|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
|
#ifndef FWCore_Concurrency_hardware_pause_h
#define FWCore_Concurrency_hardware_pause_h
// -*- C++ -*-
//
// Package: Concurrency
// Class : hardware_pause
//
/**\class hardware_pause hardware_pause.h FWCore/Concurrency/interface/hardware_pause.h
Description: assembler instruction to allow a short pause
Usage:
This hardware instruction tells the CPU to pause momentarily. This can be useful
in the case where one is doing a 'spin lock' on a quantity that you expect to change
within a few clock cycles.
*/
//
// Original Author: Chris Jones
// Created: Thu Feb 21 13:55:57 CST 2013
// $Id$
//
//NOTE: Taken from libdispatch shims/atomics.h
#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 2)
#define hardware_pause() asm("")
#endif
#if defined(__x86_64__) || defined(__i386__)
#undef hardware_pause
#define hardware_pause() asm("pause")
#endif
#endif
|