From 6cfe0ddd014597113e0635fcdecba9db0cc2c64b Mon Sep 17 00:00:00 2001
From: sotech117 <michael_foiani@brown.edu>
Date: Sun, 11 Feb 2024 07:36:50 +0000
Subject: basic implementation of most functions. not tested, but generally
 well thought out

---
 kernel/proc/proc.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 56 insertions(+), 3 deletions(-)

(limited to 'kernel/proc/proc.c')

diff --git a/kernel/proc/proc.c b/kernel/proc/proc.c
index 6155b58..fd253f6 100644
--- a/kernel/proc/proc.c
+++ b/kernel/proc/proc.c
@@ -340,7 +340,7 @@ void proc_kill_all()
         }
     }
 
-    // kill the current proc
+    // kill this proc
     do_exit(0);
 }
 
@@ -416,7 +416,58 @@ void proc_destroy(proc_t *proc)
  */
 pid_t do_waitpid(pid_t pid, int *status, int options)
 {
-    NOT_YET_IMPLEMENTED("PROCS: do_waitpid");
+    // NOT_YET_IMPLEMENTED("PROCS: do_waitpid");
+
+    if (pid == 0 || options != 0 || pid < -1)
+    {
+        return -ENOTSUP;
+    }
+
+    if (pid > 0)
+    {
+        proc_t *child = proc_lookup(pid);
+        if (child == NULL || child->p_pproc != curproc)
+        {
+            return -ECHILD;
+        }
+
+        // sleep until this specific child process exits
+        while (child->p_state != PROC_DEAD)
+        {
+            sched_sleep_on(&curproc->p_wait);
+        }
+
+        if (status != NULL)
+        {
+            *status = child->p_status;
+        }
+        proc_destroy(child);
+
+        return pid;
+    }
+    else if (pid == -1)
+    {
+        if (list_empty(&curproc->p_children))
+        {
+            return -ECHILD;
+        }
+
+        proc_t *child;
+        list_iterate(&curproc->p_children, child, proc_t, p_child_link)
+        {
+            if (child->p_state == PROC_DEAD)
+            {
+                if (status != NULL)
+                {
+                    *status = child->p_status;
+                }
+
+                proc_destroy(child);
+                return child->p_pid;
+            }
+        }
+    }
+
     return 0;
 }
 
@@ -425,7 +476,9 @@ pid_t do_waitpid(pid_t pid, int *status, int options)
  */
 void do_exit(long status)
 {
-    NOT_YET_IMPLEMENTED("PROCS: do_exit");
+    // NOT_YET_IMPLEMENTED("PROCS: do_exit");
+
+    kthread_exit((void *)status);
 }
 
 /*==========
-- 
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