From a27bec5e8874e018a52d66e874e798b515b09773 Mon Sep 17 00:00:00 2001
From: Johan Wikman <johan.wikman@mariadb.com>
Date: Fri, 21 Apr 2017 19:57:45 +0300
Subject: [PATCH] Add return value to Worker::init()

Cleaner to return status than exit upon failure.
---
 server/core/gateway.cc         | 29 ++++------------
 server/core/maxscale/worker.hh |  4 ++-
 server/core/worker.cc          | 61 ++++++++++++++++++++++------------
 3 files changed, 50 insertions(+), 44 deletions(-)

diff --git a/server/core/gateway.cc b/server/core/gateway.cc
index 4989acc47..9d53c128c 100644
--- a/server/core/gateway.cc
+++ b/server/core/gateway.cc
@@ -12,27 +12,7 @@
  */
 
 /**
- * @file gateway.c - The gateway entry point.
- *
- * @verbatim
- * Revision History
- *
- * Date         Who                     Description
- * 23-05-2013   Massimiliano Pinto      epoll loop test
- * 12-06-2013   Mark Riddoch            Add the -p option to set the
- *                                      listening port
- *                                      and bind addr is 0.0.0.0
- * 19/06/13     Mark Riddoch            Extract the epoll functionality
- * 21/06/13     Mark Riddoch            Added initial config support
- * 27/06/13
- * 28/06/13     Vilho Raatikka          Added necessary headers, example functions and
- *                                      calls to log manager and to query classifier.
- *                                      Put example code behind SS_DEBUG macros.
- * 05/02/14     Mark Riddoch            Addition of version string
- * 29/06/14     Massimiliano Pinto      Addition of pidfile
- * 10/08/15     Markus Makela           Added configurable directory locations
- * 19/01/16     Markus Makela           Set cwd to log directory
- * @endverbatim
+ * @file gateway.c - The entry point of MaxScale
  */
 
 #include <maxscale/cdefs.h>
@@ -1910,7 +1890,12 @@ int main(int argc, char **argv)
         goto return_main;
     }
 
-    Worker::init();
+    if (!Worker::init())
+    {
+        MXS_ERROR("Failed to initialize workers.");
+        rc = MAXSCALE_INTERNALERROR;
+        goto return_main;
+    }
 
     /* Init MaxScale modules */
     if (!modules_process_init())
diff --git a/server/core/maxscale/worker.hh b/server/core/maxscale/worker.hh
index 48b19a486..8d93b99fb 100644
--- a/server/core/maxscale/worker.hh
+++ b/server/core/maxscale/worker.hh
@@ -75,8 +75,10 @@ public:
      *
      * To be called once at process startup. This will cause as many workers
      * to be created as the number of threads defined.
+     *
+     * @return True if the initialization succeeded, false otherwise.
      */
-    static void init();
+    static bool init();
 
     /**
      * Finalize the worker mechanism.
diff --git a/server/core/worker.cc b/server/core/worker.cc
index 52ac58e84..54e46a9f6 100644
--- a/server/core/worker.cc
+++ b/server/core/worker.cc
@@ -39,6 +39,7 @@ namespace
  */
 static struct this_unit
 {
+    bool     initialized;       // Whether the initialization has been performed.
     int      n_workers;         // How many workers there are.
     Worker** ppWorkers;         // Array of worker instances.
     int      number_poll_spins; // Maximum non-block polls
@@ -46,8 +47,11 @@ static struct this_unit
 
 } this_unit =
 {
+    false,
     0,
-    NULL
+    NULL,
+    0,
+    0
 };
 
 static thread_local struct this_thread
@@ -154,47 +158,62 @@ Worker::~Worker()
 }
 
 // static
-void Worker::init()
+bool Worker::init()
 {
+    ss_dassert(!this_unit.initialized);
+
     this_unit.n_workers = config_threadcount();
     this_unit.number_poll_spins = config_nbpolls();
     this_unit.max_poll_sleep = config_pollsleep();
-
     this_unit.ppWorkers = new (std::nothrow) Worker* [this_unit.n_workers] (); // Zero initialized array
 
-    if (!this_unit.ppWorkers)
+    if (this_unit.ppWorkers)
     {
-        // If we cannot allocate the array, we just exit.
-        exit(-1);
-    }
-
-    for (int i = 0; i < this_unit.n_workers; ++i)
-    {
-        Worker* pWorker = Worker::create(i);
-
-        if (pWorker)
+        for (int i = 0; i < this_unit.n_workers; ++i)
         {
-            this_unit.ppWorkers[i] = pWorker;
-        }
-        else
-        {
-            // If a worker cannot be created, we just exit. No way we can continue.
-            exit(-1);
+            Worker* pWorker = Worker::create(i);
+
+            if (pWorker)
+            {
+                this_unit.ppWorkers[i] = pWorker;
+            }
+            else
+            {
+                for (int j = i - 1; j >= 0; --j)
+                {
+                    delete this_unit.ppWorkers[j];
+                }
+
+                delete this_unit.ppWorkers;
+                this_unit.ppWorkers = NULL;
+                break;
+            }
+
+            if (this_unit.ppWorkers)
+            {
+                this_unit.initialized = true;
+            }
         }
     }
 
-    MXS_NOTICE("Workers created!");
+    return this_unit.initialized;
 }
 
 void Worker::finish()
 {
-    for (int i = 0; i < this_unit.n_workers; ++i)
+    ss_dassert(this_unit.initialized);
+
+    for (int i = this_unit.n_workers - 1; i >= 0; --i)
     {
         Worker* pWorker = this_unit.ppWorkers[i];
 
         delete pWorker;
         this_unit.ppWorkers[i] = NULL;
     }
+
+    delete [] this_unit.ppWorkers;
+    this_unit.ppWorkers = NULL;
+    this_unit.initialized = false;
 }
 
 namespace