--- /dev/null
+/* Borrowed from ./boehm-gc.c */
+
+/* GC Handles */
+
+#include "config.h"
+
+#include <glib.h>
+#include <mono/metadata/mono-gc.h>
+#include <mono/metadata/gc-internals.h>
+#include <mono/metadata/profiler-private.h>
+#include <mono/utils/mono-compiler.h>
+#include <mono/metadata/null-gc-handles.h>
+
+
+#ifdef HAVE_NULL_GC
+
+#define HIDE_POINTER(obj) (obj)
+#define REVEAL_POINTER(obj) (obj)
+
+#define GC_call_with_alloc_lock(fnptr,arg) ((fnptr)((arg)))
+
+static mono_mutex_t handle_section;
+#define lock_handles(handles) mono_os_mutex_lock (&handle_section)
+#define unlock_handles(handles) mono_os_mutex_unlock (&handle_section)
+
+typedef struct {
+ guint32 *bitmap;
+ gpointer *entries;
+ guint32 size;
+ guint8 type;
+ guint slot_hint : 24; /* starting slot for search in bitmap */
+ /* 2^16 appdomains should be enough for everyone (though I know I'll regret this in 20 years) */
+ /* we alloc this only for weak refs, since we can get the domain directly in the other cases */
+ guint16 *domain_ids;
+} HandleData;
+
+#define EMPTY_HANDLE_DATA(type) {NULL, NULL, 0, (type), 0, NULL}
+
+/* weak and weak-track arrays will be allocated in malloc memory
+ */
+static HandleData gc_handles [] = {
+ EMPTY_HANDLE_DATA (HANDLE_WEAK),
+ EMPTY_HANDLE_DATA (HANDLE_WEAK_TRACK),
+ EMPTY_HANDLE_DATA (HANDLE_NORMAL),
+ EMPTY_HANDLE_DATA (HANDLE_PINNED)
+};
+
+#define BITMAP_SIZE (sizeof (*((HandleData *)NULL)->bitmap) * CHAR_BIT)
+
+void
+null_gc_handles_init (void)
+{
+ mono_os_mutex_init_recursive (&handle_section);
+}
+
+static void
+mono_gc_weak_link_add (void **link_addr, MonoObject *obj, gboolean track)
+{
+ /* libgc requires that we use HIDE_POINTER... */
+ *link_addr = (void*)HIDE_POINTER (obj);
+}
+
+static void
+mono_gc_weak_link_remove (void **link_addr, gboolean track)
+{
+ *link_addr = NULL;
+}
+
+static gpointer
+reveal_link (gpointer link_addr)
+{
+ void **link_a = (void **)link_addr;
+ return REVEAL_POINTER (*link_a);
+}
+
+static MonoObject *
+mono_gc_weak_link_get (void **link_addr)
+{
+ MonoObject *obj = (MonoObject *)GC_call_with_alloc_lock (reveal_link, link_addr);
+ if (obj == (MonoObject *) -1)
+ return NULL;
+ return obj;
+}
+
+static inline gboolean
+slot_occupied (HandleData *handles, guint slot) {
+ return handles->bitmap [slot / BITMAP_SIZE] & (1 << (slot % BITMAP_SIZE));
+}
+
+static inline void
+vacate_slot (HandleData *handles, guint slot) {
+ handles->bitmap [slot / BITMAP_SIZE] &= ~(1 << (slot % BITMAP_SIZE));
+}
+
+static inline void
+occupy_slot (HandleData *handles, guint slot) {
+ handles->bitmap [slot / BITMAP_SIZE] |= 1 << (slot % BITMAP_SIZE);
+}
+
+static int
+find_first_unset (guint32 bitmap)
+{
+ int i;
+ for (i = 0; i < 32; ++i) {
+ if (!(bitmap & (1 << i)))
+ return i;
+ }
+ return -1;
+}
+
+static void
+handle_data_alloc_entries (HandleData *handles)
+{
+ handles->size = 32;
+ if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
+ handles->entries = (void **)g_malloc0 (sizeof (*handles->entries) * handles->size);
+ handles->domain_ids = (guint16 *)g_malloc0 (sizeof (*handles->domain_ids) * handles->size);
+ } else {
+ handles->entries = (void **)mono_gc_alloc_fixed (sizeof (*handles->entries) * handles->size, NULL, MONO_ROOT_SOURCE_GC_HANDLE, "gc handles table");
+ }
+ handles->bitmap = (guint32 *)g_malloc0 (handles->size / CHAR_BIT);
+}
+
+static gint
+handle_data_next_unset (HandleData *handles)
+{
+ gint slot;
+ for (slot = handles->slot_hint; slot < handles->size / BITMAP_SIZE; ++slot) {
+ if (handles->bitmap [slot] == 0xffffffff)
