java类初始化
· 2 min read
Method* InstanceKlass::class_initializer() const {
Method* clinit = find_method(
vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
if (clinit != NULL && clinit->has_valid_initializer_flags()) {
return clinit;
}
return NULL;
}
寻找方法：
src\hotspot\share\oops\instanceKlass.cpp
int InstanceKlass::find_method_index(const Array<Method*>* methods,
const Symbol* name,
const Symbol* signature,
OverpassLookupMode overpass_mode,
StaticLookupMode static_mode,
PrivateLookupMode private_mode) {
const bool skipping_overpass = (overpass_mode == OverpassLookupMode::skip);
const bool skipping_static = (static_mode == StaticLookupMode::skip);
const bool skipping_private = (private_mode == PrivateLookupMode::skip);
const int hit = quick_search(methods, name);
if (hit != -1) {
const Method* const m = methods->at(hit);
// Do linear search to find matching signature. First, quick check
// for common case, ignoring overpasses if requested.
if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
return hit;
}
// search downwards through overloaded methods
int i;
for (i = hit - 1; i >= 0; --i) {
const Method* const m = methods->at(i);
assert(m->is_method(), "must be method");
if (m->name() != name) {
break;
}
if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
return i;
}
}
// search upwards
for (i = hit + 1; i < methods->length(); ++i) {
const Method* const m = methods->at(i);
assert(m->is_method(), "must be method");
if (m->name() != name) {
break;
}
if (method_matches(m, signature, skipping_overpass, skipping_static, skipping_private)) {
return i;
}
}
// not found
#ifdef ASSERT
const int index = (skipping_overpass || skipping_static || skipping_private) ? -1 :
linear_search(methods, name, signature);
assert(-1 == index, "binary search should have found entry %d", index);
#endif
}
return -1;
}