Bugfixing in progress. Strange bug: wait_on adds to waiters but later not in waiters.

6 files changed, 54 insertions, 41 deletions

diff --git a/src/kernel/core/idt.c b/src/kernel/core/idt.c
index f99460f..f3dd63b 100644
--- a/src/kernel/core/idt.c
+++ b/src/kernel/core/idt.c
@@ -91,6 +91,7 @@ static isr_handler_t ex_handlers[32] = {0};
 
 /*	Called in interrupt.s when an exception fires (interrupt 0 to 31) */
 void idt_ex_handler(registers_t *regs) {
+	dbg_printf("Ex handler: %d\n", regs->int_no);
 	if (ex_handlers[regs->int_no] != 0) {
 		ex_handlers[regs->int_no](regs);
 	} else {
@@ -114,21 +115,21 @@ void idt_ex_handler(registers_t *regs) {
 void idt_irq_handler(registers_t *regs) {
 	int st = enter_critical(CL_EXCL);	// if someone tries to yield(), an assert will fail
 
+	dbg_printf("irq%d.", regs->err_code);
+
 	if (regs->err_code > 7) {
 		outb(0xA0, 0x20);
 	}
 	outb(0x20, 0x20);
 
-	if (regs->err_code == 0) {
-		irq0_handler(regs, st);
-	} else {
-		/*dbg_printf("irq%d.", regs->err_code);*/
+	if (irq_handlers[regs->err_code] != 0) {
+		irq_handlers[regs->err_code](regs);
+	}
 
-		if (irq_handlers[regs->err_code] != 0) {
-			irq_handlers[regs->err_code](regs);
-		}
+	exit_critical(st);
 
-		exit_critical(st);
+	if (regs->err_code == 0) {
+		threading_irq0_handler();
 	}
 
 	// maybe exit
diff --git a/src/kernel/core/thread.c b/src/kernel/core/thread.c
index 4e15c0e..ed2c185 100644
--- a/src/kernel/core/thread.c
+++ b/src/kernel/core/thread.c
@@ -19,7 +19,6 @@ void resume_context(saved_context_t *ctx);
 thread_t *current_thread = 0;
 
 static hashtbl_t *waiters = 0;			// threads waiting on a ressource
-STATIC_MUTEX(waiters_mutex);
 
 // ====================== //
 // THE PROGRAMMABLE TIMER //
@@ -44,6 +43,8 @@ void set_pit_frequency(uint32_t freq) {
 int enter_critical(int level) {
 	asm volatile("cli");
 
+	/*dbg_printf(" >%d< ", level);*/
+
 	if (current_thread == 0) return CL_EXCL;
 
 	int prev_level = current_thread->critical_level;
@@ -57,6 +58,8 @@ int enter_critical(int level) {
 void exit_critical(int prev_level) {
 	asm volatile("cli");
 
+	/*dbg_printf(" <%d> ", prev_level);*/
+
 	if (current_thread == 0) return;
 
 	if (prev_level < current_thread->critical_level) current_thread->critical_level = prev_level;
@@ -117,6 +120,8 @@ void run_scheduler() {
 	// At this point, interrupts are disabled
 	// This function is expected NEVER TO RETURN
 
+	thread_t *prev_thread = current_thread;
+
 	if (current_thread != 0 && current_thread->state == T_STATE_RUNNING) {
 		current_thread->last_ran = get_kernel_time();
 		if (current_thread->proc) current_thread->proc->last_ran = current_thread->last_ran;
@@ -124,7 +129,7 @@ void run_scheduler() {
 	}
 	current_thread = dequeue_thread();
 
-	/*dbg_printf("[0x%p]\n", current_thread);*/
+	if (current_thread != prev_thread) dbg_printf("[0x%p]\n", current_thread);
 
 	if (current_thread != 0) {
 		thread_t *ptr = current_thread;
@@ -221,11 +226,10 @@ void delete_thread(thread_t *t) {
 // SETUP CODE //
 // ========== //
 
