Home | History | Annotate | Download | only in runtime
      1 // Copyright 2012 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 package runtime
      6 
      7 func checkgoarm() {
      8 	// TODO(minux): FP checks like in os_linux_arm.go.
      9 
     10 	// osinit not called yet, so ncpu not set: must use getncpu directly.
     11 	if getncpu() > 1 && goarm < 7 {
     12 		print("runtime: this system has multiple CPUs and must use\n")
     13 		print("atomic synchronization instructions. Recompile using GOARM=7.\n")
     14 		exit(1)
     15 	}
     16 }
     17 
     18 //go:nosplit
     19 func cputicks() int64 {
     20 	// Currently cputicks() is used in blocking profiler and to seed runtimefastrand1().
     21 	// runtimenanotime() is a poor approximation of CPU ticks that is enough for the profiler.
     22 	// TODO: need more entropy to better seed fastrand1.
     23 	return nanotime()
     24 }
     25