update lab1-8 codes and docs. now version is 0.2

code/lab8/user/forktree.c

@@ -3,7 +3,7 @@
 #include <string.h>
 
 #define DEPTH 4
-
+#define SLEEP_TIME 400
 void forktree(const char *cur);
 
 void
@@ -31,6 +31,8 @@ forktree(const char *cur) {
 
 int
 main(void) {
+    cprintf("forktree process will sleep %d ticks\n",SLEEP_TIME);
+    sleep(SLEEP_TIME);
     forktree("");
     return 0;
 }

code/lab8/user/libs/syscall.c

@@ -84,7 +84,7 @@ sys_sleep(unsigned int time) {
     return syscall(SYS_sleep, time);
 }
 
-size_t
+int
 sys_gettime(void) {
     return syscall(SYS_gettime);
 }

code/lab8/user/libs/syscall.h

@@ -11,7 +11,7 @@ int sys_getpid(void);
 int sys_putc(int c);
 int sys_pgdir(void);
 int sys_sleep(unsigned int time);
-size_t sys_gettime(void);
+int sys_gettime(void);
 
 struct stat;
 struct dirent;