Merge branch 'threadpool-sched-getattr-runtime-check' into 'master'

Add runtime checks and a fallback if we can't get the thread scheduler settings

Closes #2007

See merge request GNOME/glib!1327

glib/gthread-posix.c

@@ -1162,7 +1162,7 @@ g_system_thread_free (GRealThread *thread)
   g_slice_free (GThreadPosix, pt);
 }
 
-void
+gboolean
 g_system_thread_get_scheduler_settings (GThreadSchedulerSettings *scheduler_settings)
 {
   /* FIXME: Implement the same for macOS and the BSDs so it doesn't go through
@@ -1202,11 +1202,18 @@ g_system_thread_get_scheduler_settings (GThreadSchedulerSettings *scheduler_sett
             }
           else
             {
-              g_error ("Failed to get thread scheduler attributes: %s", g_strerror (errsv));
+              g_debug ("Failed to get thread scheduler attributes: %s", g_strerror (errsv));
+              g_free (scheduler_settings->attr);
+
+              return FALSE;
             }
         }
     }
   while (res == -1);
+
+  return TRUE;
+#else
+  return FALSE;
 #endif
 }
 

glib/gthread-win32.c

@@ -428,11 +428,13 @@ g_thread_win32_proxy (gpointer data)
   return 0;
 }
 
-void
+gboolean
 g_system_thread_get_scheduler_settings (GThreadSchedulerSettings *scheduler_settings)
 {
   HANDLE current_thread = GetCurrentThread ();
   scheduler_settings->thread_prio = GetThreadPriority (current_thread);
+
+  return TRUE;
 }
 
 GRealThread *

glib/gthread.c

@@ -902,11 +902,12 @@ g_thread_new_internal (const gchar *name,
                                           name, func, data, error);
 }
 
-void
+gboolean
 g_thread_get_scheduler_settings (GThreadSchedulerSettings *scheduler_settings)
 {
-  g_return_if_fail (scheduler_settings != NULL);
-  g_system_thread_get_scheduler_settings (scheduler_settings);
+  g_return_val_if_fail (scheduler_settings != NULL, FALSE);
+
+  return g_system_thread_get_scheduler_settings (scheduler_settings);
 }
 
 /**

glib/gthreadpool.c

@@ -114,9 +114,9 @@ static gint max_unused_threads = 2;
 static gint kill_unused_threads = 0;
 static guint max_idle_time = 15 * 1000;
 
-#ifdef HAVE_GTHREAD_SCHEDULER_SETTINGS
 static GThreadSchedulerSettings shared_thread_scheduler_settings;
-#else
+static gboolean have_shared_thread_scheduler_settings = FALSE;
+
 typedef struct
 {
   /* Either thread or error are set in the end. Both transfer-full. */
@@ -127,7 +127,6 @@ typedef struct
 
 static GCond spawn_thread_cond;
 static GAsyncQueue *spawn_thread_queue;
-#endif
 
 static void             g_thread_pool_queue_push_unlocked (GRealThreadPool  *pool,
                                                            gpointer          data);
@@ -294,7 +293,6 @@ g_thread_pool_wait_for_new_task (GRealThreadPool *pool)
   return task;
 }
 
-#ifndef HAVE_GTHREAD_SCHEDULER_SETTINGS
 static gpointer
 g_thread_pool_spawn_thread (gpointer data)
 {
@@ -326,7 +324,6 @@ g_thread_pool_spawn_thread (gpointer data)
 
   return NULL;
 }
-#endif
 
 static gpointer
 g_thread_pool_thread_proxy (gpointer data)
@@ -475,23 +472,26 @@ g_thread_pool_start_thread (GRealThreadPool  *pool,
            * providing them if supported by the GThread implementation or by
            * going via our helper thread.
            */
-#ifdef HAVE_GTHREAD_SCHEDULER_SETTINGS
-          thread = g_thread_new_internal (name, g_thread_proxy, g_thread_pool_thread_proxy, pool, 0, &shared_thread_scheduler_settings, error);
-#else
-          SpawnThreadData spawn_thread_data = { (GThreadPool *) pool, NULL, NULL };
+          if (have_shared_thread_scheduler_settings)
+            {
+              thread = g_thread_new_internal (name, g_thread_proxy, g_thread_pool_thread_proxy, pool, 0, &shared_thread_scheduler_settings, error);
+            }
+          else
+            {
+              SpawnThreadData spawn_thread_data = { (GThreadPool *) pool, NULL, NULL };
 
