Cleaned up the use of thread types

The THREAD type was not used everywhere and pthread_t was used instead.
The thread creation function also returned the address of a stack allocated
value which isn't guaranteed to be usable.

server/core/gateway.c

@@ -1059,13 +1059,13 @@ int main(int argc, char **argv)
     int      daemon_pipe[2] = {-1, -1};
     bool     parent_process;
     int      child_status;
-    void**   threads = NULL;   /*< thread list */
+    THREAD*   threads = NULL;   /*< thread list */
     char     mysql_home[PATH_MAX+1];
     char     datadir_arg[10+PATH_MAX+1];  /*< '--datadir='  + PATH_MAX */
     char     language_arg[11+PATH_MAX+1]; /*< '--language=' + PATH_MAX */
     char*    cnf_file_path = NULL;        /*< conf file, to be freed */
     char*    cnf_file_arg = NULL;         /*< conf filename from cmd-line arg */
-    void*    log_flush_thr = NULL;
+    THREAD    log_flush_thr;
     char*    tmp_path;
     char*    tmp_var;
     int      option_index;
@@ -1940,9 +1940,14 @@ int main(int argc, char **argv)
      * Start periodic log flusher thread.
      */
     log_flush_timeout_ms = 1000;
-    log_flush_thr = thread_start(
+
-        log_flush_cb,
+    if (thread_start(&log_flush_thr, log_flush_cb, (void *) &log_flush_timeout_ms) == NULL)
-        (void *)&log_flush_timeout_ms);
+    {
+        char* logerr = "Failed to start log flushing thread.";
+        print_log_n_stderr(true, !daemon_mode, logerr, logerr, 0);
+        rc = MAXSCALE_INTERNALERROR;
+        goto return_main;
+    }
 
     /*
      * Start the housekeeper thread
@@ -1954,14 +1959,22 @@ int main(int argc, char **argv)
      * configured as the main thread will also poll.
      */
     n_threads = config_threadcount();
-    threads = (void **)calloc(n_threads, sizeof(void *));
+    threads = calloc(n_threads, sizeof(THREAD));
     /*<
      * Start server threads.
      */
     for (thread_id = 0; thread_id < n_threads - 1; thread_id++)
     {
-        threads[thread_id] = thread_start(worker_thread_main, (void *)(thread_id + 1));
+        if (thread_start(&threads[thread_id], worker_thread_main,
+                         (void *)(thread_id + 1)) == NULL)
+        {
+            char* logerr = "Failed to start worker thread.";
+            print_log_n_stderr(true, !daemon_mode, logerr, logerr, 0);
+            rc = MAXSCALE_INTERNALERROR;
+            goto return_main;
         }
+    }
+
     MXS_NOTICE("MaxScale started with %d server threads.", config_threadcount());
     /**
      * Successful start, notify the parent process that it can exit.

server/core/housekeeper.c

@@ -20,6 +20,7 @@
 #include <housekeeper.h>
 #include <thread.h>
 #include <spinlock.h>
+#include <log_manager.h>
 
 /**
  * @file housekeeper.c  Provide a mechanism to run periodic tasks
@@ -54,6 +55,7 @@ static SPINLOCK tasklock = SPINLOCK_INIT;
 
 static int do_shutdown = 0;
 long hkheartbeat = 0; /*< One heartbeat is 100 milliseconds */
+static THREAD hk_thr_handle;
 
 static void hkthread(void *);
 
@@ -63,7 +65,10 @@ static void hkthread(void *);
 void
 hkinit()
 {
-    thread_start(hkthread, NULL);
+    if (thread_start(&hk_thr_handle, hkthread, NULL) == NULL)
+    {
+        MXS_ERROR("Failed to start housekeeper thread.");
+    }
 }
 
