Merge in jdk-24+33 (24.2)

PullRequest: labsjdk-ce/146

Author: OracleLabsAutomation

src/hotspot/share/gc/shared/gcVMOperations.cpp

@@ -140,8 +140,8 @@ void VM_GC_Operation::doit_epilogue() {
 }
 
 bool VM_GC_HeapInspection::doit_prologue() {
-  if (_full_gc && UseZGC) {
-    // ZGC cannot perform a synchronous GC cycle from within the VM thread.
+  if (_full_gc && (UseZGC || UseShenandoahGC)) {
+    // ZGC and Shenandoah cannot perform a synchronous GC cycle from within the VM thread.
     // So VM_GC_HeapInspection::collect() is a noop. To respect the _full_gc
     // flag a synchronous GC cycle is performed from the caller thread in the
     // prologue.

src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp

@@ -1468,6 +1468,18 @@ size_t ShenandoahHeap::max_tlab_size() const {
   return ShenandoahHeapRegion::max_tlab_size_words();
 }
 
+void ShenandoahHeap::collect_as_vm_thread(GCCause::Cause cause) {
+  // These requests are ignored because we can't easily have Shenandoah jump into
+  // a synchronous (degenerated or full) cycle while it is in the middle of a concurrent
+  // cycle. We _could_ cancel the concurrent cycle and then try to run a cycle directly
+  // on the VM thread, but this would confuse the control thread mightily and doesn't
+  // seem worth the trouble. Instead, we will have the caller thread run (and wait for) a
+  // concurrent cycle in the prologue of the heap inspect/dump operation. This is how
+  // other concurrent collectors in the JVM handle this scenario as well.
+  assert(Thread::current()->is_VM_thread(), "Should be the VM thread");
+  guarantee(cause == GCCause::_heap_dump || cause == GCCause::_heap_inspection, "Invalid cause");
+}
+
 void ShenandoahHeap::collect(GCCause::Cause cause) {
   control_thread()->request_gc(cause);
 }
@@ -1548,7 +1560,9 @@ void ShenandoahHeap::set_active_generation() {
 void ShenandoahHeap::on_cycle_start(GCCause::Cause cause, ShenandoahGeneration* generation) {
   shenandoah_policy()->record_collection_cause(cause);
 
-  assert(gc_cause()  == GCCause::_no_gc, "Over-writing cause");
+  const GCCause::Cause current = gc_cause();
+  assert(current == GCCause::_no_gc, "Over-writing cause: %s, with: %s",
+         GCCause::to_string(current), GCCause::to_string(cause));
   assert(_gc_generation == nullptr, "Over-writing _gc_generation");
 
   set_gc_cause(cause);

src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp

@@ -608,6 +608,7 @@ class ShenandoahHeap : public CollectedHeap {
   MemRegion reserved_region() const { return _reserved; }
   bool is_in_reserved(const void* addr) const { return _reserved.contains(addr); }
 
+  void collect_as_vm_thread(GCCause::Cause cause) override;
   void collect(GCCause::Cause cause) override;
   void do_full_collection(bool clear_all_soft_refs) override;
 

src/hotspot/share/opto/subnode.cpp

@@ -1623,27 +1623,17 @@ Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
     return new BoolNode( ncmp, _test.negate() );
   }
 
