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comparison src/os/windows/vm/os_windows.cpp @ 7632:2ef7061f13b4

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Merge
author zgu
date Tue, 22 Jan 2013 11:54:16 -0800
parents edd23b35b1a5 22ba8c8ce6a6
children 3ac7d10a6572 9fae07c31641
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equal deleted inserted replaced
7631:edd23b35b1a5 7632:2ef7061f13b4
1 /* 1 /*
2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved. 2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 * 4 *
5 * This code is free software; you can redistribute it and/or modify it 5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as 6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. 7 * published by the Free Software Foundation.
2958 if (res == NULL) { 2958 if (res == NULL) {
2959 warning("NUMA page allocation failed"); 2959 warning("NUMA page allocation failed");
2960 } 2960 }
2961 if( Verbose && PrintMiscellaneous ) { 2961 if( Verbose && PrintMiscellaneous ) {
2962 reserveTimer.stop(); 2962 reserveTimer.stop();
2963 tty->print_cr("reserve_memory of %Ix bytes took %ld ms (%ld ticks)", bytes, 2963 tty->print_cr("reserve_memory of %Ix bytes took " JLONG_FORMAT " ms (" JLONG_FORMAT " ticks)", bytes,
2964 reserveTimer.milliseconds(), reserveTimer.ticks()); 2964 reserveTimer.milliseconds(), reserveTimer.ticks());
2965 } 2965 }
2966 } 2966 }
2967 assert(res == NULL || addr == NULL || addr == res, 2967 assert(res == NULL || addr == NULL || addr == res,
2968 "Unexpected address from reserve."); 2968 "Unexpected address from reserve.");
4317 hFile = CreateFile(file_name, GENERIC_READ, FILE_SHARE_READ, NULL, 4317 hFile = CreateFile(file_name, GENERIC_READ, FILE_SHARE_READ, NULL,
4318 OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL); 4318 OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
4319 if (hFile == NULL) { 4319 if (hFile == NULL) {
4320 if (PrintMiscellaneous && Verbose) { 4320 if (PrintMiscellaneous && Verbose) {
4321 DWORD err = GetLastError(); 4321 DWORD err = GetLastError();
4322 tty->print_cr("CreateFile() failed: GetLastError->%ld."); 4322 tty->print_cr("CreateFile() failed: GetLastError->%ld.", err);
4323 } 4323 }
4324 return NULL; 4324 return NULL;
4325 } 4325 }
4326 4326
4327 if (allow_exec) { 4327 if (allow_exec) {
4367 HANDLE hMap = CreateFileMapping(hFile, NULL, PAGE_WRITECOPY, 0, 0, 4367 HANDLE hMap = CreateFileMapping(hFile, NULL, PAGE_WRITECOPY, 0, 0,
4368 NULL /*file_name*/); 4368 NULL /*file_name*/);
4369 if (hMap == NULL) { 4369 if (hMap == NULL) {
4370 if (PrintMiscellaneous && Verbose) { 4370 if (PrintMiscellaneous && Verbose) {
4371 DWORD err = GetLastError(); 4371 DWORD err = GetLastError();
4372 tty->print_cr("CreateFileMapping() failed: GetLastError->%ld."); 4372 tty->print_cr("CreateFileMapping() failed: GetLastError->%ld.", err);
4373 } 4373 }
4374 CloseHandle(hFile); 4374 CloseHandle(hFile);
4375 return NULL; 4375 return NULL;
4376 } 4376 }
4377 4377
4577 Millis -= prd ; 4577 Millis -= prd ;
4578 } 4578 }
4579 } 4579 }
4580 v = _Event ; 4580 v = _Event ;
4581 _Event = 0 ; 4581 _Event = 0 ;
4582 // see comment at end of os::PlatformEvent::park() below:
4582 OrderAccess::fence() ; 4583 OrderAccess::fence() ;
4583 // If we encounter a nearly simultanous timeout expiry and unpark() 4584 // If we encounter a nearly simultanous timeout expiry and unpark()
4584 // we return OS_OK indicating we awoke via unpark(). 4585 // we return OS_OK indicating we awoke via unpark().
4585 // Implementor's license -- returning OS_TIMEOUT would be equally valid, however. 4586 // Implementor's license -- returning OS_TIMEOUT would be equally valid, however.
4586 return (v >= 0) ? OS_OK : OS_TIMEOUT ; 4587 return (v >= 0) ? OS_OK : OS_TIMEOUT ;
4614 guarantee (_Event >= 0, "invariant") ; 4615 guarantee (_Event >= 0, "invariant") ;
4615 } 4616 }
4616 4617
4617 void os::PlatformEvent::unpark() { 4618 void os::PlatformEvent::unpark() {
4618 guarantee (_ParkHandle != NULL, "Invariant") ; 4619 guarantee (_ParkHandle != NULL, "Invariant") ;
4619 int v ; 4620
4620 for (;;) { 4621 // Transitions for _Event:
4621 v = _Event ; // Increment _Event if it's < 1. 4622 // 0 :=> 1
4622 if (v > 0) { 4623 // 1 :=> 1
4623 // If it's already signaled just return. 4624 // -1 :=> either 0 or 1; must signal target thread
4624 // The LD of _Event could have reordered or be satisfied 4625 // That is, we can safely transition _Event from -1 to either
4625 // by a read-aside from this processor's write buffer. 4626 // 0 or 1. Forcing 1 is slightly more efficient for back-to-back
4626 // To avoid problems execute a barrier and then 4627 // unpark() calls.
4627 // ratify the value. A degenerate CAS() would also work. 4628 // See also: "Semaphores in Plan 9" by Mullender & Cox
4628 // Viz., CAS (v+0, &_Event, v) == v). 4629 //
4629 OrderAccess::fence() ; 4630 // Note: Forcing a transition from "-1" to "1" on an unpark() means
4630 if (_Event == v) return ; 4631 // that it will take two back-to-back park() calls for the owning
4631 continue ; 4632 // thread to block. This has the benefit of forcing a spurious return
4632 } 4633 // from the first park() call after an unpark() call which will help
4633 if (Atomic::cmpxchg (v+1, &_Event, v) == v) break ; 4634 // shake out uses of park() and unpark() without condition variables.
4634 } 4635
4635 if (v < 0) { 4636 if (Atomic::xchg(1, &_Event) >= 0) return;
4636 ::SetEvent (_ParkHandle) ; 4637
4637 } 4638 ::SetEvent(_ParkHandle);
4638 } 4639 }
4639 4640
4640 4641
4641 // JSR166 4642 // JSR166
4642 // ------------------------------------------------------- 4643 // -------------------------------------------------------