+/* Function type for the CALLBACK argument of iterate_over_lwps. */
+typedef int (iterate_over_lwps_ftype) (struct lwp_info *lwp, void *arg);
+
+/* Iterate over all LWPs. Calls CALLBACK with its second argument set
+ to DATA for every LWP in the list. If CALLBACK returns nonzero for
+ a particular LWP, return a pointer to the structure describing that
+ LWP immediately. Otherwise return NULL. This function must be
+ provided by the client. */
+
+extern struct lwp_info *iterate_over_lwps (ptid_t filter,
+ iterate_over_lwps_ftype callback,
+ void *data);
+
+/* Return the ptid of LWP. */
+
+extern ptid_t ptid_of_lwp (struct lwp_info *lwp);
+
+/* Set the architecture-specific data of LWP. This function must be
+ provided by the client. */
+
+extern void lwp_set_arch_private_info (struct lwp_info *lwp,
+ struct arch_lwp_info *info);
+
+/* Return the architecture-specific data of LWP. This function must
+ be provided by the client. */
+
+extern struct arch_lwp_info *lwp_arch_private_info (struct lwp_info *lwp);
+
+/* Return nonzero if LWP is stopped, zero otherwise. This function
+ must be provided by the client. */
+
+extern int lwp_is_stopped (struct lwp_info *lwp);
+
+/* Return the reason the LWP last stopped. This function must be
+ provided by the client. */
+
+extern enum target_stop_reason lwp_stop_reason (struct lwp_info *lwp);
+
+/* Cause LWP to stop. This function must be provided by the
+ client. */
+
+extern void linux_stop_lwp (struct lwp_info *lwp);
+
+/* Return nonzero if we are single-stepping this LWP at the ptrace
+ level. */
+
+extern int lwp_is_stepping (struct lwp_info *lwp);
+