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 args) G_GNUC_NORETURN;
  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 #ifndef __GNUC__
  49         /* Even though we tell gcc that this function doesn't return,
  50          * other compilers won't see that.
  51          */
  52         return(NULL);
  53 #endif
  54 }
  55
  56 void _wapi_collection_init (void)
  57 {
  58         pthread_attr_t attr;
  59         int ret;
  60
  61         ret = pthread_attr_init (&attr);
  62         g_assert (ret == 0);
  63
  64 #ifdef HAVE_PTHREAD_ATTR_SETSTACKSIZE
  65 #if defined(__FreeBSD__) || defined(__NetBSD__)
  66         ret = pthread_attr_setstacksize (&attr, 65536);
  67 #else
  68         ret = pthread_attr_setstacksize (&attr, PTHREAD_STACK_MIN);
  69 #endif
  70         g_assert (ret == 0);
  71 #endif
  72
  73         ret = pthread_create (&collection_thread_id, &attr, collection_thread,
  74                               NULL);
  75         if (ret != 0) {
  76                 g_error ("%s: Couldn't create handle collection thread: %s",
  77                          __func__, g_strerror (ret));
  78         }
  79 }
  80
  81 void _wapi_handle_collect (void)
  82 {
  83         guint32 count = _wapi_shared_layout->collection_count;
  84         int i, thr_ret;
  85
  86 #ifdef DEBUG
  87         g_message ("%s: (%d) Starting a collection", __func__,
  88                    _wapi_getpid ());
  89 #endif
  90
  91         /* Become the collection master */
  92         thr_ret = _wapi_handle_lock_shared_handles ();
  93         g_assert (thr_ret == 0);
  94
  95 #ifdef DEBUG
  96         g_message ("%s: (%d) Master set", __func__, _wapi_getpid ());
  97 #endif
  98
  99         /* If count has changed, someone else jumped in as master */
 100         if (count == _wapi_shared_layout->collection_count) {
 101                 guint32 too_old = (guint32)(time(NULL) & 0xFFFFFFFF) - _WAPI_HANDLE_COLLECTION_EXPIRED_INTERVAL;
 102
 103                 for (i = 0; i < _WAPI_HANDLE_INITIAL_COUNT; i++) {
 104                         struct _WapiHandleShared *data;
 105
 106                         data = &_wapi_shared_layout->handles[i];
 107                         if (data->timestamp < too_old) {
 108 #ifdef DEBUG
 109                                 g_message ("%s: (%d) Deleting handle 0x%x", __func__, _wapi_getpid (), i);
 110 #endif
 111                                 memset (&_wapi_shared_layout->handles[i], '\0', sizeof(struct _WapiHandleShared));
 112                         }
 113                 }
 114
 115                 for (i = 0; i < _wapi_fileshare_layout->hwm; i++) {
 116                         struct _WapiFileShare *file_share = &_wapi_fileshare_layout->share_info[i];
 117
 118                         if (file_share->timestamp < too_old) {
 119                                 memset (file_share, '\0',
 120                                         sizeof(struct _WapiFileShare));
 121                         }
 122                 }
 123
 124                 InterlockedIncrement ((gint32 *)&_wapi_shared_layout->collection_count);
 125         }
 126
 127         _wapi_handle_unlock_shared_handles ();
 128
 129 #ifdef DEBUG
 130         g_message ("%s: (%d) Collection done", __func__, _wapi_getpid ());
 131 #endif
 132 }