From 78bbb9b58d7e7b0816f11fe1d4c97ad5a37df01e Mon Sep 17 00:00:00 2001
From: Oran Agra <oran@redislabs.com>
Date: Sun, 25 Aug 2019 10:11:48 +0300
Subject: [PATCH] Modlue fork is killed when the parent exists

---
 src/module.c | 26 +++++++++++++++-----------
 src/server.c |  6 ++++++
 src/server.h |  1 +
 3 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/src/module.c b/src/module.c
index 03cc3670..6f3be61a 100644
--- a/src/module.c
+++ b/src/module.c
@@ -5086,20 +5086,11 @@ int RM_ExitFromChild(int retcode)
     return REDISMODULE_OK;
 }
 
-/* Can be used to kill the forked child process from the parent process.
- * child_pid whould be the return value of RedisModule_Fork. */
-int RM_KillForkChild(int child_pid)
-{
+void TerminateModuleForkChild(int wait) {
     int statloc;
-    /* No module child? return. */
-    if (server.module_child_pid == -1) return REDISMODULE_ERR;
-    /* Make sure the module knows the pid it wants to kill (not trying to
-     * randomly kill other module's forks) */
-    if (server.module_child_pid != child_pid) return REDISMODULE_ERR;
-    /* Kill module child, wait for child exit. */
     serverLog(LL_NOTICE,"Killing running module fork child: %ld",
         (long) server.module_child_pid);
-    if (kill(server.module_child_pid,SIGUSR1) != -1) {
+    if (kill(server.module_child_pid,SIGUSR1) != -1 && wait) {
         while(wait3(&statloc,0,NULL) != server.module_child_pid);
     }
     /* Reset the buffer accumulating changes while the child saves. */
@@ -5108,6 +5099,19 @@ int RM_KillForkChild(int child_pid)
     moduleForkInfo.done_handler_user_data = NULL;
     closeChildInfoPipe();
     updateDictResizePolicy();
+}
+
+/* Can be used to kill the forked child process from the parent process.
+ * child_pid whould be the return value of RedisModule_Fork. */
+int RM_KillForkChild(int child_pid)
+{
+    /* No module child? return. */
+    if (server.module_child_pid == -1) return REDISMODULE_ERR;
+    /* Make sure the module knows the pid it wants to kill (not trying to
+     * randomly kill other module's forks) */
+    if (server.module_child_pid != child_pid) return REDISMODULE_ERR;
+    /* Kill module child, wait for child exit. */
+    TerminateModuleForkChild(1);
     return REDISMODULE_OK;
 }
 
diff --git a/src/server.c b/src/server.c
index 675b638d..31418e01 100644
--- a/src/server.c
+++ b/src/server.c
@@ -3551,6 +3551,12 @@ int prepareForShutdown(int flags) {
         killRDBChild();
     }
 
+    /* Kill module child if there is one. */
+    if (server.module_child_pid != -1) {
+        serverLog(LL_WARNING,"There is a module fork child. Killing it!");
+        TerminateModuleForkChild(0);
+    }
+
     if (server.aof_state != AOF_OFF) {
         /* Kill the AOF saving child as the AOF we already have may be longer
          * but contains the full dataset anyway. */
diff --git a/src/server.h b/src/server.h
index deaaf263..7aa4bc2b 100644
--- a/src/server.h
+++ b/src/server.h
@@ -1532,6 +1532,7 @@ void moduleReleaseGIL(void);
 void moduleNotifyKeyspaceEvent(int type, const char *event, robj *key, int dbid);
 void moduleCallCommandFilters(client *c);
 void ModuleForkDoneHandler(int exitcode, int bysignal);
+void TerminateModuleForkChild(int wait);
 
 /* Utils */
 long long ustime(void);