chan 介绍
chan 是纯 C 实现的 Go 的 Channels，示例代码：
#include <pthread.h>
#include <stdio.h>
#include "chan.h"
chan_t* chan;
void* ping()
{
// Send blocks until receiver is ready.
chan_send(chan, "ping");
return NULL;
}
int main()
{
// Initialize unbuffered channel.
chan = chan_init(0);
pthread_t th;
pthread_create(&th, NULL, ping, NULL);
// Receive blocks until sender is ready.
void* msg;
chan_recv(chan, &msg);
printf("%s\n", msg);
// Clean up channel.
chan_dispose(chan);
}