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 #undef DEBUG
  22
  23 static pthread_t collection_thread_id;
  24
  25 static gpointer collection_thread (gpointer unused G_GNUC_UNUSED)
  26 {
  27         struct timespec sleepytime;
  28
  29         sleepytime.tv_sec = _WAPI_HANDLE_COLLECTION_UPDATE_INTERVAL;
  30         sleepytime.tv_nsec = 0;
  31
  32         while (_wapi_has_shut_down == FALSE) {
  33                 nanosleep (&sleepytime, NULL);
  34
  35                 //_wapi_handle_dump ();
  36                 _wapi_handle_update_refs ();
  37
  38                 /* This is an abuse of the collection thread, but it's
  39                  * better than creating a new thread just for one more
  40                  * function.
  41                  */
  42                 _wapi_process_reap ();
  43         }
  44
  45         pthread_exit (NULL);
  46
  47         return(NULL);
  48 }
  49
  50 void _wapi_collection_init (void)
  51 {
  52         pthread_attr_t attr;
  53         int ret;
  54
  55         ret = pthread_attr_init (&attr);
  56         g_assert (ret == 0);
  57
  58 #ifdef HAVE_PTHREAD_ATTR_SETSTACKSIZE
  59 #if defined(__FreeBSD__) || defined(__NetBSD__)
  60         ret = pthread_attr_setstacksize (&attr, 65536);
  61 #else
  62         ret = pthread_attr_setstacksize (&attr, PTHREAD_STACK_MIN);
  63 #endif
  64         g_assert (ret == 0);
  65 #endif
  66
  67         ret = pthread_create (&collection_thread_id, &attr, collection_thread,
  68                               NULL);
  69         if (ret != 0) {
  70                 g_error ("%s: Couldn't create handle collection thread: %s",
  71                          __func__, g_strerror (ret));
  72         }
  73 }
  74
  75 void _wapi_handle_collect (void)
  76 {
  77         guint32 count = _wapi_shared_layout->collection_count;
  78         int i, thr_ret;
  79
  80 #ifdef DEBUG
  81         g_message ("%s: (%d) Starting a collection", __func__,
  82                    _wapi_getpid ());
  83 #endif
  84
  85         /* Become the collection master */
  86         thr_ret = _wapi_handle_lock_shared_handles ();
  87         g_assert (thr_ret == 0);
  88
  89 #ifdef DEBUG
  90         g_message ("%s: (%d) Master set", __func__, _wapi_getpid ());
  91 #endif
  92
  93         /* If count has changed, someone else jumped in as master */
  94         if (count == _wapi_shared_layout->collection_count) {
  95                 guint32 too_old = (guint32)(time(NULL) & 0xFFFFFFFF) - _WAPI_HANDLE_COLLECTION_EXPIRED_INTERVAL;
  96
  97                 for (i = 0; i < _WAPI_HANDLE_INITIAL_COUNT; i++) {
  98                         struct _WapiHandleShared *data;
  99
 100                         data = &_wapi_shared_layout->handles[i];
 101                         if (data->timestamp < too_old) {
 102 #ifdef DEBUG
 103                                 g_message ("%s: (%d) Deleting handle 0x%x", __func__, _wapi_getpid (), i);
 104 #endif
 105                                 memset (&_wapi_shared_layout->handles[i], '\0', sizeof(struct _WapiHandleShared));
 106                         }
 107                 }
 108
 109                 for (i = 0; i < _wapi_fileshare_layout->hwm; i++) {
 110                         struct _WapiFileShare *file_share = &_wapi_fileshare_layout->share_info[i];
 111
 112                         if (file_share->timestamp < too_old) {
 113                                 memset (file_share, '\0',
 114                                         sizeof(struct _WapiFileShare));
 115                         }
 116                 }
 117
 118                 InterlockedIncrement ((gint32 *)&_wapi_shared_layout->collection_count);
 119         }
 120
 121         _wapi_handle_unlock_shared_handles ();
 122
 123 #ifdef DEBUG
 124         g_message ("%s: (%d) Collection done", __func__, _wapi_getpid ());
 125 #endif
 126 }