module/spl/spl-thread.c

   1 /*****************************************************************************\
   2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
   3  *  Copyright (C) 2007 The Regents of the University of California.
   4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
   5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
   6  *  UCRL-CODE-235197
   7  *
   8  *  This file is part of the SPL, Solaris Porting Layer.
   9  *  For details, see <http://github.com/behlendorf/spl/>.
  10  *
  11  *  The SPL is free software; you can redistribute it and/or modify it
  12  *  under the terms of the GNU General Public License as published by the
  13  *  Free Software Foundation; either version 2 of the License, or (at your
  14  *  option) any later version.
  15  *
  16  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  17  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19  *  for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License along
  22  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  23  *****************************************************************************
  24  *  Solaris Porting Layer (SPL) Thread Implementation.
  25 \*****************************************************************************/
  26
  27 #include <sys/thread.h>
  28 #include <sys/kmem.h>
  29
  30 #ifdef DEBUG_SUBSYSTEM
  31 #undef DEBUG_SUBSYSTEM
  32 #endif
  33
  34 #define DEBUG_SUBSYSTEM S_THREAD
  35
  36 /*
  37  * Thread interfaces
  38  */
  39 typedef struct thread_priv_s {
  40         unsigned long tp_magic;         /* Magic */
  41         int tp_name_size;               /* Name size */
  42         char *tp_name;                  /* Name (without _thread suffix) */
  43         void (*tp_func)(void *);        /* Registered function */
  44         void *tp_args;                  /* Args to be passed to function */
  45         size_t tp_len;                  /* Len to be passed to function */
  46         int tp_state;                   /* State to start thread at */
  47         pri_t tp_pri;                   /* Priority to start threat at */
  48 } thread_priv_t;
  49
  50 static int
  51 thread_generic_wrapper(void *arg)
  52 {
  53         thread_priv_t *tp = (thread_priv_t *)arg;
  54         void (*func)(void *);
  55         void *args;
  56
  57         ASSERT(tp->tp_magic == TP_MAGIC);
  58         func = tp->tp_func;
  59         args = tp->tp_args;
  60         set_current_state(tp->tp_state);
  61         set_user_nice((kthread_t *)get_current(), PRIO_TO_NICE(tp->tp_pri));
  62         kmem_free(tp->tp_name, tp->tp_name_size);
  63         kmem_free(tp, sizeof(thread_priv_t));
  64
  65         if (func)
  66                 func(args);
  67
  68         return 0;
  69 }
  70
  71 void
  72 __thread_exit(void)
  73 {
  74         ENTRY;
  75         EXIT;
  76         complete_and_exit(NULL, 0);
  77         /* Unreachable */
  78 }
  79 EXPORT_SYMBOL(__thread_exit);
  80
  81 /* thread_create() may block forever if it cannot create a thread or
  82  * allocate memory.  This is preferable to returning a NULL which Solaris
  83  * style callers likely never check for... since it can't fail. */
  84 kthread_t *
  85 __thread_create(caddr_t stk, size_t  stksize, thread_func_t func,
  86                 const char *name, void *args, size_t len, proc_t *pp,
  87                 int state, pri_t pri)
  88 {
  89         thread_priv_t *tp;
  90         struct task_struct *tsk;
  91         char *p;
  92         ENTRY;
  93
  94         /* Option pp is simply ignored */
  95         /* Variable stack size unsupported */
  96         ASSERT(stk == NULL);
  97
  98         tp = kmem_alloc(sizeof(thread_priv_t), KM_SLEEP);
  99         if (tp == NULL)
 100                 RETURN(NULL);
 101
 102         tp->tp_magic = TP_MAGIC;
 103         tp->tp_name_size = strlen(name) + 1;
 104
 105         tp->tp_name = kmem_alloc(tp->tp_name_size, KM_SLEEP);
 106         if (tp->tp_name == NULL) {
 107                 kmem_free(tp, sizeof(thread_priv_t));
 108                 RETURN(NULL);
 109         }
 110
 111         strncpy(tp->tp_name, name, tp->tp_name_size);
 112
 113         /* Strip trailing "_thread" from passed name which will be the func
 114          * name since the exposed API has no parameter for passing a name.
 115          */
 116         p = strstr(tp->tp_name, "_thread");
 117         if (p)
 118                 p[0] = '\0';
 119
 120         tp->tp_func  = func;
 121         tp->tp_args  = args;
 122         tp->tp_len   = len;
 123         tp->tp_state = state;
 124         tp->tp_pri   = pri;
 125
 126         tsk = kthread_create(thread_generic_wrapper, (void *)tp, tp->tp_name);
 127         if (IS_ERR(tsk)) {
 128                 CERROR("Failed to create thread: %ld\n", PTR_ERR(tsk));
 129                 RETURN(NULL);
 130         }
 131
 132         wake_up_process(tsk);
 133         RETURN((kthread_t *)tsk);
 134 }
 135 EXPORT_SYMBOL(__thread_create);