github.com/hbdrawn/golang@v0.0.0-20141214014649-6b835209aba2/src/runtime/runtime.go (about)

     1  // Copyright 2009 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  //go:generate go run wincallback.go
     8  
     9  var ticks struct {
    10  	lock mutex
    11  	val  uint64
    12  }
    13  
    14  var tls0 [8]uintptr // available storage for m0's TLS; not necessarily used; opaque to GC
    15  
    16  // Note: Called by runtime/pprof in addition to runtime code.
    17  func tickspersecond() int64 {
    18  	r := int64(atomicload64(&ticks.val))
    19  	if r != 0 {
    20  		return r
    21  	}
    22  	lock(&ticks.lock)
    23  	r = int64(ticks.val)
    24  	if r == 0 {
    25  		t0 := nanotime()
    26  		c0 := cputicks()
    27  		usleep(100 * 1000)
    28  		t1 := nanotime()
    29  		c1 := cputicks()
    30  		if t1 == t0 {
    31  			t1++
    32  		}
    33  		r = (c1 - c0) * 1000 * 1000 * 1000 / (t1 - t0)
    34  		if r == 0 {
    35  			r++
    36  		}
    37  		atomicstore64(&ticks.val, uint64(r))
    38  	}
    39  	unlock(&ticks.lock)
    40  	return r
    41  }
    42  
    43  func makeStringSlice(n int) []string {
    44  	return make([]string, n)
    45  }
    46  
    47  // TODO: Move to parfor.go when parfor.c becomes parfor.go.
    48  func parforalloc(nthrmax uint32) *parfor {
    49  	return &parfor{
    50  		thr:     &make([]parforthread, nthrmax)[0],
    51  		nthrmax: nthrmax,
    52  	}
    53  }
    54  
    55  var envs []string
    56  var argslice []string
    57  
    58  // called from syscall
    59  func runtime_envs() []string { return envs }
    60  
    61  // called from os
    62  func runtime_args() []string { return argslice }