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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "signal_catcher.h"
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include "class_linker.h"
#include "file.h"
#include "heap.h"
#include "os.h"
#include "runtime.h"
#include "thread.h"
#include "thread_list.h"
#include "utils.h"
namespace art {
SignalCatcher::SignalCatcher(const std::string& stack_trace_file)
: stack_trace_file_(stack_trace_file),
lock_("SignalCatcher lock"),
cond_("SignalCatcher::cond_"),
thread_(NULL) {
SetHaltFlag(false);
// Create a raw pthread; its start routine will attach to the runtime.
CHECK_PTHREAD_CALL(pthread_create, (&pthread_, NULL, &Run, this), "signal catcher thread");
MutexLock mu(lock_);
while (thread_ == NULL) {
cond_.Wait(lock_);
}
}
SignalCatcher::~SignalCatcher() {
// Since we know the thread is just sitting around waiting for signals
// to arrive, send it one.
SetHaltFlag(true);
CHECK_PTHREAD_CALL(pthread_kill, (pthread_, SIGQUIT), "signal catcher shutdown");
CHECK_PTHREAD_CALL(pthread_join, (pthread_, NULL), "signal catcher shutdown");
}
void SignalCatcher::SetHaltFlag(bool new_value) {
MutexLock mu(lock_);
halt_ = new_value;
}
bool SignalCatcher::ShouldHalt() {
MutexLock mu(lock_);
return halt_;
}
void SignalCatcher::Output(const std::string& s) {
if (stack_trace_file_.empty()) {
LOG(INFO) << s;
return;
}
ScopedThreadStateChange tsc(Thread::Current(), Thread::kVmWait);
int fd = open(stack_trace_file_.c_str(), O_APPEND | O_CREAT | O_WRONLY, 0666);
if (fd == -1) {
PLOG(ERROR) << "Unable to open stack trace file '" << stack_trace_file_ << "'";
return;
}
UniquePtr<File> file(OS::FileFromFd(stack_trace_file_.c_str(), fd));
if (!file->WriteFully(s.data(), s.size())) {
PLOG(ERROR) << "Failed to write stack traces to '" << stack_trace_file_ << "'";
} else {
LOG(INFO) << "Wrote stack traces to '" << stack_trace_file_ << "'";
}
close(fd);
}
void SignalCatcher::HandleSigQuit() {
Runtime* runtime = Runtime::Current();
ThreadList* thread_list = runtime->GetThreadList();
ClassLinker* class_linker = runtime->GetClassLinker();
LOG(INFO) << "Heap lock owner tid: " << Heap::GetLockOwner() << "\n"
<< "ThreadList lock owner tid: " << thread_list->GetLockOwner() << "\n"
<< "ClassLinker classes lock owner tid: " << class_linker->GetClassesLockOwner() << "\n"
<< "ClassLinker dex lock owner tid: " << class_linker->GetDexLockOwner() << "\n";
thread_list->SuspendAll();
std::ostringstream os;
os << "\n"
<< "\n"
<< "----- pid " << getpid() << " at " << GetIsoDate() << " -----\n";
std::string cmdline;
if (ReadFileToString("/proc/self/cmdline", &cmdline)) {
std::replace(cmdline.begin(), cmdline.end(), '\0', ' ');
os << "Cmd line: " << cmdline << "\n";
}
runtime->Dump(os);
if (false) {
std::string maps;
if (ReadFileToString("/proc/self/maps", &maps)) {
os << "/proc/self/maps:\n" << maps;
}
}
os << "----- end " << getpid() << " -----\n";
thread_list->ResumeAll();
Output(os.str());
}
void SignalCatcher::HandleSigUsr1() {
LOG(INFO) << "SIGUSR1 forcing GC (no HPROF)";
Heap::CollectGarbage();
}
int WaitForSignal(Thread* thread, sigset_t& mask) {
ScopedThreadStateChange tsc(thread, Thread::kVmWait);
// Signals for sigwait() must be blocked but not ignored. We
// block signals like SIGQUIT for all threads, so the condition
// is met. When the signal hits, we wake up, without any signal
// handlers being invoked.
// Sleep in sigwait() until a signal arrives. gdb causes EINTR failures.
int signal_number;
int rc = TEMP_FAILURE_RETRY(sigwait(&mask, &signal_number));
if (rc != 0) {
PLOG(FATAL) << "sigwait failed";
}
return signal_number;
}
void* SignalCatcher::Run(void* arg) {
SignalCatcher* signal_catcher = reinterpret_cast<SignalCatcher*>(arg);
CHECK(signal_catcher != NULL);
Runtime* runtime = Runtime::Current();
runtime->AttachCurrentThread("Signal Catcher", true);
Thread::Current()->SetState(Thread::kRunnable);
{
MutexLock mu(signal_catcher->lock_);
signal_catcher->thread_ = Thread::Current();
signal_catcher->cond_.Broadcast();
}
// Set up mask with signals we want to handle.
sigset_t mask;
sigemptyset(&mask);
sigaddset(&mask, SIGQUIT);
sigaddset(&mask, SIGUSR1);
while (true) {
int signal_number = WaitForSignal(signal_catcher->thread_, mask);
if (signal_catcher->ShouldHalt()) {
runtime->DetachCurrentThread();
return NULL;
}
LOG(INFO) << *signal_catcher->thread_ << ": reacting to signal " << signal_number;
switch (signal_number) {
case SIGQUIT:
signal_catcher->HandleSigQuit();
break;
case SIGUSR1:
signal_catcher->HandleSigUsr1();
break;
default:
LOG(ERROR) << "Unexpected signal %d" << signal_number;
break;
}
}
}
} // namespace art
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