 /**

server/core/spinlock.c

@@ -87,7 +87,7 @@ spinlock_acquire(SPINLOCK *lock)
         }
     }
     lock->acquired++;
-    lock->owner = THREAD_SHELF();
+    lock->owner = thread_self();
     atomic_add(&(lock->waiting), -1);
 #endif
 }
@@ -112,7 +112,7 @@ spinlock_acquire_nowait(SPINLOCK *lock)
 #endif
 #if SPINLOCK_PROFILE
     lock->acquired++;
-    lock->owner = THREAD_SHELF();
+    lock->owner = thread_self();
 #endif
     return TRUE;
 }

server/core/test/testspinlock.c

@@ -111,7 +111,7 @@ static int
 test2()
 {
 SPINLOCK	lck;
-void		*handle;
+THREAD		handle;
 struct timespec sleeptime;
 
     sleeptime.tv_sec = 10;
@@ -120,7 +120,7 @@ struct timespec sleeptime;
 	acquire_time = 0;
 	spinlock_init(&lck);
 	spinlock_acquire(&lck);
-	handle = thread_start(test2_helper, (void *)&lck);
+	thread_start(&handle, test2_helper, (void *)&lck);
 	nanosleep(&sleeptime, NULL);
 	spinlock_release(&lck);
 	thread_wait(handle);
@@ -206,7 +206,7 @@ static int
 test3()
 {
 // SPINLOCK	lck;
-void		*handle[THREADS];
+THREAD          handle[THREADS];
 int             i;
 int             tnum[THREADS];
 time_t          rawtime;
@@ -220,7 +220,7 @@ time_t          rawtime;
     for (i = 0; i<THREADS; i++) {
         threadrun[i] = 0;
         tnum[i] = i;
-        handle[i] = thread_start(test3_helper, &tnum[i]);
+        thread_start(&handle[i], test3_helper, &tnum[i]);
     }
     for (i = 0; i<THREADS; i++) {
         fprintf(stderr, "spinlock_test 3 thread %d ran %d times, no wait %d times before waits.\n", i, threadrun[i], nowait[i]);

server/core/thread.c

@@ -16,7 +16,7 @@
  * Copyright MariaDB Corporation Ab 2013-2014
  */
 #include <thread.h>
-#include <pthread.h>
+
 /**
  * @file thread.c  - Implementation of thread related operations
  *
@@ -33,20 +33,18 @@
 /**
  * Start a polling thread
  *
+ * @param thd       Pointer to the THREAD object 
  * @param entry     The entry point to call
  * @param arg       The argument to pass the thread entry point
- * @return      The thread handle
+ * @return          The thread handle or NULL if an error occurred
  */
-void *
+THREAD *thread_start(THREAD *thd, void (*entry)(void *), void *arg)
-thread_start(void (*entry)(void *), void *arg)
 {
-    pthread_t thd;
+    if (pthread_create(thd, NULL, (void *(*)(void *))entry, arg) != 0)
-
-    if (pthread_create(&thd, NULL, (void *(*)(void *))entry, arg) != 0)
     {
         return NULL;
     }
-    return (void *)thd;
+    return thd;
 }
 
 /**
@@ -55,7 +53,7 @@ thread_start(void (*entry)(void *), void *arg)
  * @param thd   The thread handle
  */
 void
-thread_wait(void *thd)
+thread_wait(THREAD thd)
 {
     void *rval;
 
@@ -71,7 +69,6 @@ void
 thread_millisleep(int ms)
 {
     struct timespec req;
-
     req.tv_sec = ms / 1000;
     req.tv_nsec = (ms % 1000) * 1000000;
     nanosleep(&req, NULL);

server/include/thread.h

@@ -17,22 +17,25 @@
  *
  * Copyright MariaDB Corporation Ab 2013-2014
  */
-#include <pthread.h>
 
 /**
  * @file thread.h       The gateway threading interface
  *
  * An encapsulation of the threading used by the gateway. This is designed to
- * isolate the majority of the gateway code from th epthread library, enabling
+ * isolate the majority of the gateway code from the pthread library, enabling
  * the gateway to be ported to a different threading package with the minimum
  * of changes.
  */
 
+/**
+ * Thread type and thread identifier function macros
+ */
+#include <pthread.h>
 #define THREAD         pthread_t
-#define THREAD_SHELF pthread_self
+#define thread_self()  pthread_self()
 
-extern void *thread_start(void (*entry)(void *), void *arg);
+extern THREAD *thread_start(THREAD *thd, void (*entry)(void *), void *arg);
-extern void thread_wait(void *thd);
+extern void thread_wait(THREAD thd);
 extern void thread_millisleep(int ms);
 
 #endif

server/modules/monitor/galeramon.c

@@ -200,7 +200,11 @@ startMonitor(void *arg, void* opt)
         memset(handle->events, true, sizeof(handle->events));
     }
 
