From 900828cc4b92e95b4810c00df9759ab9a07429c7 Mon Sep 17 00:00:00 2001
From: Max Romanov <max.romanov@gmail.com>
Date: Thu, 17 Feb 2022 12:33:46 +0000
Subject: Fixing isolated process PID manipulation.

Registering an isolated PID in the global PID hash is wrong
because it can be duplicated.  Isolated processes are stored only
in the children list until the response for the WHOAMI message is
processed and the global PID is discovered.

To remove isolated siblings, a pointer to the children list is
introduced in the nxt_process_init_t struct.

This closes #633 issue on GitHub.
---
 src/nxt_application.c | 75 ++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 59 insertions(+), 16 deletions(-)

(limited to 'src/nxt_application.c')

diff --git a/src/nxt_application.c b/src/nxt_application.c
index 594574b1..556f1ffb 100644
--- a/src/nxt_application.c
+++ b/src/nxt_application.c
@@ -23,6 +23,13 @@
 #endif
 
 
+#ifdef WCOREDUMP
+#define NXT_WCOREDUMP(s) WCOREDUMP(s)
+#else
+#define NXT_WCOREDUMP(s) 0
+#endif
+
+
 typedef struct {
     nxt_app_type_t  type;
     nxt_str_t       version;
@@ -636,6 +643,8 @@ nxt_proto_start_process_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg)
     process->data.app = nxt_app_conf;
     process->stream = msg->port_msg.stream;
 
+    init->siblings = &nxt_proto_children;
+
     ret = nxt_process_start(task, process);
     if (nxt_slow_path(ret == NXT_ERROR)) {
         nxt_process_use(task, process, -1);
@@ -711,15 +720,19 @@ nxt_proto_process_created_handler(nxt_task_t *task, nxt_port_recv_msg_t *msg)
         nxt_debug(task, "app process %PI (aka %PI) is created", isolated_pid,
                   pid);
 
-        nxt_runtime_process_remove(task->thread->runtime, process);
-
         process->pid = pid;
 
-        nxt_runtime_process_add(task, process);
-
     } else {
         nxt_debug(task, "app process %PI is created", isolated_pid);
     }
+
+    if (!process->registered) {
+        nxt_assert(!nxt_queue_is_empty(&process->ports));
+
+        nxt_runtime_process_add(task, process);
+
+        nxt_port_use(task, nxt_process_port_first(process), -1);
+    }
 }
 
 
@@ -753,7 +766,11 @@ nxt_proto_sigchld_handler(nxt_task_t *task, void *obj, void *data)
     int            status;
     nxt_err_t      err;
     nxt_pid_t      pid;
+    nxt_port_t     *port;
     nxt_process_t  *process;
+    nxt_runtime_t  *rt;
+
+    rt = task->thread->runtime;
 
     nxt_debug(task, "proto sigchld handler signo:%d (%s)",
               (int) (uintptr_t) obj, data);
@@ -783,32 +800,58 @@ nxt_proto_sigchld_handler(nxt_task_t *task, void *obj, void *data)
             return;
         }
 
+        process = nxt_proto_process_remove(task, pid);
+
         if (WTERMSIG(status)) {
-#ifdef WCOREDUMP
-            nxt_alert(task, "app process (isolated %PI) exited on signal %d%s",
-                      pid, WTERMSIG(status),
-                      WCOREDUMP(status) ? " (core dumped)" : "");
-#else
-            nxt_alert(task, "app process (isolated %PI) exited on signal %d",
-                      pid, WTERMSIG(status));
-#endif
+            if (rt->is_pid_isolated) {
+                nxt_alert(task, "app process %PI (isolated %PI) "
+                                "exited on signal %d%s",
+                          process != NULL ? process->pid : 0,
+                          pid, WTERMSIG(status),
+                          NXT_WCOREDUMP(status) ? " (core dumped)" : "");
+
+            } else {
+                nxt_alert(task, "app process %PI exited on signal %d%s",
+                          pid, WTERMSIG(status),
+                          NXT_WCOREDUMP(status) ? " (core dumped)" : "");
+            }
 
         } else {
-            nxt_trace(task, "app process (isolated %PI) exited with code %d",
-                      pid, WEXITSTATUS(status));
+            if (rt->is_pid_isolated) {
+                nxt_trace(task, "app process %PI (isolated %PI) "
+                                "exited with code %d",
+                          process != NULL ? process->pid : 0,
+                          pid, WEXITSTATUS(status));
+
+            } else {
+                nxt_trace(task, "app process %PI exited with code %d",
+                          pid, WEXITSTATUS(status));
+            }
         }
 
-        process = nxt_proto_process_remove(task, pid);
         if (process == NULL) {
             continue;
         }
 
+        if (process->registered) {
+            port = NULL;
+
+        } else {
+            nxt_assert(!nxt_queue_is_empty(&process->ports));
+
+            port = nxt_process_port_first(process);
+        }
+
         if (process->state != NXT_PROCESS_STATE_CREATING) {
             nxt_port_remove_notify_others(task, process);
         }
 
         nxt_process_close_ports(task, process);
 
+        if (port != NULL) {
+            nxt_port_use(task, port, -1);
+        }
+
         if (nxt_proto_exiting && nxt_queue_is_empty(&nxt_proto_children)) {
             nxt_process_quit(task, 0);
             return;
@@ -1122,7 +1165,7 @@ nxt_proto_process_add(nxt_task_t *task, nxt_process_t *process)
         break;
 
     default:
-        nxt_debug(task, "process (isolated %PI) failed to add",
+        nxt_alert(task, "process (isolated %PI) failed to add",
                   process->isolated_pid);
         break;
     }
-- 
cgit