xnu-4903.221.2.tar.gz

[apple/xnu.git] / bsd / pthread / pthread_priority.c

diff --git a/bsd/pthread/pthread_priority.c b/bsd/pthread/pthread_priority.c
new file mode 100644 (file)
index 0000000..53cda95
--- /dev/null
+++ b/bsd/pthread/pthread_priority.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2017 Apple Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ *
+ */
+
+#include <pthread/priority_private.h>
+
+#ifndef QOS_MIN_RELATIVE_PRIORITY // from <sys/qos.h> in userspace
+#define QOS_MIN_RELATIVE_PRIORITY -15
+#endif
+
+pthread_priority_t
+_pthread_priority_normalize(pthread_priority_t pp)
+{
+       if (pp & _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG) {
+               return _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG;
+       }
+       if (_pthread_priority_has_qos(pp)) {
+               int relpri = _pthread_priority_relpri(pp);
+               if (relpri > 0 || relpri < QOS_MIN_RELATIVE_PRIORITY) {
+                       pp |= _PTHREAD_PRIORITY_PRIORITY_MASK;
+               }
+               return pp & (_PTHREAD_PRIORITY_OVERCOMMIT_FLAG |
+                               _PTHREAD_PRIORITY_FALLBACK_FLAG |
+                               _PTHREAD_PRIORITY_QOS_CLASS_MASK |
+                               _PTHREAD_PRIORITY_PRIORITY_MASK);
+       }
+       return _pthread_unspecified_priority();
+}
+
+pthread_priority_t
+_pthread_priority_normalize_for_ipc(pthread_priority_t pp)
+{
+       if (_pthread_priority_has_qos(pp)) {
+               int relpri = _pthread_priority_relpri(pp);
+               if (relpri > 0 || relpri < QOS_MIN_RELATIVE_PRIORITY) {
+                       pp |= _PTHREAD_PRIORITY_PRIORITY_MASK;
+               }
+               return pp & (_PTHREAD_PRIORITY_QOS_CLASS_MASK |
+                               _PTHREAD_PRIORITY_PRIORITY_MASK);
+       }
+       return _pthread_unspecified_priority();
+}
+
+pthread_priority_t
+_pthread_priority_combine(pthread_priority_t base_pp, thread_qos_t qos)
+{
+       if (base_pp & _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG) {
+               return _PTHREAD_PRIORITY_EVENT_MANAGER_FLAG;
+       }
+
+       if (base_pp & _PTHREAD_PRIORITY_FALLBACK_FLAG) {
+               if (!qos) {
+                       return base_pp;
+               }
+       } else if (qos < _pthread_priority_thread_qos(base_pp)) {
+               return base_pp;
+       }
+
+       return _pthread_priority_make_from_thread_qos(qos, 0,
+                       base_pp & _PTHREAD_PRIORITY_OVERCOMMIT_FLAG);
+}