gio: tests: memory-monitor-psi: test for the PSI backend of GMemoryMonitor

This tests the PSI backend when receiving the signal.

gio/tests/memory-monitor-psi.c

@@ -0,0 +1,120 @@
+/* GIO - GLib Input, Output and Streaming Library
+ *
+ * Copyright 2025 Red Hat, Inc.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <glib/glib.h>
+#include <glib/gstdio.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "gio.h"
+#include "gmemorymonitorpsi.h"
+
+typedef struct
+{
+  char *mock_psi_path;
+  char *mock_proc_path;
+} SetupData;
+
+static void
+tests_setup (SetupData *setup_data,
+             gconstpointer data)
+{
+  char *proc_contents = NULL;
+  GError *local_error = NULL;
+
+  setup_data->mock_psi_path = g_build_filename (g_get_tmp_dir (), "cgroup", NULL);
+  g_assert_no_errno (mkfifo (setup_data->mock_psi_path, S_IRUSR | S_IWUSR));
+
+  setup_data->mock_proc_path = g_build_filename (g_get_tmp_dir (), "psi-proc", NULL);
+  proc_contents = g_strdup_printf ("0::%s", setup_data->mock_psi_path);
+  g_file_set_contents_full (setup_data->mock_proc_path, proc_contents,
+                            -1, G_FILE_SET_CONTENTS_NONE,
+                            S_IRUSR | S_IWUSR, &local_error);
+  g_assert_no_error (local_error);
+  g_free (proc_contents);
+}
+
+static void
+tests_teardown (SetupData *setup_data,
+                gconstpointer data)
+{
+  g_unlink (setup_data->mock_proc_path);
+  g_free (setup_data->mock_proc_path);
+  g_unlink (setup_data->mock_psi_path);
+  g_free (setup_data->mock_psi_path);
+}
+
+static void
+memory_monitor_psi_signal_cb (GMemoryMonitor *m,
+                              GMemoryMonitorWarningLevel level,
+                              gpointer user_data)
+{
+  int *out_warning_level = user_data;
+
+  *out_warning_level = level;
+
+  g_main_context_wakeup (NULL);
+}
+
+static void
+test_receive_signals (SetupData *setup, gconstpointer data)
+{
+  GMemoryMonitorPsi *monitor;
+  unsigned long warning_id;
+  int warning_level = -1;
+  GError *local_error = NULL;
+
+  monitor = g_object_new (G_TYPE_MEMORY_MONITOR_PSI,
+                          "proc-path", setup->mock_proc_path,
+                          NULL);
+  g_initable_init (G_INITABLE (monitor), NULL, &local_error);
+  g_assert_no_error (local_error);
+
+  g_file_set_contents (setup->mock_psi_path,
+                       "test",
+                       -1,
+                       &local_error);
+  g_assert_no_error (local_error);
+
+  warning_id = g_signal_connect (monitor, "low-memory-warning",
+                                 G_CALLBACK (memory_monitor_psi_signal_cb), &warning_level);
+
+  while (warning_level == -1)
+    g_main_context_iteration (NULL, TRUE);
+
+  g_assert_true (warning_level == 50 ||
+                 warning_level == 100 ||
+                 warning_level == 255);
+
+  g_signal_handler_disconnect (monitor, warning_id);
+  g_object_unref (monitor);
+}
+
+int
+main (int argc, char **argv)
+{
+  g_setenv ("GIO_USE_MEMORY_MONITOR", "psi", TRUE);
+
+  g_test_init (&argc, &argv, G_TEST_OPTION_ISOLATE_DIRS, NULL);
+  g_test_add ("/memory-monitor-psi/receive-signal", SetupData, NULL,
+              tests_setup, test_receive_signals, tests_teardown);
+
+  return g_test_run ();
+}

gio/tests/meson.build

@@ -155,6 +155,12 @@ gio_tests = {
   'win32-appinfo' : {},
 }
 
+if host_system == 'linux'
+  gio_tests += {
+    'memory-monitor-psi' : {},
+  }
+endif
+
 if glib_conf.has('HAVE_SYSINFO')
   gio_tests += {
     'memory-monitor-poll' : {},