merged-all

Author: adarshnin

defs.h

@@ -124,13 +124,14 @@ void            wakeup(void*);
 void            yield(void);
 int             sendkill(int, int);
 int             signal(int, sighandler_t);
-void 		check_pending_signal(void);	
+void 		    check_pending_signal(void);	
 void            stop_handler();
 void            cont_handler();
-void            term_handler();
+void            term_handler(struct proc*);
 void            handle_signal(struct proc*, int);
 void            user_handler(struct proc*, int);
-int 		sigret(void);
+int 		    sigret(void);
+int 		    pause(void);
 
 
 // swtch.S

proc.c

@@ -23,6 +23,7 @@ struct proc test;
 // };
 
 void *p;
+int paused = 0;
 
 int nextpid = 1;
 extern void forkret(void);
@@ -537,6 +538,7 @@ int
 sendkill(int pid, int signum)
 {
   struct proc *p;
+  cprintf("sendkill: %d\n", signum);
   acquire(&ptable.lock);
   for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){
     if(p->pid == pid){
@@ -548,8 +550,19 @@ sendkill(int pid, int signum)
         p->psignals[signum] = 1; //For other signals
       }
       release(&ptable.lock);
-      if (p->state == SLEEPING && p->killed != 1){
-        handle_signal(p, signum);
+      cprintf("paused = %d\n", paused);
+      if (p->state == SLEEPING){
+        if(paused == 1 && (signum == SIGTERM || signum == SIGINT || signum == SIGKILL)){
+          // For processes which are SLEEPING by pause()
+          paused = 0;
+          handle_signal(p, SIGCONT);
+          // Continue the process (to return -1) only when Terminate signals given
+        }
+        else if (paused == 0 && p->killed != 1){
+          // For Stopped process
+          handle_signal(p, signum);
+        }
+     
       }
       return 0;
     }
@@ -558,6 +571,16 @@ sendkill(int pid, int signum)
   return -1;
 }
 
+int
+pause()
+{
+  paused = 1;
+  cprintf("pause: Going to sleep\n");
+  acquire(&q.lock);
+  sleep(p, &q.lock);
+  release(&q.lock);
+  return -1;
+}
 
 int 
 signal(int signum, sighandler_t handler)
@@ -659,7 +682,7 @@ handle_signal(struct proc *curproc, int i)
       case SIGUSR1:
       case SIGUSR2:
       case SIGVTALRM:
-        term_handler();
+        term_handler(curproc);
         break;
       case SIGCHLD:
       case SIGURG:
@@ -699,18 +722,21 @@ check_pending_signal(void)
 
 }
 
-void term_handler()
+void term_handler(struct proc *argp)
 {
   cprintf("in term handler\n");
-  struct proc *p = myproc();
+  struct proc *p = argp;
   acquire(&ptable.lock);
+  if(p->state == SLEEPING){
+    p->state = RUNNABLE;
+  }
   p->killed = 1;
-  // sched();
 
   // Terminate the process
   release(&ptable.lock);
 }
 
+
 void 
 cont_handler()
 {

syscall.c

@@ -106,7 +106,7 @@ extern int sys_uptime(void);
 extern int sys_sendkill(void);
 extern int sys_signal(void);
 extern int sys_sigret(void);
-
+extern int sys_pause(void);
 
 static int (*syscalls[])(void) = {
 [SYS_fork]    sys_fork,
@@ -133,6 +133,7 @@ static int (*syscalls[])(void) = {
 [SYS_sendkill] sys_sendkill,
 [SYS_signal]   sys_signal,
 [SYS_sigret]   sys_sigret, 
+[SYS_pause]   sys_pause,
 
