265 // determined by filter. If e is a void* entry in queue's buffer,
266 // filter_out(e) must be a valid expression whose value is convertible
267 // to bool. Entries are removed (filtered out) if the result is true,
268 // retained if false.
269 template<typename Filter>
270 inline void SATBMarkQueueSet::apply_filter(Filter filter_out, SATBMarkQueue& queue) {
271   void** buf = queue.buffer();
272 
273   if (buf == nullptr) {
274     // Nothing to do, and avoid pointer arithmetic on nullptr below.
275     return;
276   }
277 
278   // Two-fingered compaction toward the end.
279   void** src = buf + queue.index();
280   void** dst = buf + queue.current_capacity();
281   assert(src <= dst, "invariant");
282   for ( ; src < dst; ++src) {
283     // Search low to high for an entry to keep.
284     void* entry = *src;
285     if (!filter_out(entry)) {
286       // Found keeper.  Search high to low for an entry to discard.
287       while (src < --dst) {
288         if (filter_out(*dst)) {
289           *dst = entry;         // Replace discard with keeper.
290           break;
291         }
292       }
293       // If discard search failed (src == dst), the outer loop will also end.
294     }
295   }
296   // dst points to the lowest retained entry, or the end of the buffer
297   // if all the entries were filtered out.
298   queue.set_index(dst - buf);
299 }
300 
301 #endif // SHARE_GC_SHARED_SATBMARKQUEUE_HPP

265 // determined by filter. If e is a void* entry in queue's buffer,
266 // filter_out(e) must be a valid expression whose value is convertible
267 // to bool. Entries are removed (filtered out) if the result is true,
268 // retained if false.
269 template<typename Filter>
270 inline void SATBMarkQueueSet::apply_filter(Filter filter_out, SATBMarkQueue& queue) {
271   void** buf = queue.buffer();
272 
273   if (buf == nullptr) {
274     // Nothing to do, and avoid pointer arithmetic on nullptr below.
275     return;
276   }
277 
278   // Two-fingered compaction toward the end.
279   void** src = buf + queue.index();
280   void** dst = buf + queue.current_capacity();
281   assert(src <= dst, "invariant");
282   for ( ; src < dst; ++src) {
283     // Search low to high for an entry to keep.
284     void* entry = *src;
285     if (entry != nullptr && !filter_out(entry)) {
286       // Found keeper.  Search high to low for an entry to discard.
287       while (src < --dst) {
288         if (*dst == nullptr || filter_out(*dst)) {
289           *dst = entry;         // Replace discard with keeper.
290           break;
291         }
292       }
293       // If discard search failed (src == dst), the outer loop will also end.
294     }
295   }
296   // dst points to the lowest retained entry, or the end of the buffer
297   // if all the entries were filtered out.
298   queue.set_index(dst - buf);
299 }
300 
301 #endif // SHARE_GC_SHARED_SATBMARKQUEUE_HPP