+ continue;
+ handles->slot_hint = slot;
+ return find_first_unset (handles->bitmap [slot]);
+ }
+ return -1;
+}
+
+static gint
+handle_data_first_unset (HandleData *handles)
+{
+ gint slot;
+ for (slot = 0; slot < handles->slot_hint; ++slot) {
+ if (handles->bitmap [slot] == 0xffffffff)
+ continue;
+ handles->slot_hint = slot;
+ return find_first_unset (handles->bitmap [slot]);
+ }
+ return -1;
+}
+
+/* Returns the index of the current slot in the bitmap. */
+static void
+handle_data_grow (HandleData *handles, gboolean track)
+{
+ guint32 *new_bitmap;
+ guint32 new_size = handles->size * 2; /* always double: we memset to 0 based on this below */
+
+ /* resize and copy the bitmap */
+ new_bitmap = (guint32 *)g_malloc0 (new_size / CHAR_BIT);
+ memcpy (new_bitmap, handles->bitmap, handles->size / CHAR_BIT);
+ g_free (handles->bitmap);
+ handles->bitmap = new_bitmap;
+
+ /* resize and copy the entries */
+ if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
+ gpointer *entries;
+ guint16 *domain_ids;
+ gint i;
+ domain_ids = (guint16 *)g_malloc0 (sizeof (*handles->domain_ids) * new_size);
+ entries = (void **)g_malloc0 (sizeof (*handles->entries) * new_size);
+ memcpy (domain_ids, handles->domain_ids, sizeof (*handles->domain_ids) * handles->size);
+ for (i = 0; i < handles->size; ++i) {
+ MonoObject *obj = mono_gc_weak_link_get (&(handles->entries [i]));
+ if (obj) {
+ mono_gc_weak_link_add (&(entries [i]), obj, track);
+ mono_gc_weak_link_remove (&(handles->entries [i]), track);
+ } else {
+ g_assert (!handles->entries [i]);
+ }
+ }
+ g_free (handles->entries);
+ g_free (handles->domain_ids);
+ handles->entries = entries;
+ handles->domain_ids = domain_ids;
+ } else {
+ gpointer *entries;
+ entries = (void **)mono_gc_alloc_fixed (sizeof (*handles->entries) * new_size, NULL, MONO_ROOT_SOURCE_GC_HANDLE, "gc handles table");
+ mono_gc_memmove_aligned (entries, handles->entries, sizeof (*handles->entries) * handles->size);
+ mono_gc_free_fixed (handles->entries);
+ handles->entries = entries;
+ }
+ handles->slot_hint = handles->size / BITMAP_SIZE;
+ handles->size = new_size;
+}
+
+static guint32
+alloc_handle (HandleData *handles, MonoObject *obj, gboolean track)
+{
+ gint slot, i;
+ guint32 res;
+ lock_handles (handles);
+ if (!handles->size)
+ handle_data_alloc_entries (handles);
+ i = handle_data_next_unset (handles);
+ if (i == -1 && handles->slot_hint != 0)
+ i = handle_data_first_unset (handles);
+ if (i == -1) {
+ handle_data_grow (handles, track);
+ i = 0;
+ }
+ slot = handles->slot_hint * BITMAP_SIZE + i;
+ occupy_slot (handles, slot);
+ handles->entries [slot] = NULL;
+ if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
+ /*FIXME, what to use when obj == null?*/
+ handles->domain_ids [slot] = (obj ? mono_object_get_domain (obj) : mono_domain_get ())->domain_id;
+ if (obj)
+ mono_gc_weak_link_add (&(handles->entries [slot]), obj, track);
+ } else {
+ handles->entries [slot] = obj;
+ }
+
+#ifndef DISABLE_PERFCOUNTERS
+ mono_perfcounters->gc_num_handles++;
+#endif
+ unlock_handles (handles);
+ res = MONO_GC_HANDLE (slot, handles->type);
+ mono_profiler_gc_handle (MONO_PROFILER_GC_HANDLE_CREATED, handles->type, res, obj);
+ return res;
+}
+
+/**
+ * mono_gchandle_new:
+ * \param obj managed object to get a handle for
+ * \param pinned whether the object should be pinned
+ *
+ * This returns a handle that wraps the object, this is used to keep a
+ * reference to a managed object from the unmanaged world and preventing the
+ * object from being disposed.
