SYSTEM CALL IMPLEMENT

src/userprog/syscall.c

@@ -3,19 +3,170 @@
 #include <syscall-nr.h>
 #include "threads/interrupt.h"
 #include "threads/thread.h"
+#include "devices/shutdown.h"
 
 static void syscall_handler (struct intr_frame *);
 
+void syscall_halt(void);
+void syscall_exit(int status);
+int syscall_wait(pid_t pid);
+bool syscall_create(const char* file_name, unsigned initial_size);
+bool syscall_remove(const char* file_name, unsigned initial_size);
+
+/*System call initializer*/
 void
 syscall_init (void)
 {
+  //LOOK AT LOCK_INIT
+  lock_init (&filesys_lock);
   intr_register_int (0x30, 3, INTR_ON, syscall_handler, "syscall");
 }
 
-
+/*Handler for system commands.*/
 static void
-syscall_handler (struct intr_frame *f UNUSED)
+syscall_handler (struct intr_frame *f)
+{
+  //LOOK AGAIN UNTIL SWITCH-CASE
+  if (!FILE_LOCK_INIT)
+  {
+    lock_init(&file_system_lock);
+    FILE_LOCK_INIT = true;
+  }
+  
+  int syscall_number;
+  ASSERT( sizeof(syscall_number) == 4 ); // 4byte x86
+
+  read(f->esp, &syscall_number, sizeof(syscall_number));
+  thread_current()->current_esp = f->esp;
+
+  switch (syscall_number) {
+  case SYSCALL_HALT: // 0
+    {
+      /*Terminate PintOS*/
+      syscall_halt();
+      break;
+    }
+
+  case SYSCALL_EXIT: // 1
+    {
+      int arg;
+      /*Get argument*/
+      read(f->esp + 4, &arg, sizeof(arg));
+      /*Terminate program*/
+      syscall_exit(arg);
+      break;
+    }
+
+
+  case SYSCALL_WAIT: // 2
     {
-  printf ("system call!\n");
+      pid_t pid;
+      /*Get argument*/
+      read(f->esp + 4, &pid, sizeof(pid_t));
+      /*Wait for child process*/
+      f->eax = syscall_wait(pid);
+      break;
+    }
+
+  case SYSCALL_CREATE: // 3
+    {
+      const char* file_name;
+      unsigned initial_size;
+
+      /*Get file name and size*/
+      read(f->esp + 4, &file_name, sizeof(file_name));
+      read(f->esp + 8, &initial_size, sizeof(initial_size));
+
+      /*Create file*/
+      f->eax =  syscall_create(file_name, initial_size);
+      break;
+    }
+
+  case SYSCALL_REMOVE: // 4
+    {
+      const char* file_name;
+      bool return_code;
+      
+      /*Get file name*/
+      read(f->esp + 4, &file_name, sizeof(file_name));
+
+      /*Remove file*/ 
+      f->eax = syscall_remove(file_name);
+      break;
+    }
+
+  /* Unimplemented system calls */
+  default:
+    printf("ERROR: system call ( %d ) has not implemented!\n", syscall_number);
+
+    /* Terminate. */
+    sys_exit(-1);
+    break;
+  }
+
+}
+
+/********SYSTEMCALLS********/
+
+/* Halt */
+void syscall_halt(void) {
+  shutdown_power_off(); /* From shutdown.h */
+}
+
+/* Exit */
+void syscall_exit(int status) {
+  printf("%s: exit(%d)\n", thread_current()->name, status);
+  //LOOK AT PCB
+  struct process_control_block *pcb = thread_current()->pcb;
+  if(pcb != NULL) {
+    pcb->exitcode = status;
+  }
+  
   thread_exit();
 }
+
+/* Wait */
+int syscall_wait(pid_t pid)
+{
+  return process_wait(pid);
+}
+
+/* Create File */
+bool syscall_create(const char* file_name, unsigned initial_size) {
+  bool if_created = false;
+  //LOOK AT ACQUIRE AND RELEASE
+  lock_acquire (&filesys_lock);
+  if( filesys_create(file_name, initial_size)==true){
+    if_created = true;
+  }
+  lock_release (&filesys_lock);
+  return if_created;
+}
+
+/* Remove File */
+bool syscall_remove(const char* file_name, unsigned initial_size) {
+  bool if_removed = false;
+  //LOOK AT ACQUIRE AND RELEASE
+  lock_acquire (&filesys_lock);
+  if( filesys_remove(file_name, initial_size)==true){
+    if_removed = true;
+  }
+  lock_release (&filesys_lock);
+  return if_removed;
+}
+
+/****OTHER FUNCTIONS****/
+static int read(void *src, void *dst, size_t bytes)
+{
+  int32_t value;
+  size_t i;
+  for (i = 0; i < bytes; i++)
+  {
+    value = get_user(src + i);
+    if (value == -1) // segfault or invalid memory access
+      fail_invalid_access();
+
+    *(char *)(dst + i) = value & 0xff;
+  }
+  return (int)bytes;
+}

src/userprog/syscall.h

@@ -3,4 +3,11 @@
 
 void syscall_init (void);
 
+/*PROTOTYPES*/
+void syscall_halt(void);
+void syscall_exit(int status);
+int syscall_wait(pid_t pid);
+bool syscall_create(const char* file_name, unsigned initial_size);
+bool syscall_remove(const char* file_name, unsigned initial_size);
+
 #endif /* userprog/syscall.h */