Add stack usage benchmark (#1698)

.circleci/config.yml

@@ -186,6 +186,16 @@ jobs:
       - store_test_results:
           path: test-results
 
+  benchmark-stack-size:
+    <<: *defaults
+    steps:
+      - attach_workspace:
+          at: .
+      - run:
+          name: stack-size
+          command: |
+            pytest -s benchmark/stack_usage.py  | sed -n 's/## //pg'
+
   test-emsdk:
     <<: *defaults
     resource_class: small
@@ -331,6 +341,9 @@ workflows:
       - test-js:
           requires:
             - build-core
+      - benchmark-stack-size:
+          requires:
+            - build-core
       - benchmark:
           requires:
             - build-packages

benchmark/stack_usage.py

@@ -0,0 +1,78 @@
+import pytest
+
+
+@pytest.fixture(scope="session")
+def print_info():
+    headings = [
+        "browser",
+        "py_usage",
+        "js_depth",
+        "py_depth",
+        "js_depth/py_usage",
+        "js_depth/py_depth",
+    ]
+    fmt = "## {{:{:d}s}}  {{:{:d}.2f}}  {{:{:d}g}}  {{:{:d}g}}  {{:{:d}g}}  {{:{:d}g}}".format(
+        *map(len, headings)
+    )
+    printed_heading = False
+
+    def print_info(*args):
+        nonlocal printed_heading
+        if not printed_heading:
+            printed_heading = True
+            print("## " + "  ".join(headings))
+        print(fmt.format(*args))
+
+    yield print_info
+
+
+@pytest.mark.skip_refcount_check
+@pytest.mark.skip_pyproxy_check
+def test_stack_usage(selenium, print_info):
+    res = selenium.run_js(
+        """
+        window.measure_available_js_stack_depth = () => {
+            let depth = 0;
+            function recurse() { depth += 1; recurse(); }
+            try { recurse(); } catch (err) { }
+            return depth;
+        };
+        let py_usage = pyodide.runPython(`
+            from js import measure_available_js_stack_depth
+            def recurse(n):
+                return measure_available_js_stack_depth() if n==0 else recurse(n-1)
+            (recurse(0)-recurse(100))/100
+        `);
+        let js_depth = measure_available_js_stack_depth();
+        window.py_depth = [0];
+        try {
+        pyodide.runPython(`
+        import sys
+        from js import py_depth
+        sys.setrecursionlimit(2000)
+        def infiniterecurse():
+            py_depth[0] += 1
+            infiniterecurse()
+        infiniterecurse()
+        `);
+        } catch {}
+
+        py_depth = py_depth[0];
+        return [
+            py_usage,
+            js_depth,
+            py_depth,
+            Math.floor(js_depth/py_usage),
+            Math.floor(js_depth/py_depth),
+        ]
+        """
+    )
+    # "py_usage",
+    # "js_depth",
+    # "py_depth",
+    # "js_depth/py_usage",
+    # "js_depth/py_depth",
+
+    print_info(selenium.browser, *res)
+
+    selenium.clean_logs()