Built-in class variables

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In addition to the special built-in variables, __arg1 through __arg32 and __rv, Vue also defines a set of general-purpose built-in variables. These general-purpose built-in variables are discussed in more detail in this section and some probe manager specific built-in variables are discussed in their respective probe manager section. Built-in class variables are functions, but are treated as variables by ProbeVue. Therefore, you can use these built-in variables in the predicate section of a Vue clause.

The following built-in variables are supported in Vue:

__tid: Thread ID of traced thread.
__pid: Process ID of traced thread.
__ppid: Parent process ID of traced thread.
__pgid: Process group ID of traced thread.
__pname: Process name of traced thread.
__uid, __euid: Real and effective user ID of traced thread.
__trcid: Process ID of tracing process (that is, of the probevue command)
__errno: Current errno value for the traced thread.
__kernelmode: Current executable mode: is either 1 (in kernel mode) or 0 (in user mode).
__r3, ..., __r10: General purpose register values (for function parameters or return values).
__curthread: Current thread.
__curproc: Current process.
__ublock: User area of the current process.
__mst: Built-in variable to access the hardware register content of the current thread's machine state save area (MST).
__stat: Built-in variable to provides access to the system statistics for various AIX® kernel components.

The following script is an example using built-in variables:

	@@syscall:*:read:entry
	{
		printf("Thread ID:%d, Process ID:%d, Parent Process ID:%d\n",
				__tid, __pid, __ppid);
		printf("Process Group ID: %d\n", __pgid);
		printf("Process name = %s\n", __pname);
	
		printf("Real UID=%d, Effective UID=%d\n", __uid, __euid);S
	       
		printf("probevue command process ID = %d\n", __trcid);
	
		printf("Errno = %d\n", __errno);
		printf("Mode = %s\n", __kernelmode == 1 ? "kernel" : "user");
	
		printf("Current values of GPRs: r3=0x%016llx, r4=0x%016llx, r5=0x%016llx\n",
				__r3, __r4, __r5);
		printf("                        r6=0x%016llx, r7=0x%016llx, r8=0x%016llx\n",
				__r6, __r7, __r8);
		printf("                        r9=0x%016llx, r10=0x%016llx\n",
				__r9, __r10);
	}