universe_more.cpp

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/* Copyright 1994, 1995 LongView Technologies L.L.C. $Revision: 1.50 $ */
/* Copyright (c) 2006, Sun Microsystems, Inc.
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# include "incls/_precompiled.incl"
# include "incls/_universe.more.cpp.incl"

bool GCInProgress = false;

oop Universe::tenure(oop p) {
  tenuring_threshold = 0;               // tenure everything
  scavenge(&p);
# define checkIt(s) assert(s->used() == 0, "new spaces should be empty");
  APPLY_TO_YOUNG_SPACES(checkIt)
# undef checkIt
  return p;
}

bool Universe::can_scavenge() {
  // don't scavenge if we're in critical vm operation
  if (processSemaphore) return false;

  if (BlockScavenge::is_blocked()) return false;

  // don't scavenge if we're allocating in the VM process.
  if (DeltaProcess::active()->in_vm_operation()) return false;

  return true;
}

extern "C" void scavenge_and_allocate(int size) {
  Universe::scavenge_and_allocate(size, NULL);
}

oop* Universe::scavenge_and_allocate(int size, oop* p) {
  // Fix this:
  //  If it is a huge object we are allocating we should
  //  allocate it in old_space and return without doing a scavenge  
  if (!can_scavenge()) return allocate_tenured(size);

  VM_Scavenge op(p);
  VMProcess::execute(&op);
  assert(DeltaProcess::active()->last_Delta_fp() != NULL, "last Delta fp should be present");
  assert(DeltaProcess::active()->last_Delta_sp() != NULL, "last Delta fp should be present");
  return allocate_without_scavenge(size);
}

void Universe::scavenge_oop(oop* p) { *p = (*p)->scavenge(); }

bool Universe::needs_garbage_collection() {
  return old_gen.free() < new_gen.to()->capacity();
}

void Universe::scavenge(oop* p) {
  // %note
  //   the symbol_table can be ignored during scavenge since all
  //   all symbols are tenured.
  FlagSetting fl(GCInProgress, true);
  ResourceMark rm;
  scavengeCount++;
  assert(!processSemaphore, "processSemaphore shouldn't be set");
  {
    EventMarker m("scavenging");
    TraceTime   t("Scavenge", PrintScavenge);

    if (PrintScavenge && WizardMode) {
      std->print(" %d",tenuring_threshold);
    }
    
    if (VerifyBeforeScavenge) verify();

    WeakArrayRegister::begin_scavenge();

    // Getting ready for scavenge
    age_table->clear();

    new_gen.to_space->clear();

    // Save top of to_space and old_gen
    NewWaterMark to_mark  = new_gen.to_space->top_mark();
    OldWaterMark old_mark =           old_gen.top_mark();

    // Scavenge all roots
    if (p) SCAVENGE_TEMPLATE(p);

    Universe::roots_do(scavenge_oop);
    Handles::oops_do(scavenge_oop);

    {FOR_EACH_OLD_SPACE(s) s->scavenge_recorded_stores();}

    Processes::scavenge_contents();
    NotificationQueue::oops_do(&Universe::scavenge_oop);

    // Scavenge promoted contents in to_space and old_gen until done.

    while (   (old_mark != old_gen.top_mark()) 
           || (to_mark != new_gen.to_space->top_mark())) {
      old_gen.scavenge_contents_from(&old_mark);
      new_gen.to_space->scavenge_contents_from(&to_mark);
    }

    WeakArrayRegister::check_and_scavenge_contents();

    new_gen.swap_spaces();

    // Set the desired survivor size to half the real survivor space
    int desired_survivor_size = new_gen.to()->capacity()/2;
    tenuring_threshold = age_table->tenuring_threshold(desired_survivor_size/oopSize);
    
    if (VerifyAfterScavenge) verify(true);
    
    // do this at end so an overflow during a scavenge doesnt cause another one
    NeedScavenge = false;
  }
}

space* Universe::spaceFor(void* p) {
  if (new_gen.from()->contains(p)) return new_gen.from();
  if (new_gen.eden()->contains(p)) return new_gen.eden();
  {FOR_EACH_OLD_SPACE(s) if (s->contains(p)) return s;}
  ShouldNotReachHere(); // not in any space
  return NULL;
}

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