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/* -*- 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/syscall.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
namespace mozilla {
namespace baseprofiler {
static int64_t MicrosecondsSince1970() {
struct timeval tv;
gettimeofday(&tv, NULL);
return int64_t(tv.tv_sec) * 1000000 + int64_t(tv.tv_usec);
}
void* GetStackTop(void* aGuess) {
pthread_t thread = pthread_self();
return pthread_get_stackaddr_np(thread);
}
class PlatformData {
public:
explicit PlatformData(BaseProfilerThreadId aThreadId)
: mProfiledThread(mach_thread_self()) {}
~PlatformData() {
// Deallocate Mach port for thread.
mach_port_deallocate(mach_task_self(), mProfiledThread);
}
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 TimeStamp& aNow, 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.
#if defined(__x86_64__)
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
#elif defined(__aarch64__)
thread_state_flavor_t flavor = ARM_THREAD_STATE64;
arm_thread_state64_t state;
mach_msg_type_number_t count = ARM_THREAD_STATE64_COUNT;
# if __DARWIN_UNIX03
# define REGISTER_FIELD(name) __##name
# else
# define REGISTER_FIELD(name) name
# endif // __DARWIN_UNIX03
#else
# error "unknown architecture"
#endif
if (thread_get_state(samplee_thread, flavor,
reinterpret_cast<natural_t*>(&state),
&count) == KERN_SUCCESS) {
Registers regs;
#if defined(__x86_64__)
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;
#elif defined(__aarch64__)
regs.mPC = reinterpret_cast<Address>(state.REGISTER_FIELD(pc));
regs.mSP = reinterpret_cast<Address>(state.REGISTER_FIELD(sp));
regs.mFP = reinterpret_cast<Address>(state.REGISTER_FIELD(fp));
regs.mLR = reinterpret_cast<Address>(state.REGISTER_FIELD(lr));
#else
# error "unknown architecture"
#endif
aProcessRegs(regs, aNow);
}
#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, uint32_t aFeatures)
: mSampler(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) { mSampler.Disable(aLock); }
// END SamplerThread target specifics
////////////////////////////////////////////////////////////////////////
static void PlatformInit(PSLockRef aLock) {}
// clang-format off
#if defined(HAVE_NATIVE_UNWIND)
// Derive the stack pointer from the frame pointer. The 0x10 offset is
// 8 bytes for the previous frame pointer and 8 bytes for the return
// address both stored on the stack after at the beginning of the current
// frame.
# define REGISTERS_SYNC_POPULATE(regs) \
regs.mSP = reinterpret_cast<Address>(__builtin_frame_address(0)) + 0x10; \
_Pragma("GCC diagnostic push") \
_Pragma("GCC diagnostic ignored \"-Wframe-address\"") \
regs.mFP = reinterpret_cast<Address>(__builtin_frame_address(1)); \
_Pragma("GCC diagnostic pop") \
regs.mPC = reinterpret_cast<Address>( \
__builtin_extract_return_addr(__builtin_return_address(0))); \
regs.mLR = 0;
#endif
// clang-format on
} // namespace baseprofiler
} // namespace mozilla
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