archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-09-21 11:34:38 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

Merge

Browse source
This commit is contained in:
Y. Srinivas Ramakrishna 2008-06-12 13:50:55 -07:00
commit ac061d0424
782 changed files with 51393 additions and 7280 deletions
Download patch file Download diff file Expand all files Collapse all files

50
hotspot/src/share/vm/oops/markOop.hpp
View file

@ -29,8 +29,10 @@
//
// Bit-format of an object header (most significant first):
//
//
// unused:0/25 hash:25/31 age:4 biased_lock:1 lock:2 = 32/64 bits
// 32 bits: unused:0 hash:25 age:4 biased_lock:1 lock:2
// 64 bits: unused:24 hash:31 cms:2 age:4 biased_lock:1 lock:2
// unused:20 size:35 cms:2 age:4 biased_lock:1 lock:2 (if cms
// free chunk)
//
// - hash contains the identity hash value: largest value is
// 31 bits, see os::random(). Also, 64-bit vm's require
@ -91,6 +93,7 @@ class markOopDesc: public oopDesc {
biased_lock_bits = 1,
max_hash_bits = BitsPerWord - age_bits - lock_bits - biased_lock_bits,
hash_bits = max_hash_bits > 31 ? 31 : max_hash_bits,
cms_bits = LP64_ONLY(1) NOT_LP64(0),
epoch_bits = 2
};
@ -106,7 +109,8 @@ class markOopDesc: public oopDesc {
enum { lock_shift = 0,
biased_lock_shift = lock_bits,
age_shift = lock_bits + biased_lock_bits,
hash_shift = lock_bits + biased_lock_bits + age_bits,
cms_shift = age_shift + age_bits,
hash_shift = cms_shift + cms_bits,
epoch_shift = hash_shift
};
@ -118,7 +122,9 @@ class markOopDesc: public oopDesc {
age_mask = right_n_bits(age_bits),
age_mask_in_place = age_mask << age_shift,
epoch_mask = right_n_bits(epoch_bits),
epoch_mask_in_place = epoch_mask << epoch_shift
epoch_mask_in_place = epoch_mask << epoch_shift,
cms_mask = right_n_bits(cms_bits),
cms_mask_in_place = cms_mask << cms_shift
#ifndef _WIN64
,hash_mask = right_n_bits(hash_bits),
hash_mask_in_place = (address_word)hash_mask << hash_shift
@ -348,4 +354,40 @@ class markOopDesc: public oopDesc {
// see the definition in markOop.cpp for the gory details
bool should_not_be_cached() const;
// These markOops indicate cms free chunk blocks and not objects.
// In 64 bit, the markOop is set to distinguish them from oops.
// These are defined in 32 bit mode for vmStructs.
const static uintptr_t cms_free_chunk_pattern = 0x1;
// Constants for the size field.
enum { size_shift = cms_shift + cms_bits,
size_bits = 35 // need for compressed oops 32G
};
// These values are too big for Win64
const static uintptr_t size_mask = LP64_ONLY(right_n_bits(size_bits))
NOT_LP64(0);
const static uintptr_t size_mask_in_place =
(address_word)size_mask << size_shift;
#ifdef _LP64
static markOop cms_free_prototype() {
return markOop(((intptr_t)prototype() & ~cms_mask_in_place) |
((cms_free_chunk_pattern & cms_mask) << cms_shift));
}
uintptr_t cms_encoding() const {
return mask_bits(value() >> cms_shift, cms_mask);
}
bool is_cms_free_chunk() const {
return is_neutral() &&
(cms_encoding() & cms_free_chunk_pattern) == cms_free_chunk_pattern;
}
size_t get_size() const { return (size_t)(value() >> size_shift); }
static markOop set_size_and_free(size_t size) {
assert((size & ~size_mask) == 0, "shouldn't overflow size field");
return markOop(((intptr_t)cms_free_prototype() & ~size_mask_in_place) |
(((intptr_t)size & size_mask) << size_shift));
}
#endif // _LP64
};