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#include "Task.ns.h"
#include <MemoryManager/PhysMem.ns.h>
#define INVALID_TASK_MAGIC 0xBEEFFEED
#define TEMP_STACK_SIZE 256 //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();
extern "C" u32int idle_task(void*);
namespace Task {
SimpleList <Process*> *processes = 0;
SimpleList <Thread*> *threads = 0;
SimpleList <Thread*> *currentThread = 0;
Process* currentProcess = 0;
SimpleList<Thread*> *idleThread = 0;
u32int nextpid = 1;
u32int temp_stack[TEMP_STACK_SIZE]; //Temporary stack used for finishing current thread
Thread* currThread() {
return currentThread->v();
}
Process* currProcess() {
return currentProcess;
}
Process* getKernelProcess() {
if (processes == 0) PANIC("kko");
return processes->last()->v();
}
void initialize(String cmdline, VirtualTerminal *vt) {
asm volatile ("cli");
threads = 0;
processes = 0;
currentProcess = Process::createKernel(cmdline, vt);
currentThread = threads;
Thread* idle = new Thread(idle_task, 0, true);
for (SimpleList<Thread*> *iter = threads; iter != 0; iter = iter->next()) {
if (iter->v() == idle) {
idleThread = iter;
break;
}
}
asm volatile ("sti");
}
SimpleList<Thread*> *nextThread() {
//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()) {
return iter;
}
if (iter == currentThread) break;
}
return idleThread;
}
void doSwitch() {
if (currentThread == NULL or currentProcess == NULL) return;
u32int esp, ebp, eip;
asm volatile("mov %%esp, %0" : "=r"(esp));
asm volatile("mov %%ebp, %0" : "=r"(ebp));
eip = read_eip();
if (eip == 0x12345) {
return;
}
//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();
currentProcess = t->getProcess();
esp = t->getEsp();
ebp = t->getEbp();
eip = t->getEip();
asm volatile("cli");
t->setKernelStack();
asm volatile(" \
mov %%eax, %%ebp; \
mov %%ebx, %%esp; \
mov $0x12345, %%eax; \
jmp *%%ecx;"
: : "a"(ebp), "b"(esp), "c"(eip));
}
void triggerSwitch() {
asm volatile("int $65");
}
u32int nextPid() {
return nextpid++;
}
bool IRQwakeup(u8int irq) {
bool r = false;
for (SimpleList<Thread*> *iter = threads; iter != 0; iter = iter->next()) {
r = r or iter->v()->irqHappens(irq);
}
return r;
}
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;
iter->v()->getPagedir()->tablesPhysical[id] = tablePhys;
}
}
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)
asm volatile("cli");
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(" \
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) {
unregisterThread(t); //...//
threads = threads->cons(t);
}
void unregisterThread(Thread* t) {
if (threads == 0) return; //Tasking not yet initialized
threads = threads->removeOnce(t);
}
void registerProcess(Process* p) {
unregisterProcess(p); //...//
processes = processes->cons(p);
}
void unregisterProcess(Process* p) {
if (processes == 0) return; //Tasking not yet initialized
processes = processes->removeOnce(p);
}
}
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