contiki-main.c 一打印观察 <contiki学习之五>

说明：本文依赖于 contiki/platform/native/contiki-main.c 文件。　

在项目工程目录下的hello-world.c 文件里面，有许多的宏，但没有最关键的main()函数出现，也无法知道这个文件里的 "hello world"什么时候打印。那么只能根据makefile文件的框架和提示，进入到 contiki/platform/ 目录下一探明白。由于前面选择的是 contiki/examples/hello-world/ 目录下的工程进行学习，那么这里也就进入到 contiki/platform/native/ 目录下并使用 find 命令查找下 main()即可：

1 find -name "*.c" | xargs grep "main"

当然，它存在于 contiki-main.c 这个文件中。下面将使用最廉价的printf() 来调试程序了。

-----------------------------------------------------------------------

注：我暂时只关心 contiki-main.c文件中的 main() 函数。

------------------------------------------------------------------------

添加printf()如下：

  1 int
  2 main(int argc, char **argv)
  3 {
  4 #if UIP_CONF_IPV6
  5 #if UIP_CONF_IPV6_RPL
  6   printf(CONTIKI_VERSION_STRING " started with IPV6, RPL
");
  7 #else
  8   printf(CONTIKI_VERSION_STRING " started with IPV6
");
  9 #endif
 10 #else
 11   printf(CONTIKI_VERSION_STRING " started
");
 12 #endif
 13 
 14   /* crappy way of remembering and accessing argc/v */
 15   contiki_argc = argc;
 16   contiki_argv = argv;
 17 
 18   /* native under windows is hardcoded to use the first one or two args */
 19   /* for wpcap configuration so this needs to be "removed" from         */
 20   /* contiki_args (used by the native-border-router) */
 21 #ifdef __CYGWIN__
 22   contiki_argc--;
 23   contiki_argv++;
 24 #ifdef UIP_FALLBACK_INTERFACE
 25   contiki_argc--;
 26   contiki_argv++;
 27 #endif
 28 #endif
 29 
 30   printf("contiki-main_function!-->
");
 31   process_init();
 32   printf("process init over!------>
");
 33   process_start(&etimer_process, NULL);
 34   printf("process_start now------->
");
 35   ctimer_init();
 36   printf("ctimer_init()----------->
");
 37   rtimer_init();
 38   printf("rtimer_init()----------->
");
 39 
 40 #if WITH_GUI
 41   process_start(&ctk_process, NULL);
 42 #endif
 43  
 44   printf("set_rime_addr()-------->
");
 45   set_rime_addr();
 46 
 47   printf("netstack_init()-------->
");
 48   netstack_init();
 49   printf("MAC %s RDC %s NETWORK %s
", NETSTACK_MAC.name, NETSTACK_RDC.name, NETSTACK_NETWORK.name);
 50 
 51 #if WITH_UIP6
 52   queuebuf_init();
 53 
 54   memcpy(&uip_lladdr.addr, serial_id, sizeof(uip_lladdr.addr));
 55 
 56   process_start(&tcpip_process, NULL);
 57 #ifdef __CYGWIN__
 58   process_start(&wpcap_process, NULL);
 59 #endif
 60   printf("Tentative link-local IPv6 address ");
 61   {
 62     uip_ds6_addr_t *lladdr;
 63     int i;
 64     lladdr = uip_ds6_get_link_local(-1);
 65     for(i = 0; i < 7; ++i) {
 66       printf("%02x%02x:", lladdr->ipaddr.u8[i * 2],
 67              lladdr->ipaddr.u8[i * 2 + 1]);
 68     }
 69     /* make it hardcoded... */
 70     lladdr->state = ADDR_AUTOCONF;
 71 
 72     printf("%02x%02x
", lladdr->ipaddr.u8[14], lladdr->ipaddr.u8[15]);
 73   }
 74 #else
 75   process_start(&tcpip_process, NULL);
 76 #endif
 77 
 78   printf("serial_line_init()----------->
");
 79   serial_line_init();
 80 
 81   printf("autostart_start()-=---------->
");
 82   autostart_start(autostart_processes);
 83 
 84   /* Make standard output unbuffered. */
 85   setvbuf(stdout, (char *)NULL, _IONBF, 0);
 86 
 87   select_set_callback(STDIN_FILENO, &stdin_fd);
 88 //  while(1) {
 89       printf("loop....
");
 90     fd_set fdr;
 91     fd_set fdw;
 92     int maxfd;
 93     int i;
 94     int retval;
 95     struct timeval tv;
 96 
 97     retval = process_run();
 98 
 99     tv.tv_sec = 0;
100     tv.tv_usec = retval ? 1 : 1000;
101 
102     FD_ZERO(&fdr);
103     FD_ZERO(&fdw);
104     maxfd = 0;
105     for(i = 0; i <= select_max; i++) {
106       if(select_callback[i] != NULL && select_callback[i]->set_fd(&fdr, &fdw)) {
107         maxfd = i;
108       }
109     }
110 
111     retval = select(maxfd + 1, &fdr, &fdw, NULL, &tv);
112     if(retval < 0) {
113       if(errno != EINTR) {
114         perror("select");
115       }
116     } else if(retval > 0) {
117       /* timeout => retval == 0 */
118       for(i = 0; i <= maxfd; i++) {
119         if(select_callback[i] != NULL) {
120           select_callback[i]->handle_fd(&fdr, &fdw);
121         }
122       }
123     }
124     printf("etimer_request_poll!------------->
");
125     etimer_request_poll();
126 
127 #if WITH_GUI
128     if(console_resize()) {
129        ctk_restore();
130     }
131 #endif /* WITH_GUI */
132 //  }
133     printf("main_function over....--->
");
134 
135   return 0;
136 }

上面是我自己修改后的 main()函数，然后make运行后的结果如下：

 1 $./hello-world.native 
 2 Contiki-2.6-1549-g01bd045 started
 3 contiki-main_function!-->
 4 process init over!------>
 5 process_start now------->
 6 ctimer_init()----------->
 7 rtimer_init()----------->
 8 set_rime_addr()-------->
 9 Rime started with address 2.1
10 netstack_init()-------->
11 MAC nullmac RDC nullrdc NETWORK Rime
12 serial_line_init()----------->
13 autostart_start()-=---------->
14 Hello, world
15 loop....
16 etimer_request_poll!------------->
17 main_function over....--->

从上面的打印信息来看，hello world 打印是在执行了下面这行代码后出现的：

1 autostart_start(autostart_processes);

既然如此，那就开始了---看看它们的流程。

contiki-main.c 一 打印观察 <contiki学习之五>

contiki-main.c 一打印观察 <contiki学习之五>