[sysprof] helpers: add async helper to list processes

[Christian Hergert <chergert src gnome org>]

commit e54b17a4be2c42ac5e0965f49a98484577a81cdc
Author: Christian Hergert <chergert redhat com>
Date:   Fri May 17 19:46:10 2019 -0700

    helpers: add async helper to list processes

 src/helpers.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/helpers.h | 35 ++++++++++++++++-----------
 2 files changed, 97 insertions(+), 14 deletions(-)
---
diff --git a/src/helpers.c b/src/helpers.c
index ebba685..603ee99 100644
--- a/src/helpers.c
+++ b/src/helpers.c
@@ -328,3 +328,79 @@ helpers_can_see_pids (void)
 
   return TRUE;
 }
+
+static void
+helpers_list_processes_worker (GTask        *task,
+                               gpointer      source_object,
+                               gpointer      task_data,
+                               GCancellable *cancellable)
+{
+  g_autofree gint32 *processes = NULL;
+  gsize n_processes;
+
+  g_assert (G_IS_TASK (task));
+  g_assert (!cancellable || G_IS_CANCELLABLE (cancellable));
+
+  if (helpers_list_processes (&processes, &n_processes))
+    {
+      GArray *ar;
+
+      ar = g_array_new (FALSE, FALSE, sizeof (gint32));
+      g_array_append_vals (ar, processes, n_processes);
+      g_task_return_pointer (task,
+                             g_steal_pointer (&ar),
+                             (GDestroyNotify) g_array_unref);
+
+      return;
+    }
+
+  g_task_return_new_error (task,
+                           G_IO_ERROR,
+                           G_IO_ERROR_FAILED,
+                           "Failed to list processes");
+}
+
+void
+helpers_list_processes_async (GCancellable        *cancellable,
+                              GAsyncReadyCallback  callback,
+                              gpointer             user_data)
+{
+  g_autoptr(GTask) task = NULL;
+
+  g_return_if_fail (!cancellable || G_IS_CANCELLABLE (cancellable));
+
+  task = g_task_new (NULL, cancellable, callback, user_data);
+  g_task_set_source_tag (task, helpers_list_processes_async);
+  g_task_run_in_thread (task, helpers_list_processes_worker);
+}
+
+gboolean
+helpers_list_processes_finish (GAsyncResult  *result,
+                               gint32       **processes,
+                               gsize         *n_processes,
+                               GError       **error)
+{
+  g_autoptr(GArray) ret = NULL;
+
+  g_return_val_if_fail (G_IS_TASK (result), FALSE);
+
+  if ((ret = g_task_propagate_pointer (G_TASK (result), error)))
+    {
+      if (n_processes)
+        *n_processes = ret->len;
+
+      if (processes)
+        *processes = (gint32 *)(gpointer)g_array_free (ret, FALSE);
+
+      return TRUE;
+    }
+  else
+    {
+      if (processes)
+        *processes = NULL;
+      if (n_processes)
+        *n_processes = 0;
+    }
+
+  return FALSE;
+}
diff --git a/src/helpers.h b/src/helpers.h
index 212106b..0aa0470 100644
--- a/src/helpers.h
+++ b/src/helpers.h
@@ -27,19 +27,26 @@
 
 G_BEGIN_DECLS
 
-gboolean helpers_can_see_pids    (void);
-gboolean helpers_list_processes  (gint32      **processes,
-                                  gsize        *n_processes);
-gboolean helpers_perf_event_open (GVariant     *options,
-                                  gint32        pid,
-                                  gint32        cpu,
-                                  gint          group_fd,
-                                  guint64       flags,
-                                  gint         *out_fd);
-gboolean helpers_get_proc_file   (const gchar  *path,
-                                  gchar       **contents,
-                                  gsize        *len);
-gboolean helpers_get_proc_fd     (const gchar  *path,
-                                  gint         *out_fd);
+gboolean helpers_can_see_pids          (void);
+gboolean helpers_list_processes        (gint32              **processes,
+                                        gsize                *n_processes);
+void     helpers_list_processes_async  (GCancellable         *cancellable,
+                                        GAsyncReadyCallback   callback,
+                                        gpointer              user_data);
+gboolean helpers_list_processes_finish (GAsyncResult         *result,
+                                        gint32              **processes,
+                                        gsize                *n_processes,
+                                        GError              **error);
+gboolean helpers_perf_event_open       (GVariant             *options,
+                                        gint32                pid,
+                                        gint32                cpu,
+                                        gint                  group_fd,
+                                        guint64               flags,
+                                        gint                 *out_fd);
+gboolean helpers_get_proc_file         (const gchar          *path,
+                                        gchar               **contents,
+                                        gsize                *len);
+gboolean helpers_get_proc_fd           (const gchar          *path,
+                                        gint                 *out_fd);
 
 G_END_DECLS