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src/os_cpu/solaris_x86/vm/threadLS_solaris_x86.cpp
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@@ -1,7 +1,7 @@
/*
- * Copyright (c) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
@@ -24,169 +24,29 @@
#include "precompiled.hpp"
#include "runtime/thread.inline.hpp"
#include "runtime/threadLocalStorage.hpp"
-#ifdef AMD64
-extern "C" Thread* fs_load(ptrdiff_t tlsOffset);
-extern "C" intptr_t fs_thread();
-#else
-// From solaris_i486.s
-extern "C" Thread* gs_load(ptrdiff_t tlsOffset);
-extern "C" intptr_t gs_thread();
-#endif // AMD64
+// True thread-local variable
+__thread Thread * ThreadLocalStorage::_thr_current = NULL;
-// tlsMode encoding:
-//
-// pd_tlsAccessUndefined : uninitialized
-// pd_tlsAccessSlow : not available
-// pd_tlsAccessIndirect :
-// old-style indirect access - present in "T1" libthread.
-// use thr_slot_sync_allocate() to attempt to allocate a slot.
-// pd_tlsAccessDirect :
-// new-style direct access - present in late-model "T2" libthread.
-// Allocate the offset (slot) via _thr_slot_offset() or by
-// defining an IE- or LE-mode TLS/TSD slot in the launcher and then passing
-// that offset into libjvm.so.
-// See http://sac.eng/Archives/CaseLog/arc/PSARC/2003/159/.
-//
-// Note that we have a capability gap - some early model T2 forms
-// (e.g., unpatched S9) have neither _thr_slot_sync_allocate() nor
-// _thr_slot_offset(). In that case we revert to the usual
-// thr_getspecific accessor.
-//
+// Implementations needed to support the shared API
-static ThreadLocalStorage::pd_tlsAccessMode tlsMode = ThreadLocalStorage::pd_tlsAccessUndefined ;
-static ptrdiff_t tlsOffset = 0 ;
-static thread_key_t tlsKey ;
+void ThreadLocalStorage::pd_invalidate_all() {} // nothing to do
-typedef int (*TSSA_Entry) (ptrdiff_t *, int, int) ;
-typedef ptrdiff_t (*TSO_Entry) (int) ;
+bool ThreadLocalStorage::_initialized = false;
-ThreadLocalStorage::pd_tlsAccessMode ThreadLocalStorage::pd_getTlsAccessMode ()
-{
- guarantee (tlsMode != pd_tlsAccessUndefined, "tlsMode not set") ;
- return tlsMode ;
+void ThreadLocalStorage::init() {
+ _initialized = true;
}
-ptrdiff_t ThreadLocalStorage::pd_getTlsOffset () {
- guarantee (tlsMode != pd_tlsAccessUndefined, "tlsMode not set") ;
- return tlsOffset ;
+bool ThreadLocalStorage::is_initialized() {
+ return _initialized;
}
-// TODO: Consider the following improvements:
-//
-// 1. Convert from thr_*specific* to pthread_*specific*.
-// The pthread_ forms are slightly faster. Also, the
-// pthread_ forms have a pthread_key_delete() API which
-// would aid in clean JVM shutdown and the eventual goal
-// of permitting a JVM to reinstantiate itself withing a process.
-//
-// 2. See ThreadLocalStorage::init(). We end up allocating
-// two TLS keys during VM startup. That's benign, but we could collapse
-// down to one key without too much trouble.
-//
-// 3. MacroAssembler::get_thread() currently emits calls to thr_getspecific().
-// Modify get_thread() to call Thread::current() instead.
-//
-// 4. Thread::current() currently uses a cache keyed by %gs:[0].
-// (The JVM has PSARC permission to use %g7/%gs:[0]
-// as an opaque temporally unique thread identifier).
-// For C++ access to a thread's reflexive "self" pointer we
-// should consider using one of the following:
-// a. a radix tree keyed by %esp - as in EVM.
-// This requires two loads (the 2nd dependent on the 1st), but
-// is easily inlined and doesn't require a "miss" slow path.
-// b. a fast TLS/TSD slot allocated by _thr_slot_offset
-// or _thr_slot_sync_allocate.
-//
-// 5. 'generate_code_for_get_thread' is a misnomer.
-// We should change it to something more general like
-// pd_ThreadSelf_Init(), for instance.
-//
-
-static void AllocateTLSOffset ()
-{
- int rslt ;
- TSSA_Entry tssa ;
- TSO_Entry tso ;
- ptrdiff_t off ;
-
- guarantee (tlsMode == ThreadLocalStorage::pd_tlsAccessUndefined, "tlsMode not set") ;
- tlsMode = ThreadLocalStorage::pd_tlsAccessSlow ;
- tlsOffset = 0 ;
-#ifndef AMD64
-
- tssa = (TSSA_Entry) dlsym (RTLD_DEFAULT, "thr_slot_sync_allocate") ;
- if (tssa != NULL) {
- off = -1 ;
- rslt = (*tssa)(&off, NULL, NULL) ; // (off,dtor,darg)
- if (off != -1) {
- tlsOffset = off ;
- tlsMode = ThreadLocalStorage::pd_tlsAccessIndirect ;
- return ;
- }
- }
-
- rslt = thr_keycreate (&tlsKey, NULL) ;
- if (rslt != 0) {
- tlsMode = ThreadLocalStorage::pd_tlsAccessSlow ; // revert to slow mode
- return ;
- }
-
- tso = (TSO_Entry) dlsym (RTLD_DEFAULT, "_thr_slot_offset") ;
- if (tso != NULL) {
- off = (*tso)(tlsKey) ;
- if (off >= 0) {
- tlsOffset = off ;
- tlsMode = ThreadLocalStorage::pd_tlsAccessDirect ;
- return ;
- }
- }
-
- // Failure: Too bad ... we've allocated a TLS slot we don't need and there's
- // no provision in the ABI for returning the slot.
- //
- // If we didn't find a slot then then:
- // 1. We might be on liblwp.
- // 2. We might be on T2 libthread, but all "fast" slots are already
- // consumed
- // 3. We might be on T1, and all TSD (thr_slot_sync_allocate) slots are
- // consumed.
- // 4. We might be on T2 libthread, but it's be re-architected
- // so that fast slots are no longer g7-relative.
- //
-
- tlsMode = ThreadLocalStorage::pd_tlsAccessSlow ;
- return ;
-#endif // AMD64
+Thread* ThreadLocalStorage::get_thread_slow() {
+ return thread();
}
-void ThreadLocalStorage::generate_code_for_get_thread() {
- AllocateTLSOffset() ;
-}
-
-void ThreadLocalStorage::set_thread_in_slot(Thread *thread) {
- guarantee (tlsMode != pd_tlsAccessUndefined, "tlsMode not set") ;
- if (tlsMode == pd_tlsAccessIndirect) {
-#ifdef AMD64
- intptr_t tbase = fs_thread();
-#else
- intptr_t tbase = gs_thread();
-#endif // AMD64
- *((Thread**) (tbase + tlsOffset)) = thread ;
- } else
- if (tlsMode == pd_tlsAccessDirect) {
- thr_setspecific (tlsKey, (void *) thread) ;
- // set with thr_setspecific and then readback with gs_load to validate.
-#ifdef AMD64
- guarantee (thread == fs_load(tlsOffset), "tls readback failure") ;
-#else
- guarantee (thread == gs_load(tlsOffset), "tls readback failure") ;
-#endif // AMD64
- }
-}
-
-
extern "C" Thread* get_thread() {
return ThreadLocalStorage::thread();
}
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