jdk-sandbox: comparison hotspot/src/share/vm/code/nmethod.cpp

equal deleted inserted replaced

-:70fb742e40aa
+:d27050bdfb04
 #include "shark/sharkCompiler.hpp"
 #endif
 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
+unsigned char nmethod::_global_unloading_clock = 0;
 #ifdef DTRACE_ENABLED
 // Only bother with this argument setup if dtrace is available
 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
 }
 // Fill in default values for various flag fields
 void nmethod::init_defaults() {
 _state                      = in_use;
+_unloading_clock            = 0;
 _marked_for_reclamation     = 0;
 _has_flushed_dependencies   = 0;
 _has_unsafe_access          = 0;
 _has_method_handle_invokes  = 0;
 _lazy_critical_native       = 0;
 #endif
 _oops_do_mark_link       = NULL;
 _jmethod_id              = NULL;
 _osr_link                = NULL;
-_scavenge_root_link      = NULL;
+if (UseG1GC) {
+_unloading_next        = NULL;
+} else {
+_scavenge_root_link    = NULL;
+}
 _scavenge_root_state     = 0;
 _compiler                = NULL;
 #if INCLUDE_RTM_OPT
 _rtm_state               = NoRTM;
 #endif
 }
 }
 }
 }
+void nmethod::verify_clean_inline_caches() {
+assert_locked_or_safepoint(CompiledIC_lock);
+// If the method is not entrant or zombie then a JMP is plastered over the
+// first few bytes.  If an oop in the old code was there, that oop
+// should not get GC'd.  Skip the first few bytes of oops on
+// not-entrant methods.
+address low_boundary = verified_entry_point();
+if (!is_in_use()) {
+low_boundary += NativeJump::instruction_size;
+// %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
+// This means that the low_boundary is going to be a little too high.
+// This shouldn't matter, since oops of non-entrant methods are never used.
+// In fact, why are we bothering to look at oops in a non-entrant method??
+}
+ResourceMark rm;
+RelocIterator iter(this, low_boundary);
+while(iter.next()) {
+switch(iter.type()) {
+case relocInfo::virtual_call_type:
+case relocInfo::opt_virtual_call_type: {
+CompiledIC *ic = CompiledIC_at(&iter);
+// Ok, to lookup references to zombies here
+CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
+if( cb != NULL && cb->is_nmethod() ) {
+nmethod* nm = (nmethod*)cb;
+// Verify that inline caches pointing to both zombie and not_entrant methods are clean
+if (!nm->is_in_use() || (nm->method()->code() != nm)) {
+assert(ic->is_clean(), "IC should be clean");
+}
+}
+break;
+}
+case relocInfo::static_call_type: {
+CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
+CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
+if( cb != NULL && cb->is_nmethod() ) {
+nmethod* nm = (nmethod*)cb;
+// Verify that inline caches pointing to both zombie and not_entrant methods are clean
+if (!nm->is_in_use() || (nm->method()->code() != nm)) {
+assert(csc->is_clean(), "IC should be clean");
+}
+}
+break;
+}
+}
+}
+}
+int nmethod::verify_icholder_relocations() {
+int count = 0;
+RelocIterator iter(this);
+while(iter.next()) {
+if (iter.type() == relocInfo::virtual_call_type) {
+if (CompiledIC::is_icholder_call_site(iter.virtual_call_reloc())) {
+CompiledIC *ic = CompiledIC_at(&iter);
+if (TraceCompiledIC) {
+tty->print("noticed icholder " INTPTR_FORMAT " ", p2i(ic->cached_icholder()));
+ic->print();
+}
+assert(ic->cached_icholder() != NULL, "must be non-NULL");
+count++;
+}
+}
+}
+return count;
+}
 // This is a private interface with the sweeper.
 void nmethod::mark_as_seen_on_stack() {
 assert(is_alive(), "Must be an alive method");
 // Set the traversal mark to ensure that the sweeper does 2
 // cleaning passes before moving to zombie.
 if (mdo == NULL)  return;
 // There is a benign race here.  See comments in methodData.hpp.
 mdo->inc_decompile_count();
 }
+void nmethod::increase_unloading_clock() {
+_global_unloading_clock++;
+if (_global_unloading_clock == 0) {
+// _nmethods are allocated with _unloading_clock == 0,
+// so 0 is never used as a clock value.
+_global_unloading_clock = 1;
+}
+}
+void nmethod::set_unloading_clock(unsigned char unloading_clock) {
+OrderAccess::release_store((volatile jubyte*)&_unloading_clock, unloading_clock);
+}
+unsigned char nmethod::unloading_clock() {
+return (unsigned char)OrderAccess::load_acquire((volatile jubyte*)&_unloading_clock);
+}
 void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
 post_compiled_method_unload();
 // Since this nmethod is being unloaded, make sure that dependencies
 // Transitioning directly from live to unloaded -- so
 // we need to force a cache clean-up; remember this
 // for later on.
