12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_MEMORY_GCLOCKER_HPP
  26 #define SHARE_VM_MEMORY_GCLOCKER_HPP
  27 
  28 #include "gc_interface/collectedHeap.hpp"
  29 #include "memory/genCollectedHeap.hpp"
  30 #include "memory/universe.hpp"
  31 #include "oops/oop.hpp"

  32 #ifdef TARGET_OS_FAMILY_linux
  33 # include "os_linux.inline.hpp"
  34 # include "thread_linux.inline.hpp"
  35 #endif
  36 #ifdef TARGET_OS_FAMILY_solaris
  37 # include "os_solaris.inline.hpp"
  38 # include "thread_solaris.inline.hpp"
  39 #endif
  40 #ifdef TARGET_OS_FAMILY_windows
  41 # include "os_windows.inline.hpp"
  42 # include "thread_windows.inline.hpp"
  43 #endif
  44 #ifdef TARGET_OS_FAMILY_bsd
  45 # include "os_bsd.inline.hpp"
  46 # include "thread_bsd.inline.hpp"
  47 #endif
  48 
  49 // The direct lock/unlock calls do not force a collection if an unlock
  50 // decrements the count to zero. Avoid calling these if at all possible.
  51 
  52 class GC_locker: public AllStatic {
  53  private:
  54   // The _jni_lock_count keeps track of the number of threads that are
  55   // currently in a critical region.  It's only kept up to date when
  56   // _needs_gc is true.  The current value is computed during
  57   // safepointing and decremented during the slow path of GC_locker
  58   // unlocking.
  59   static volatile jint _jni_lock_count;  // number of jni active instances.
  60 
  61   static volatile jint _lock_count;      // number of other active instances
  62   static volatile bool _needs_gc;        // heap is filling, we need a GC
  63                                          // note: bool is typedef'd as jint
  64   static volatile bool _doing_gc;        // unlock_critical() is doing a GC
  65 
  66 #ifdef ASSERT

  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_MEMORY_GCLOCKER_HPP
  26 #define SHARE_VM_MEMORY_GCLOCKER_HPP
  27 
  28 #include "gc_interface/collectedHeap.hpp"
  29 #include "memory/genCollectedHeap.hpp"
  30 #include "memory/universe.hpp"
  31 #include "oops/oop.hpp"
  32 #include "runtime/thread.inline.hpp"
  33 #ifdef TARGET_OS_FAMILY_linux
  34 # include "os_linux.inline.hpp"

  35 #endif
  36 #ifdef TARGET_OS_FAMILY_solaris
  37 # include "os_solaris.inline.hpp"

  38 #endif
  39 #ifdef TARGET_OS_FAMILY_windows
  40 # include "os_windows.inline.hpp"

  41 #endif
  42 #ifdef TARGET_OS_FAMILY_bsd
  43 # include "os_bsd.inline.hpp"

  44 #endif
  45 
  46 // The direct lock/unlock calls do not force a collection if an unlock
  47 // decrements the count to zero. Avoid calling these if at all possible.
  48 
  49 class GC_locker: public AllStatic {
  50  private:
  51   // The _jni_lock_count keeps track of the number of threads that are
  52   // currently in a critical region.  It's only kept up to date when
  53   // _needs_gc is true.  The current value is computed during
  54   // safepointing and decremented during the slow path of GC_locker
  55   // unlocking.
  56   static volatile jint _jni_lock_count;  // number of jni active instances.
  57 
  58   static volatile jint _lock_count;      // number of other active instances
  59   static volatile bool _needs_gc;        // heap is filling, we need a GC
  60                                          // note: bool is typedef'd as jint
  61   static volatile bool _doing_gc;        // unlock_critical() is doing a GC
  62 
  63 #ifdef ASSERT