-    handle->tid = (THREAD) thread_start(monitorMain, mon);
+    if (thread_start(&handle->thread, monitorMain, mon) == NULL)
+    {
+        MXS_ERROR("Failed to start monitor thread for monitor '%s'.", mon->name);
+    }
+
     return handle;
 }
 
@@ -216,7 +220,7 @@ stopMonitor(void *arg)
     GALERA_MONITOR *handle = (GALERA_MONITOR *) mon->handle;
 
     handle->shutdown = 1;
-    thread_wait((void *) handle->tid);
+    thread_wait(handle->thread);
 }
 
 /**

server/modules/monitor/galeramon.h

@@ -51,7 +51,7 @@
 typedef struct
 {
     SPINLOCK lock; /**< The monitor spinlock */
-    pthread_t tid; /**< id of monitor thread */
+    THREAD thread; /**< Monitor thread */
     int shutdown; /**< Flag to shutdown the monitor thread */
     int status; /**< Monitor status */
     unsigned long id; /**< Monitor ID */

server/modules/monitor/mmmon.c

@@ -173,7 +173,12 @@ startMonitor(void *arg, void* opt)
     {
         memset(handle->events, true, sizeof(handle->events));
     }
-    handle->tid = (THREAD) thread_start(monitorMain, mon);
+
+    if (thread_start(handle->thread, monitorMain, mon) == NULL)
+    {
+        MXS_ERROR("Failed to start monitor thread for monitor '%s'.", mon->name);
+    }
+
     return handle;
 }
 
@@ -189,7 +194,7 @@ stopMonitor(void *arg)
     MM_MONITOR *handle = (MM_MONITOR *) mon->handle;
 
     handle->shutdown = 1;
-    thread_wait((void *) handle->tid);
+    thread_wait((void *) handle->thread);
 }
 
 /**

server/modules/monitor/mmmon.h

@@ -44,7 +44,7 @@
 typedef struct
 {
     SPINLOCK lock; /**< The monitor spinlock */
-    pthread_t tid; /**< id of monitor thread */
+    THREAD thread; /**< Monitor thread */
     int shutdown; /**< Flag to shutdown the monitor thread */
     int status; /**< Monitor status */
     unsigned long id; /**< Monitor ID */

server/modules/monitor/mysql_mon.c

@@ -205,7 +205,11 @@ startMonitor(void *arg, void* opt)
         memset(handle->events, true, sizeof(handle->events));
     }
 
-    handle->tid = (THREAD) thread_start(monitorMain, monitor);
+    if (thread_start(&handle->thread, monitorMain, monitor) == NULL)
+    {
+        MXS_ERROR("Failed to start monitor thread for monitor '%s'.", monitor->name);
+    }
+
     return handle;
 }
 
@@ -221,7 +225,7 @@ stopMonitor(void *arg)
     MYSQL_MONITOR *handle = (MYSQL_MONITOR *) mon->handle;
 
     handle->shutdown = 1;
-    thread_wait((void *) handle->tid);
+    thread_wait(handle->thread);
 }
 
 /**

server/modules/monitor/mysqlmon.h

@@ -60,7 +60,7 @@
 typedef struct
 {
     SPINLOCK lock; /**< The monitor spinlock */
-    pthread_t tid; /**< id of monitor thread */
+    THREAD thread; /**< Monitor thread */
     int shutdown; /**< Flag to shutdown the monitor thread */
     int status; /**< Monitor status */
     unsigned long id; /**< Monitor ID */

server/modules/monitor/ndbclustermon.c

@@ -164,7 +164,12 @@ startMonitor(void *arg, void* opt)
     {
         memset(handle->events, true, sizeof(handle->events));
     }
-    handle->tid = (THREAD) thread_start(monitorMain, mon);
+
+    if (thread_start(&handle->thread, monitorMain, mon) == NULL)
+    {
+        MXS_ERROR("Failed to start monitor thread for monitor '%s'.", mon->name);
+    }
+
     return handle;
 }
 
@@ -180,7 +185,7 @@ stopMonitor(void *arg)
     MYSQL_MONITOR *handle = (MYSQL_MONITOR *) mon->handle;
 
     handle->shutdown = 1;
-    thread_wait((void *) handle->tid);
+    thread_wait(handle->thread);
 }
 
 /**