Imported Upstream version 5.18.0.207

Former-commit-id: 3b152f462918d427ce18620a2cbe4f8b79650449

external/llvm/lib/Support/Windows/RWMutex.inc

@@ -1,129 +0,0 @@
-//= llvm/Support/Win32/Mutex.inc - Win32 Reader/Writer Mutual Exclusion Lock  =//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the Win32 specific (non-pthread) RWMutex class.
-//
-//===----------------------------------------------------------------------===//
-
-//===----------------------------------------------------------------------===//
-//=== WARNING: Implementation here must contain only generic Win32 code that
-//===          is guaranteed to work on *all* Win32 variants.
-//===----------------------------------------------------------------------===//
-
-#include "WindowsSupport.h"
-
-namespace llvm {
-
-// Windows has slim read-writer lock support on Vista and higher, so we
-// will attempt to load the APIs.  If they exist, we will use them, and
-// if not, we will fall back on critical sections.  When we drop support
-// for XP, we can stop lazy-loading these APIs and just use them directly.
-#if defined(__MINGW32__)
-  // Taken from WinNT.h
-  typedef struct _RTL_SRWLOCK {
-    PVOID Ptr;
-  } RTL_SRWLOCK, *PRTL_SRWLOCK;
-
-  // Taken from WinBase.h
-  typedef RTL_SRWLOCK SRWLOCK, *PSRWLOCK;
-#endif
-
-static VOID (WINAPI *fpInitializeSRWLock)(PSRWLOCK lock) = NULL;
-static VOID (WINAPI *fpAcquireSRWLockExclusive)(PSRWLOCK lock) = NULL;
-static VOID (WINAPI *fpAcquireSRWLockShared)(PSRWLOCK lock) = NULL;
-static VOID (WINAPI *fpReleaseSRWLockExclusive)(PSRWLOCK lock) = NULL;
-static VOID (WINAPI *fpReleaseSRWLockShared)(PSRWLOCK lock) = NULL;
-
-static bool sHasSRW = false;
-
-static bool loadSRW() {
-  static bool sChecked = false;
-  if (!sChecked) {
-    sChecked = true;
-
-    if (HMODULE hLib = ::GetModuleHandleW(L"Kernel32.dll")) {
-      fpInitializeSRWLock =
-        (VOID (WINAPI *)(PSRWLOCK))::GetProcAddress(hLib,
-                                               "InitializeSRWLock");
-      fpAcquireSRWLockExclusive =
-        (VOID (WINAPI *)(PSRWLOCK))::GetProcAddress(hLib,
-                                               "AcquireSRWLockExclusive");
-      fpAcquireSRWLockShared =
-        (VOID (WINAPI *)(PSRWLOCK))::GetProcAddress(hLib,
-                                               "AcquireSRWLockShared");
-      fpReleaseSRWLockExclusive =
-        (VOID (WINAPI *)(PSRWLOCK))::GetProcAddress(hLib,
-                                               "ReleaseSRWLockExclusive");
-      fpReleaseSRWLockShared =
-        (VOID (WINAPI *)(PSRWLOCK))::GetProcAddress(hLib,
-                                               "ReleaseSRWLockShared");
-
-      if (fpInitializeSRWLock != NULL) {
-        sHasSRW = true;
-      }
-    }
-  }
-  return sHasSRW;
-}
-
-sys::RWMutexImpl::RWMutexImpl() {
-  if (loadSRW()) {
-    data_ = calloc(1, sizeof(SRWLOCK));
-    fpInitializeSRWLock(static_cast<PSRWLOCK>(data_));
-  } else {
-    data_ = calloc(1, sizeof(CRITICAL_SECTION));
-    InitializeCriticalSection(static_cast<LPCRITICAL_SECTION>(data_));
-  }
-}
-
-sys::RWMutexImpl::~RWMutexImpl() {
-  if (!sHasSRW)
-    DeleteCriticalSection(static_cast<LPCRITICAL_SECTION>(data_));
-  // Nothing to do in the case of slim reader/writers except free the memory.
-  free(data_);
-}
-
-bool sys::RWMutexImpl::reader_acquire() {
-  if (sHasSRW) {
-    fpAcquireSRWLockShared(static_cast<PSRWLOCK>(data_));
-  } else {
-    EnterCriticalSection(static_cast<LPCRITICAL_SECTION>(data_));
-  }
-  return true;
-}
-
-bool sys::RWMutexImpl::reader_release() {
-  if (sHasSRW) {
-    fpReleaseSRWLockShared(static_cast<PSRWLOCK>(data_));
-  } else {
-    LeaveCriticalSection(static_cast<LPCRITICAL_SECTION>(data_));
-  }
-  return true;
-}
-
-bool sys::RWMutexImpl::writer_acquire() {
-  if (sHasSRW) {
-    fpAcquireSRWLockExclusive(static_cast<PSRWLOCK>(data_));
-  } else {
-    EnterCriticalSection(static_cast<LPCRITICAL_SECTION>(data_));
-  }
-  return true;
-}
-
-bool sys::RWMutexImpl::writer_release() {
-  if (sHasSRW) {
-    fpReleaseSRWLockExclusive(static_cast<PSRWLOCK>(data_));
-  } else {
-    LeaveCriticalSection(static_cast<LPCRITICAL_SECTION>(data_));
-  }
-  return true;
-}
-
-
-}