From 615d121a768e3d2031fb840d796b980beb0272b4 Mon Sep 17 00:00:00 2001
From: Yorick Barbanneau <ephase@xieme-art.org>
Date: Tue, 16 Nov 2021 21:51:00 +0100
Subject: [PATCH] TD2 I.6+ Implement thread counter

---
 code/Makefile.dep           |  4 ++--
 code/userprog/addrspace.cc  |  5 +++++
 code/userprog/addrspace.h   |  1 +
 code/userprog/userthread.cc | 25 ++++++++++++++++++-------
 4 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/code/Makefile.dep b/code/Makefile.dep
index e42a43b..1678db3 100644
--- a/code/Makefile.dep
+++ b/code/Makefile.dep
@@ -41,8 +41,8 @@ CFLAGS += -fsanitize=undefined
 LDFLAGS += -fsanitize=undefined
 
 # décommenté TD1 - partie V
-#CFLAGS += -fsanitize=address
-#LDFLAGS += -fsanitize=address -lpthread
+CFLAGS += -fsanitize=address
+LDFLAGS += -fsanitize=address -lpthread
 endif
 
 ifeq ($(NACHOS_SYS),MAC_OS_SYS)
diff --git a/code/userprog/addrspace.cc b/code/userprog/addrspace.cc
index 9543006..2aed310 100644
--- a/code/userprog/addrspace.cc
+++ b/code/userprog/addrspace.cc
@@ -128,6 +128,11 @@ AddrSpace::AddrSpace (OpenFile * executable)
 
     pageTable[0].valid = FALSE;			// Catch NULL dereference
 
+    #ifdef CHANGED
+    DEBUG('x', "Initialise thread counter\n");
+    Threads = 1;
+    #endif //CHANGED
+
     AddrSpaceList.Append(this);
 }
 
diff --git a/code/userprog/addrspace.h b/code/userprog/addrspace.h
index a5169a9..bd44fdd 100644
--- a/code/userprog/addrspace.h
+++ b/code/userprog/addrspace.h
@@ -41,6 +41,7 @@ class AddrSpace:public dontcopythis
 				// Dump program layout as SVG
     unsigned NumPages() { return numPages; }
     #ifdef CHANGED
+    int Threads;            // count number of threads into address space
     int AllocateUserStack();
     #endif
   private:
diff --git a/code/userprog/userthread.cc b/code/userprog/userthread.cc
index 8565913..014d574 100644
--- a/code/userprog/userthread.cc
+++ b/code/userprog/userthread.cc
@@ -7,7 +7,7 @@
 
 
 static void StartUserThread( void * args ){
-    
+
     DEBUG('x', "Enter StartUserThread function\n");
     // retrieve function and arguments
     // create a ThreadArgs_t struct and cast args content into it
@@ -15,7 +15,7 @@ static void StartUserThread( void * args ){
     ThreadArgs_t * cpy_args;
     cpy_args = (ThreadArgs_t *) args;
     int stack_addr = currentThread->space->AllocateUserStack();
-    
+
     // init register
     for (int i = 0; i < NumTotalRegs; i++ ) {
         machine->WriteRegister(i, 0);
@@ -25,7 +25,7 @@ static void StartUserThread( void * args ){
     machine->WriteRegister(PCReg, cpy_args->f);
     machine->WriteRegister (NextPCReg, machine->ReadRegister(PCReg) + 4);
     DEBUG('x',"PCReg: 0x%x, NextPCReg: 0x%x\n", cpy_args->f, cpy_args->f + 4);
-    
+
     // init register 4: arguments
     machine->WriteRegister(4, cpy_args->arg);
     DEBUG('x',"Register 4: 0x%x\n", cpy_args->arg);
@@ -34,6 +34,10 @@ static void StartUserThread( void * args ){
     machine->WriteRegister(StackReg, stack_addr);
     DEBUG('x',"StackRegister: 0x%x\n", stack_addr);
 
+    // All our registers have values, we can desallocate our cpy_args
+    free(cpy_args);
+    cpy_args = NULL;
+
     // run our thread
     machine->Run();
 }
@@ -41,24 +45,31 @@ static void StartUserThread( void * args ){
 int do_ThreadCreate(int f, int arg){
 
     DEBUG('x',"Enter do_ThreadCreate function\n");
-    
+
     // Initialize our structure we'll pass to StartUserThread
     ThreadArgs_t * args = (ThreadArgs_t *) malloc(sizeof(ThreadArgs_t));
     args->f = f;
     args->arg = arg;
-    
+
     // create a new Thread and start it
     Thread * newThread = new Thread("new thread");
+
+    // increment number of threads
+    currentThread->space->Threads++;
+    DEBUG('x', "Increase numbers of Threads:%d\n",currentThread->space->Threads);
+
     newThread->space = currentThread->space;
     newThread->Start(StartUserThread, args);
-    
+
     return 0;
 }
 
 void do_ThreadExit(){
     DEBUG('x', "Enter do_ThreadExit function\n");
     // TODO: what should we do with thread space?
-    //       Probalely desallocate it...
+    //       Probalely desallocate it... if no threads remain
+    currentThread->space->Threads--;
+    DEBUG('x', "Decrease numbers of Threads:%d\n",currentThread->space->Threads);
     currentThread->Finish();
 }
 #endif