+/* Return nonzero iff PTID corresponds to a ravenscar task. */
+
+static int
+is_ravenscar_task (ptid_t ptid)
+{
+ /* By construction, ravenscar tasks have their LWP set to zero.
+ Also make sure that the TID is nonzero, as some remotes, when
+ asked for the list of threads, will return the first thread
+ as having its TID set to zero. For instance, TSIM version
+ 2.0.48 for LEON3 sends 'm0' as a reply to the 'qfThreadInfo'
+ query, which the remote protocol layer then treats as a thread
+ whose TID is 0. This is obviously not a ravenscar task. */
+ return ptid_get_lwp (ptid) == 0 && ptid_get_tid (ptid) != 0;
+}
+
+/* Given PTID, which can be either a ravenscar task or a CPU thread,
+ return which CPU that ptid is running on.
+
+ This assume that PTID is a valid ptid_t. Otherwise, a gdb_assert
+ will be triggered. */
+
+static int
+ravenscar_get_thread_base_cpu (ptid_t ptid)
+{
+ int base_cpu;
+
+ if (is_ravenscar_task (ptid))
+ {
+ struct ada_task_info *task_info = ada_get_task_info_from_ptid (ptid);
+
+ gdb_assert (task_info != NULL);
+ base_cpu = task_info->base_cpu;
+ }
+ else
+ {
+ /* We assume that the LWP of the PTID is equal to the CPU number. */
+ base_cpu = ptid_get_lwp (ptid);
+ }
+
+ return base_cpu;
+}
+
+/* Given a ravenscar task (identified by its ptid_t PTID), return nonzero
+ if this task is the currently active task on the cpu that task is
+ running on.
+
+ In other words, this function determine which CPU this task is
+ currently running on, and then return nonzero if the CPU in question
+ is executing the code for that task. If that's the case, then
+ that task's registers are in the CPU bank. Otherwise, the task
+ is currently suspended, and its registers have been saved in memory. */
+
+static int
+ravenscar_task_is_currently_active (ptid_t ptid)
+{
+ ptid_t active_task_ptid
+ = ravenscar_active_task (ravenscar_get_thread_base_cpu (ptid));
+
+ return ptid_equal (ptid, active_task_ptid);
+}
+
+/* Return the CPU thread (as a ptid_t) on which the given ravenscar
+ task is running.
+
+ This is the thread that corresponds to the CPU on which the task
+ is running. */
+
+static ptid_t
+get_base_thread_from_ravenscar_task (ptid_t ptid)
+{
+ int base_cpu;
+
+ if (!is_ravenscar_task (ptid))
+ return ptid;
+
+ base_cpu = ravenscar_get_thread_base_cpu (ptid);
+ return ptid_build (ptid_get_pid (ptid), base_cpu, 0);
+}
+