jdk-sandbox: comparison hotspot/src/share/vm/gc_implementation/parallelScavenge/psYoungGen.cpp

equal deleted inserted replaced

-:579c7d4ed068
+:f0b20be4165d
 {}
 void PSYoungGen::initialize_virtual_space(ReservedSpace rs, size_t alignment) {
 assert(_init_gen_size != 0, "Should have a finite size");
 _virtual_space = new PSVirtualSpace(rs, alignment);
-if (!_virtual_space->expand_by(_init_gen_size)) {
+if (!virtual_space()->expand_by(_init_gen_size)) {
 vm_exit_during_initialization("Could not reserve enough space for "
 "object heap");
 }
 }
 initialize_work();
 }
 void PSYoungGen::initialize_work() {
-_reserved = MemRegion((HeapWord*)_virtual_space->low_boundary(),
+_reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
-(HeapWord*)_virtual_space->high_boundary());
+(HeapWord*)virtual_space()->high_boundary());
-MemRegion cmr((HeapWord*)_virtual_space->low(),
+MemRegion cmr((HeapWord*)virtual_space()->low(),
-(HeapWord*)_virtual_space->high());
+(HeapWord*)virtual_space()->high());
 Universe::heap()->barrier_set()->resize_covered_region(cmr);
+if (ZapUnusedHeapArea) {
+// Mangle newly committed space immediately because it
+// can be done here more simply that after the new
+// spaces have been computed.
+SpaceMangler::mangle_region(cmr);
+}
 if (UseNUMA) {
 _eden_space = new MutableNUMASpace();
 } else {
 _eden_space = new MutableSpace();
 _gen_counters = new PSGenerationCounters("new", 0, 3, _virtual_space);
 // Compute maximum space sizes for performance counters
 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
 size_t alignment = heap->intra_heap_alignment();
-size_t size = _virtual_space->reserved_size();
+size_t size = virtual_space()->reserved_size();
 size_t max_survivor_size;
 size_t max_eden_size;
 if (UseAdaptiveSizePolicy) {
 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
 // Compute sizes
 size_t alignment = heap->intra_heap_alignment();
-size_t size = _virtual_space->committed_size();
+size_t size = virtual_space()->committed_size();
 size_t survivor_size = size / InitialSurvivorRatio;
 survivor_size = align_size_down(survivor_size, alignment);
 // ... but never less than an alignment
 survivor_size = MAX2(survivor_size, alignment);
 _to_counters->update_capacity();
 }
 }
 void PSYoungGen::set_space_boundaries(size_t eden_size, size_t survivor_size) {
-assert(eden_size < _virtual_space->committed_size(), "just checking");
+assert(eden_size < virtual_space()->committed_size(), "just checking");
 assert(eden_size > 0  && survivor_size > 0, "just checking");
 // Initial layout is Eden, to, from. After swapping survivor spaces,
 // that leaves us with Eden, from, to, which is step one in our two
 // step resize-with-live-data procedure.
-char *eden_start = _virtual_space->low();
+char *eden_start = virtual_space()->low();
 char *to_start   = eden_start + eden_size;
 char *from_start = to_start   + survivor_size;
 char *from_end   = from_start + survivor_size;
-assert(from_end == _virtual_space->high(), "just checking");
+assert(from_end == virtual_space()->high(), "just checking");
 assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
 assert(is_object_aligned((intptr_t)to_start),   "checking alignment");
 assert(is_object_aligned((intptr_t)from_start), "checking alignment");
 MemRegion eden_mr((HeapWord*)eden_start, (HeapWord*)to_start);
 MemRegion to_mr  ((HeapWord*)to_start, (HeapWord*)from_start);
 MemRegion from_mr((HeapWord*)from_start, (HeapWord*)from_end);
-eden_space()->initialize(eden_mr, true);
+eden_space()->initialize(eden_mr, true, ZapUnusedHeapArea);
-to_space()->initialize(to_mr  , true);
+to_space()->initialize(to_mr  , true, ZapUnusedHeapArea);
-from_space()->initialize(from_mr, true);
+from_space()->initialize(from_mr, true, ZapUnusedHeapArea);
 }
 #ifndef PRODUCT
 void PSYoungGen::space_invariants() {
 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
 char* from_start = (char*)from_space()->bottom();
 char* from_end   = (char*)from_space()->end();
 char* to_start   = (char*)to_space()->bottom();
 char* to_end     = (char*)to_space()->end();
-guarantee(eden_start >= _virtual_space->low(), "eden bottom");
+guarantee(eden_start >= virtual_space()->low(), "eden bottom");
