1 //===-- esan_sideline.h -----------------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file is a part of EfficiencySanitizer, a family of performance tuners. 11 // 12 // Esan sideline thread support. 13 //===----------------------------------------------------------------------===// 14 15 #ifndef ESAN_SIDELINE_H 16 #define ESAN_SIDELINE_H 17 18 #include "sanitizer_common/sanitizer_atomic.h" 19 #include "sanitizer_common/sanitizer_internal_defs.h" 20 21 namespace __esan { 22 23 typedef void (*SidelineFunc)(void *Arg); 24 25 // Currently only one sideline thread is supported. 26 // It calls the SidelineFunc passed to launchThread once on each sample at the 27 // given frequency in real time (i.e., wall clock time). 28 class SidelineThread { 29 public: 30 // We cannot initialize any fields in the constructor as it will be called 31 // *after* launchThread for a static instance, as esan.module_ctor is called 32 // before static initializers. SidelineThread()33 SidelineThread() {} ~SidelineThread()34 ~SidelineThread() {} 35 36 // To simplify declaration in sanitizer code where we want to avoid 37 // heap allocations, the constructor and destructor do nothing and 38 // launchThread and joinThread do the real work. 39 // They should each be called just once. 40 bool launchThread(SidelineFunc takeSample, void *Arg, u32 FreqMilliSec); 41 bool joinThread(); 42 43 // Must be called from the sideline thread itself. 44 bool adjustTimer(u32 FreqMilliSec); 45 46 private: 47 static int runSideline(void *Arg); 48 static void registerSignal(int SigNum); 49 static void handleSidelineSignal(int SigNum, void *SigInfo, void *Ctx); 50 51 char *Stack; 52 SidelineFunc sampleFunc; 53 void *FuncArg; 54 u32 Freq; 55 uptr SidelineId; 56 atomic_uintptr_t SidelineExit; 57 }; 58 59 } // namespace __esan 60 61 #endif // ESAN_SIDELINE_H 62