[glib/1525-task-result: 2/2] gtask: Compress GTask struct using a bitfield

[Philip Withnall <pwithnall src gnome org>]

commit 290bb0dd1b5169806e7de2a17ad22a3432661d31
Author: Philip Withnall <withnall endlessm com>
Date:   Mon Oct 1 21:51:18 2018 +0100

    gtask: Compress GTask struct using a bitfield
    
    There are a lot of gbooleans in the private GTask struct, which seems a
    bit wasteful. Use a bitfield to compress the struct a bit.
    
    This reduces the size of the struct from 216 bytes to 168 bytes on my
    64-bit machine.
    
    One of the fields needs to remain separate, since it’s used from a
    TRACE() macro which calls typeof() on it.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>

 gio/gtask.c | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)
---
diff --git a/gio/gtask.c b/gio/gtask.c
index a31bd613a..a40bc01b4 100644
--- a/gio/gtask.c
+++ b/gio/gtask.c
@@ -551,20 +551,26 @@ struct _GTask {
   gint64 creation_time;
   gint priority;
   GCancellable *cancellable;
-  gboolean check_cancellable;
 
   GAsyncReadyCallback callback;
   gpointer callback_data;
-  gboolean completed;
 
   GTaskThreadFunc task_func;
   GMutex lock;
   GCond cond;
-  gboolean return_on_cancel;
+
+  /* This can’t be in the bit field because we access it from TRACE(). */
   gboolean thread_cancelled;
-  gboolean synchronous;
-  gboolean thread_complete;
-  gboolean blocking_other_task;
+
+  gboolean check_cancellable : 1;
+  gboolean completed : 1;
+  gboolean return_on_cancel : 1;
+  gboolean synchronous : 1;
+  gboolean thread_complete : 1;
+  gboolean blocking_other_task : 1;
+  gboolean had_error : 1;
+  gboolean result_set : 1;
+  gboolean ever_returned : 1;
 
   GError *error;
   union {
@@ -573,9 +579,6 @@ struct _GTask {
     gboolean boolean;
   } result;
   GDestroyNotify result_destroy;
-  gboolean had_error;
-  gboolean result_set;
-  gboolean ever_returned;
 };
 
 #define G_TASK_IS_THREADED(task) ((task)->task_func != NULL)
@@ -1635,7 +1638,7 @@ g_task_propagate_pointer (GTask   *task,
   if (g_task_propagate_error (task, error))
     return NULL;
 
-  g_return_val_if_fail (task->result_set == TRUE, NULL);
+  g_return_val_if_fail (task->result_set, NULL);
 
   task->result_destroy = NULL;
   task->result_set = FALSE;
@@ -1691,7 +1694,7 @@ g_task_propagate_int (GTask   *task,
   if (g_task_propagate_error (task, error))
     return -1;
 
-  g_return_val_if_fail (task->result_set == TRUE, -1);
+  g_return_val_if_fail (task->result_set, -1);
 
   task->result_set = FALSE;
   return task->result.size;
@@ -1746,7 +1749,7 @@ g_task_propagate_boolean (GTask   *task,
   if (g_task_propagate_error (task, error))
     return FALSE;
 
-  g_return_val_if_fail (task->result_set == TRUE, FALSE);
+  g_return_val_if_fail (task->result_set, FALSE);
 
   task->result_set = FALSE;
   return task->result.boolean;