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-rw-r--r--interrupt/fault.cpp6
-rw-r--r--os/thread.cpp3
-rw-r--r--os/thread.h35
3 files changed, 36 insertions, 8 deletions
diff --git a/interrupt/fault.cpp b/interrupt/fault.cpp
index 016b74b..9af0eb8 100644
--- a/interrupt/fault.cpp
+++ b/interrupt/fault.cpp
@@ -12,7 +12,11 @@ inline void __attribute__((naked)) switch_context() {
asm volatile ("str sp, [%0]" :: "r" (&Thread::active_thread->sp));
// Update running thread.
- Thread::active_thread = Thread::active_thread->next;
+ if(!Thread::reschedule()) {
+ // TODO: Set SLEEPONEXIT
+ } else {
+ // TODO: Clear SLEEPONEXIT
+ }
// Fetch stack pointer for new thread.
asm volatile ("ldr sp, [%0]" :: "r" (&Thread::active_thread->sp));
diff --git a/os/thread.cpp b/os/thread.cpp
index 426fffd..0f2437d 100644
--- a/os/thread.cpp
+++ b/os/thread.cpp
@@ -1,4 +1,5 @@
#include "thread.h"
-Thread Thread::main_thread __attribute__ ((init_priority (1000)));
+List<Thread> Thread::ready_queue __attribute__ ((init_priority (1000)));
+Thread Thread::main_thread __attribute__ ((init_priority (1001)));
Thread* Thread::active_thread = &Thread::main_thread;
diff --git a/os/thread.h b/os/thread.h
index 7486d01..72ee275 100644
--- a/os/thread.h
+++ b/os/thread.h
@@ -2,6 +2,7 @@
#define THREAD_H
#include <stdint.h>
+#include <util/intrusive_list.h>
class Thread {
friend void switch_context();
@@ -32,15 +33,38 @@ class Thread {
int_frame_t* sp;
- Thread* next;
+ ListHandle<Thread> queue_handle;
+
+ static List<Thread> ready_queue;
static Thread* active_thread;
static Thread main_thread;
- Thread() : next(this) {}
+ static bool reschedule() {
+ //active_thread = active_thread->next;
+
+ // TODO: Check whether active thread still is ready.
+
+ // Move thread to end of ready queue.
+ ready_queue.append(active_thread->queue_handle);
+
+ // Check whether any threads are ready to run.
+ if(ready_queue.empty()) {
+ return false;
+ }
+
+ // Set front of ready queue as active.
+ active_thread = ready_queue.begin()->p;
+
+ return true;
+ }
+
+ Thread() : queue_handle(this) {
+ ready_queue.append(queue_handle);
+ }
public:
- Thread(void* stack, uint32_t stack_size, void (*func)()) {
+ Thread(void* stack, uint32_t stack_size, void (*func)()) : queue_handle(this) {
sp = (int_frame_t*)((uint8_t*)stack + stack_size - sizeof(int_frame_t));
sp->lr_ex = 0xfffffff9;
@@ -51,12 +75,11 @@ class Thread {
}
void start() {
- next = active_thread->next;
- active_thread->next = this;
+ ready_queue.append(queue_handle);
}
static inline void yield() {
- asm volatile("svc 0");
+ asm volatile("svc 0" ::: "memory");
}
};