-  // Change ((x & (m - 1)) u< m) into (m > 0)
-  // This is the off-by-one variant of ((x & m) u<= m)
-  if (cop == Op_CmpU &&
-      _test._test == BoolTest::lt &&
-      cmp1_op == Op_AndI) {
-    Node* l = cmp1->in(1);
-    Node* r = cmp1->in(2);
-    for (int repeat = 0; repeat < 2; repeat++) {
-      bool match = r->Opcode() == Op_AddI && r->in(2)->find_int_con(0) == -1 &&
-                   r->in(1) == cmp2;
-      if (match) {
-        // arraylength known to be non-negative, so a (arraylength != 0) is sufficient,
-        // but to be compatible with the array range check pattern, use (arraylength u> 0)
-        Node* ncmp = cmp2->Opcode() == Op_LoadRange
-                     ? phase->transform(new CmpUNode(cmp2, phase->intcon(0)))
-                     : phase->transform(new CmpINode(cmp2, phase->intcon(0)));
-        return new BoolNode(ncmp, BoolTest::gt);
-      } else {
-        // commute and try again
-        l = cmp1->in(2);
-        r = cmp1->in(1);
+  // Transform: "((x & (m - 1)) <u m)" or "(((m - 1) & x) <u m)" into "(m >u 0)"
+  // This is case [CMPU_MASK] which is further described at the method comment of BoolNode::Value_cmpu_and_mask().
+  if (cop == Op_CmpU && _test._test == BoolTest::lt && cmp1_op == Op_AndI) {
+    Node* m = cmp2; // RHS: m
+    for (int add_idx = 1; add_idx <= 2; add_idx++) { // LHS: "(m + (-1)) & x" or "x & (m + (-1))"?
+      Node* maybe_m_minus_1 = cmp1->in(add_idx);
+      if (maybe_m_minus_1->Opcode() == Op_AddI &&
+          maybe_m_minus_1->in(2)->find_int_con(0) == -1 &&
+          maybe_m_minus_1->in(1) == m) {
+        Node* m_cmpu_0 = phase->transform(new CmpUNode(m, phase->intcon(0)));
+        return new BoolNode(m_cmpu_0, BoolTest::gt);
       }
     }
   }
@@ -1809,24 +1799,79 @@ Node *BoolNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   //    }
 }
 
-//------------------------------Value------------------------------------------
-// Change ((x & m) u<= m) or ((m & x) u<= m) to always true
-// Same with ((x & m) u< m+1) and ((m & x) u< m+1)
+// We use the following Lemmas/insights for the following two transformations (1) and (2):
+//   x & y <=u y, for any x and y           (Lemma 1, masking always results in a smaller unsigned number)
+//   y <u y + 1 is always true if y != -1   (Lemma 2, (uint)(-1 + 1) == (uint)(UINT_MAX + 1) which overflows)
+//   y <u 0 is always false for any y       (Lemma 3, 0 == UINT_MIN and nothing can be smaller than that)
+//
+// (1a) Always:     Change ((x & m) <=u m  ) or ((m & x) <=u m  ) to always true   (true by Lemma 1)
+// (1b) If m != -1: Change ((x & m) <u  m + 1) or ((m & x) <u  m + 1) to always true:
+//    x & m <=u m          is always true   // (Lemma 1)
+//    x & m <=u m <u m + 1 is always true   // (Lemma 2: m <u m + 1, if m != -1)
+//
+// A counter example for (1b), if we allowed m == -1:
+//     (x & m)  <u m + 1
+//     (x & -1) <u 0
+//      x       <u 0
+//   which is false for any x (Lemma 3)
+//
+// (2) Change ((x & (m - 1)) <u m) or (((m - 1) & x) <u m) to (m >u 0)
+// This is the off-by-one variant of the above.
+//
+// We now prove that this replacement is correct. This is the same as proving
+//   "m >u 0" if and only if "x & (m - 1) <u m", i.e. "m >u 0 <=> x & (m - 1) <u m"
+//
+// We use (Lemma 1) and (Lemma 3) from above.
+//
+// Case "x & (m - 1) <u m => m >u 0":
+//   We prove this by contradiction:
+//     Assume m <=u 0 which is equivalent to m == 0:
+//   and thus
+//     x & (m - 1) <u m = 0               // m == 0
+//     y           <u     0               // y = x & (m - 1)
+//   by Lemma 3, this is always false, i.e. a contradiction to our assumption.
+//
+// Case "m >u 0 => x & (m - 1) <u m":
+//   x & (m - 1) <=u (m - 1)              // (Lemma 1)
+//   x & (m - 1) <=u (m - 1) <u m         // Using assumption m >u 0, no underflow of "m - 1"
+//
+//
+// Note that the signed version of "m > 0":
+//   m > 0 <=> x & (m - 1) <u m
+// does not hold:
+//   Assume m == -1 and x == -1:
+//     x  & (m - 1) <u m
+//     -1 & -2      <u -1
+//     -2           <u -1
+//     UINT_MAX - 1 <u UINT_MAX           // Signed to unsigned numbers
+// which is true while
+//   m > 0
+// is false which is a contradiction.
+//
+// (1a) and (1b) is covered by this method since we can directly return a true value as type while (2) is covered
+// in BoolNode::Ideal since we create a new non-constant node (see [CMPU_MASK]).
 const Type* BoolNode::Value_cmpu_and_mask(PhaseValues* phase) const {
   Node* cmp = in(1);
   if (cmp != nullptr && cmp->Opcode() == Op_CmpU) {
     Node* cmp1 = cmp->in(1);
     Node* cmp2 = cmp->in(2);
 
