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 #include <mono/utils/atomic.h>
  21
  22 #if 0
  23 // #define DEBUG(...) g_message(__VA_ARGS__)
  24 #else
  25 #define DEBUG(...)
  26 #endif
  27
  28 static pthread_t collection_thread_id;
  29
  30 static gpointer collection_thread (gpointer unused G_GNUC_UNUSED)
  31 {
  32         struct timespec sleepytime;
  33
  34         sleepytime.tv_sec = _WAPI_HANDLE_COLLECTION_UPDATE_INTERVAL;
  35         sleepytime.tv_nsec = 0;
  36
  37         while (_wapi_has_shut_down == FALSE) {
  38                 nanosleep (&sleepytime, NULL);
  39
  40                 //_wapi_handle_dump ();
  41                 _wapi_handle_update_refs ();
  42         }
  43
  44         pthread_exit (NULL);
  45
  46         return(NULL);
  47 }
  48
  49 void _wapi_collection_init (void)
  50 {
  51         pthread_attr_t attr;
  52         int ret;
  53         int set_stacksize = 0;
  54
  55  retry:
  56         ret = pthread_attr_init (&attr);
  57         g_assert (ret == 0);
  58
  59 #if defined(HAVE_PTHREAD_ATTR_SETSTACKSIZE)
  60         if (set_stacksize == 0) {
  61                         ret = pthread_attr_setstacksize (&attr, MAX (65536, PTHREAD_STACK_MIN));
  62                         g_assert (ret == 0);
  63         } else if (set_stacksize == 1) {
  64                         ret = pthread_attr_setstacksize (&attr, 131072);
  65                         g_assert (ret == 0);
  66         }
  67 #endif
  68
  69         ret = pthread_create (&collection_thread_id, &attr, collection_thread,
  70                               NULL);
  71         if (ret != 0 && set_stacksize < 2) {
  72                 set_stacksize++;
  73                 goto retry;
  74         }
  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         if (!_wapi_shm_enabled ())
  87                 return;
  88
  89         DEBUG ("%s: (%d) Starting a collection", __func__, _wapi_getpid ());
  90
  91         /* Become the collection master */
  92         thr_ret = _wapi_handle_lock_shared_handles ();
  93         g_assert (thr_ret == 0);
  94
  95         thr_ret = _wapi_shm_sem_lock (_WAPI_SHARED_SEM_FILESHARE);
  96         g_assert (thr_ret == 0);
  97
  98         DEBUG ("%s: (%d) Master set", __func__, _wapi_getpid ());
  99
 100         /* If count has changed, someone else jumped in as master */
 101         if (count == _wapi_shared_layout->collection_count) {
 102                 guint32 too_old = (guint32)(time(NULL) & 0xFFFFFFFF) - _WAPI_HANDLE_COLLECTION_EXPIRED_INTERVAL;
 103
 104                 for (i = 0; i < _WAPI_HANDLE_INITIAL_COUNT; i++) {
 105                         struct _WapiHandleShared *data;
 106
 107                         data = &_wapi_shared_layout->handles[i];
 108                         if (data->timestamp < too_old) {
 109                                 DEBUG ("%s: (%d) Deleting handle 0x%x", __func__, _wapi_getpid (), i);
 110                                 memset (&_wapi_shared_layout->handles[i], '\0', sizeof(struct _WapiHandleShared));
 111                         }
 112                 }
 113
 114                 for (i = 0; i < _wapi_fileshare_layout->hwm; i++) {
 115                         struct _WapiFileShare *file_share = &_wapi_fileshare_layout->share_info[i];
 116
 117                         if (file_share->timestamp < too_old) {
 118                                 memset (file_share, '\0',
 119                                         sizeof(struct _WapiFileShare));
 120                         }
 121                 }
 122
 123                 InterlockedIncrement ((gint32 *)&_wapi_shared_layout->collection_count);
 124         }
 125
 126         thr_ret = _wapi_shm_sem_unlock (_WAPI_SHARED_SEM_FILESHARE);
 127         g_assert (thr_ret == 0);
 128
 129         _wapi_handle_unlock_shared_handles ();
 130
 131         DEBUG ("%s: (%d) Collection done", __func__, _wapi_getpid ());
 132 }