 };
 

syscall.h

@@ -23,3 +23,4 @@
 #define SYS_sendkill  22
 #define SYS_signal  23
 #define SYS_sigret 24
+#define SYS_pause 24

sysproc.c

@@ -117,3 +117,8 @@ int
 sys_sigret(void){
   return sigret();
 }
+
+int
+sys_pause(void){
+  return pause();
+}

testkill.c

@@ -23,24 +23,47 @@ void handler(int signal){
 
 
 int main(){
-  int i;
-  int pid = fork(); 
-  if (pid == 0){
-    signal(SIGTSTP, handler);
-    sleep(100);
-    for (i = 0; i < 500; i++){
-      printf (1, "num - %d\n", i);
+    // int pid = fork();
+
+    // if(pid == 0) {
+    //     sleep(200);
+    //     int i = 0;
+    //     while (1) {
+    //         printf(1,"%d\n",i++);
+    //     }
+    // } 
+    // else
+    // {
+    //     for(int i = 0; i < 1; i++){
+    //         sleep(200);
+    //         sendkill(pid, SIGSTOP);
+    //         sleep(200);
+    //         sendkill(pid, SIGCONT);
+    //     }
+    //     sleep(200);
+    //     printf(1, "SIGSTOP Test Passed\n");
+    //     printf(1, "SIGCONT Test Passed\n");
+    //     sendkill(pid, SIGTERM);
+    //     printf(1, "SIGTERM Test Passed\n");
+    //     wait();
+    // }
+    int ret = 0;
+
+    int pid = fork();
+
+    if(pid == 0) {
+        ret = pause();
+        if (-1 == ret)
+            printf(1,"Process exited\n");
+        } 
+    else
+    {
+        printf(1,"Parent\n");
+
+        sendkill(pid, SIGTERM);
+        wait();
     }
-    printf (1, "child over\n");
-  }
-  else{
-    printf (1, "in parent\n");
-    sleep(200);
-    // sendkill(pid, SIGCONT); 
-    //sendkill(pid, SIGSTOP); 
-    sendkill(pid, SIGTSTP); 
-    wait();
-  }
-  printf (1, "over\n");
-  exit();
-}
+   
+    
+    exit();
+}

user.h

@@ -25,6 +25,7 @@ int sleep(int);
 int uptime(void);
 int sendkill(int, int);
 int signal(int, void(*)(int));
+int pause(void);
 
 // ulib.c
 int stat(const char*, struct stat*);

usertests.c

@@ -7,6 +7,7 @@
 #include "syscall.h"
 #include "traps.h"
 #include "memlayout.h"
+#include "signal.h"
 
 char buf[8192];
 char name[3];
@@ -1737,6 +1738,56 @@ void argptest()
   printf(1, "arg test passed\n");
 }
 
+// Signals Testing
+void signals()
+{
+  int i, pid, ret;
+  printf(stdout, "signals test\n");
+  pid = fork();
+
+  if(pid == 0) {
+    sleep(200);
+    i = 0;
+    while (1) {
+        i++;
+    }
+  } 
+  else
+  {
+    for(i = 0; i < 2; i++){
+        sleep(200);
+        sendkill(pid, SIGSTOP);
+        sleep(200);
+        sendkill(pid, SIGCONT);
+    }
+    sleep(200);
+    printf(1, "SIGSTOP Test Passed\n");
+    printf(1, "SIGCONT Test Passed\n");
+    sendkill(pid, SIGTERM);
+    printf(1, "SIGTERM Test Passed\n");
+    wait();
+  }
+
+  // pause() testing
+  ret = 0;
+  pid = fork();
+
+  if(pid == 0) {
+    ret = pause();
+    if (-1 == ret)
+        printf(1,"Process exited\n");
+    } 
+  else
+  {
+    printf(1,"Parent\n");
+
+    sendkill(pid, SIGTERM);
+    wait();
+  }
+  
+  printf(stdout, "signals test ok\n");
+}
+
 unsigned long randstate = 1;
 unsigned int
 rand()
@@ -1756,6 +1807,7 @@ main(int argc, char *argv[])
   }
   close(open("usertests.ran", O_CREATE));
 
+  signals();
   argptest();
   createdelete();
   linkunlink();

usys.S

@@ -32,3 +32,4 @@ SYSCALL(uptime)
 SYSCALL(sendkill)
 SYSCALL(signal)
 SYSCALL(sigret)
+SYSCALL(pause)