 guarantee(eden_start < eden_end, "eden space consistency");
 guarantee(from_start < from_end, "from space consistency");
 guarantee(to_start < to_end, "to space consistency");
 // Check whether from space is below to space
 if (from_start < to_start) {
 // Eden, from, to
 guarantee(eden_end <= from_start, "eden/from boundary");
 guarantee(from_end <= to_start,   "from/to boundary");
-guarantee(to_end <= _virtual_space->high(), "to end");
+guarantee(to_end <= virtual_space()->high(), "to end");
 } else {
 // Eden, to, from
 guarantee(eden_end <= to_start, "eden/to boundary");
 guarantee(to_end <= from_start, "to/from boundary");
-guarantee(from_end <= _virtual_space->high(), "from end");
+guarantee(from_end <= virtual_space()->high(), "from end");
 }
 // More checks that the virtual space is consistent with the spaces
-assert(_virtual_space->committed_size() >=
+assert(virtual_space()->committed_size() >=
 (eden_space()->capacity_in_bytes() +
 to_space()->capacity_in_bytes() +
 from_space()->capacity_in_bytes()), "Committed size is inconsistent");
-assert(_virtual_space->committed_size() <= _virtual_space->reserved_size(),
+assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(),
 "Space invariant");
 char* eden_top = (char*)eden_space()->top();
 char* from_top = (char*)from_space()->top();
 char* to_top = (char*)to_space()->top();
-assert(eden_top <= _virtual_space->high(), "eden top");
+assert(eden_top <= virtual_space()->high(), "eden top");
-assert(from_top <= _virtual_space->high(), "from top");
+assert(from_top <= virtual_space()->high(), "from top");
-assert(to_top <= _virtual_space->high(), "to top");
+assert(to_top <= virtual_space()->high(), "to top");
-_virtual_space->verify();
+virtual_space()->verify();
 }
 #endif
 void PSYoungGen::resize(size_t eden_size, size_t survivor_size) {
 // Resize the generation if needed. If the generation resize
 }
 }
 bool PSYoungGen::resize_generation(size_t eden_size, size_t survivor_size) {
-const size_t alignment = _virtual_space->alignment();
+const size_t alignment = virtual_space()->alignment();
-size_t orig_size = _virtual_space->committed_size();
+size_t orig_size = virtual_space()->committed_size();
 bool size_changed = false;
 // There used to be this guarantee there.
 // guarantee ((eden_size + 2*survivor_size)  <= _max_gen_size, "incorrect input arguments");
 // Code below forces this requirement.  In addition the desired eden
 if (desired_size > orig_size) {
 // Grow the generation
 size_t change = desired_size - orig_size;
 assert(change % alignment == 0, "just checking");
-if (!_virtual_space->expand_by(change)) {
+HeapWord* prev_high = (HeapWord*) virtual_space()->high();
+if (!virtual_space()->expand_by(change)) {
 return false; // Error if we fail to resize!
 }
+if (ZapUnusedHeapArea) {
+// Mangle newly committed space immediately because it
+// can be done here more simply that after the new
+// spaces have been computed.
+HeapWord* new_high = (HeapWord*) virtual_space()->high();
+MemRegion mangle_region(prev_high, new_high);
+SpaceMangler::mangle_region(mangle_region);
+}
 size_changed = true;
 } else if (desired_size < orig_size) {
 size_t desired_change = orig_size - desired_size;
 assert(desired_change % alignment == 0, "just checking");
 if (size_changed) {
 post_resize();
 if (Verbose && PrintGC) {
-size_t current_size  = _virtual_space->committed_size();
+size_t current_size  = virtual_space()->committed_size();
 gclog_or_tty->print_cr("PSYoung generation size changed: "
 SIZE_FORMAT "K->" SIZE_FORMAT "K",
 orig_size/K, current_size/K);
 }
 }
-guarantee(eden_plus_survivors <= _virtual_space->committed_size() ||
+guarantee(eden_plus_survivors <= virtual_space()->committed_size() ||
-_virtual_space->committed_size() == max_size(), "Sanity");
+virtual_space()->committed_size() == max_size(), "Sanity");
 return true;
 }
+#ifndef PRODUCT
+// In the numa case eden is not mangled so a survivor space
+// moving into a region previously occupied by a survivor
+// may find an unmangled region.  Also in the PS case eden
+// to-space and from-space may not touch (i.e., there may be
+// gaps between them due to movement while resizing the
+// spaces).  Those gaps must be mangled.
