issue #159: verify no more than 20 tasks exist on the remote

tests/ansible/integration/all.yml

@@ -6,5 +6,6 @@
 - import_playbook: action/all.yml
 - import_playbook: become/all.yml
 - import_playbook: connection_loader/all.yml
-- import_playbook: runner/all.yml
+- import_playbook: context_service/all.yml
 - import_playbook: playbook_semantics/all.yml
+- import_playbook: runner/all.yml

tests/ansible/integration/context_service/all.yml

@@ -0,0 +1 @@
+- import_playbook: lru_one_target.yml

tests/ansible/integration/context_service/lru_one_target.yml

@@ -0,0 +1,33 @@
+# Verify a maximum number of contexts are possible on one machine.
+
+- hosts: all
+  any_errors_fatal: true
+  tasks:
+    - name: integration/context_service/lru_one_target.yml
+      assert:
+        that: true
+
+    - name: Spin up a bunch of interpreters
+      custom_python_detect_environment:
+      become: true
+      vars:
+        ansible_become_user: "mitogen__user{{item}}"
+      with_sequence: start=1 end=21
+      register: first_run
+
+    - name: Reuse them
+      custom_python_detect_environment:
+      become: true
+      vars:
+        ansible_become_user: "mitogen__user{{item}}"
+      with_sequence: start=1 end=21
+      register: second_run
+
+    - assert:
+        that:
+        - first_run.results[item|int].pid == second_run.results[item|int].pid
+      with_items: start=0 end=20
+
+    - assert:
+        that:
+        - first_run.results[-1].pid != second_run.results[-1].pid