From: Matthias Kruk <m@m10k.eu>
Date: Tue, 29 Oct 2019 05:09:56 +0000 (+0900)
Subject: Add process_exit() function
X-Git-Url: https://git.corax.cc/?a=commitdiff_plain;h=31db72afdf47322b3b813aacfcf69f88f69fa5dc;p=corax

Add process_exit() function
---

diff --git a/kernel/core/process.c b/kernel/core/process.c
index e4fb472..8f70ec9 100644
--- a/kernel/core/process.c
+++ b/kernel/core/process.c
@@ -7,6 +7,13 @@
 #include <debug.h>
 #include <process.h>
 #include "fd.h"
+#include "sched.h"
+
+enum procstate {
+	PROC_STATE_INIT = 0,
+	PROC_STATE_READY,
+	PROC_STATE_EXIT
+};
 
 struct process {
 	struct pagedir *p_pgdir;
@@ -19,6 +26,9 @@ struct process {
 		pid_t        sender;
 	} p_inbox[32];
 
+	enum procstate p_state;
+	int            p_status;
+
 	struct fd      p_fds[16];
 };
 
@@ -30,10 +40,6 @@ struct proc_list {
 static pid_t _next_pid = 100;
 static struct proc_list *_procs;
 
-extern int  sched_enqueue(task_t*);
-extern void sched_wait(pid_t);
-extern int  sched_signal(pid_t);
-
 static inline int NQ(process_t *p)
 {
 	struct proc_list *pl;
@@ -148,6 +154,8 @@ int process_create(process_t **dst, pid_t pid, u32_t ppl, void *entry)
 			goto cleanup;
 		}
 
+		proc->p_state = PROC_STATE_READY;
+
 		if(sched_enqueue(proc->p_tasks) != 0) {
 			PANIC("sched_enqueue() failed for a new task\n");
 		}
@@ -400,3 +408,68 @@ pid_t process_get_id(process_t *proc)
 {
 	return(proc->p_id);
 }
+
+int process_exit(process_t *proc, int status)
+{
+	int ret_val;
+
+	ret_val = -EINVAL;
+
+	if(proc) {
+		if(proc->p_state == PROC_STATE_EXIT) {
+			ret_val = -EALREADY;
+		} else {
+			task_t *cur;
+			task_t *t;
+			int reschedule;
+
+			reschedule = 0;
+
+			cur = task_get_current();
+
+			/* FIXME: Properly deal with the process's remaining tasks */
+
+			for(t = proc->p_tasks; t; t = NULL /* t = t->next */) {
+				t->t_state = TASK_STATE_EXIT;
+
+				/*
+				 * If sched_dequeue() fails, there is a good chance that the
+				 * task pointed to by `t' is currently running (since running
+				 * tasks are neither on the ready queue nor on the wait queue),
+				 * so we have to stop the task.
+				 */
+				if(sched_dequeue(t) < 0) {
+					/*
+					 * However, don't terminate the current task, since we still
+					 * need it - we're not done here, after all.
+					 */
+
+					if(t == cur) {
+						reschedule = 1;
+					} else {
+						/* FIXME: Stop the task */
+					}
+				}
+			}
+
+			ret_val = 0;
+			proc->p_status = status;
+
+			/*
+			 * If this function is called within the context of the
+			 * process, we need to reschedule to make sure we don't
+			 * return to the caller.
+			 */
+			if(reschedule) {
+				/*
+				 * sched_tick() will not put the running task back on the ready
+				 * queue if it is in state TASK_STATE_EXIT, so this is the proper
+				 * way to stop the current task.
+				 */
+				sched_tick();
+			}
+		}
+	}
+
+	return(ret_val);
+}
diff --git a/kernel/include/process.h b/kernel/include/process.h
index ca42c6e..4c3baf3 100644
--- a/kernel/include/process.h
+++ b/kernel/include/process.h
@@ -46,5 +46,6 @@ int           process_signal(pid_t);
 
 void*         process_get_tasks(process_t*);
 pid_t         process_get_id(process_t*);
+int           process_exit(process_t*, int);
 
 #endif /* __PROCESS_H */