[process] Add process_running()

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/process.c

  * have no effect.
  */
 void process_add ( struct process *process ) {
-	if ( list_empty ( &process->list ) ) {
+	if ( ! process_running ( process ) ) {
 		DBGC ( process, "PROCESS %p starting\n", process );
 		ref_get ( process->refcnt );
 		list_add_tail ( &process->list, &run_queue );
  * have no effect.
  */
 void process_del ( struct process *process ) {
-	if ( ! list_empty ( &process->list ) ) {
+	if ( process_running ( process ) ) {
 		DBGC ( process, "PROCESS %p stopping\n", process );
 		list_del ( &process->list );
 		INIT_LIST_HEAD ( &process->list );

src/include/ipxe/process.h

 	process_add ( process );
 }
 
+/**
+ * Check if process is running
+ *
+ * @v process		Process
+ * @ret running		Process is running
+ */
+static inline __attribute__ (( always_inline )) int
+process_running ( struct process *process ) {
+	return ( ! list_empty ( &process->list ) );
+}
+
 /** Permanent process table */
 #define PERMANENT_PROCESSES __table ( struct process, "processes" )