pyverbs: Release Python GIL when calling blocking CMID functions

This releases the Python GIL when calling the following functions:
- rdma_get_request (CMID.get_request)
- rdma_get_send_comp (CMID.get_send_comp)
- rdma_get_recv_comp (CMID.get_recv_comp)

This allows the user to create a functional multithreaded Python
application using the PyVerbs API.

Signed-off-by: Timon Kruiper <Timon.Kruiper@Teledyne.com>

Author: Timon-Kruiper

pyverbs/cmid.pyx

@@ -446,7 +446,8 @@ cdef class CMID(PyverbsCM):
         :return: New CMID representing the connection request.
         """
         to_conn = CMID()
-        ret = cm.rdma_get_request(self.id, &to_conn.id)
+        with nogil:
+            ret = cm.rdma_get_request(self.id, &to_conn.id)
         if ret != 0:
             raise PyverbsRDMAErrno('Failed to get request, no connection established')
         self.ctx = Context(cmid=to_conn)
@@ -776,7 +777,8 @@ cdef class CMID(PyverbsCM):
         :return: The retrieved WC or None if there is no completions
         """
         cdef v.ibv_wc wc
-        ret = cm.rdma_get_recv_comp(self.id, &wc)
+        with nogil:
+            ret = cm.rdma_get_recv_comp(self.id, &wc)
         if ret < 0:
             raise PyverbsRDMAErrno('Failed to retrieve receive completion')
         elif ret == 0:
@@ -794,7 +796,8 @@ cdef class CMID(PyverbsCM):
         :return: The retrieved WC or None if there is no completions
         """
         cdef v.ibv_wc wc
-        ret = cm.rdma_get_send_comp(self.id, &wc)
+        with nogil:
+            ret = cm.rdma_get_send_comp(self.id, &wc)
         if ret < 0:
             raise PyverbsRDMAErrno('Failed to retrieve send completion')
         elif ret == 0:

pyverbs/librdmacm.pxd

@@ -109,7 +109,7 @@ cdef extern from '<rdma/rdma_cma.h>':
     int rdma_destroy_id(rdma_cm_id *id)
     int rdma_get_remote_ece(rdma_cm_id *id, ibv_ece *ece)
     int rdma_set_local_ece(rdma_cm_id *id, ibv_ece *ece)
-    int rdma_get_request(rdma_cm_id *listen, rdma_cm_id **id)
+    int rdma_get_request(rdma_cm_id *listen, rdma_cm_id **id) nogil
     int rdma_bind_addr(rdma_cm_id *id, sockaddr *addr)
     int rdma_resolve_addr(rdma_cm_id *id, sockaddr *src_addr,
                           sockaddr *dst_addr, int timeout_ms)
@@ -149,8 +149,8 @@ cdef extern from '<rdma/rdma_verbs.h>':
     int rdma_post_write(rdma_cm_id *id, void *context, void *addr,
                         size_t length, ibv_mr *mr, int flags,
                         uint64_t remote_addr, uint32_t rkey)
-    int rdma_get_send_comp(rdma_cm_id *id, ibv_wc *wc)
-    int rdma_get_recv_comp(rdma_cm_id *id, ibv_wc *wc)
+    int rdma_get_send_comp(rdma_cm_id *id, ibv_wc *wc) nogil
+    int rdma_get_recv_comp(rdma_cm_id *id, ibv_wc *wc) nogil
     ibv_mr *rdma_reg_msgs(rdma_cm_id *id, void *addr, size_t length)
     ibv_mr *rdma_reg_read(rdma_cm_id *id, void *addr, size_t length)
     ibv_mr *rdma_reg_write(rdma_cm_id *id, void *addr, size_t length)