404 lines
13 KiB
C
404 lines
13 KiB
C
/**
|
|
* \file
|
|
*/
|
|
|
|
#include "cpu/halt.h"
|
|
#include "cpu/paging.h"
|
|
#include "cpu/serial.h"
|
|
#include "cpu/tasking_helpers.h"
|
|
#include "kmalloc.h"
|
|
#include "tasking.h"
|
|
#include <sys/types.h>
|
|
#include <string.h>
|
|
|
|
#define MAX_PROCS 32768 //!< Maximum number of processes that can be running at a time
|
|
#define HAS_UNBLOCKED_THREADS(proc) (proc->num_threads!=proc->num_threads_blocked) //!< Macro to check whethe a process has unblocked threads
|
|
#define NUM_UNBLOCKED_THREADS(proc) (proc->num_threads-proc->num_threads_blocked) //!< Macro to get the number of unblocked threads for a process
|
|
#define SAME_PROC(thread1,thread2) (thread1->process->pid==thread2->process->pid) //!< Macro to check whether two threads have the same PID
|
|
pid_t next_pid=0; //!< PID to use for the next created process
|
|
size_t num_procs=0; //!< Number of non-exited processes
|
|
Process processes[MAX_PROCS]; //!< Array pf processes by PID
|
|
char proc_schedule_bmap[MAX_PROCS/8]; //!< Bitmap of what processes are scheduled
|
|
Thread* current_thread; //!< Currently running thread
|
|
static Thread* ready_to_run_head=NULL; //!< Head of the linked list of ready to run threads
|
|
static Thread* ready_to_run_tail=NULL; //!< Tail of the linked list of ready to run threads
|
|
|
|
/**
|
|
* Check whether a process is scheduled
|
|
* \param index The PID to check
|
|
* \return whether the process is scheduled
|
|
*/
|
|
static char is_proc_scheduled(pid_t index) {
|
|
size_t byte=index/8;
|
|
size_t bit=index%8;
|
|
char entry=proc_schedule_bmap[byte];
|
|
return (entry&(1<<bit))>0;
|
|
}
|
|
|
|
/**
|
|
* Mark a process as scheduled
|
|
* \param index The PID to mark
|
|
*/
|
|
static void mark_proc_scheduled(pid_t index) {
|
|
if (is_proc_scheduled(index)) {
|
|
serial_printf("Attempt to schedule a thread in a process with a scheduled thread! (PID %d)\n",index);
|
|
halt();
|
|
}
|
|
size_t byte=index/8;
|
|
size_t bit=index%8;
|
|
proc_schedule_bmap[byte]=proc_schedule_bmap[byte]|(1<<bit);
|
|
}
|
|
|
|
/**
|
|
* Unmark a process as scheduled
|
|
* \param index The PID to unmark
|
|
*/
|
|
static void unmark_proc_scheduled(pid_t index) {
|
|
size_t byte=index/8;
|
|
size_t bit=index%8;
|
|
proc_schedule_bmap[byte]=proc_schedule_bmap[byte]&(~(1<<bit));
|
|
}
|
|
|
|
/**
|
|
* Schedules a thread if the thread's prcess does not have a scheduled thread
|
|
* \param thread The thread to schedule
|
|
*/
|
|
void schedule_thread(Thread* thread) {
|
|
if(!is_proc_scheduled(thread->process->pid)) {
|
|
if (ready_to_run_head) {
|
|
thread->state=THREAD_READY;
|
|
// ready_to_run_tail->next_ready_to_run=thread;
|
|
// thread->prev_ready_to_run=ready_to_run_tail;
|
|
// ready_to_run_tail=thread;
|
|
if (thread==ready_to_run_head) {
|
|
serial_printf("TASKING DATA STRUCTURES CORRUPT!!!!\n");
|
|
halt();
|
|
}
|
|
thread->next_ready_to_run=ready_to_run_head;
|
|
ready_to_run_head->prev_ready_to_run=thread;
|
|
ready_to_run_head=thread;
|
|
mark_proc_scheduled(thread->process->pid);
|
|
} else if (current_thread) {
|
|
thread->state=THREAD_READY;
|
|
ready_to_run_head=thread;
|
|
ready_to_run_tail=thread;
|
|
mark_proc_scheduled(thread->process->pid);
|
|
} else {
|
|
thread->state=THREAD_RUNNING;
|
|
current_thread=thread;
|
|
}
|
|
}
|
|
}
|
|
|
|
void tasking_create_task(void* eip,void* address_space,char kmode,void* param1,void* param2,char isThread) {
|
|
if (next_pid>MAX_PROCS && !isThread) {
|
|
serial_printf("Failed to create a process, as 32k processes have been created already.\n");
|
|
halt(); //Cannot ever create more than 32k processes, as I don't currently reuse PIDs.
