QNX Developer Support
|This version of this document is no longer maintained. For the latest documentation, see http://www.qnx.com/developers/docs.|
Lock the attribute structure
#include <sys/iofunc.h> int iofunc_attr_lock( iofunc_attr_t *attr );
- A pointer to the iofunc_attr_t structure that you want to lock.
Use the -l c option to qcc to link against this library. This library is usually included automatically.
The iofunc_attr_lock() function locks the attribute structure that attr points to, preventing other threads in the resource manager from changing information.
Note that this is a counting locking mechanism. This means that a given thread can lock the attributes structure multiple times; it must then unlock the attributes structure a corresponding number of times in order to have the attributes structure considered unlocked. If another thread attempts to lock the structure while a thread has the structure locked, the other thread blocks.
- On the first use, all kernel mutex objects were in use.
Writing a Resource Manager chapter of the Programmer's Guide.