PERL_SYS_TERM() should be called once on exit only, this fixes the message

panic: MUTEX_LOCK (22) [op.c:352].
BEGIN failed--compilation aborted.
... [alert] ... perl_parse() failed: 9
Scalars leaked: 2

on threaded perl during second reconfiguration.

PERL_SYS_INIT() should be called once too.

src/http/modules/perl/ngx_http_perl_module.c

diff --git a/src/http/modules/perl/ngx_http_perl_module.c b/src/http/modules/perl/ngx_http_perl_module.c
index b11320d..b8352f0 100644
--- a/src/http/modules/perl/ngx_http_perl_module.c
+++ b/src/http/modules/perl/ngx_http_perl_module.c
@@ -67,6 +67,8 @@
 static void ngx_http_perl_cleanup_perl(void *data);
 #endif
 
+static void ngx_http_perl_exit(ngx_cycle_t *cycle);
+
 
 static ngx_command_t  ngx_http_perl_commands[] = {
 
@@ -128,7 +130,7 @@
     NULL,                                  /* init thread */
     NULL,                                  /* exit thread */
     NULL,                                  /* exit process */
-    NULL,                                  /* exit master */
+    ngx_http_perl_exit,                    /* exit master */
     NGX_MODULE_V1_PADDING
 };
 
@@ -478,12 +480,13 @@
 
 #endif
 
-    PERL_SYS_INIT(&ngx_argc, &ngx_argv);
+    if (nginx_stash == NULL) {
+        PERL_SYS_INIT(&ngx_argc, &ngx_argv);
+    }
 
     pmcf->perl = ngx_http_perl_create_interpreter(cf, pmcf);
 
     if (pmcf->perl == NULL) {
-        PERL_SYS_TERM();
         return NGX_CONF_ERROR;
     }
 
@@ -788,8 +791,6 @@
     (void) perl_destruct(perl);
 
     perl_free(perl);
-
-    PERL_SYS_TERM();
 }
 
 #endif
@@ -1001,3 +1002,10 @@
 
     return NGX_CONF_OK;
 }
+
+
+static void
+ngx_http_perl_exit(ngx_cycle_t *cycle)
+{
+    PERL_SYS_TERM();
+}