 CodeCache::set_needs_cache_clean(true);
 }
+// Unregister must be done before the state change
+Universe::heap()->unregister_nmethod(this);
 _state = unloaded;
 // Log the unloading.
 log_state_change();
 // attempt to report the event in the unlikely scenario where the
 // event is enabled at the time the nmethod is made a zombie.
 set_unload_reported();
 }
+void static clean_ic_if_metadata_is_dead(CompiledIC *ic, BoolObjectClosure *is_alive) {
+if (ic->is_icholder_call()) {
+// The only exception is compiledICHolder oops which may
+// yet be marked below. (We check this further below).
+CompiledICHolder* cichk_oop = ic->cached_icholder();
+if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) &&
+cichk_oop->holder_klass()->is_loader_alive(is_alive)) {
+return;
+}
+} else {
+Metadata* ic_oop = ic->cached_metadata();
+if (ic_oop != NULL) {
+if (ic_oop->is_klass()) {
+if (((Klass*)ic_oop)->is_loader_alive(is_alive)) {
+return;
+}
+} else if (ic_oop->is_method()) {
+if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) {
+return;
+}
+} else {
+ShouldNotReachHere();
+}
+}
+}
+ic->set_to_clean();
+}
 // This is called at the end of the strong tracing/marking phase of a
 // GC to unload an nmethod if it contains otherwise unreachable
 // oops.
 void nmethod::do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred) {
 if (unloading_occurred) {
 RelocIterator iter(this, low_boundary);
 while(iter.next()) {
 if (iter.type() == relocInfo::virtual_call_type) {
 CompiledIC *ic = CompiledIC_at(&iter);
-if (ic->is_icholder_call()) {
+clean_ic_if_metadata_is_dead(ic, is_alive);
-// The only exception is compiledICHolder oops which may
-// yet be marked below. (We check this further below).
-CompiledICHolder* cichk_oop = ic->cached_icholder();
-if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) &&
-cichk_oop->holder_klass()->is_loader_alive(is_alive)) {
-continue;
-}
-} else {
-Metadata* ic_oop = ic->cached_metadata();
-if (ic_oop != NULL) {
-if (ic_oop->is_klass()) {
-if (((Klass*)ic_oop)->is_loader_alive(is_alive)) {
-continue;
-}
-} else if (ic_oop->is_method()) {
-if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) {
-continue;
-}
-} else {
-ShouldNotReachHere();
-}
-}
-}
-ic->set_to_clean();
 }
 }
 }
 // Compiled code
 }
 }
 // Ensure that all metadata is still alive
 verify_metadata_loaders(low_boundary, is_alive);
+}
+template <class CompiledICorStaticCall>
+static bool clean_if_nmethod_is_unloaded(CompiledICorStaticCall *ic, address addr, BoolObjectClosure *is_alive, nmethod* from) {
+// Ok, to lookup references to zombies here
+CodeBlob *cb = CodeCache::find_blob_unsafe(addr);
+if (cb != NULL && cb->is_nmethod()) {
+nmethod* nm = (nmethod*)cb;
+if (nm->unloading_clock() != nmethod::global_unloading_clock()) {
+// The nmethod has not been processed yet.
+return true;
+}
+// Clean inline caches pointing to both zombie and not_entrant methods
+if (!nm->is_in_use() || (nm->method()->code() != nm)) {
+ic->set_to_clean();
+assert(ic->is_clean(), err_msg("nmethod " PTR_FORMAT "not clean %s", from, from->method()->name_and_sig_as_C_string()));
+}
+}
+return false;
+}
+static bool clean_if_nmethod_is_unloaded(CompiledIC *ic, BoolObjectClosure *is_alive, nmethod* from) {
+return clean_if_nmethod_is_unloaded(ic, ic->ic_destination(), is_alive, from);
+}
+static bool clean_if_nmethod_is_unloaded(CompiledStaticCall *csc, BoolObjectClosure *is_alive, nmethod* from) {
+return clean_if_nmethod_is_unloaded(csc, csc->destination(), is_alive, from);
+}
+bool nmethod::do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred) {
+ResourceMark rm;
+// Make sure the oop's ready to receive visitors
+assert(!is_zombie() && !is_unloaded(),
+"should not call follow on zombie or unloaded nmethod");
+// If the method is not entrant then a JMP is plastered over the
+// first few bytes.  If an oop in the old code was there, that oop
+// should not get GC'd.  Skip the first few bytes of oops on
+// not-entrant methods.
