We now use a temporary stack in task management for :

- deleting current thread whe it finishes
- doing everything that goes with that

8 files changed, 44 insertions, 26 deletions

diff --git a/Source/Kernel/Melon.ke b/Source/Kernel/Melon.ke
index 99e1599..3eb5982 100755
--- a/Source/Kernel/Melon.ke
+++ b/Source/Kernel/Melon.ke
diff --git a/Source/Kernel/MemoryManager/PageDirectory.class.cpp b/Source/Kernel/MemoryManager/PageDirectory.class.cpp
index 2c8507f..13fbc36 100644
--- a/Source/Kernel/MemoryManager/PageDirectory.class.cpp
+++ b/Source/Kernel/MemoryManager/PageDirectory.class.cpp
@@ -43,7 +43,6 @@ PageDirectory::PageDirectory(PageDirectory* other) {
 }
 
 PageDirectory::~PageDirectory() {
-	PageAlloc::free((void*)tablesPhysical);
 	for (int i = 0; i < 768; i++) {		//Only free addresses below 0xC0000000, upper is kernel space
 		if (tables[i] != 0) {
 			for (int j = 0; j < 1024; j++) {
@@ -52,6 +51,7 @@ PageDirectory::~PageDirectory() {
 			PageAlloc::free((void*)tables[i]);
 		}
 	}
+	PageAlloc::free((void*)tablesPhysical);
 }
 
 page_t *PageDirectory::getPage(u32int address, bool make) {
diff --git a/Source/Kernel/MemoryManager/PhysMem.ns.cpp b/Source/Kernel/MemoryManager/PhysMem.ns.cpp
index 1794106..382e8a4 100644
--- a/Source/Kernel/MemoryManager/PhysMem.ns.cpp
+++ b/Source/Kernel/MemoryManager/PhysMem.ns.cpp
@@ -61,8 +61,9 @@ void freeFrame(page_t *page) {
 	if (page->frame == 0) {
 		return;
 	} else {
-		if (page->frame >= 0x100)	//First 1M are reserved (system)
-			frames->clearBit(page->frame / 0x1000);
+		if (page->frame >= 0x100) {	//First 1M are reserved (system)
+			frames->clearBit(page->frame);
+		}
 		page->frame = 0;
 	}
 }
diff --git a/Source/Kernel/SyscallManager/IDT.ns.cpp b/Source/Kernel/SyscallManager/IDT.ns.cpp
index 1a62d88..fcab741 100644
--- a/Source/Kernel/SyscallManager/IDT.ns.cpp
+++ b/Source/Kernel/SyscallManager/IDT.ns.cpp
@@ -74,9 +74,9 @@ extern "C" void interrupt_handler(registers_t regs) {
 		doSwitch = doSwitch or Task::IRQwakeup(regs.int_no - 32);
 	}
 	if (regs.int_no == 66) {	//This syscall signals to kernel that thread ended.
-		Task::currentThreadExits(regs.eax);
+		Task::currentThreadExits(regs.eax);	//DO NOT COUNT ON COMMING BACK FROM HERE
 	}
-	if (doSwitch) Task::doSwitch();	//DO NEVER COUNT ON COMMING BACK FROM HERE
+	if (doSwitch) Task::doSwitch();	//DO NOT COUNT ON COMMING BACK FROM HERE EITHER
 }
 
 namespace IDT {
diff --git a/Source/Kernel/TaskManager/Process.class.cpp b/Source/Kernel/TaskManager/Process.class.cpp
index 6b07e7a..2706986 100644
--- a/Source/Kernel/TaskManager/Process.class.cpp
+++ b/Source/Kernel/TaskManager/Process.class.cpp
@@ -64,7 +64,7 @@ void Process::exit() {
 		iter->v()->close(false);
 		delete iter->v();
 	}
-	delete m_fileDescriptors;
+	delete m_fileDescriptors; //Will recursively delete whole list
 	m_state = P_FINISHED;
 }
 
diff --git a/Source/Kernel/TaskManager/Task.ns.cpp b/Source/Kernel/TaskManager/Task.ns.cpp
index 4db05bc..66eca94 100644
--- a/Source/Kernel/TaskManager/Task.ns.cpp
+++ b/Source/Kernel/TaskManager/Task.ns.cpp
@@ -1,5 +1,9 @@
 #include "Task.ns.h"
 #include <Library/Vector.class.h>
+#include <MemoryManager/PhysMem.ns.h>
+
+#define INVALID_TASK_MAGIC 0xBEEFFEED
+#define TEMP_STACK_SIZE 128 //This must be big enough so that we can call all we need to call when a task finishes
 
 //From Task.wtf.asm
 extern "C" u32int read_eip();
@@ -16,12 +20,7 @@ SimpleList<Thread*> *idleThread = 0;
 
 u32int nextpid = 1;
 
-struct finished_thread_t {	//Forms a linked list
-	Thread* thread;
-	u32int errcode;
-};
-SimpleList<finished_thread_t> *firstFinishedThread = 0;
-
+u32int temp_stack[TEMP_STACK_SIZE];	//Temporary stack used for finishing current thread
 
