alarm task finished

Makefile

@@ -213,7 +213,8 @@ endif
 ifeq ($(LAB),traps)
 UPROGS += \
 	$U/_call\
-	$U/_bttest
+	$U/_bttest\
+	$U/_alarmtest
 endif
 
 ifeq ($(LAB),lazy)

kernel/proc.c

@@ -132,6 +132,12 @@ found:
     return 0;
   }
 
+   if((p->pre_trapframe = (struct trapframe *)kalloc()) == 0){
+    freeproc(p);
+    release(&p->lock);
+    return 0;
+  }
+
   // An empty user page table.
   p->pagetable = proc_pagetable(p);
   if(p->pagetable == 0){
@@ -160,6 +166,9 @@ freeproc(struct proc *p)
   p->trapframe = 0;
   if(p->pagetable)
     proc_freepagetable(p->pagetable, p->sz);
+  if(p->pre_trapframe)
+    kfree((void*)p->pre_trapframe);
+  p->pre_trapframe = 0;
   p->pagetable = 0;
   p->sz = 0;
   p->pid = 0;

kernel/proc.h

@@ -104,4 +104,8 @@ struct proc {
   struct file *ofile[NOFILE];  // Open files
   struct inode *cwd;           // Current directory
   char name[16];               // Process name (debugging)
+  int alarm_cnt;               // Alarm count
+  int inter_cnt;               // interrupts count 
+  uint64 handler;              // alarm func address
+  struct trapframe *pre_trapframe;
 };

kernel/syscall.c

@@ -101,6 +101,8 @@ extern uint64 sys_unlink(void);
 extern uint64 sys_link(void);
 extern uint64 sys_mkdir(void);
 extern uint64 sys_close(void);
+extern uint64 sys_sigalarm(void);
+extern uint64 sys_sigreturn(void);
 
 // An array mapping syscall numbers from syscall.h
 // to the function that handles the system call.
@@ -126,6 +128,8 @@ static uint64 (*syscalls[])(void) = {
 [SYS_link]    sys_link,
 [SYS_mkdir]   sys_mkdir,
 [SYS_close]   sys_close,
+[SYS_sigalarm] sys_sigalarm,
+[SYS_sigreturn] sys_sigreturn,
 };
 
 void

kernel/syscall.h

@@ -20,3 +20,5 @@
 #define SYS_link   19
 #define SYS_mkdir  20
 #define SYS_close  21
+#define SYS_sigalarm 22
+#define SYS_sigreturn 23

kernel/sysproc.c

@@ -93,3 +93,28 @@ sys_uptime(void)
   release(&tickslock);
   return xticks;
 }
+
+uint64
+sys_sigalarm(void)
+{
+  int alarm_cnt;
+  uint64 addr;
+  struct proc *p = myproc();
+  argint(0, &alarm_cnt);
+  argaddr(1, &addr);
+
+  p->inter_cnt = 0;
+  p->handler = addr;
+  p->alarm_cnt = alarm_cnt;
+
+  return 0;
+}
+
+uint64
+sys_sigreturn(void)
+{
+  struct proc* p = myproc();
+  *p->trapframe = *p->pre_trapframe;
+  p->inter_cnt = 0;
+  return p->pre_trapframe->a0;
+}

kernel/trap.c

@@ -77,8 +77,15 @@ usertrap(void)
     exit(-1);
 
   // give up the CPU if this is a timer interrupt.
-  if(which_dev == 2)
-    yield();
+  if(which_dev == 2){
+    p->inter_cnt++;
+    if (p->inter_cnt == p->alarm_cnt && 0 < p->alarm_cnt) {
+      *p->pre_trapframe = *p->trapframe;
+      p->trapframe->epc = p->handler;
+    } else {
+      yield();
+    }
+  }
 
   usertrapret();
 }

time.txt

@@ -0,0 +1 @@
+8

user/user.h

@@ -22,6 +22,8 @@ int getpid(void);
 char* sbrk(int);
 int sleep(int);
 int uptime(void);
+int sigalarm(int, void(*)());
+int sigreturn(void);
 
 // ulib.c
 int stat(const char*, struct stat*);

user/usys.pl

@@ -36,3 +36,5 @@ entry("getpid");
 entry("sbrk");
 entry("sleep");
 entry("uptime");
+entry("sigalarm");
+entry("sigreturn");