--- a/src/hotspot/share/code/nmethod.cpp Thu Nov 01 14:57:26 2018 +0100
+++ b/src/hotspot/share/code/nmethod.cpp Fri Nov 02 08:33:59 2018 +0100
@@ -413,7 +413,6 @@
_oops_do_mark_link = NULL;
_jmethod_id = NULL;
_osr_link = NULL;
- _unloading_next = NULL;
_scavenge_root_link = NULL;
_scavenge_root_state = 0;
#if INCLUDE_RTM_OPT
@@ -599,6 +598,7 @@
code_buffer->copy_code_and_locs_to(this);
code_buffer->copy_values_to(this);
+
if (ScavengeRootsInCode) {
Universe::heap()->register_nmethod(this);
}
@@ -757,6 +757,7 @@
code_buffer->copy_values_to(this);
debug_info->copy_to(this);
dependencies->copy_to(this);
+ clear_unloading_state();
if (ScavengeRootsInCode) {
Universe::heap()->register_nmethod(this);
}
@@ -1025,8 +1026,7 @@
mdo->inc_decompile_count();
}
-void nmethod::make_unloaded(oop cause) {
-
+void nmethod::make_unloaded() {
post_compiled_method_unload();
// This nmethod is being unloaded, make sure that dependencies
@@ -1042,11 +1042,8 @@
LogStream ls(lt);
ls.print("making nmethod " INTPTR_FORMAT
" unloadable, Method*(" INTPTR_FORMAT
- "), cause(" INTPTR_FORMAT ") ",
- p2i(this), p2i(_method), p2i(cause));
- if (cause != NULL) {
- cause->print_value_on(&ls);
- }
+ ") ",
+ p2i(this), p2i(_method));
ls.cr();
}
// Unlink the osr method, so we do not look this up again
@@ -1079,12 +1076,6 @@
// Make the class unloaded - i.e., change state and notify sweeper
assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
- if (is_in_use()) {
- // 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);
@@ -1092,7 +1083,7 @@
_state = unloaded;
// Log the unloading.
- log_state_change(cause);
+ log_state_change();
#if INCLUDE_JVMCI
// The method can only be unloaded after the pointer to the installed code
@@ -1116,7 +1107,7 @@
}
}
-void nmethod::log_state_change(oop cause) const {
+void nmethod::log_state_change() const {
if (LogCompilation) {
if (xtty != NULL) {
ttyLocker ttyl; // keep the following output all in one block
@@ -1129,9 +1120,6 @@
(_state == zombie ? " zombie='1'" : ""));
}
log_identity(xtty);
- if (cause != NULL) {
- xtty->print(" cause='%s'", cause->klass()->external_name());
- }
xtty->stamp();
xtty->end_elem();
}
@@ -1380,21 +1368,6 @@
}
}
-
-// If this oop is not live, the nmethod can be unloaded.
-bool nmethod::can_unload(BoolObjectClosure* is_alive, oop* root) {
- assert(root != NULL, "just checking");
- oop obj = *root;
- if (obj == NULL || is_alive->do_object_b(obj)) {
- return false;
- }
-
- // An nmethod might be unloaded simply because one of its constant oops has gone dead.
- // No actual classes need to be unloaded in order for this to occur.
- make_unloaded(obj);
- return true;
-}
-
// ------------------------------------------------------------------
// post_compiled_method_load_event
// new method for install_code() path
@@ -1468,70 +1441,6 @@
set_unload_reported();
}
-bool nmethod::unload_if_dead_at(RelocIterator* iter_at_oop, BoolObjectClosure *is_alive) {
- assert(iter_at_oop->type() == relocInfo::oop_type, "Wrong relocation type");
-
- oop_Relocation* r = iter_at_oop->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) {
- // Unload this nmethod if the oop is dead.
- if (can_unload(is_alive, r->oop_addr())) {
- return true;;
- }
- }
-
- return false;
-}
-
-bool nmethod::do_unloading_scopes(BoolObjectClosure* is_alive) {
- // 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)) {
- return true;
- }
- }
- return false;
-}
-
-bool nmethod::do_unloading_oops(address low_boundary, BoolObjectClosure* is_alive) {
- // Compiled code
-
- // Prevent extra code cache walk for platforms that don't have immediate oops.
- if (relocInfo::mustIterateImmediateOopsInCode()) {
- RelocIterator iter(this, low_boundary);
- while (iter.next()) {
- if (iter.type() == relocInfo::oop_type) {
- if (unload_if_dead_at(&iter, is_alive)) {
- return true;
- }
- }
- }
- }
-
- return do_unloading_scopes(is_alive);
-}
-
-#if INCLUDE_JVMCI
-bool nmethod::do_unloading_jvmci() {
- if (_jvmci_installed_code != NULL) {
- if (JNIHandles::is_global_weak_cleared(_jvmci_installed_code)) {
- if (_jvmci_installed_code_triggers_invalidation) {
- // The reference to the installed code has been dropped so invalidate
- // this nmethod and allow the sweeper to reclaim it.
- make_not_entrant();
- }
- clear_jvmci_installed_code();
- }
- }
- return false;
-}
-#endif
-
// Iterate over metadata calling this function. Used by RedefineClasses
void nmethod::metadata_do(void f(Metadata*)) {
{
@@ -1579,6 +1488,34 @@
if (_method != NULL) f(_method);
}
+
+// 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(bool unloading_occurred) {
+ // Make sure the oop's ready to receive visitors
+ assert(!is_zombie() && !is_unloaded(),
+ "should not call follow on zombie or unloaded nmethod");
+
+ if (is_unloading()) {
+ make_unloaded();
+ } else {
+#if INCLUDE_JVMCI
+ if (_jvmci_installed_code != NULL) {
+ if (JNIHandles::is_global_weak_cleared(_jvmci_installed_code)) {
+ if (_jvmci_installed_code_triggers_invalidation) {
+ make_not_entrant();
+ }
+ clear_jvmci_installed_code();
+ }
+ }
+#endif
+
+ unload_nmethod_caches(unloading_occurred);
+ }
+}
+
void nmethod::oops_do(OopClosure* f, bool allow_zombie) {
// make sure the oops ready to receive visitors
assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");