diff -ruN -U 10 kozos03/kozos.h kozos04/kozos.h
--- kozos03/kozos.h	Sun Oct 21 22:32:45 2007
+++ kozos04/kozos.h	Sun Oct 21 22:32:45 2007
@@ -8,15 +8,16 @@
 /* syscall */
 int kz_run(kz_func func, char *name, int pri, int argc, char *argv[]);
 void kz_exit();
 int kz_wait();
 int kz_sleep();
 int kz_wakeup(int id);
 int kz_getid();
 int kz_chpri(int pri);
 int kz_send(int id, int size, char *p);
 int kz_recv(int *idp, char **pp);
+int kz_timer(int msec);
 
 /* library */
 void kz_start(kz_func func, char *name, int pri, int argc, char *argv[]);
 
 #endif
diff -ruN -U 10 kozos03/syscall.c kozos04/syscall.c
--- kozos03/syscall.c	Sun Oct 21 22:32:45 2007
+++ kozos04/syscall.c	Sun Oct 21 22:32:45 2007
@@ -81,10 +81,18 @@
 }
 
 int kz_recv(int *idp, char **pp)
 {
   kz_syscall_param_t param;
   param.un.recv.idp = idp;
   param.un.recv.pp = pp;
   kz_syscall(KZ_SYSCALL_TYPE_RECV, &param);
   return param.un.recv.ret;
 }
+
+int kz_timer(int msec)
+{
+  kz_syscall_param_t param;
+  param.un.timer.msec = msec;
+  kz_syscall(KZ_SYSCALL_TYPE_TIMER, &param);
+  return param.un.timer.ret;
+}
diff -ruN -U 10 kozos03/syscall.h kozos04/syscall.h
--- kozos03/syscall.h	Sun Oct 21 22:32:45 2007
+++ kozos04/syscall.h	Sun Oct 21 22:32:45 2007
@@ -6,20 +6,21 @@
 typedef enum {
   KZ_SYSCALL_TYPE_RUN,
   KZ_SYSCALL_TYPE_EXIT,
   KZ_SYSCALL_TYPE_WAIT,
   KZ_SYSCALL_TYPE_SLEEP,
   KZ_SYSCALL_TYPE_WAKEUP,
   KZ_SYSCALL_TYPE_GETID,
   KZ_SYSCALL_TYPE_CHPRI,
   KZ_SYSCALL_TYPE_SEND,
   KZ_SYSCALL_TYPE_RECV,
+  KZ_SYSCALL_TYPE_TIMER,
 } kz_syscall_type_t;
 
 typedef struct {
   union {
     struct {
       kz_func func;
       char *name;
       int pri;
       int argc;
       char **argv;
@@ -49,16 +50,20 @@
       int id;
       int size;
       char *p;
       int ret;
     } send;
     struct {
       int *idp;
       char **pp;
       int ret;
     } recv;
+    struct {
+      int msec;
+      int ret;
+    } timer;
   } un;
 } kz_syscall_param_t;
 
 void kz_syscall(kz_syscall_type_t type, kz_syscall_param_t *param);
 
 #endif
diff -ruN -U 10 kozos03/thread.c kozos04/thread.c
--- kozos03/thread.c	Sun Oct 21 22:32:45 2007
+++ kozos04/thread.c	Sun Oct 21 22:32:45 2007
@@ -5,23 +5,30 @@
 #include <unistd.h>
 #include <setjmp.h>
 
 #include "kozos.h"
 #include "syscall.h"
 #include "thread.h"
 
