go/src/runtime/debug.go

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package runtime

import "unsafe"

// Breakpoint executes a breakpoint trap.
func Breakpoint()

// LockOSThread wires the calling goroutine to its current operating system thread.
// Until the calling goroutine exits or calls UnlockOSThread, it will always
// execute in that thread, and no other goroutine can.
func LockOSThread()

// UnlockOSThread unwires the calling goroutine from its fixed operating system thread.
// If the calling goroutine has not called LockOSThread, UnlockOSThread is a no-op.
func UnlockOSThread()

// GOMAXPROCS sets the maximum number of CPUs that can be executing
// simultaneously and returns the previous setting.  If n < 1, it does not
// change the current setting.
// The number of logical CPUs on the local machine can be queried with NumCPU.
// This call will go away when the scheduler improves.
func GOMAXPROCS(n int) int {
	g := getg()
	g.m.scalararg[0] = uintptr(n)
	onM(gomaxprocs_m)
	n = int(g.m.scalararg[0])
	g.m.scalararg[0] = 0
	return n
}

func gomaxprocs_m() // proc.c

// NumCPU returns the number of logical CPUs on the local machine.
func NumCPU() int {
	return int(ncpu)
}

// NumCgoCall returns the number of cgo calls made by the current process.
func NumCgoCall() int64 {
	var n int64
	for mp := (*m)(atomicloadp(unsafe.Pointer(&allm))); mp != nil; mp = mp.alllink {
		n += int64(mp.ncgocall)
	}
	return n
}

// NumGoroutine returns the number of goroutines that currently exist.
func NumGoroutine() int {
	return int(gcount())
}

func gcount() int32