tests: Use fork instead of forkserver

Make sure test can be successfully run on pyton 3.14.

According to
https://docs.python.org/dev/whatsnew/3.14.html#multiprocessing

The default start method (see Contexts and start methods) changed from
fork to forkserver on platforms other than macOS & Windows where it was
already spawn. If you require the threading incompatible fork start
method you must explicitly request it using a context from
multiprocessing.get_context() (preferred) or change the default via
multiprocessing.set_start_method().

See also https://bugzilla.redhat.com/show_bug.cgi?id=2326934 for
reference on the reported bug for the Fedora package.

Signed-off-by: Matteo Centenaro <[email protected]>

tests/test_multiprocessing.py

@@ -29,7 +29,14 @@ def r(self, request):
             valkey.Valkey, request=request, single_connection_client=False
         )
 
-    def test_close_connection_in_child(self, master_host):
+    @pytest.fixture()
+    def multiprocessing_ctx(self):
+        curr_start_method = multiprocessing.get_start_method(allow_none=False)
+        if curr_start_method == "forkserver":
+            return multiprocessing.get_context("fork")
+        return multiprocessing.get_context(curr_start_method)
+
+    def test_close_connection_in_child(self, master_host, multiprocessing_ctx):
         """
         A connection owned by a parent and closed by a child doesn't
         destroy the file descriptors so a parent can still use it.
@@ -43,7 +50,7 @@ def target(conn):
             assert conn.read_response() == b"PONG"
             conn.disconnect()
 
-        proc = multiprocessing.Process(target=target, args=(conn,))
+        proc = multiprocessing_ctx.Process(target=target, args=(conn,))
         proc.start()
         proc.join(3)
         assert proc.exitcode == 0
@@ -55,7 +62,7 @@ def target(conn):
         conn.send_command("ping")
         assert conn.read_response() == b"PONG"
 
-    def test_close_connection_in_parent(self, master_host):
+    def test_close_connection_in_parent(self, master_host, multiprocessing_ctx):
         """
         A connection owned by a parent is unusable by a child if the parent
         (the owning process) closes the connection.
@@ -73,7 +80,7 @@ def target(conn, ev):
                 conn.send_command("ping")
 
         ev = multiprocessing.Event()
-        proc = multiprocessing.Process(target=target, args=(conn, ev))
+        proc = multiprocessing_ctx.Process(target=target, args=(conn, ev))
         proc.start()
 
         conn.disconnect()
@@ -83,7 +90,7 @@ def target(conn, ev):
         assert proc.exitcode == 0
 
     @pytest.mark.parametrize("max_connections", [1, 2, None])
-    def test_pool(self, max_connections, master_host):
+    def test_pool(self, max_connections, master_host, multiprocessing_ctx):
         """
         A child will create its own connections when using a pool created
         by a parent.
@@ -107,7 +114,7 @@ def target(pool):
                     assert conn.send_command("ping") is None
                     assert conn.read_response() == b"PONG"
 
-        proc = multiprocessing.Process(target=target, args=(pool,))
+        proc = multiprocessing_ctx.Process(target=target, args=(pool,))
         proc.start()
         proc.join(3)
         assert proc.exitcode == 0
@@ -120,7 +127,9 @@ def target(pool):
             assert conn.read_response() == b"PONG"
 
     @pytest.mark.parametrize("max_connections", [1, 2, None])
-    def test_close_pool_in_main(self, max_connections, master_host):
+    def test_close_pool_in_main(
+        self, max_connections, master_host, multiprocessing_ctx
+    ):
         """
         A child process that uses the same pool as its parent isn't affected
         when the parent disconnects all connections within the pool.
@@ -145,23 +154,23 @@ def target(pool, disconnect_event):
 
         ev = multiprocessing.Event()
 
-        proc = multiprocessing.Process(target=target, args=(pool, ev))
+        proc = multiprocessing_ctx.Process(target=target, args=(pool, ev))
         proc.start()
 
         pool.disconnect()
         ev.set()
         proc.join(3)
         assert proc.exitcode == 0
 
-    def test_valkey_client(self, r):
+    def test_valkey_client(self, r, multiprocessing_ctx):
         "A valkey client created in a parent can also be used in a child"
         assert r.ping() is True
 
         def target(client):
             assert client.ping() is True
             del client
 
-        proc = multiprocessing.Process(target=target, args=(r,))
+        proc = multiprocessing_ctx.Process(target=target, args=(r,))
         proc.start()
         proc.join(3)
         assert proc.exitcode == 0