     if (cmp1->Opcode() == Op_AndI) {
-      Node* bound = nullptr;
+      Node* m = nullptr;
       if (_test._test == BoolTest::le) {
-        bound = cmp2;
+        // (1a) "((x & m) <=u m)", cmp2 = m
+        m = cmp2;
       } else if (_test._test == BoolTest::lt && cmp2->Opcode() == Op_AddI && cmp2->in(2)->find_int_con(0) == 1) {
-        bound = cmp2->in(1);
+        // (1b) "(x & m) <u m + 1" and "(m & x) <u m + 1", cmp2 = m + 1
+        Node* rhs_m = cmp2->in(1);
+        const TypeInt* rhs_m_type = phase->type(rhs_m)->isa_int();
+        if (rhs_m_type->_lo > -1 || rhs_m_type->_hi < -1) {
+          // Exclude any case where m == -1 is possible.
+          m = rhs_m;
+        }
       }
 
-      if (cmp1->in(2) == bound || cmp1->in(1) == bound) {
+      if (cmp1->in(2) == m || cmp1->in(1) == m) {
         return TypeInt::ONE;
       }
     }

src/hotspot/share/services/heapDumper.cpp

@@ -2349,11 +2349,10 @@ void VM_HeapDumper::dump_threads(AbstractDumpWriter* writer) {
 }
 
 bool VM_HeapDumper::doit_prologue() {
-  if (_gc_before_heap_dump && UseZGC) {
-    // ZGC cannot perform a synchronous GC cycle from within the VM thread.
-    // So ZCollectedHeap::collect_as_vm_thread() is a noop. To respect the
-    // _gc_before_heap_dump flag a synchronous GC cycle is performed from
-    // the caller thread in the prologue.
+  if (_gc_before_heap_dump && (UseZGC || UseShenandoahGC)) {
+    // ZGC and Shenandoah cannot perform a synchronous GC cycle from within the VM thread.
+    // So collect_as_vm_thread() is a noop. To respect the _gc_before_heap_dump flag a
+    // synchronous GC cycle is performed from the caller thread in the prologue.
     Universe::heap()->collect(GCCause::_heap_dump);
   }
   return VM_GC_Operation::doit_prologue();

src/java.base/share/man/java.md

@@ -1,5 +1,5 @@
 ---
-# Copyright (c) 1994, 2024, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 1994, 2025, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -4002,11 +4002,40 @@ archive, you should make sure that the archive is created by at least version
 -   The CDS archive cannot be loaded if any JAR files in the class path or
     module path are modified after the archive is generated.
 
