8318415: Adjust describing comment of os_getChildren after 8315026

Reviewed-by: rriggs

src/java.base/macosx/native/libjava/ProcessHandleImpl_macosx.c

@@ -47,13 +47,21 @@
 void os_initNative(JNIEnv *env, jclass clazz) {}
 
 /*
- * Returns the children of the requested pid and optionally each parent.
- *
- * Use sysctl to accumulate any process whose parent pid is zero or matches.
- * The resulting pids are stored into the array of longs.
+ * Return pids of active processes, and optionally parent pids and
+ * start times for each process.
+ * For a specific non-zero pid jpid, only the direct children are returned.
+ * If the pid jpid is zero, all active processes are returned.
+ * Uses sysctl to accumulates any process following the rules above.
+ * The resulting pids are stored into an array of longs named jarray.
  * The number of pids is returned if they all fit.
- * If the parentArray is non-null, store the parent pid.
- * If the array is too short, excess pids are not stored and
+ * If the parentArray is non-null, store also the parent pid.
+ * In this case the parentArray must have the same length as the result pid array.
+ * Of course in the case of a given non-zero pid all entries in the parentArray
+ * will contain this pid, so this array does only make sense in the case of a given
+ * zero pid.
+ * If the jstimesArray is non-null, store also the start time of the pid.
+ * In this case the jstimesArray must have the same length as the result pid array.
+ * If the array(s) (is|are) too short, excess pids are not stored and
  * the desired length is returned.
  */
 jint os_getChildren(JNIEnv *env, jlong jpid, jlongArray jarray,

src/java.base/unix/native/libjava/ProcessHandleImpl_unix.c

@@ -485,7 +485,7 @@ void unix_getUserInfo(JNIEnv* env, jobject jinfo, uid_t uid) {
 }
 
 /*
- * The following functions are common on Solaris, Linux and AIX.
+ * The following functions are for Linux
  */
 
 #if defined (__linux__)