-void irq0_handler(registers_t *regs, int crit_level) {
+void irq0_handler(registers_t *regs) {
 	notify_time_pass(1000000 / TASK_SWITCH_FREQUENCY);
-
-	exit_critical(crit_level);
-
+}
+void threading_irq0_handler() {
 	if (current_thread != 0 && current_thread->critical_level == CL_USER) {
 		save_context_and_enter_scheduler(&current_thread->ctx);
 	}
@@ -235,7 +239,7 @@ void threading_setup(entry_t cont, void* arg) {
 	ASSERT(waiters != 0);
 
 	set_pit_frequency(TASK_SWITCH_FREQUENCY);
-	// no need to set irq0 handler
+	idt_set_irq_handler(IRQ0, &irq0_handler);
 
 	thread_t *t = new_thread(cont, arg);
 	ASSERT(t != 0);
@@ -265,7 +269,8 @@ void start_thread(thread_t *t) {
 }
 
 void yield() {
-	ASSERT(current_thread != 0 && current_thread->critical_level != CL_EXCL);
+	ASSERT(current_thread != 0);
+	ASSERT(current_thread->critical_level != CL_EXCL);
 
 	save_context_and_enter_scheduler(&current_thread->ctx);
 }
@@ -275,10 +280,11 @@ bool wait_on(void* x) {
 }
 
 bool wait_on_many(void** x, size_t n) {
-	ASSERT(current_thread != 0 && current_thread->critical_level != CL_EXCL);
+	ASSERT(current_thread != 0);
+	ASSERT(current_thread->critical_level != CL_EXCL);
 	ASSERT(n > 0);
 
-	mutex_lock(&waiters_mutex);
+	int st = enter_critical(CL_NOINT);
 
 	//  ---- Check we can wait on all the requested objects
 	bool ok = true;
@@ -291,34 +297,34 @@ bool wait_on_many(void** x, size_t n) {
 			}
 		} else if (prev_th != (void*)1) {
 			ok = false;
+			break;
 		}
 	}
 	if (!ok) {
-		mutex_unlock(&waiters_mutex);
+		exit_critical(st);
 		return false;
 	}
 
 	//  ---- Set ourselves as the waiting thread for all the requested objets
-	int st = enter_critical(CL_NOSWITCH);
 
+	dbg_printf("Wait on many: ");
 	for (size_t i = 0; i < n; i++) {
 		ASSERT(hashtbl_change(waiters, x[i], current_thread));
+		dbg_printf("0x%p (0x%p) ", x[i], hashtbl_find(waiters, x[i]));
 	}
+	dbg_printf("\n");
 
 	//  ---- Go to sleep
-	mutex_unlock(&waiters_mutex);
 
 	current_thread->state = T_STATE_PAUSED;
 	save_context_and_enter_scheduler(&current_thread->ctx);
 
 	//  ---- Remove ourselves from the list
-	mutex_lock(&waiters_mutex);
 
 	for (size_t i = 0; i < n; i++) {
 		ASSERT(hashtbl_change(waiters, x[i], (void*)1));
 	}
 
-	mutex_unlock(&waiters_mutex);
 	exit_critical(st);
 
 	//  ---- Check that we weren't waked up because of a kill request
@@ -368,15 +374,17 @@ void exit() {
 }
 
 bool resume_on(void* x) {
+
 	thread_t *thread;
 
 	bool ret = false;
 
-	mutex_lock(&waiters_mutex);
 	int st = enter_critical(CL_NOINT);
 
 	thread = hashtbl_find(waiters, x);
 
+	dbg_printf("Resume on 0x%p : 0x%p\n", x, thread);
+
 	if (thread != 0 && thread != (void*)1) {
 		if (thread->state == T_STATE_PAUSED) {
 			thread->state = T_STATE_RUNNING;
@@ -387,7 +395,6 @@ bool resume_on(void* x) {
 		}
 	}
 
