runtime.go

Documentation: runtime

		 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  import (
		 8  	"runtime/internal/atomic"
		 9  	_ "unsafe" // for go:linkname
		10  )
		11  
		12  //go:generate go run wincallback.go
		13  //go:generate go run mkduff.go
		14  //go:generate go run mkfastlog2table.go
		15  
		16  var ticks struct {
		17  	lock mutex
		18  	pad	uint32 // ensure 8-byte alignment of val on 386
		19  	val	uint64
		20  }
		21  
		22  // Note: Called by runtime/pprof in addition to runtime code.
		23  func tickspersecond() int64 {
		24  	r := int64(atomic.Load64(&ticks.val))
		25  	if r != 0 {
		26  		return r
		27  	}
		28  	lock(&ticks.lock)
		29  	r = int64(ticks.val)
		30  	if r == 0 {
		31  		t0 := nanotime()
		32  		c0 := cputicks()
		33  		usleep(100 * 1000)
		34  		t1 := nanotime()
		35  		c1 := cputicks()
		36  		if t1 == t0 {
		37  			t1++
		38  		}
		39  		r = (c1 - c0) * 1000 * 1000 * 1000 / (t1 - t0)
		40  		if r == 0 {
		41  			r++
		42  		}
		43  		atomic.Store64(&ticks.val, uint64(r))
		44  	}
		45  	unlock(&ticks.lock)
		46  	return r
		47  }
		48  
		49  var envs []string
		50  var argslice []string
		51  
		52  //go:linkname syscall_runtime_envs syscall.runtime_envs
		53  func syscall_runtime_envs() []string { return append([]string{}, envs...) }
		54  
		55  //go:linkname syscall_Getpagesize syscall.Getpagesize
		56  func syscall_Getpagesize() int { return int(physPageSize) }
		57  
		58  //go:linkname os_runtime_args os.runtime_args
		59  func os_runtime_args() []string { return append([]string{}, argslice...) }
		60  
		61  //go:linkname syscall_Exit syscall.Exit
		62  //go:nosplit
		63  func syscall_Exit(code int) {
		64  	exit(int32(code))
		65  }
		66
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