//go:build !plan9 && !windows

// Test that callbacks from C to Go in the same C-thread always get the same m.
// Make sure the extra M bind to the C-thread.

package main

/*
extern void CheckBindM();
*/
import "C"

import (
	"fmt"
	"os"
	"runtime"
	"sync"
	"sync/atomic"
)

var (
	mutex      = sync.Mutex{}
	cThreadToM = map[uintptr]uintptr{}
	started    = atomic.Uint32{}
)

#define CHECKCALLS 100

static void* checkBindMThread(void* thread) {
	int i;
	for (i = 0; i < CHECKCALLS; i++) {
		GoCheckBindM((uintptr_t)thread);
		usleep(1);
	}
	return NULL;
}

void CheckBindM() {
	int i;
	pthread_t s[CTHREADS];

	for (i = 0; i < CTHREADS; i++) {
		pthread_create(&s[i], NULL, checkBindMThread, &s[i]);
	}
	for (i = 0; i < CTHREADS; i++) {
		pthread_join(s[i], NULL);
	}