mono/io-layer/collection.c

   1 /*
   2  * collection.c:  Garbage collection for handles
   3  *
   4  * Author:
   5  *      Dick Porter (dick@ximian.com)
   6  *
   7  * (C) 2004-2006 Novell, Inc.
   8  */
   9
  10 #include <config.h>
  11 #include <glib.h>
  12 #include <pthread.h>
  13 #include <signal.h>
  14 #include <sys/types.h>
  15 #include <unistd.h>
  16
  17 #include <mono/io-layer/wapi.h>
  18 #include <mono/io-layer/collection.h>
  19 #include <mono/io-layer/handles-private.h>
  20
  21 #define LOGDEBUG(...)
  22 // #define LOGDEBUG(...) g_message(__VA_ARGS__)
  23
  24 static pthread_t collection_thread_id;
  25
  26 static gpointer collection_thread (gpointer unused G_GNUC_UNUSED)
  27 {
  28         struct timespec sleepytime;
  29
  30         sleepytime.tv_sec = _WAPI_HANDLE_COLLECTION_UPDATE_INTERVAL;
  31         sleepytime.tv_nsec = 0;
  32
  33         while (_wapi_has_shut_down == FALSE) {
  34                 nanosleep (&sleepytime, NULL);
  35
  36                 //_wapi_handle_dump ();
  37                 _wapi_handle_update_refs ();
  38
  39                 /* This is an abuse of the collection thread, but it's
  40                  * better than creating a new thread just for one more
  41                  * function.
  42                  */
  43                 _wapi_process_reap ();
  44         }
  45
  46         pthread_exit (NULL);
  47
  48         return(NULL);
  49 }
  50
  51 void _wapi_collection_init (void)
  52 {
  53         pthread_attr_t attr;
  54         int ret;
  55         int set_stacksize = 0;
  56
  57  retry:
  58         ret = pthread_attr_init (&attr);
  59         g_assert (ret == 0);
  60
  61 #if defined(HAVE_PTHREAD_ATTR_SETSTACKSIZE)
  62         if (set_stacksize == 0) {
  63                         ret = pthread_attr_setstacksize (&attr, MAX (65536, PTHREAD_STACK_MIN));
  64                         g_assert (ret == 0);
  65         } else if (set_stacksize == 1) {
  66                         ret = pthread_attr_setstacksize (&attr, 131072);
  67                         g_assert (ret == 0);
  68         }
  69 #endif
  70
  71         ret = pthread_create (&collection_thread_id, &attr, collection_thread,
  72                               NULL);
  73         if (ret != 0 && set_stacksize < 2) {
  74                 set_stacksize++;
  75                 goto retry;
  76         }
  77         if (ret != 0) {
  78                 g_error ("%s: Couldn't create handle collection thread: %s",
  79                          __func__, g_strerror (ret));
  80         }
  81 }
  82
  83 void _wapi_handle_collect (void)
  84 {
  85         guint32 count = _wapi_shared_layout->collection_count;
  86         int i, thr_ret;
  87
  88         LOGDEBUG ("%s: (%d) Starting a collection", __func__, _wapi_getpid ());
  89
  90         /* Become the collection master */
  91         thr_ret = _wapi_handle_lock_shared_handles ();
  92         g_assert (thr_ret == 0);
  93
  94         LOGDEBUG ("%s: (%d) Master set", __func__, _wapi_getpid ());
  95
  96         /* If count has changed, someone else jumped in as master */
  97         if (count == _wapi_shared_layout->collection_count) {
  98                 guint32 too_old = (guint32)(time(NULL) & 0xFFFFFFFF) - _WAPI_HANDLE_COLLECTION_EXPIRED_INTERVAL;
  99
 100                 for (i = 0; i < _WAPI_HANDLE_INITIAL_COUNT; i++) {
 101                         struct _WapiHandleShared *data;
 102
 103                         data = &_wapi_shared_layout->handles[i];
 104                         if (data->timestamp < too_old) {
 105                                 LOGDEBUG ("%s: (%d) Deleting handle 0x%x", __func__, _wapi_getpid (), i);
 106                                 memset (&_wapi_shared_layout->handles[i], '\0', sizeof(struct _WapiHandleShared));
 107                         }
 108                 }
 109
 110                 for (i = 0; i < _wapi_fileshare_layout->hwm; i++) {
 111                         struct _WapiFileShare *file_share = &_wapi_fileshare_layout->share_info[i];
 112
 113                         if (file_share->timestamp < too_old) {
 114                                 memset (file_share, '\0',
 115                                         sizeof(struct _WapiFileShare));
 116                         }
 117                 }
 118
 119                 InterlockedIncrement ((gint32 *)&_wapi_shared_layout->collection_count);
 120         }
 121
 122         _wapi_handle_unlock_shared_handles ();
 123
 124         LOGDEBUG ("%s: (%d) Collection done", __func__, _wapi_getpid ());
 125 }