+ *
+ * If \p pinned is false the address of the object can not be obtained, if it is
+ * true the address of the object can be obtained. This will also pin the
+ * object so it will not be possible by a moving garbage collector to move the
+ * object.
+ *
+ * \returns a handle that can be used to access the object from
+ * unmanaged code.
+ */
+guint32
+mono_gchandle_new (MonoObject *obj, gboolean pinned)
+{
+ return alloc_handle (&gc_handles [pinned? HANDLE_PINNED: HANDLE_NORMAL], obj, FALSE);
+}
+
+/**
+ * mono_gchandle_new_weakref:
+ * \param obj managed object to get a handle for
+ * \param track_resurrection Determines how long to track the object, if this is set to TRUE, the object is tracked after finalization, if FALSE, the object is only tracked up until the point of finalization.
+ *
+ * This returns a weak handle that wraps the object, this is used to
+ * keep a reference to a managed object from the unmanaged world.
+ * Unlike the \c mono_gchandle_new the object can be reclaimed by the
+ * garbage collector. In this case the value of the GCHandle will be
+ * set to zero.
+ *
+ * If \p track_resurrection is TRUE the object will be tracked through
+ * finalization and if the object is resurrected during the execution
+ * of the finalizer, then the returned weakref will continue to hold
+ * a reference to the object. If \p track_resurrection is FALSE, then
+ * the weak reference's target will become NULL as soon as the object
+ * is passed on to the finalizer.
+ *
+ * \returns a handle that can be used to access the object from
+ * unmanaged code.
+ */
+guint32
+mono_gchandle_new_weakref (MonoObject *obj, gboolean track_resurrection)
+{
+ return alloc_handle (&gc_handles [track_resurrection? HANDLE_WEAK_TRACK: HANDLE_WEAK], obj, track_resurrection);
+}
+
+/**
+ * mono_gchandle_get_target:
+ * \param gchandle a GCHandle's handle.
+ *
+ * The handle was previously created by calling \c mono_gchandle_new or
+ * \c mono_gchandle_new_weakref.
+ *
+ * \returns A pointer to the \c MonoObject* represented by the handle or
+ * NULL for a collected object if using a weakref handle.
+ */
+MonoObject*
+mono_gchandle_get_target (guint32 gchandle)
+{
+ guint slot = MONO_GC_HANDLE_SLOT (gchandle);
+ guint type = MONO_GC_HANDLE_TYPE (gchandle);
+ HandleData *handles = &gc_handles [type];
+ MonoObject *obj = NULL;
+ if (type >= HANDLE_TYPE_MAX)
+ return NULL;
+
+ lock_handles (handles);
+ if (slot < handles->size && slot_occupied (handles, slot)) {
+ if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
+ obj = mono_gc_weak_link_get (&handles->entries [slot]);
+ } else {
+ obj = (MonoObject *)handles->entries [slot];
+ }
+ } else {
+ /* print a warning? */
+ }
+ unlock_handles (handles);
+ /*g_print ("get target of entry %d of type %d: %p\n", slot, handles->type, obj);*/
+ return obj;
+}
+
+void
+mono_gchandle_set_target (guint32 gchandle, MonoObject *obj)
+{
+ guint slot = MONO_GC_HANDLE_SLOT (gchandle);
+ guint type = MONO_GC_HANDLE_TYPE (gchandle);
+ HandleData *handles = &gc_handles [type];
+ MonoObject *old_obj = NULL;
+
+ g_assert (type < HANDLE_TYPE_MAX);
+ lock_handles (handles);
+ if (slot < handles->size && slot_occupied (handles, slot)) {
+ if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
+ old_obj = (MonoObject *)handles->entries [slot];
+ if (handles->entries [slot])
+ mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
+ if (obj)
+ mono_gc_weak_link_add (&handles->entries [slot], obj, handles->type == HANDLE_WEAK_TRACK);
+ /*FIXME, what to use when obj == null?*/
+ handles->domain_ids [slot] = (obj ? mono_object_get_domain (obj) : mono_domain_get ())->domain_id;
+ } else {
+ handles->entries [slot] = obj;
+ }
+ } else {
+ /* print a warning? */
+ }
+ /*g_print ("changed entry %d of type %d to object %p (in slot: %p)\n", slot, handles->type, obj, handles->entries [slot]);*/
+ unlock_handles (handles);
+}
+
+/**
+ * mono_gchandle_is_in_domain:
+ * \param gchandle a GCHandle's handle.