-          g_async_queue_lock (spawn_thread_queue);
+              g_async_queue_lock (spawn_thread_queue);
 
-          g_async_queue_push_unlocked (spawn_thread_queue, &spawn_thread_data);
+              g_async_queue_push_unlocked (spawn_thread_queue, &spawn_thread_data);
 
-          while (!spawn_thread_data.thread && !spawn_thread_data.error)
-            g_cond_wait (&spawn_thread_cond, _g_async_queue_get_mutex (spawn_thread_queue));
+              while (!spawn_thread_data.thread && !spawn_thread_data.error)
+                g_cond_wait (&spawn_thread_cond, _g_async_queue_get_mutex (spawn_thread_queue));
 
-          thread = spawn_thread_data.thread;
-          if (!thread)
-            g_propagate_error (error, g_steal_pointer (&spawn_thread_data.error));
-          g_async_queue_unlock (spawn_thread_queue);
-#endif
+              thread = spawn_thread_data.thread;
+              if (!thread)
+                g_propagate_error (error, g_steal_pointer (&spawn_thread_data.error));
+              g_async_queue_unlock (spawn_thread_queue);
+            }
         }
 
       if (thread == NULL)
@@ -605,13 +605,16 @@ g_thread_pool_new (GFunc      func,
        */
       if (!exclusive)
         {
-#ifdef HAVE_GTHREAD_SCHEDULER_SETTINGS
-          g_thread_get_scheduler_settings (&shared_thread_scheduler_settings);
-#else
-          spawn_thread_queue = g_async_queue_new ();
-          g_cond_init (&spawn_thread_cond);
-          g_thread_new ("pool-spawner", g_thread_pool_spawn_thread, NULL);
-#endif
+          if (g_thread_get_scheduler_settings (&shared_thread_scheduler_settings))
+            {
+              have_shared_thread_scheduler_settings = TRUE;
+            }
+          else
+            {
+              spawn_thread_queue = g_async_queue_new ();
+              g_cond_init (&spawn_thread_cond);
+              g_thread_new ("pool-spawner", g_thread_pool_spawn_thread, NULL);
+            }
         }
     }
   G_UNLOCK (init);

glib/gthreadprivate.h

@@ -74,7 +74,7 @@ void            g_system_thread_free            (GRealThread  *thread);
 void            g_system_thread_exit            (void);
 void            g_system_thread_set_name        (const gchar  *name);
 
-void g_system_thread_get_scheduler_settings (GThreadSchedulerSettings *scheduler_settings);
+gboolean        g_system_thread_get_scheduler_settings (GThreadSchedulerSettings *scheduler_settings);
 
 /* gthread.c */
 GThread *g_thread_new_internal (const gchar *name,
@@ -85,7 +85,7 @@ GThread *g_thread_new_internal (const gchar *name,
                                 const GThreadSchedulerSettings *scheduler_settings,
                                 GError **error);
 
-void g_thread_get_scheduler_settings (GThreadSchedulerSettings *scheduler_settings);
+gboolean g_thread_get_scheduler_settings (GThreadSchedulerSettings *scheduler_settings);
 
 gpointer        g_thread_proxy                  (gpointer      thread);
 

meson.build

@@ -1731,7 +1731,7 @@ else
     glib_conf.set('HAVE_PTHREAD_GETNAME_NP', 1)
   endif
 
-  if cc.has_header_symbol('sys/syscall.h', 'SYS_sched_getattr,')
+  if cc.has_header_symbol('sys/syscall.h', 'SYS_sched_getattr')
     glib_conf.set('HAVE_SYS_SCHED_GETATTR', 1)
   endif