|
|
}
|
|
pid_t pid=isThread ? (pid_t)param2 : next_pid++;
|
|
Process* proc=&processes[pid];
|
|
Thread* thread=kmalloc(sizeof(Thread));
|
|
proc->num_threads++;
|
|
thread->process=proc;
|
|
thread->errno=0;
|
|
thread->tid=proc->next_tid++;
|
|
thread->prev_ready_to_run=NULL;
|
|
thread->next_ready_to_run=NULL;
|
|
thread->prev_thread_in_process=NULL;
|
|
thread->state=THREAD_READY;
|
|
if (isThread) {
|
|
thread->address_space=proc->first_thread->address_space;
|
|
thread->next_thread_in_process=proc->first_thread;
|
|
proc->first_thread->prev_thread_in_process=thread;
|
|
} else {
|
|
thread->address_space=address_space;
|
|
thread->next_thread_in_process=NULL;
|
|
proc->priv=current_thread ? current_thread->process->priv : 1;
|
|
proc->pid=pid;
|
|
num_procs++;
|
|
}
|
|
proc->first_thread=thread;
|
|
setup_kstack(thread,param1,param2,kmode,eip);
|
|
schedule_thread(thread);
|
|
// serial_printf("Created thread with PID %d and TID %d.\n",proc->pid,thread->tid);
|
|
}
|
|
|
|
void tasking_init() {
|
|
for (size_t i = 0; i < MAX_PROCS; i++) {
|
|
memset(&processes[i],0,sizeof(Process));
|
|
}
|
|
|
|
tasking_create_task(NULL,get_address_space(),1,NULL,NULL,0);
|
|
}
|
|
|
|
char tasking_is_privleged() {
|
|
return current_thread->process->priv;
|
|
}
|
|
|
|
pid_t tasking_get_PID() {
|
|
return current_thread->process->pid;
|
|
}
|
|
|
|
pid_t tasking_get_TID() {
|
|
return current_thread->tid;
|
|
}
|
|
|
|
int* tasking_get_errno_address() {
|
|
return ¤t_thread->errno;
|
|
}
|
|
|
|
pid_t tasking_new_thread(void* start,pid_t pid,void* param) {
|
|
tasking_create_task(start,NULL,0,param,(void*)pid,1);
|
|
return processes[pid].first_thread->tid;
|
|
}
|
|
|
|
/**
|
|
* Get the next ready thread in a list of threads, starting at the specified thread's next thread
|
|
* \param thread The start thread
|
|
* \param thread_to_skip A thread to skip even if it's ready
|
|
* \return the next ready thread
|
|
*/
|
|
static Thread* get_next_ready_thread(Thread* thread,Thread* thread_to_skip) {
|
|
#ifndef DOXYGEN_SHOULD_SKIP_THIS
|
|
#define HELPER \
|
|
while (thread&&(thread->state!=THREAD_READY||thread==thread_to_skip)) { \
|
|
thread=thread->next_thread_in_process; \
|
|
}
|
|
//end define
|
|
#endif
|
|
Thread* start_of_list=thread->process->first_thread;
|
|
thread=thread->next_thread_in_process;
|
|
HELPER;
|
|
if (!thread) {
|
|
thread=start_of_list;
|
|
HELPER;
|
|
}
|
|
return thread;
|
|
#undef HELPER
|
|
}
|
|
|
|
/**
|
|
* Switch to a thread and schedule the next ready thread in the current process, if there is one.
