Refactor of process management.

The process abstraction has changed to:

  setup(task, process)
  start(task, process_data)
  prefork(task, process, mp)

The prefork() occurs in the main process right before fork.

The file src/nxt_main_process.c is completely free of process
specific logic.

The creation of a process now supports a PROCESS_CREATED state.  The
The setup() function of each process can set its state to either
created or ready.  If created, a MSG_PROCESS_CREATED is sent to main
process, where external setup can be done (required for rootfs under
container).

The core processes (discovery, controller and router) doesn't need
external setup, then they all proceeds to their start() function
straight away.

In the case of applications, the load of the module happens at the
process setup() time and The module's init() function has changed
to be the start() of the process.

The module API has changed to:

  setup(task, process, conf)
  start(task, data)

As a direct benefit of the PROCESS_CREATED message, the clone(2) of
processes using pid namespaces now doesn't need to create a pipe
to make the child block until parent setup uid/gid mappings nor it
needs to receive the child pid.

1 files changed, 7 insertions, 4 deletions

diff --git a/src/perl/nxt_perl_psgi.c b/src/perl/nxt_perl_psgi.c
index 548e6daa..5e9200dc 100644
--- a/src/perl/nxt_perl_psgi.c
+++ b/src/perl/nxt_perl_psgi.c
@@ -95,8 +95,8 @@ static int nxt_perl_psgi_result_array(PerlInterpreter *my_perl,
 static void nxt_perl_psgi_result_cb(PerlInterpreter *my_perl, SV *result,
     nxt_unit_request_info_t *req);
 
-static nxt_int_t nxt_perl_psgi_init(nxt_task_t *task,
-    nxt_common_app_conf_t *conf);
+static nxt_int_t nxt_perl_psgi_start(nxt_task_t *task,
+    nxt_process_data_t *conf);
 static void nxt_perl_psgi_request_handler(nxt_unit_request_info_t *req);
 static void nxt_perl_psgi_atexit(void);
 
@@ -119,7 +119,7 @@ NXT_EXPORT nxt_app_module_t  nxt_app_module = {
     nxt_string("perl"),
     PERL_VERSION_STRING,
     NULL,
-    nxt_perl_psgi_init,
+    nxt_perl_psgi_start,
 };
 
 
@@ -1134,14 +1134,17 @@ nxt_perl_psgi_result_cb(PerlInterpreter *my_perl, SV *result,
 
 
 static nxt_int_t
-nxt_perl_psgi_init(nxt_task_t *task, nxt_common_app_conf_t *conf)
+nxt_perl_psgi_start(nxt_task_t *task, nxt_process_data_t *data)
 {
     int                     rc;
     nxt_unit_ctx_t          *unit_ctx;
     nxt_unit_init_t         perl_init;
     PerlInterpreter         *my_perl;
+    nxt_common_app_conf_t   *conf;
     nxt_perl_psgi_module_t  module;
 
+    conf = data->app;
+
     my_perl = nxt_perl_psgi_interpreter_init(task, conf->u.perl.script,
                                              &module.app);