 #define SIG_NUM 32
 #define STACK_SIZE 0x8000
 
+typedef struct _kz_timebuf {
+  struct _kz_timebuf *next;
+  int msec;
+  kz_thread *thp;
+} kz_timebuf;
+
 kz_thread threads[THREAD_NUM];
 kz_thread *readyque[PRI_NUM];
 static jmp_buf intr_env;
+static kz_timebuf *timers;
 
 kz_thread *current;
 
 static void getcurrent()
 {
   readyque[current->pri] = current->next;
   current->next = NULL;
 }
 
 static int putcurrent()
@@ -205,20 +212,61 @@
   if (current->messages == NULL) {
     /* メッセージが無いのでブロックする */
     return -1;
   }
 
   recvmsg();
   putcurrent();
   return current->syscall.param->un.recv.ret;
 }
 
+static int thread_timer(int msec)
+{
+  kz_timebuf **tmpp;
+  kz_timebuf *tmp;
+
+  tmp = malloc(sizeof(*tmp));
+  tmp->next = NULL;
+  tmp->thp = current;
+
+  for (tmpp = &timers; *tmpp; tmpp = &((*tmpp)->next)) {
+    if (msec < (*tmpp)->msec) {
+      (*tmpp)->msec -= msec;
+      break;
+    }
+    msec -= (*tmpp)->msec;
+  }
+
+  if (msec == 0) msec++;
+  tmp->msec = msec;
+  tmp->next = *tmpp;
+  *tmpp = tmp;
+
+  ualarm(timers->msec * 1000, 0);
+
+  putcurrent();
+  return 0;
+}
+
+void alarm_handler()
+{
+  kz_timebuf *tmp;
+
+  sendmsg(timers->thp, 0, 0, NULL);
+  tmp = timers;
+  timers = timers->next;
+  free(tmp);
+  if (timers) {
+    ualarm(timers->msec * 1000, 0);
+  }
+}
+
 static void syscall_proc()
 {
   /* システムコールの実行中にcurrentが書き換わるのでポインタを保存しておく */
   kz_syscall_param_t *p = current->syscall.param;
 
   getcurrent();
 
   switch (current->syscall.type) {
   case KZ_SYSCALL_TYPE_RUN:
     p->un.run.ret = thread_run(p->un.run.func, p->un.run.name, p->un.run.pri,
@@ -242,20 +290,23 @@
     break;
   case KZ_SYSCALL_TYPE_CHPRI:
     p->un.chpri.ret = thread_chpri(p->un.chpri.pri);
     break;
   case KZ_SYSCALL_TYPE_SEND:
     p->un.send.ret = thread_send(p->un.send.id, p->un.send.size, p->un.send.p);
     break;
   case KZ_SYSCALL_TYPE_RECV:
     p->un.recv.ret = thread_recv(p->un.recv.idp, p->un.recv.pp);
     break;
+  case KZ_SYSCALL_TYPE_TIMER:
+    p->un.timer.ret = thread_timer(p->un.timer.msec);
+    break;
   default:
     break;
   }
   return;
 }
 
 static void dispatch()
 {
   int i;
   for (i = 0; i < PRI_NUM; i++) {
@@ -267,20 +318,23 @@
   }
   current = readyque[i];
 }
 
 static void thread_intrvec(int signo)
 {
   switch (signo) {
   case SIGSYS: /* システムコール */
     syscall_proc();
     break;
+  case SIGALRM: /* タイマ割込み発生 */
+    alarm_handler();
+    break;
   case SIGBUS: /* ダウン要因発生 */
   case SIGSEGV:
   case SIGTRAP:
   case SIGILL:
     {
       fprintf(stderr, "error %s\n", current->name);
       /* ダウン要因発生により継続不可能なので，スリープ状態にする*/
       getcurrent();
     }
     break;
@@ -301,21 +355,24 @@
   if (setjmp(current->context.env) == 0) {
     longjmp(intr_env, signo);
   }
 }
 
 static void thread_start(kz_func func, char *name, int pri, int argc, char *argv[])
 {
   memset(threads, 0, sizeof(threads));
   memset(readyque, 0, sizeof(readyque));
 
+  timers = NULL;
+
   signal(SIGSYS, thread_intr);
+  signal(SIGALRM, thread_intr);
 
   /*
    * current 未定のためにシステムコール発行はできないので，
    * 直接関数を呼び出してスレッド作成する．
    */
   current = NULL;
   current = (kz_thread *)thread_run(func, name, pri, argc, argv);
 
   longjmp(current->context.env, 1);
 }