--   If any of the VM options `--upgrade-module-path`, `--patch-module` or
-    `--limit-modules` are specified, CDS is disabled. This means that the
-    JVM will execute without loading any CDS archives. In addition, if
-    you try to create a CDS archive with any of these 3 options specified,
-    the JVM will report an error.
+### Module related options
+
+The following module related options are supported by CDS: `--module-path`, `--module`,
+`--add-modules`, and `--enable-native-access`.
+
+The values for these options (if specified), should be identical when creating and using the
+CDS archive. Otherwise, if there is a mismatch of any of these options, the CDS archive may be
+partially or completely disabled, leading to lower performance.
+
+- If the -XX:+AOTClassLinking options *was* used during CDS archive creation, the CDS archive
+  cannot be used, and the following error message is printed:
+
+  `CDS archive has aot-linked classes. It cannot be used when archived full module graph is not used`
+
+- If the -XX:+AOTClassLinking options *was not* used during CDS archive creation, the CDS archive
+  can be used, but the "archived module graph" feature will be disabled. This can lead to increased
+  start-up time.
+
+To diagnose problems with the above options, you can add `-Xlog:cds` to the application's VM
+arguments. For example, if `--add-modules jdk.jconcole` was specified during archive creation
+and `--add-modules jdk.incubator.vector` is specified during runtime, the following messages will
+be logged:
+
+ `Mismatched values for property jdk.module.addmods`
+
+ `runtime jdk.incubator.vector dump time jdk.jconsole`
+
+ `subgraph jdk.internal.module.ArchivedBootLayer cannot be used because full module graph is disabled`
+
+If any of the VM options `--upgrade-module-path`, `--patch-module` or
+`--limit-modules` are specified, CDS is disabled. This means that the
+JVM will execute without loading any CDS archives. In addition, if
+you try to create a CDS archive with any of these 3 options specified,
+the JVM will report an error.
 
 ## Performance Tuning Examples
 

src/java.base/windows/classes/java/lang/ProcessImpl.java

@@ -204,13 +204,14 @@ private static String[] getTokensFromCommand(String command) {
     private static final int VERIFICATION_LEGACY = 3;
     // See Command shell overview for documentation of special characters.
     // https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-xp/bb490954(v=technet.10)
-    private static final char ESCAPE_VERIFICATION[][] = {
+    private static final String ESCAPE_VERIFICATION[] = {
         // We guarantee the only command file execution for implicit [cmd.exe] run.
         //    http://technet.microsoft.com/en-us/library/bb490954.aspx
-        {' ', '\t', '\"', '<', '>', '&', '|', '^'},
-        {' ', '\t', '\"', '<', '>'},
-        {' ', '\t', '\"', '<', '>'},
-        {' ', '\t'}
+        // All space characters require quoting are checked in needsEscaping().
+        "\"<>&|^",
+        "\"<>",
+        "\"<>",
+        ""
     };
 
     private static String createCommandLine(int verificationType,
@@ -325,9 +326,14 @@ private static boolean needsEscaping(int verificationType, String arg) {
         }
 
         if (!argIsQuoted) {
-            char testEscape[] = ESCAPE_VERIFICATION[verificationType];
-            for (int i = 0; i < testEscape.length; ++i) {
-                if (arg.indexOf(testEscape[i]) >= 0) {
+            for (int i = 0; i < arg.length(); i++) {
+                char ch = arg.charAt(i);
+                if (Character.isLetterOrDigit(ch))
+                    continue;   // skip over common characters
+                // All space chars require quotes and other mode specific characters
+                if (Character.isSpaceChar(ch) ||
+                        Character.isWhitespace(ch) ||
+                        ESCAPE_VERIFICATION[verificationType].indexOf(ch) >= 0) {
                     return true;
                 }
             }

src/java.desktop/share/native/libawt/java2d/SurfaceData.h

@@ -60,7 +60,7 @@ typedef struct {
 
 #define UNSAFE_TO_SUB(a, b) \
     (((b >= 0) && (a < 0) && (a < (INT_MIN + b))) || \
-     ((b < 0) && (a >= 0) && (-b > (INT_MAX - a)))) \
+     ((b < 0) && (a >= 0) && (a > (INT_MAX + b)))) \
 
 /*
  * The SurfaceDataRasInfo structure is used to pass in and return various

test/hotspot/jtreg/compiler/c2/gvn/TestBoolNodeGVN.java

@@ -56,27 +56,47 @@ public static boolean testShouldReplaceCpmUCase1(int x, int m) {
     @Test
     @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
     @IR(failOn = IRNode.CMP_U,
-            phase = CompilePhase.AFTER_PARSING,
-            applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+        phase = CompilePhase.AFTER_PARSING,
+        applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
     public static boolean testShouldReplaceCpmUCase2(int x, int m) {
         return !(Integer.compareUnsigned((m & x), m) > 0);
     }
 