 Thread* currThread() {
 	return currentThread->v();
@@ -53,20 +52,15 @@ void initialize(String cmdline, VirtualTerminal *vt) {
 }
 
 SimpleList<Thread*> *nextThread() {
-	//Clean up finished threads
-	while (firstFinishedThread != 0) {
-		if (firstFinishedThread->v().thread == currentThread->v()) break;
-		firstFinishedThread->v().thread->finish(firstFinishedThread->v().errcode);
-		firstFinishedThread = firstFinishedThread->delThis();
-	}
-
 	//Find next thread
+	if ((u32int)currentThread == INVALID_TASK_MAGIC) {
+		currentThread = threads;	//This will happen when we come here just after current thread has finished
+	}
 	SimpleList<Thread*> *iter = currentThread;
 	while (1) {
 		iter = iter->next();
 		if (iter == 0) iter = threads;
 		if (iter->v()->runnable() and iter->v() != idleThread->v()) {
-			if (firstFinishedThread != 0 and firstFinishedThread->v().thread == iter->v()) return idleThread;
 			return iter;
 		}
 		if (iter == currentThread) break;
@@ -88,7 +82,8 @@ void doSwitch() {
 		return;
 	}
 
-	if ((u32int)currentThread->v() != 0xFFFFFFFF) currentThread->v()->setState(esp, ebp, eip);
+	//This will happen when we come here just after current thread has finished
+	if ((u32int)currentThread != INVALID_TASK_MAGIC) currentThread->v()->setState(esp, ebp, eip);
 
 	currentThread = nextThread();
 	Thread* t = currentThread->v();
@@ -127,6 +122,8 @@ bool IRQwakeup(u8int irq) {
 }
 
 void allocKernelPageTable(u32int id, page_table_t *table, u32int tablePhys) {
+	kernelPageDirectory->tables[id] = table;
+	kernelPageDirectory->tablesPhysical[id] = tablePhys;
 	if (id < 768) return;	//this would be a BUG
 	for (SimpleList<Process*> *iter = processes; iter != 0; iter = iter->next()) {
 		iter->v()->getPagedir()->tables[id] = table;
@@ -134,9 +131,28 @@ void allocKernelPageTable(u32int id, page_table_t *table, u32int tablePhys) {
 	}
 }
 
-void currentThreadExits(u32int errcode) {
-	finished_thread_t tmp = {currentThread->v(), errcode};
-	firstFinishedThread = firstFinishedThread->cons(tmp);
+void currThreadExitProceed(u32int errcode) {
+	currentThread->v()->finish(errcode);
+	currentThread = (SimpleList<Thread*>*)INVALID_TASK_MAGIC;
+	doSwitch();  //Normally never come back from here
+}
+
+void currentThreadExits(u32int errcode) {	//Call currThreadExitProceed with a working stack (we use temp_stack)
+	u32int* stack = &temp_stack[TEMP_STACK_SIZE];
+	stack--;
+	*stack = errcode;
+	stack--;
+	*stack = 0;
+	u32int esp = (u32int)(stack), ebp = (u32int)(stack + 1), eip = (u32int)currThreadExitProceed;
+
+	asm volatile("			\
+			cli;			\
+			mov %0, %%ebp;	\
+			mov %1, %%esp;	\
+			mov %2, %%ecx;	\
+			mov %3, %%cr3;	\
+			jmp *%%ecx;"
+		: : "r"(ebp), "r"(esp), "r"(eip), "r"(kernelPageDirectory->physicalAddr));
 }
 
 void registerThread(Thread* t) {
diff --git a/Source/Kernel/TaskManager/Thread.class.cpp b/Source/Kernel/TaskManager/Thread.class.cpp
index fd5cfd9..fe1d08e 100644
--- a/Source/Kernel/TaskManager/Thread.class.cpp
+++ b/Source/Kernel/TaskManager/Thread.class.cpp
@@ -34,8 +34,9 @@ Thread::Thread(Process* process, thread_entry_t entry_point, void* data) {
 
 Thread::~Thread() {
 	Task::unregisterThread(this);
-	if (m_isKernel)
+	if (m_isKernel) {
 		PageAlloc::free((void*)m_kernelStackFrame);
+	}
 	//Don't unregister thread in process, it has probably already been done
 }
 
diff --git a/Source/Kernel/TaskManager/Thread.class.h b/Source/Kernel/TaskManager/Thread.class.h
index dffc84a..369f62f 100644
--- a/Source/Kernel/TaskManager/Thread.class.h
+++ b/Source/Kernel/TaskManager/Thread.class.h
@@ -7,7 +7,7 @@
 #define T_ZOMBIE 0
 #define T_RUNNING 1
 #define T_SLEEPING 2
-#define T_IRQWAIT 3		//This can only happen if process->uid == 0 (root)
+#define T_IRQWAIT 3	
 
 typedef u32int(*thread_entry_t)(void*);