|
|
* \param thread The thread to switch to
|
|
*/
|
|
void switch_to_thread(Thread* thread) {
|
|
// Unlink the thread from the list of ready-to-run threads
|
|
if (thread!=ready_to_run_head) {
|
|
thread->prev_ready_to_run->next_ready_to_run=thread->next_ready_to_run;
|
|
if (thread->next_ready_to_run) {
|
|
thread->next_ready_to_run->prev_ready_to_run=thread->prev_ready_to_run;
|
|
}
|
|
} else {
|
|
ready_to_run_head=thread->next_ready_to_run;
|
|
if (ready_to_run_head==NULL) {
|
|
ready_to_run_tail=NULL;
|
|
}
|
|
}
|
|
unmark_proc_scheduled(thread->process->pid);
|
|
thread->prev_ready_to_run=NULL;
|
|
thread->next_ready_to_run=NULL;
|
|
if (current_thread->state==THREAD_RUNNING) {
|
|
current_thread->state=THREAD_READY;
|
|
}
|
|
//Get the next ready thread in the current process
|
|
Thread* current_thread_next_ready=get_next_ready_thread(current_thread,thread);
|
|
if (!current_thread_next_ready) {
|
|
//This process is fully blocked, try the process of the thread we're yielding to
|
|
current_thread_next_ready=get_next_ready_thread(thread,thread);
|
|
}
|
|
if (current_thread_next_ready) {
|
|
schedule_thread(current_thread_next_ready);
|
|
}
|
|
thread->state=THREAD_RUNNING;
|
|
// serial_printf("Switching to PID %d TID %d.\n",thread->process->pid,thread->tid);
|
|
switch_to_thread_asm(thread);
|
|
}
|
|
|
|
void tasking_yield() {
|
|
if (ready_to_run_head) {
|
|
// serial_printf("Attempting to switch to PID %d TID %d\n",ready_to_run_head->process->pid,ready_to_run_head->tid);
|
|
switch_to_thread(ready_to_run_head);
|
|
} else {
|
|
if (NUM_UNBLOCKED_THREADS(current_thread->process)>1) {
|
|
// Thread* thread=get_next_ready_thread(current_thread,current_thread);
|
|
// schedule_thread(thread);
|
|
// yield();
|
|
serial_printf("The ready to run list is empty, and the current process has other unblocked threads? This is an invalid state! Halting!\n");
|
|
halt();
|
|
} else if (NUM_UNBLOCKED_THREADS(current_thread->process)==1) {
|
|
return;
|
|
} else {
|
|
if (num_procs==0) {
|
|
serial_printf("All processes exited, halting\n");
|
|
asm volatile("cli");
|
|
for(;;);
|
|
halt();
|
|
} else {
|
|
// serial_printf("All threads in all processes blocked, waiting for an IRQ which unblocks a thread\n");
|
|
// All threads in all processes blocked, so wait for an IRQ whose handler unblocks a thread.
|
|
do { wait_for_unblocked_thread_asm(); } while (ready_to_run_head==NULL);
|
|
}
|
|
// serial_printf("Attempting to switch to PID %d TID %d\n",ready_to_run_head->process->pid,ready_to_run_head->tid);
|
|
switch_to_thread(ready_to_run_head);
|
|
}
|
|
}
|
|
}
|
|
|
|
void tasking_block(thread_state newstate) {
|
|
if (ready_to_run_head==current_thread) {
|
|
ready_to_run_head=ready_to_run_head->next_ready_to_run;
|
|
if (ready_to_run_head==NULL) {
|
|
ready_to_run_tail=NULL;
|
|
}
|
|
}
|
|
if (ready_to_run_tail==current_thread) {
|
|
ready_to_run_tail=ready_to_run_tail->prev_ready_to_run;
|
|
if (ready_to_run_tail==NULL) {
|
|
ready_to_run_head=NULL;
|
|
}
|
|
}
|
|
if (ready_to_run_head&&ready_to_run_head->next_ready_to_run) {
|
|
for (Thread* thread=ready_to_run_head->next_ready_to_run;thread!=NULL;thread=thread->next_ready_to_run) {
|
|
if (thread==current_thread) {
|
|
thread->prev_ready_to_run->next_ready_to_run=thread->next_ready_to_run;
|
|
if (thread->next_ready_to_run) {
|
|
thread->next_ready_to_run->prev_ready_to_run=thread->prev_ready_to_run;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
for (Thread* thread=current_thread->process->first_thread;thread!=NULL;thread=thread->next_thread_in_process) {
|
|
if (thread->tid==current_thread->tid) {
|
|
thread->state=newstate;
|
|
}
|
|
}
|
|
current_thread->process->num_threads_blocked++;
|
|
tasking_yield();
|
|
}
|
|
|
|
/**
|
|
* Get a thread
|
|
* \param pid The PID of the thread
|
|
* \param tid The TID of the thread