     @Test
-    @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
+    @Arguments(values = {Argument.DEFAULT, Argument.RANDOM_EACH})
     @IR(failOn = IRNode.CMP_U,
-            phase = CompilePhase.AFTER_PARSING,
-            applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+        phase = CompilePhase.AFTER_PARSING,
+        applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
     public static boolean testShouldReplaceCpmUCase3(int x, int m) {
+        m = Math.max(0, m);
         return Integer.compareUnsigned((x & m), m + 1) < 0;
     }
 
     @Test
-    @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
+    @Arguments(values = {Argument.DEFAULT, Argument.RANDOM_EACH})
     @IR(failOn = IRNode.CMP_U,
-            phase = CompilePhase.AFTER_PARSING,
-            applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+        phase = CompilePhase.AFTER_PARSING,
+        applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
     public static boolean testShouldReplaceCpmUCase4(int x, int m) {
+        m = Math.max(0, m);
+        return Integer.compareUnsigned((m & x), m + 1) < 0;
+    }
+
+    @Test
+    @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
+    @IR(counts = {IRNode.CMP_U, "1"}, // m could be -1 and thus optimization cannot be applied
+        phase = CompilePhase.AFTER_PARSING,
+        applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+    public static boolean testShouldNotReplaceCpmUCase1(int x, int m) {
+        return Integer.compareUnsigned((x & m), m + 1) < 0;
+    }
+
+    @Test
+    @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
+    @IR(counts = {IRNode.CMP_U, "1"}, // m could be -1 and thus optimization cannot be applied
+        phase = CompilePhase.AFTER_PARSING,
+        applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+    public static boolean testShouldNotReplaceCpmUCase2(int x, int m) {
         return Integer.compareUnsigned((m & x), m + 1) < 0;
     }
 
@@ -92,40 +112,41 @@ public static boolean testShouldHaveCpmUCase1(int x, int m) {
     @Test
     @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
     @IR(counts = {IRNode.CMP_U, "1"},
-            phase = CompilePhase.AFTER_PARSING,
-            applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+        phase = CompilePhase.AFTER_PARSING,
+        applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
     public static boolean testShouldHaveCpmUCase2(int x, int m) {
         return !(Integer.compareUnsigned((m & x), m - 1) > 0);
     }
 
     @Test
     @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
     @IR(counts = {IRNode.CMP_U, "1"},
-            phase = CompilePhase.AFTER_PARSING,
-            applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+        phase = CompilePhase.AFTER_PARSING,
+        applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
     public static boolean testShouldHaveCpmUCase3(int x, int m) {
         return Integer.compareUnsigned((x & m), m + 2) < 0;
     }
 
     @Test
     @Arguments(values = {Argument.DEFAULT, Argument.DEFAULT})
     @IR(counts = {IRNode.CMP_U, "1"},
-            phase = CompilePhase.AFTER_PARSING,
-            applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
+        phase = CompilePhase.AFTER_PARSING,
+        applyIfPlatformOr = {"x64", "true", "aarch64", "true", "riscv64", "true"})
     public static boolean testShouldHaveCpmUCase4(int x, int m) {
         return Integer.compareUnsigned((m & x), m + 2) < 0;
     }
 
     private static void testCorrectness() {
         int[] values = {
-                0, 1, 5, 8, 16, 42, 100, new Random().nextInt(0, Integer.MAX_VALUE), Integer.MAX_VALUE
+                -100, -42, -16, -8, -5, -1, 0, 1, 5, 8, 16, 42, 100,
+                new Random().nextInt(), Integer.MAX_VALUE, Integer.MIN_VALUE
         };
 
         for (int x : values) {
             for (int m : values) {
-                if (!testShouldReplaceCpmUCase1(x, m) |
-                    !testShouldReplaceCpmUCase2(x, m) |
-                    !testShouldReplaceCpmUCase3(x, m) |
+                if (!testShouldReplaceCpmUCase1(x, m) ||
+                    !testShouldReplaceCpmUCase2(x, m) ||
+                    !testShouldReplaceCpmUCase3(x, m) ||
                     !testShouldReplaceCpmUCase4(x, m)) {
                     throw new RuntimeException("Bad result for x = " + x + " and m = " + m + ", expected always true");
                 }