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8213436: Obsolete UseMembar

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Reviewed-by: kvn, dholmes, mdoerr, adinn
This commit is contained in:
Mikael Vidstedt 2018-11-08 11:45:13 -08:00
parent 38a1e5ffbc
commit f69921f2fc
57 changed files with 43 additions and 655 deletions
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50
src/hotspot/share/runtime/os.hpp
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@ -100,8 +100,6 @@ class os: AllStatic {
private:
static OSThread* _starting_thread;
static address _polling_page;
static volatile int32_t * _mem_serialize_page;
static uintptr_t _serialize_page_mask;
public:
static size_t _page_sizes[page_sizes_max];
@ -420,54 +418,6 @@ class os: AllStatic {
static bool is_readable_pointer(const void* p);
static bool is_readable_range(const void* from, const void* to);
// Routines used to serialize the thread state without using membars
static void serialize_thread_states();
// Since we write to the serialize page from every thread, we
// want stores to be on unique cache lines whenever possible
// in order to minimize CPU cross talk. We pre-compute the
// amount to shift the thread* to make this offset unique to
// each thread.
static int get_serialize_page_shift_count() {
return SerializePageShiftCount;
}
static void set_serialize_page_mask(uintptr_t mask) {
_serialize_page_mask = mask;
}
static unsigned int get_serialize_page_mask() {
return _serialize_page_mask;
}
static void set_memory_serialize_page(address page);
static address get_memory_serialize_page() {
return (address)_mem_serialize_page;
}
static inline void write_memory_serialize_page(JavaThread *thread) {
uintptr_t page_offset = ((uintptr_t)thread >>
get_serialize_page_shift_count()) &
get_serialize_page_mask();
*(volatile int32_t *)((uintptr_t)_mem_serialize_page+page_offset) = 1;
}
static bool is_memory_serialize_page(JavaThread *thread, address addr) {
if (UseMembar) return false;
// Previously this function calculated the exact address of this
// thread's serialize page, and checked if the faulting address
// was equal. However, some platforms mask off faulting addresses
// to the page size, so now we just check that the address is
// within the page. This makes the thread argument unnecessary,
// but we retain the NULL check to preserve existing behavior.
if (thread == NULL) return false;
address page = (address) _mem_serialize_page;
return addr >= page && addr < (page + os::vm_page_size());
}
static void block_on_serialize_page_trap();
// threads
enum ThreadType {