-	mutex_unlock(&waiters_mutex);
 	exit_critical(st);
 
 	return ret;
diff --git a/src/kernel/core/worker.c b/src/kernel/core/worker.c
index cb7bf34..6852329 100644
--- a/src/kernel/core/worker.c
+++ b/src/kernel/core/worker.c
@@ -49,21 +49,24 @@ void worker_thread(void* x) {
 
 	while (true) {
 		mutex_lock(&tasks_mutex);
-		worker_task_t *t = btree_upper(tasks, &zero64);
-		next_task_time = (t == 0 ? UINT64_MAX : t->time);
-		if (t != 0 && t->time <= time) {
-			btree_remove_v(tasks, &t->time, t);
+
+		worker_task_t *next_task = btree_upper(tasks, &zero64);
+		next_task_time = (next_task == 0 ? UINT64_MAX : next_task->time);
+
+		if (next_task != 0 && next_task->time <= time) {
+			btree_remove_v(tasks, &next_task->time, next_task);
 		} else {
-			t = 0;
+			next_task = 0;
 		}
+
 		mutex_unlock(&tasks_mutex);
 		
-		if (t != 0) {
-			prng_add_entropy((uint8_t*)&t, sizeof(t));
+		if (next_task != 0) {
+			prng_add_entropy((uint8_t*)&next_task, sizeof(next_task));
 
 			// do task :-)
-			t->fun(t->data);
-			free(t);
+			next_task->fun(next_task->data);
+			free(next_task);
 		} else {
 			ASSERT(wait_on(current_thread));
 		}
@@ -79,11 +82,12 @@ bool worker_push_in(int usecs, entry_t fun, void* data) {
 	t->data = data;
 
 	mutex_lock(&tasks_mutex);
+
 	btree_add(tasks, &t->time, t);
-	mutex_unlock(&tasks_mutex);
-	
 	if (t->time < next_task_time) next_task_time = t->time;
 
+	mutex_unlock(&tasks_mutex);
+
 	return true;
 }
 
@@ -95,6 +99,7 @@ void notify_time_pass(int usecs) {
 	time += usecs;
 	if (next_task_time <= time) {
 		for (int i = 0; i < nworkers; i++) {
+			if (workers[i] == 0) continue;
 			if (resume_on(workers[i])) break;
 		}
 	}
diff --git a/src/kernel/dev/pckbd.c b/src/kernel/dev/pckbd.c
index a911b85..8a4c002 100644
--- a/src/kernel/dev/pckbd.c
+++ b/src/kernel/dev/pckbd.c
@@ -105,7 +105,7 @@ size_t pckbd_read(fs_handle_t *h, size_t offset, size_t len, char *buf) {
 }
 
 int pckbd_poll(fs_handle_t *h, void** out_wait_obj) {
-	*out_wait_obj = &pckbd_buf;
+	if (out_wait_obj) *out_wait_obj = &pckbd_buf;
 
 	return (pckbd_buf_used > 0 ? SEL_READ : 0);
 }
diff --git a/src/kernel/include/thread.h b/src/kernel/include/thread.h
index 4b140fa..698c4c6 100644
--- a/src/kernel/include/thread.h
+++ b/src/kernel/include/thread.h
@@ -46,7 +46,7 @@ thread_t *new_thread(entry_t entry, void* data);	// thread is PAUSED, and must b
 void start_thread(thread_t *t);
 void delete_thread(thread_t *t);
 
-void irq0_handler(registers_t *regs, int crit_level);
+void threading_irq0_handler();
 
 extern thread_t *current_thread;
 
diff --git a/src/kernel/user/syscall.c b/src/kernel/user/syscall.c
index 3a67350..606ab3f 100644
--- a/src/kernel/user/syscall.c
+++ b/src/kernel/user/syscall.c
@@ -311,7 +311,7 @@ static uint32_t select_sc(sc_args_t args) {
 
 	bool ret = false;
 
-	int st = enter_critical(CL_NOSWITCH);
+	int st = enter_critical(CL_NOINT);
 
 	while (true) {
 		//  ---- Poll FDs, if any is ok then return it
@@ -328,10 +328,10 @@ static uint32_t select_sc(sc_args_t args) {
 
 		uint64_t time = get_kernel_time();
 
-		//  ---- If none of the handles given is a valid handle, return false
-		if (n_wait_objs == 0) break;
 		//  ---- If any is ok, return true
 		if (ret) break;
+		//  ---- If none of the handles given is a valid handle, return false
+		if (n_wait_objs == 0) break;
 		//  ---- If the timeout is over, return false
 		if (timeout >= 0 && time - select_begin_time >= (uint64_t)timeout) break;