Revision control

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <unistd.h>
#include <sys/mman.h>
#include <mach/mach_init.h>
#include <mach-o/getsect.h>

#include <AvailabilityMacros.h>

#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <libkern/OSAtomic.h>
#include <mach/mach.h>
#include <mach/semaphore.h>
#include <mach/task.h>
#include <mach/thread_act.h>
#include <mach/vm_statistics.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <sys/sysctl.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <math.h>

// this port is based off of v8 svn revision 9837

/* static */ int
Thread::GetCurrentId()
{
  return gettid();
}

void*
GetStackTop(void* aGuess)
{
  pthread_t thread = pthread_self();
  return pthread_get_stackaddr_np(thread);
}

class PlatformData
{
public:
  explicit PlatformData(int aThreadId) : mProfiledThread(mach_thread_self())
  {
    MOZ_COUNT_CTOR(PlatformData);
  }

  ~PlatformData() {
    // Deallocate Mach port for thread.
    mach_port_deallocate(mach_task_self(), mProfiledThread);

    MOZ_COUNT_DTOR(PlatformData);
  }

  thread_act_t ProfiledThread() { return mProfiledThread; }

private:
  // Note: for mProfiledThread Mach primitives are used instead of pthread's
  // because the latter doesn't provide thread manipulation primitives required.
  // For details, consult "Mac OS X Internals" book, Section 7.3.
  thread_act_t mProfiledThread;
};

////////////////////////////////////////////////////////////////////////
// BEGIN Sampler target specifics

Sampler::Sampler(PSLockRef aLock)
{
}

void
Sampler::Disable(PSLockRef aLock)
{
}

template<typename Func>
void
Sampler::SuspendAndSampleAndResumeThread(PSLockRef aLock,
                                         const RegisteredThread& aRegisteredThread,
                                         const Func& aProcessRegs)
{
  thread_act_t samplee_thread =
    aRegisteredThread.GetPlatformData()->ProfiledThread();

  //----------------------------------------------------------------//
  // Suspend the samplee thread and get its context.

  // We're using thread_suspend on OS X because pthread_kill (which is what we
  // at one time used on Linux) has less consistent performance and causes
  // strange crashes, see bug 1166778 and bug 1166808.  thread_suspend
  // is also just a lot simpler to use.

  if (KERN_SUCCESS != thread_suspend(samplee_thread)) {
    return;
  }

  //----------------------------------------------------------------//
  // Sample the target thread.

  // WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
  //
  // The profiler's "critical section" begins here.  We must be very careful
  // what we do here, or risk deadlock.  See the corresponding comment in
  // platform-linux-android.cpp for details.

  thread_state_flavor_t flavor = x86_THREAD_STATE64;
  x86_thread_state64_t state;
  mach_msg_type_number_t count = x86_THREAD_STATE64_COUNT;
# if __DARWIN_UNIX03
#  define REGISTER_FIELD(name) __r ## name
# else
#  define REGISTER_FIELD(name) r ## name
# endif  // __DARWIN_UNIX03

  if (thread_get_state(samplee_thread,
                       flavor,
                       reinterpret_cast<natural_t*>(&state),
                       &count) == KERN_SUCCESS) {
    Registers regs;
    regs.mPC = reinterpret_cast<Address>(state.REGISTER_FIELD(ip));
    regs.mSP = reinterpret_cast<Address>(state.REGISTER_FIELD(sp));
    regs.mFP = reinterpret_cast<Address>(state.REGISTER_FIELD(bp));
    regs.mLR = 0;

    aProcessRegs(regs);
  }

#undef REGISTER_FIELD

  //----------------------------------------------------------------//
  // Resume the target thread.

  thread_resume(samplee_thread);

  // The profiler's critical section ends here.
  //
  // WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
}

// END Sampler target specifics
////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////
// BEGIN SamplerThread target specifics

static void*
ThreadEntry(void* aArg)
{
  auto thread = static_cast<SamplerThread*>(aArg);
  thread->Run();
  return nullptr;
}

SamplerThread::SamplerThread(PSLockRef aLock,
                             uint32_t aActivityGeneration,
                             double aIntervalMilliseconds)
  : Sampler(aLock)
  , mActivityGeneration(aActivityGeneration)
  , mIntervalMicroseconds(
      std::max(1, int(floor(aIntervalMilliseconds * 1000 + 0.5))))
  , mThread{nullptr}
{
  pthread_attr_t* attr_ptr = nullptr;
  if (pthread_create(&mThread, attr_ptr, ThreadEntry, this) != 0) {
    MOZ_CRASH("pthread_create failed");
  }
}

SamplerThread::~SamplerThread()
{
  pthread_join(mThread, nullptr);
}

void
SamplerThread::SleepMicro(uint32_t aMicroseconds)
{
  usleep(aMicroseconds);
  // FIXME: the OSX 10.12 page for usleep says "The usleep() function is
  // obsolescent.  Use nanosleep(2) instead."  This implementation could be
  // merged with the linux-android version.  Also, this doesn't handle the
  // case where the usleep call is interrupted by a signal.
}

void
SamplerThread::Stop(PSLockRef aLock)
{
  Sampler::Disable(aLock);
}

// END SamplerThread target specifics
////////////////////////////////////////////////////////////////////////

static void
PlatformInit(PSLockRef aLock)
{
}

#if defined(HAVE_NATIVE_UNWIND)
void
Registers::SyncPopulate()
{
  asm (
      // Compute caller's %rsp by adding to %rbp:
      // 8 bytes for previous %rbp, 8 bytes for return address
      "leaq 0x10(%%rbp), %0\n\t"
      // Dereference %rbp to get previous %rbp
      "movq (%%rbp), %1\n\t"
      :
      "=r"(mSP),
      "=r"(mFP)
  );
  mPC = reinterpret_cast<Address>(__builtin_extract_return_addr(
                                    __builtin_return_address(0)));
  mLR = 0;
}
#endif