+address low_boundary = verified_entry_point();
+if (is_not_entrant()) {
+low_boundary += NativeJump::instruction_size;
+// %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
+// (See comment above.)
+}
+// The RedefineClasses() API can cause the class unloading invariant
+// to no longer be true. See jvmtiExport.hpp for details.
+// Also, leave a debugging breadcrumb in local flag.
+bool a_class_was_redefined = JvmtiExport::has_redefined_a_class();
+if (a_class_was_redefined) {
+// This set of the unloading_occurred flag is done before the
+// call to post_compiled_method_unload() so that the unloading
+// of this nmethod is reported.
+unloading_occurred = true;
+}
+// Exception cache
+clean_exception_cache(is_alive);
+bool is_unloaded = false;
+bool postponed = false;
+RelocIterator iter(this, low_boundary);
+while(iter.next()) {
+switch (iter.type()) {
+case relocInfo::virtual_call_type:
+if (unloading_occurred) {
+// If class unloading occurred we first iterate over all inline caches and
+// clear ICs where the cached oop is referring to an unloaded klass or method.
+clean_ic_if_metadata_is_dead(CompiledIC_at(&iter), is_alive);
+}
+postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
+break;
+case relocInfo::opt_virtual_call_type:
+postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
+break;
+case relocInfo::static_call_type:
+postponed |= clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this);
+break;
+case relocInfo::oop_type:
+if (!is_unloaded) {
+// Unload check
+oop_Relocation* r = iter.oop_reloc();
+// Traverse those oops directly embedded in the code.
+// Other oops (oop_index>0) are seen as part of scopes_oops.
+assert(1 == (r->oop_is_immediate()) +
+(r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
+"oop must be found in exactly one place");
+if (r->oop_is_immediate() && r->oop_value() != NULL) {
+if (can_unload(is_alive, r->oop_addr(), unloading_occurred)) {
+is_unloaded = true;
+}
+}
+}
+break;
+}
+}
+if (is_unloaded) {
+return postponed;
+}
+// Scopes
+for (oop* p = oops_begin(); p < oops_end(); p++) {
+if (*p == Universe::non_oop_word())  continue;  // skip non-oops
+if (can_unload(is_alive, p, unloading_occurred)) {
+is_unloaded = true;
+break;
+}
+}
+if (is_unloaded) {
+return postponed;
+}
+// Ensure that all metadata is still alive
+verify_metadata_loaders(low_boundary, is_alive);
+return postponed;
+}
+void nmethod::do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred) {
+ResourceMark rm;
+// Make sure the oop's ready to receive visitors
+assert(!is_zombie(),
+"should not call follow on zombie nmethod");
+// If the method is not entrant then a JMP is plastered over the
+// first few bytes.  If an oop in the old code was there, that oop
+// should not get GC'd.  Skip the first few bytes of oops on
+// not-entrant methods.
+address low_boundary = verified_entry_point();
+if (is_not_entrant()) {
+low_boundary += NativeJump::instruction_size;
+// %%% Note:  On SPARC we patch only a 4-byte trap, not a full NativeJump.
+// (See comment above.)
+}
+RelocIterator iter(this, low_boundary);
+while(iter.next()) {
+switch (iter.type()) {
+case relocInfo::virtual_call_type:
+clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
+break;
+case relocInfo::opt_virtual_call_type:
+clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
+break;
+case relocInfo::static_call_type:
+clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this);
+break;
+}
+}
 }
 #ifdef ASSERT
 class CheckClass : AllStatic {
 nmethod* cur = _oops_do_mark_nmethods;
 while (cur != NMETHOD_SENTINEL) {
 assert(cur != NULL, "not NULL-terminated");
 nmethod* next = cur->_oops_do_mark_link;
 cur->_oops_do_mark_link = NULL;
-cur->fix_oop_relocations();
+cur->verify_oop_relocations();
 NOT_PRODUCT(if (TraceScavenge)  cur->print_on(tty, "oops_do, unmark"));
 cur = next;
 }
 void* required = _oops_do_mark_nmethods;
 void* observed = Atomic::cmpxchg_ptr(NULL, &_oops_do_mark_nmethods, required);
 }
 virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
 };
 void nmethod::verify_scavenge_root_oops() {
+if (UseG1GC) {
+return;
+}
 if (!on_scavenge_root_list()) {
 // Actually look inside, to verify the claim that it's clean.
 DebugScavengeRoot debug_scavenge_root(this);
 oops_do(&debug_scavenge_root);
 if (!debug_scavenge_root.ok())

changeset 25492	d27050bdfb04
parent 25491	70fb742e40aa
child 26558	b7df27df6384