|
|
* \return the thread wih the specified PID and TID
|
|
*/
|
|
static Thread* get_thread(pid_t pid,pid_t tid) {
|
|
if (processes[pid].num_threads==0) {
|
|
serial_printf("PID %d does not exist!\n",pid);
|
|
return NULL;
|
|
}
|
|
Thread* thread=processes[pid].first_thread;
|
|
for (;thread!=NULL;thread=thread->next_thread_in_process) {
|
|
if (thread->tid==tid) {
|
|
break;
|
|
}
|
|
}
|
|
if (!thread) {
|
|
serial_printf("PID %d TID %d does not exist!\n",pid,thread);
|
|
return NULL;
|
|
}
|
|
if (thread->tid!=tid) {
|
|
serial_printf("Error! Got wrong thread! (Wanted TID %d, got TID %d)\n",tid,thread->tid);
|
|
return NULL;
|
|
}
|
|
return thread;
|
|
}
|
|
|
|
void tasking_unblock(pid_t pid,pid_t tid) {
|
|
// serial_printf("Unblocking PID %d TID %d\n",pid,tid);
|
|
Thread* thread=get_thread(pid,tid);
|
|
if (thread==NULL) {
|
|
return;
|
|
}
|
|
if (thread->state==THREAD_EXITED||thread->state==THREAD_READY||thread->state==THREAD_RUNNING) {
|
|
serial_printf("Tried to unblock an exited/ready/running thread!\n");
|
|
return;
|
|
}
|
|
thread->state=THREAD_READY;
|
|
thread->process->num_threads_blocked--;
|
|
schedule_thread(thread);
|
|
}
|
|
|
|
void tasking_exit(int code) {
|
|
// serial_printf("PID %d is exiting with code %d.\n",current_thread->process->pid,code);
|
|
if (ready_to_run_head&&SAME_PROC(ready_to_run_head,current_thread)) {
|
|
ready_to_run_head=ready_to_run_head->next_ready_to_run;
|
|
if (ready_to_run_head==NULL) {
|
|
ready_to_run_tail=NULL;
|
|
}
|
|
}
|
|
if (ready_to_run_tail&&SAME_PROC(ready_to_run_tail,current_thread)) {
|
|
ready_to_run_tail=ready_to_run_tail->prev_ready_to_run;
|
|
if (ready_to_run_tail==NULL) {
|
|
ready_to_run_head=NULL;
|
|
|
|
}
|
|
}
|
|
if (ready_to_run_head&&ready_to_run_head->next_ready_to_run) {
|
|
for (Thread* thread=ready_to_run_head->next_ready_to_run;thread!=NULL;thread=thread->next_ready_to_run) {
|
|
if (SAME_PROC(thread,current_thread)) {
|
|
thread->prev_ready_to_run->next_ready_to_run=thread->next_ready_to_run;
|
|
if (thread->next_ready_to_run) {
|
|
thread->next_ready_to_run->prev_ready_to_run=thread->prev_ready_to_run;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
unmark_proc_scheduled(current_thread->process->pid);
|
|
for (Thread* thread=current_thread->process->first_thread;thread!=NULL;thread=thread->next_thread_in_process) {
|
|
thread->state=THREAD_EXITED;
|
|
}
|
|
current_thread->process->num_threads_blocked=current_thread->process->num_threads;
|
|
num_procs--;
|
|
tasking_yield();
|
|
}
|
|
|
|
void* tasking_get_address_space(pid_t pid) {
|
|
return processes[pid].first_thread->address_space;
|
|
}
|
|
|
|
void tasking_set_rpc_calling_thread(pid_t pid,pid_t tid) {
|
|
Thread* thread=get_thread(pid,tid);
|
|
thread->rpc_calling_pid=current_thread->process->pid;
|
|
thread->rpc_calling_tid=current_thread->tid;
|
|
}
|
|
|
|
pid_t tasking_get_rpc_calling_thread(pid_t* tid) {
|
|
*tid=current_thread->rpc_calling_tid;
|
|
return current_thread->rpc_calling_pid;
|
|
}
|
|
|
|
void tasking_set_rpc_ret_buf(void* buf) {
|
|
pid_t tid;
|
|
pid_t pid=tasking_get_rpc_calling_thread(&tid);
|
|
Thread* thread=get_thread(pid,tid);
|
|
thread->rpc_ret_buf=buf;
|
|
}
|
|
|
|
void* tasking_get_rpc_ret_buf() {
|
|
return current_thread->rpc_ret_buf;
|
|
}
|
|
|
|
void tasking_thread_exit() {
|
|
tasking_block(THREAD_EXITED);
|
|
}
|
|
|
|
char tasking_check_proc_exists(pid_t pid) {
|
|
if (processes[pid].num_threads==0) {
|
|
return 0;
|
|
}
|
|
char num_exited_threads=0;
|
|
for (Thread* thread=processes[pid].first_thread;thread!=NULL;thread=thread->next_thread_in_process) {
|
|
if (thread->state==THREAD_EXITED) {
|
|
num_exited_threads++;
|
|
}
|
|
}
|
|
if ((num_exited_threads=processes[pid].num_threads)&&kernel_get_num_rpc_funcs(pid)==0) {
|
|
return 0;
|
|
} else {
|
|
return 1;
|
|
}
|
|
}
|