+ * \param domain An application domain.
+ *
+ * Use this function to determine if the \p gchandle points to an
+ * object allocated in the specified \p domain.
+ *
+ * \returns TRUE if the object wrapped by the \p gchandle belongs to the specific \p domain.
+ */
+gboolean
+mono_gchandle_is_in_domain (guint32 gchandle, MonoDomain *domain)
+{
+ guint slot = MONO_GC_HANDLE_SLOT (gchandle);
+ guint type = MONO_GC_HANDLE_TYPE (gchandle);
+ HandleData *handles = &gc_handles [type];
+ gboolean result = FALSE;
+
+ if (type >= HANDLE_TYPE_MAX)
+ return FALSE;
+
+ lock_handles (handles);
+ if (slot < handles->size && slot_occupied (handles, slot)) {
+ if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
+ result = domain->domain_id == handles->domain_ids [slot];
+ } else {
+ MonoObject *obj;
+ obj = (MonoObject *)handles->entries [slot];
+ if (obj == NULL)
+ result = TRUE;
+ else
+ result = domain == mono_object_domain (obj);
+ }
+ } else {
+ /* print a warning? */
+ }
+ unlock_handles (handles);
+ return result;
+}
+
+/**
+ * mono_gchandle_free:
+ * \param gchandle a GCHandle's handle.
+ *
+ * Frees the \p gchandle handle. If there are no outstanding
+ * references, the garbage collector can reclaim the memory of the
+ * object wrapped.
+ */
+void
+mono_gchandle_free (guint32 gchandle)
+{
+ guint slot = MONO_GC_HANDLE_SLOT (gchandle);
+ guint type = MONO_GC_HANDLE_TYPE (gchandle);
+ HandleData *handles = &gc_handles [type];
+ if (type >= HANDLE_TYPE_MAX)
+ return;
+
+ lock_handles (handles);
+ if (slot < handles->size && slot_occupied (handles, slot)) {
+ if (MONO_GC_HANDLE_TYPE_IS_WEAK (handles->type)) {
+ if (handles->entries [slot])
+ mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
+ } else {
+ handles->entries [slot] = NULL;
+ }
+ vacate_slot (handles, slot);
+ } else {
+ /* print a warning? */
+ }
+#ifndef DISABLE_PERFCOUNTERS
+ mono_perfcounters->gc_num_handles--;
+#endif
+ /*g_print ("freed entry %d of type %d\n", slot, handles->type);*/
+ unlock_handles (handles);
+ mono_profiler_gc_handle (MONO_PROFILER_GC_HANDLE_DESTROYED, handles->type, gchandle, NULL);
+}
+
+/**
+ * mono_gchandle_free_domain:
+ * \param domain domain that is unloading
+ *
+ * Function used internally to cleanup any GC handle for objects belonging
+ * to the specified domain during appdomain unload.
+ */
+void
+mono_gchandle_free_domain (MonoDomain *domain)
+{
+ guint type;
+
+ for (type = HANDLE_TYPE_MIN; type < HANDLE_PINNED; ++type) {
+ guint slot;
+ HandleData *handles = &gc_handles [type];
+ lock_handles (handles);
+ for (slot = 0; slot < handles->size; ++slot) {
+ if (!slot_occupied (handles, slot))
+ continue;
+ if (MONO_GC_HANDLE_TYPE_IS_WEAK (type)) {
+ if (domain->domain_id == handles->domain_ids [slot]) {
+ vacate_slot (handles, slot);
+ if (handles->entries [slot])
+ mono_gc_weak_link_remove (&handles->entries [slot], handles->type == HANDLE_WEAK_TRACK);
+ }
+ } else {
+ if (handles->entries [slot] && mono_object_domain (handles->entries [slot]) == domain) {
+ vacate_slot (handles, slot);
+ handles->entries [slot] = NULL;
+ }
+ }
+ }
+ unlock_handles (handles);
+ }
+
+}
+#else
+
+MONO_EMPTY_SOURCE_FILE (null_gc_handles);
+#endif /* HAVE_NULL_GC */
projects / mono.git / commitdiff