Justin C. Miller
671a0ce0fb
vm_space and page_table continue to take over duties from page_manager: - creation and deletion of address spaces / pml4s - cross-address-space copies for endpoints - taking over pml4 ownership from process Also fixed the bug where the wrong process was being set in the cpu data. To solve: now the kernel process has its own vm_space which is not g_kernel_space.
110 lines
2.9 KiB
C++
110 lines
2.9 KiB
C++
#pragma once
|
|
/// \file scheduler.h
|
|
/// The task scheduler and related definitions
|
|
|
|
#include <stdint.h>
|
|
#include "objects/thread.h"
|
|
|
|
class lapic;
|
|
class process;
|
|
struct page_table;
|
|
struct cpu_state;
|
|
|
|
extern "C" void isr_handler(cpu_state*);
|
|
extern "C" void task_switch(TCB *next);
|
|
|
|
|
|
/// The task scheduler
|
|
class scheduler
|
|
{
|
|
public:
|
|
/// Total number of priority levels
|
|
static const uint8_t num_priorities = 8;
|
|
|
|
/// Maximum (least urgent/interactive) priority
|
|
static const uint8_t max_priority = num_priorities - 1;
|
|
|
|
/// Default priority on process creation
|
|
static const uint8_t default_priority = 1;
|
|
|
|
/// Lowest (most urgent) priority achieved via promotion
|
|
static const uint8_t promote_limit = 1;
|
|
|
|
/// How long the base timer quantum is, in us
|
|
static const uint64_t quantum_micros = 500;
|
|
|
|
/// How many quanta a process gets before being rescheduled
|
|
static const uint16_t process_quanta = 10;
|
|
|
|
/// Constructor.
|
|
/// \arg apic Pointer to the local APIC object
|
|
scheduler(lapic *apic);
|
|
|
|
/// Create a new process from a program image in memory.
|
|
/// \arg name Name of the program image
|
|
/// \arg data Pointer to the image data
|
|
/// \arg size Size of the program image, in bytes
|
|
void load_process(const char *name, const void *data, size_t size);
|
|
|
|
/// Create a new kernel task
|
|
/// \arg proc Function to run as a kernel task
|
|
/// \arg priority Priority to start the process with
|
|
/// \arg constant True if this task cannot be promoted/demoted
|
|
void create_kernel_task(
|
|
void (*task)(),
|
|
uint8_t priority,
|
|
bool constant = false);
|
|
|
|
/// Get the quantum for a given priority.
|
|
uint32_t quantum(int priority);
|
|
|
|
/// Start the scheduler working. This may involve starting
|
|
/// timer interrupts or other preemption methods.
|
|
void start();
|
|
|
|
/// Run the scheduler, possibly switching to a new task
|
|
void schedule();
|
|
|
|
/// Get the current TCB.
|
|
/// \returns A pointer to the current thread's TCB
|
|
inline TCB * current() { return m_current; }
|
|
|
|
inline void add_thread(TCB *t) { m_runlists[t->priority].push_back(static_cast<tcb_node*>(t)); }
|
|
|
|
/// Get a reference to the system scheduler
|
|
/// \returns A reference to the global system scheduler
|
|
static scheduler & get() { return *s_instance; }
|
|
|
|
private:
|
|
friend uintptr_t syscall_dispatch(uintptr_t, cpu_state &);
|
|
friend class process;
|
|
|
|
static constexpr uint64_t promote_frequency = 10;
|
|
|
|
/// Create a new process object. This process will have its pid
|
|
/// set but nothing else.
|
|
/// \arg user True if this thread will enter userspace
|
|
/// \returns The new process' main thread
|
|
thread * create_process(bool user);
|
|
|
|
void prune(uint64_t now);
|
|
void check_promotions(uint64_t now);
|
|
|
|
lapic *m_apic;
|
|
|
|
uint32_t m_next_pid;
|
|
uint32_t m_tick_count;
|
|
|
|
process *m_kernel_process;
|
|
tcb_node *m_current;
|
|
tcb_list m_runlists[num_priorities];
|
|
tcb_list m_blocked;
|
|
|
|
// TODO: lol a real clock
|
|
uint64_t m_clock = 0;
|
|
uint64_t m_last_promotion;
|
|
|
|
static scheduler *s_instance;
|
|
};
|
|
|