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src/hotspot/cpu/x86/sharedRuntime_x86_64.cpp
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rev 52710 : Upstream/backport Shenandoah to JDK11u
@@ -1,7 +1,7 @@
/*
- * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2018, 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
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
@@ -31,10 +31,11 @@
#include "code/debugInfoRec.hpp"
#include "code/icBuffer.hpp"
#include "code/nativeInst.hpp"
#include "code/vtableStubs.hpp"
#include "gc/shared/gcLocker.hpp"
+#include "gc/shared/collectedHeap.hpp"
#include "interpreter/interpreter.hpp"
#include "logging/log.hpp"
#include "memory/resourceArea.hpp"
#include "oops/compiledICHolder.hpp"
#include "runtime/safepointMechanism.hpp"
@@ -1432,10 +1433,106 @@
}
}
}
}
+// Pin incoming array argument of java critical method
+static void pin_critical_native_array(MacroAssembler* masm,
+ VMRegPair reg,
+ int& pinned_slot) {
+ assert(UseShenandoahGC, "only supported in Shenandoah for now");
+ __ block_comment("pin_critical_native_array {");
+ Register tmp_reg = rax;
+
+ Label is_null;
+ VMRegPair tmp;
+ VMRegPair in_reg = reg;
+ bool on_stack = false;
+
+ tmp.set_ptr(tmp_reg->as_VMReg());
+ if (reg.first()->is_stack()) {
+ // Load the arg up from the stack
+ move_ptr(masm, reg, tmp);
+ reg = tmp;
+ on_stack = true;
+ } else {
+ __ movptr(rax, reg.first()->as_Register());
+ }
+ __ testptr(reg.first()->as_Register(), reg.first()->as_Register());
+ __ jccb(Assembler::equal, is_null);
+
+ __ push(c_rarg0);
+ __ push(c_rarg1);
+ __ push(c_rarg2);
+ __ push(c_rarg3);
+#ifdef _WIN64
+ // caller-saved registers on Windows
+ __ push(r10);
+ __ push(r11);
+#else
+ __ push(c_rarg4);
+ __ push(c_rarg5);
+#endif
+
+ if (reg.first()->as_Register() != c_rarg1) {
+ __ movptr(c_rarg1, reg.first()->as_Register());
+ }
+ __ movptr(c_rarg0, r15_thread);
+ __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::pin_object)));
+
+#ifdef _WIN64
+ __ pop(r11);
+ __ pop(r10);
+#else
+ __ pop(c_rarg5);
+ __ pop(c_rarg4);
+#endif
+ __ pop(c_rarg3);
+ __ pop(c_rarg2);
+ __ pop(c_rarg1);
+ __ pop(c_rarg0);
+
+ if (on_stack) {
+ __ movptr(Address(rbp, reg2offset_in(in_reg.first())), rax);
+ __ bind(is_null);
+ } else {
+ __ movptr(reg.first()->as_Register(), rax);
+
+ // save on stack for unpinning later
+ __ bind(is_null);
+ assert(reg.first()->is_Register(), "Must be a register");
+ int offset = pinned_slot * VMRegImpl::stack_slot_size;
+ pinned_slot += VMRegImpl::slots_per_word;
+ __ movq(Address(rsp, offset), rax);
+ }
+ __ block_comment("} pin_critical_native_array");
+}
+
+// Unpin array argument of java critical method
+static void unpin_critical_native_array(MacroAssembler* masm,
+ VMRegPair reg,
+ int& pinned_slot) {
+ assert(UseShenandoahGC, "only supported in Shenandoah for now");
+ __ block_comment("unpin_critical_native_array {");
+ Label is_null;
+
+ if (reg.first()->is_stack()) {
+ __ movptr(c_rarg1, Address(rbp, reg2offset_in(reg.first())));
+ } else {
+ int offset = pinned_slot * VMRegImpl::stack_slot_size;
+ pinned_slot += VMRegImpl::slots_per_word;
+ __ movq(c_rarg1, Address(rsp, offset));
+ }
+ __ testptr(c_rarg1, c_rarg1);
+ __ jccb(Assembler::equal, is_null);
+
+ __ movptr(c_rarg0, r15_thread);
+ __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::unpin_object)));
+
+ __ bind(is_null);
+ __ block_comment("} unpin_critical_native_array");
+}
// Check GCLocker::needs_gc and enter the runtime if it's true. This
// keeps a new JNI critical region from starting until a GC has been
// forced. Save down any oops in registers and describe them in an
// OopMap.
@@ -2128,11 +2225,11 @@
// We use r14 as the oop handle for the receiver/klass
// It is callee save so it survives the call to native
const Register oop_handle_reg = r14;
- if (is_critical_native) {
+ if (is_critical_native && !Universe::heap()->supports_object_pinning()) {
check_needs_gc_for_critical_native(masm, stack_slots, total_c_args, total_in_args,
oop_handle_offset, oop_maps, in_regs, in_sig_bt);
}
//
@@ -2185,10 +2282,15 @@
// This may iterate in two different directions depending on the
// kind of native it is. The reason is that for regular JNI natives
// the incoming and outgoing registers are offset upwards and for
// critical natives they are offset down.
GrowableArray<int> arg_order(2 * total_in_args);
+ // Inbound arguments that need to be pinned for critical natives
+ GrowableArray<int> pinned_args(total_in_args);
+ // Current stack slot for storing register based array argument
+ int pinned_slot = oop_handle_offset;
+
VMRegPair tmp_vmreg;
tmp_vmreg.set2(rbx->as_VMReg());
if (!is_critical_native) {
for (int i = total_in_args - 1, c_arg = total_c_args - 1; i >= 0; i--, c_arg--) {
@@ -2232,10 +2334,16 @@
}
#endif /* ASSERT */
switch (in_sig_bt[i]) {
case T_ARRAY:
if (is_critical_native) {
+ // pin before unpack
+ if (Universe::heap()->supports_object_pinning()) {
+ assert(pinned_slot <= stack_slots, "overflow");
+ pin_critical_native_array(masm, in_regs[i], pinned_slot);
+ pinned_args.append(i);
+ }
unpack_array_argument(masm, in_regs[i], in_elem_bt[i], out_regs[c_arg + 1], out_regs[c_arg]);
c_arg++;
#ifdef ASSERT
if (out_regs[c_arg].first()->is_Register()) {
reg_destroyed[out_regs[c_arg].first()->as_Register()->encoding()] = true;
@@ -2448,10 +2556,23 @@
case T_VOID: break;
case T_LONG: break;
default : ShouldNotReachHere();
}
+ // unpin pinned arguments
+ pinned_slot = oop_handle_offset;
+ if (pinned_args.length() > 0) {
+ // save return value that may be overwritten otherwise.
+ save_native_result(masm, ret_type, stack_slots);
+ for (int index = 0; index < pinned_args.length(); index ++) {
+ int i = pinned_args.at(index);
+ assert(pinned_slot <= stack_slots, "overflow");
+ unpin_critical_native_array(masm, in_regs[i], pinned_slot);
+ }
+ restore_native_result(masm, ret_type, stack_slots);
+ }
+
// Switch thread to "native transition" state before reading the synchronization state.
// This additional state is necessary because reading and testing the synchronization
// state is not atomic w.r.t. GC, as this scenario demonstrates:
// Java thread A, in _thread_in_native state, loads _not_synchronized and is preempted.
// VM thread changes sync state to synchronizing and suspends threads for GC.
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