kc3-lang/angle/src/common/tls.h

• Show log

  Commit

• Hash : cb286073
  Author :
  Date : 2020-09-20T21:59:24
  

  Use c++ thread_local for current thread.
  
  This solves a race condition using the global context.
  Sadly we can't use an unprotected variable safely because
  it can be written/read from multiple threads doing MakeCurrent.
  
  Has about a 2 ns regression when tested in Linux/Release per
  call. "null" benchmark test went from 27 -> 29 ns/iteration.
  
  Fixes a TSAN warning that popped up in angle_end2end_tests.
  
  Test: DrawCallPerfBenchmark.Run/vulkan_null
  Test: EGLContextASANTest.DestroyContextInUse/ES3_Vulkan
  Bug: b/168744561
  Change-Id: Ic56f3faae81c1087b942a3cfc0e011b9ab439e0f
  Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2419641
  Reviewed-by: Geoff Lang <geofflang@chromium.org>
  Commit-Queue: Jamie Madill <jmadill@chromium.org>
  

Download

• src/common/tls.h

• //
  // Copyright 2014 The ANGLE Project Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  //
  
  // tls.h: Simple cross-platform interface for thread local storage.
  
  #ifndef COMMON_TLS_H_
  #define COMMON_TLS_H_
  
  #include "common/angleutils.h"
  #include "common/platform.h"
  
  namespace gl
  {
  class Context;
  }
  
  #ifdef ANGLE_PLATFORM_WINDOWS
  
  // TLS does not exist for Windows Store and needs to be emulated
  #    ifdef ANGLE_ENABLE_WINDOWS_UWP
  #        ifndef TLS_OUT_OF_INDEXES
  #            define TLS_OUT_OF_INDEXES static_cast<DWORD>(0xFFFFFFFF)
  #        endif
  #        ifndef CREATE_SUSPENDED
  #            define CREATE_SUSPENDED 0x00000004
  #        endif
  #    endif
  typedef DWORD TLSIndex;
  #    define TLS_INVALID_INDEX (TLS_OUT_OF_INDEXES)
  #elif defined(ANGLE_PLATFORM_POSIX)
  #    include <errno.h>
  #    include <pthread.h>
  #    include <semaphore.h>
  typedef pthread_key_t TLSIndex;
  #    define TLS_INVALID_INDEX (static_cast<TLSIndex>(-1))
  #else
  #    error Unsupported platform.
  #endif
  
  // TODO(kbr): for POSIX platforms this will have to be changed to take
  // in a destructor function pointer, to allow the thread-local storage
  // to be properly deallocated upon thread exit.
  TLSIndex CreateTLSIndex();
  bool DestroyTLSIndex(TLSIndex index);
  
  bool SetTLSValue(TLSIndex index, void *value);
  void *GetTLSValue(TLSIndex index);
  
  #endif  // COMMON_TLS_H_
  

Download