1 // Copyright 2011 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4 
5 #include "config.h"
6 
7 #include <stddef.h>
8 #include <sys/types.h>
9 #include <sys/time.h>
10 #include <sched.h>
11 #include <unistd.h>
12 
13 #ifdef HAVE_SYS_SELECT_H
14 #include <sys/select.h>
15 #endif
16 
17 #if defined (__i386__) || defined (__x86_64__)
18 #include <xmmintrin.h>
19 #endif
20 
21 #include "runtime.h"
22 
23 /* Spin wait.  */
24 
25 void
runtime_procyield(uint32 cnt)26 runtime_procyield (uint32 cnt)
27 {
28   volatile uint32 i;
29 
30   for (i = 0; i < cnt; ++i)
31     {
32 #if defined (__i386__) || defined (__x86_64__)
33       _mm_pause ();
34 #endif
35     }
36 }
37 
38 /* Ask the OS to reschedule this thread.  */
39 
40 void
runtime_osyield(void)41 runtime_osyield (void)
42 {
43   sched_yield ();
44 }
45 
46 /* Sleep for some number of microseconds.  */
47 
48 void
runtime_usleep(uint32 us)49 runtime_usleep (uint32 us)
50 {
51   struct timeval tv;
52 
53   tv.tv_sec = us / 1000000;
54   tv.tv_usec = us % 1000000;
55   select (0, NULL, NULL, NULL, &tv);
56 }
57