1 files changed, 59 insertions, 20 deletions

diff --git a/sys/kern/kern_spawn.c b/sys/kern/kern_spawn.c
index fcaa194..b9551f3 100644
--- a/sys/kern/kern_spawn.c
+++ b/sys/kern/kern_spawn.c
@@ -28,11 +28,13 @@
  */
 
 #include <sys/spawn.h>
+#include <sys/wait.h>
 #include <sys/proc.h>
 #include <sys/exec.h>
 #include <sys/mman.h>
 #include <sys/systm.h>
 #include <sys/errno.h>
+#include <sys/atomic.h>
 #include <sys/syslog.h>
 #include <sys/syscall.h>
 #include <sys/atomic.h>
@@ -47,7 +49,8 @@
 
 #define ARGVP_MAX (ARG_MAX / sizeof(void *))
 
-static volatile size_t nthreads = 0;
+static size_t next_pid = 1;
+extern volatile size_t g_nthreads;
 
 /*
  * TODO: envp
@@ -94,6 +97,35 @@ spawn_thunk(void)
     __builtin_unreachable();
 }
 
+pid_t
+waitpid(pid_t pid, int *wstatus, int options)
+{
+    struct proc *child, *td;
+    pid_t ret;
+
+    td = this_td();
+    child = get_child(td, pid);
+
+    if (child == NULL) {
+        return -1;
+    }
+
+    /* Wait for it to be done */
+    while (!ISSET(child->flags, PROC_ZOMB)) {
+        sched_yield();
+    }
+
+
+    /* Give back the status */
+    if (wstatus != NULL) {
+        copyout(&child->exit_status, wstatus, sizeof(*wstatus));
+    }
+
+    ret = child->pid;
+    proc_reap(child);
+    return ret;
+}
+
 /*
  * Spawn a new process
  *
@@ -166,28 +198,11 @@ spawn(struct proc *cur, void(*func)(void), void *p, int flags, struct proc **new
     newproc->mlgdr = mlgdr;
     newproc->flags |= PROC_WAITED;
 
-    newproc->pid = ++nthreads;
+    atomic_inc_64(&g_nthreads);
+    newproc->pid = next_pid++;
     signals_init(newproc);
     sched_enqueue_td(newproc);
     pid = newproc->pid;
-
-    if (ISSET(flags, SPAWN_WAIT)) {
-        cur->flags |= PROC_SLEEP;
-
-        while (ISSET(cur->flags, PROC_SLEEP)) {
-            sched_yield();
-        }
-        while (!ISSET(newproc->flags, PROC_ZOMB)) {
-            sched_yield();
-        }
-
-        if (newproc->exit_status < 0) {
-            pid = newproc->exit_status;
-        }
-
-        proc_reap(newproc);
-    }
-
     return pid;
 }
 
@@ -205,6 +220,9 @@ get_child(struct proc *cur, pid_t pid)
     struct proc *procp;
 
     TAILQ_FOREACH(procp, &cur->leafq, leaf_link) {
+        if (procp == NULL) {
+            continue;
+        }
         if (procp->pid == pid) {
             return procp;
         }
@@ -214,6 +232,27 @@ get_child(struct proc *cur, pid_t pid)
 }
 
 /*
+ * arg0: PID
+ * arg1: wstatus
+ * arg2: options
+ *
+ * Returns PID of terminated child, returns
+ * -1 on failure.
+ */
+scret_t
+sys_waitpid(struct syscall_args *scargs)
+{
+    pid_t pid;
+    int *u_wstatus;
+    int options;
+
+    pid = scargs->arg0;
+    u_wstatus = (void *)scargs->arg1;
+    options = scargs->arg2;
+    return waitpid(pid, u_wstatus, options);
+}
+
+/*
  * arg0: The file /path/to/executable
  * arg1: Argv
  * arg2: Envp (TODO)