corrupted.
   A call to `malloc' may call `__malloc_lock' recursively; that is, the sequence of calls may go `__malloc_lock', `__malloc_lock', `__malloc_unlock', `__malloc_unlock'. Any implementation of these routines must be careful to avoid causing a thread to wait for a lock that it already holds.

SEE ALSO
__malloc_lock is part of the library. The full documentation for is maintained as a Texinfo manual. If info and are properly installed at your site, the command

    info

will give you access to the complete manual.