1 files changed, 98 insertions, 0 deletions
diff --git a/src/threads/synchlist.c b/src/threads/synchlist.c
new file mode 100644
index 0000000..cc1e570
--- /dev/null
+++ b/src/threads/synchlist.c
@@ -0,0 +1,98 @@
+// synchlist.cc
+//	Routines for synchronized access to a list.
+//
+//	Implemented by surrounding the List abstraction
+//	with synchronization routines.
+//
+// 	Implemented in "monitor"-style -- surround each procedure with a
+// 	lock acquire and release pair, using condition signal and wait for
+// 	synchronization.
+//
+// Copyright (c) 1992-1993 The Regents of the University of California.
+// All rights reserved.  See copyright.h for copyright notice and limitation 
+// of liability and disclaimer of warranty provisions.
+//
+// modified by Vlad Jahundovics for Pintos (translation from C++ to C)
+
+
+#include "copyright.h"
+#include "synchlist.h"
+#include "threads/malloc.h"
+
+//----------------------------------------------------------------------
+// SynchList::SynchList
+//	Initialize the data structures needed for a 
+//	synchronized list, empty to start with.
+//	Elements can now be added to the list.
+//----------------------------------------------------------------------
+
+void sl_init(struct SynchList *sl)
+{
+  list_init(&sl->sl_list);
+  lock_init(&sl->sl_lock);
+  cond_init(&sl->sl_empty);
+}
+
+
+//----------------------------------------------------------------------
+// SynchList::~SynchList
+//	Remove and de-allocate all elements of the synchronized list
+//----------------------------------------------------------------------
+
+void sl_destroy(struct SynchList *sl)
+{
+  struct list_elem *e;
+  struct SL_element *sl_elem;
+  while(!list_empty(&sl->sl_list)){
+    e = list_pop_front(&sl->sl_list);
+    sl_elem = list_entry(e, struct SL_element, elem);
+    free(sl_elem);
+  }
+}
+
+
+//----------------------------------------------------------------------
+// SynchList::Append
+//      Append an "item" to the end of the list.  Wake up anyone
+//	waiting for an element to be appended.
+//
+//	"item" is the thing to put on the list, it can be a pointer to 
+//		anything.
+//----------------------------------------------------------------------
+
+void sl_append(struct SynchList *sl, void *item)
+{
+  lock_acquire(&sl->sl_lock);                // enforce mutual exclusive access to the list 
+  struct SL_element *sl_elem = malloc(sizeof(struct SL_element));
+  sl_elem->item = item;
+  list_push_back(&sl->sl_list, &sl_elem->elem);
+  cond_signal(&sl->sl_empty,&sl->sl_lock);  // wake up a waiter, if any
+  lock_release(&sl->sl_lock);              
+  return;
+}
+
+
+//----------------------------------------------------------------------
+// SynchList::Remove
+//      Remove an "item" from the beginning of the list.  Wait if
+//	the list is empty.
+// Returns:
+//	The removed item. 
+//----------------------------------------------------------------------
+
+void *sl_remove(struct SynchList *sl)
+{
+  struct list_elem *e;
+  void *item;
+  lock_acquire(&sl->sl_lock);                // enforce mutual exclusion
+  while(list_empty(&sl->sl_list)){
+    cond_wait(&sl->sl_empty, &sl->sl_lock);  // wait until list isn't empty
+  }
+  e = list_pop_front(&sl->sl_list);
+  struct SL_element *sl_elem = list_entry(e, struct SL_element, elem);
+  item = sl_elem->item;
+  free(sl_elem);
+  lock_release(&sl->sl_lock);
+  return item;
+}
+