diff options
Diffstat (limited to 'src/VBox/Runtime/generic/spinlock-generic.cpp')
| -rw-r--r-- | src/VBox/Runtime/generic/spinlock-generic.cpp | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/src/VBox/Runtime/generic/spinlock-generic.cpp b/src/VBox/Runtime/generic/spinlock-generic.cpp new file mode 100644 index 00000000..65109c03 --- /dev/null +++ b/src/VBox/Runtime/generic/spinlock-generic.cpp @@ -0,0 +1,227 @@ +/* $Id: spinlock-generic.cpp $ */ +/** @file + * IPRT - Spinlock, generic implementation. + */ + +/* + * Copyright (C) 2006-2019 Oracle Corporation + * + * This file is part of VirtualBox Open Source Edition (OSE), as + * available from http://www.virtualbox.org. This file is free software; + * you can redistribute it and/or modify it under the terms of the GNU + * General Public License (GPL) as published by the Free Software + * Foundation, in version 2 as it comes in the "COPYING" file of the + * VirtualBox OSE distribution. VirtualBox OSE is distributed in the + * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL) only, as it comes in the "COPYING.CDDL" file of the + * VirtualBox OSE distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + */ + + +/********************************************************************************************************************************* +* Defined Constants And Macros * +*********************************************************************************************************************************/ +/** @def RT_CFG_SPINLOCK_GENERIC_DO_SLEEP + * Force cpu yields after spinning the number of times indicated by the define. + * If 0 we will spin forever. */ +#define RT_CFG_SPINLOCK_GENERIC_DO_SLEEP 100000 + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#include <iprt/spinlock.h> +#include "internal/iprt.h" + +#include <iprt/alloc.h> +#include <iprt/asm.h> +#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) +# include <iprt/asm-amd64-x86.h> +#endif +#include <iprt/errcore.h> +#include <iprt/assert.h> +#if RT_CFG_SPINLOCK_GENERIC_DO_SLEEP +# include <iprt/thread.h> +#endif + +#include "internal/magics.h" + + +/********************************************************************************************************************************* +* Structures and Typedefs * +*********************************************************************************************************************************/ +/** + * Generic spinlock structure. + */ +typedef struct RTSPINLOCKINTERNAL +{ + /** Spinlock magic value (RTSPINLOCK_GEN_MAGIC). */ + uint32_t u32Magic; + /** The spinlock creation flags. */ + uint32_t fFlags; + /** The spinlock. */ + uint32_t volatile fLocked; + /** The saved CPU interrupt. */ + uint32_t volatile fIntSaved; +} RTSPINLOCKINTERNAL, *PRTSPINLOCKINTERNAL; + + +RTDECL(int) RTSpinlockCreate(PRTSPINLOCK pSpinlock, uint32_t fFlags, const char *pszName) +{ + PRTSPINLOCKINTERNAL pThis; + AssertReturn(fFlags == RTSPINLOCK_FLAGS_INTERRUPT_SAFE || fFlags == RTSPINLOCK_FLAGS_INTERRUPT_UNSAFE, VERR_INVALID_PARAMETER); + RT_NOREF_PV(pszName); + + /* + * Allocate. + */ + pThis = (PRTSPINLOCKINTERNAL)RTMemAlloc(sizeof(*pThis)); + if (!pThis) + return VERR_NO_MEMORY; + + /* + * Initialize and return. + */ + pThis->u32Magic = RTSPINLOCK_GEN_MAGIC; + pThis->fFlags = fFlags; + pThis->fIntSaved = 0; + ASMAtomicWriteU32(&pThis->fLocked, 0); + + *pSpinlock = pThis; + return VINF_SUCCESS; +} +RT_EXPORT_SYMBOL(RTSpinlockCreate); + + +RTDECL(int) RTSpinlockDestroy(RTSPINLOCK Spinlock) +{ + /* + * Validate input. + */ + PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock; + if (!pThis) + return VERR_INVALID_PARAMETER; + if (pThis->u32Magic != RTSPINLOCK_GEN_MAGIC) + { + AssertMsgFailed(("Invalid spinlock %p magic=%#x\n", pThis, pThis->u32Magic)); + return VERR_INVALID_PARAMETER; + } + + ASMAtomicIncU32(&pThis->u32Magic); + RTMemFree(pThis); + return VINF_SUCCESS; +} +RT_EXPORT_SYMBOL(RTSpinlockDestroy); + + +RTDECL(void) RTSpinlockAcquire(RTSPINLOCK Spinlock) +{ + PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock; + AssertMsg(pThis && pThis->u32Magic == RTSPINLOCK_GEN_MAGIC, + ("pThis=%p u32Magic=%08x\n", pThis, pThis ? (int)pThis->u32Magic : 0)); + + if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE) + { +#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) + uint32_t fIntSaved = ASMGetFlags(); +#endif + +#if RT_CFG_SPINLOCK_GENERIC_DO_SLEEP + for (;;) + { +#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) + ASMIntDisable(); +#endif + for (int c = RT_CFG_SPINLOCK_GENERIC_DO_SLEEP; c > 0; c--) + { + if (ASMAtomicCmpXchgU32(&pThis->fLocked, 1, 0)) + { +# if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) + pThis->fIntSaved = fIntSaved; +# endif + return; + } + ASMNopPause(); + } +#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) + ASMSetFlags(fIntSaved); +#endif + RTThreadYield(); + } +#else + for (;;) + { +#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) + ASMIntDisable(); +#endif + if (ASMAtomicCmpXchgU32(&pThis->fLocked, 1, 0)) + { +# if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) + pThis->fIntSaved = fIntSaved; +# endif + return; + } +#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) + ASMSetFlags(fIntSaved); +#endif + ASMNopPause(); + } +#endif + } + else + { +#if RT_CFG_SPINLOCK_GENERIC_DO_SLEEP + for (;;) + { + for (int c = RT_CFG_SPINLOCK_GENERIC_DO_SLEEP; c > 0; c--) + { + if (ASMAtomicCmpXchgU32(&pThis->fLocked, 1, 0)) + return; + ASMNopPause(); + } + RTThreadYield(); + } +#else + while (!ASMAtomicCmpXchgU32(&pThis->fLocked, 1, 0)) + ASMNopPause(); +#endif + } +} +RT_EXPORT_SYMBOL(RTSpinlockAcquire); + + +RTDECL(void) RTSpinlockRelease(RTSPINLOCK Spinlock) +{ + PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock; + AssertMsg(pThis && pThis->u32Magic == RTSPINLOCK_GEN_MAGIC, + ("pThis=%p u32Magic=%08x\n", pThis, pThis ? (int)pThis->u32Magic : 0)); + + if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE) + { +#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) + uint32_t fIntSaved = pThis->fIntSaved; + pThis->fIntSaved = 0; +#endif + + if (!ASMAtomicCmpXchgU32(&pThis->fLocked, 0, 1)) + AssertMsgFailed(("Spinlock %p was not locked!\n", pThis)); + +#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) + ASMSetFlags(fIntSaved); +#endif + } + else + { + if (!ASMAtomicCmpXchgU32(&pThis->fLocked, 0, 1)) + AssertMsgFailed(("Spinlock %p was not locked!\n", pThis)); + } +} +RT_EXPORT_SYMBOL(RTSpinlockRelease); + |