+void PSYoungGen::mangle_survivors(MutableSpace* s1,
+MemRegion s1MR,
+MutableSpace* s2,
+MemRegion s2MR) {
+// Check eden and gap between eden and from-space, in deciding
+// what to mangle in from-space.  Check the gap between from-space
+// and to-space when deciding what to mangle.
+//
+//      +--------+   +----+    +---+
+//      | eden   |   |s1  |    |s2 |
+//      +--------+   +----+    +---+
+//                 +-------+ +-----+
+//                 |s1MR   | |s2MR |
+//                 +-------+ +-----+
+// All of survivor-space is properly mangled so find the
+// upper bound on the mangling for any portion above current s1.
+HeapWord* delta_end = MIN2(s1->bottom(), s1MR.end());
+MemRegion delta1_left;
+if (s1MR.start() < delta_end) {
+delta1_left = MemRegion(s1MR.start(), delta_end);
+s1->mangle_region(delta1_left);
+}
+// Find any portion to the right of the current s1.
+HeapWord* delta_start = MAX2(s1->end(), s1MR.start());
+MemRegion delta1_right;
+if (delta_start < s1MR.end()) {
+delta1_right = MemRegion(delta_start, s1MR.end());
+s1->mangle_region(delta1_right);
+}
+// Similarly for the second survivor space except that
+// any of the new region that overlaps with the current
+// region of the first survivor space has already been
+// mangled.
+delta_end = MIN2(s2->bottom(), s2MR.end());
+delta_start = MAX2(s2MR.start(), s1->end());
+MemRegion delta2_left;
+if (s2MR.start() < delta_end) {
+delta2_left = MemRegion(s2MR.start(), delta_end);
+s2->mangle_region(delta2_left);
+}
+delta_start = MAX2(s2->end(), s2MR.start());
+MemRegion delta2_right;
+if (delta_start < s2MR.end()) {
+s2->mangle_region(delta2_right);
+}
+if (TraceZapUnusedHeapArea) {
+// s1
+gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") "
+"New region: [" PTR_FORMAT ", " PTR_FORMAT ")",
+s1->bottom(), s1->end(), s1MR.start(), s1MR.end());
+gclog_or_tty->print_cr("    Mangle before: [" PTR_FORMAT ", "
+PTR_FORMAT ")  Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")",
+delta1_left.start(), delta1_left.end(), delta1_right.start(),
+delta1_right.end());
+// s2
+gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") "
+"New region: [" PTR_FORMAT ", " PTR_FORMAT ")",
+s2->bottom(), s2->end(), s2MR.start(), s2MR.end());
+gclog_or_tty->print_cr("    Mangle before: [" PTR_FORMAT ", "
+PTR_FORMAT ")  Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")",
+delta2_left.start(), delta2_left.end(), delta2_right.start(),
+delta2_right.end());
+}
+}
+#endif // NOT PRODUCT
 void PSYoungGen::resize_spaces(size_t requested_eden_size,
 size_t requested_survivor_size) {
 assert(UseAdaptiveSizePolicy, "sanity check");
 assert(requested_eden_size > 0  && requested_survivor_size > 0,
 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
 const size_t alignment = heap->intra_heap_alignment();
 const bool maintain_minimum =
 (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
+bool eden_from_to_order = from_start < to_start;
 // Check whether from space is below to space
-if (from_start < to_start) {
+if (eden_from_to_order) {
 // Eden, from, to
+eden_from_to_order = true;
 if (PrintAdaptiveSizePolicy && Verbose) {
 gclog_or_tty->print_cr("  Eden, from, to:");
 }
 // Set eden
 // To may resize into from space as long as it is clear of live data.
 // From space must remain page aligned, though, so we need to do some
 // extra calculations.
 // First calculate an optimal to-space
-to_end   = (char*)_virtual_space->high();
+to_end   = (char*)virtual_space()->high();
 to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
 sizeof(char));
 // Does the optimal to-space overlap from-space?
 if (to_start < (char*)from_space()->end()) {
 // To space gets priority over eden resizing. Note that we position
 // to space as if we were able to resize from space, even though from
 // space is not modified.
