suse man page for struct_utrace_engine

STRUCT 
UTRACE_ENGINE(9) 					  utrace core API					   STRUCT UTRACE_ENGINE(9)

NAME
       struct_utrace_engine - per-engine structure

SYNOPSIS
       struct utrace_engine {
	 const struct utrace_engine_ops * ops;
	 void * data;
	 unsigned long flags;
       };

MEMBERS
       ops

	   struct utrace_engine_ops pointer passed to utrace_attach_task

       data
	   engine-private void * passed to utrace_attach_task

       flags
	   event mask set by utrace_set_events plus internal flag bits

DESCRIPTION
       The task itself never has to worry about engines detaching while it's doing event callbacks. These structures are removed from the task's
       active list only when it's stopped, or by the task itself.

       utrace_engine_get and utrace_engine_put maintain a reference count. When it drops to zero, the structure is freed. One reference is held
       implicitly while the engine is attached to its task.

Kernel Hackers Manual 2.6.					     July 2010						   STRUCT UTRACE_ENGINE(9)