[PlacementGroup]Add PlacementGroup wait java api (#12499)

* add part code

* add part code

* add part code

* add part code

* fix review comments

* fix compile bug

* fix compile bug

* fix review comments

* fix review comments

* fix code style

* add part code

* fix review comments

* fix review comments

* fix code style

* rebase master

* fix bug

* fix lint error

* fix compile bug

* fix newline issue

Co-authored-by: 灵洵 <fengbin.ffb@antgroup.com>

python/ray/_raylet.pyx

@@ -1169,6 +1169,18 @@ cdef class CoreWorker:
                 CCoreWorkerProcess.GetCoreWorker().
                 RemovePlacementGroup(c_placement_group_id))
 
+    def wait_placement_group_ready(self,
+                                   PlacementGroupID placement_group_id,
+                                   int32_t timeout_ms):
+        cdef CRayStatus status
+        cdef CPlacementGroupID cplacement_group_id = (
+            CPlacementGroupID.FromBinary(placement_group_id.binary()))
+        cdef int ctimeout_ms = timeout_ms
+        with nogil:
+            status = CCoreWorkerProcess.GetCoreWorker() \
+                .WaitPlacementGroupReady(cplacement_group_id, ctimeout_ms)
+        return status.ok()
+
     def submit_actor_task(self,
                           Language language,
                           ActorID actor_id,

python/ray/includes/libcoreworker.pxd

@@ -101,6 +101,8 @@ cdef extern from "ray/core_worker/core_worker.h" nogil:
             CPlacementGroupID *placement_group_id)
         CRayStatus RemovePlacementGroup(
             const CPlacementGroupID &placement_group_id)
+        CRayStatus WaitPlacementGroupReady(
+            const CPlacementGroupID &placement_group_id, int timeout_ms)
         void SubmitActorTask(
             const CActorID &actor_id, const CRayFunction &function,
             const c_vector[unique_ptr[CTaskArg]] &args,