 // Giving eden priority was tried and gave poorer performance.
-to_end   = (char*)pointer_delta(_virtual_space->high(),
+to_end   = (char*)pointer_delta(virtual_space()->high(),
 (char*)requested_survivor_size,
 sizeof(char));
 to_end   = MIN2(to_end, from_start);
 to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
 sizeof(char));
 // For PrintAdaptiveSizePolicy block  below
 size_t old_from = from_space()->capacity_in_bytes();
 size_t old_to   = to_space()->capacity_in_bytes();
-eden_space()->initialize(edenMR, true);
+if (ZapUnusedHeapArea) {
-to_space()->initialize(toMR  , true);
+// NUMA is a special case because a numa space is not mangled
-from_space()->initialize(fromMR, false);     // Note, not cleared!
+// in order to not prematurely bind its address to memory to
+// the wrong memory (i.e., don't want the GC thread to first
+// touch the memory).  The survivor spaces are not numa
+// spaces and are mangled.
+if (UseNUMA) {
+if (eden_from_to_order) {
+mangle_survivors(from_space(), fromMR, to_space(), toMR);
+} else {
+mangle_survivors(to_space(), toMR, from_space(), fromMR);
+}
+}
+// If not mangling the spaces, do some checking to verify that
+// the spaces are already mangled.
+// The spaces should be correctly mangled at this point so
+// do some checking here. Note that they are not being mangled
+// in the calls to initialize().
+// Must check mangling before the spaces are reshaped.  Otherwise,
+// the bottom or end of one space may have moved into an area
+// covered by another space and a failure of the check may
+// not correctly indicate which space is not properly mangled.
+HeapWord* limit = (HeapWord*) virtual_space()->high();
+eden_space()->check_mangled_unused_area(limit);
+from_space()->check_mangled_unused_area(limit);
+to_space()->check_mangled_unused_area(limit);
+}
+// When an existing space is being initialized, it is not
+// mangled because the space has been previously mangled.
+eden_space()->initialize(edenMR,
+SpaceDecorator::Clear,
+SpaceDecorator::DontMangle);
+to_space()->initialize(toMR,
+SpaceDecorator::Clear,
+SpaceDecorator::DontMangle);
+from_space()->initialize(fromMR,
+SpaceDecorator::DontClear,
+SpaceDecorator::DontMangle);
 assert(from_space()->top() == old_from_top, "from top changed!");
 if (PrintAdaptiveSizePolicy) {
 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
 capacity_in_bytes(), used_in_bytes());
 } else {
 st->print(" total " SIZE_FORMAT "K, used " SIZE_FORMAT "K",
 capacity_in_bytes()/K, used_in_bytes()/K);
 }
-_virtual_space->print_space_boundaries_on(st);
+virtual_space()->print_space_boundaries_on(st);
 st->print("  eden"); eden_space()->print_on(st);
 st->print("  from"); from_space()->print_on(st);
 st->print("  to  "); to_space()->print_on(st);
 }
 HeapWord* new_end = (HeapWord*)virtual_space()->high();
 assert(new_end >= space_shrinking->bottom(), "Shrink was too large");
 // Was there a shrink of the survivor space?
 if (new_end < space_shrinking->end()) {
 MemRegion mr(space_shrinking->bottom(), new_end);
-space_shrinking->initialize(mr, false /* clear */);
+space_shrinking->initialize(mr,
+SpaceDecorator::DontClear,
+SpaceDecorator::Mangle);
 }
 }
 // This method currently does not expect to expand into eden (i.e.,
 // the virtual space boundaries is expected to be consistent
 void PSYoungGen::verify(bool allow_dirty) {
 eden_space()->verify(allow_dirty);
 from_space()->verify(allow_dirty);
 to_space()->verify(allow_dirty);
 }
+#ifndef PRODUCT
+void PSYoungGen::record_spaces_top() {
+assert(ZapUnusedHeapArea, "Not mangling unused space");
+eden_space()->set_top_for_allocations();
+from_space()->set_top_for_allocations();
+to_space()->set_top_for_allocations();
+}
+#endif

changeset 971	f0b20be4165d
parent 186	32e6c95f8d9b
child 977	b90650e2a9f7