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/*
* Copyright (C) 2017 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 "InplaceSamplerClient.h"
#include <algorithm>
#include "environment.h"
#include "inplace_sampler_lib.h"
#include "utils.h"
static constexpr uint64_t EVENT_ID_FOR_INPLACE_SAMPLER = ULONG_MAX;
std::unique_ptr<InplaceSamplerClient> InplaceSamplerClient::Create(const perf_event_attr& attr,
pid_t pid,
const std::set<pid_t>& tids) {
if (pid == -1) {
LOG(ERROR) << "inplace-sampler can't monitor system wide events.";
return nullptr;
}
std::unique_ptr<InplaceSamplerClient> sampler(new InplaceSamplerClient(attr, pid, tids));
if (!sampler->ConnectServer()) {
return nullptr;
}
return sampler;
}
InplaceSamplerClient::InplaceSamplerClient(const perf_event_attr& attr, pid_t pid,
const std::set<pid_t>& tids)
: attr_(attr), pid_(pid), tids_(tids), got_start_profiling_reply_msg_(false) {
if (attr_.freq) {
sample_freq_ = attr_.sample_freq;
} else {
sample_freq_ = std::max(1u, static_cast<uint32_t>(1000000000 / attr_.sample_period));
}
}
uint64_t InplaceSamplerClient::Id() const {
return EVENT_ID_FOR_INPLACE_SAMPLER;
}
bool InplaceSamplerClient::ConnectServer() {
std::string server_path = "inplace_sampler_server_" + std::to_string(pid_);
// Try to connect server in 1s.
uint64_t timeout = GetSystemClock() + 10000000000ull;
while (GetSystemClock() < timeout) {
conn_ = UnixSocketConnection::Connect(server_path, true);
if (conn_ != nullptr) {
return true;
}
usleep(10);
}
LOG(ERROR) << "Can't find inplace_sampler_server for process " << pid_;
return false;
}
bool InplaceSamplerClient::StartPolling(IOEventLoop& loop,
const std::function<bool(Record*)>& record_callback,
const std::function<bool()>& close_callback) {
record_callback_ = record_callback;
CHECK(conn_ != nullptr);
auto read_callback = [&](const UnixSocketMessage& msg) {
return HandleMessage(msg);
};
if (!conn_->PrepareForIO(loop, read_callback, close_callback)) {
return false;
}
if (!SendStartProfilingMessage()) {
return false;
}
// If the inplace sampler doesn't reply in 3 seconds, report the error.
timeval tv;
tv.tv_sec = 3;
tv.tv_usec = 0;
auto check_reply_callback = [this]() {
if (!got_start_profiling_reply_msg_) {
LOG(ERROR) << "can't receive START_PROFILING_REPLY from process " << pid_;
return false;
}
return true;
};
return loop.AddPeriodicEvent(tv, check_reply_callback);
}
bool InplaceSamplerClient::SendStartProfilingMessage() {
std::string options;
options += "freq=" + std::to_string(sample_freq_);
if (attr_.sample_type & PERF_SAMPLE_CALLCHAIN) {
options += " dump_callchain=1";
}
if (!tids_.empty()) {
options += " tids=";
bool first = true;
for (auto& tid : tids_) {
if (first) {
first = false;
} else {
options.push_back(',');
}
options += std::to_string(tid);
}
}
size_t size = sizeof(UnixSocketMessage) + options.size() + 1;
std::unique_ptr<char[]> data(new char[size]);
UnixSocketMessage* msg = reinterpret_cast<UnixSocketMessage*>(data.get());
msg->len = size;
msg->type = START_PROFILING;
strcpy(msg->data, options.c_str());
return conn_->SendMessage(*msg, true);
}
bool InplaceSamplerClient::StopProfiling(IOEventLoop& loop,
const std::function<bool()>& close_callback) {
auto read_callback = [&](const UnixSocketMessage& msg) {
return HandleMessage(msg);
};
if (!conn_->PrepareForIO(loop, read_callback, close_callback)) {
return false;
}
// Notify inplace sampler to send buffered data and close the connection.
UnixSocketMessage msg;
msg.len = sizeof(UnixSocketMessage);
msg.type = END_PROFILING;
return conn_->SendMessage(msg, true);
}
bool InplaceSamplerClient::HandleMessage(const UnixSocketMessage& msg) {
const char* p = msg.data;
if (msg.type == START_PROFILING_REPLY) {
got_start_profiling_reply_msg_ = true;
if (strcmp(p, "ok") != 0) {
LOG(ERROR) << "receive reply from inplace_sampler_server of " << pid_ << ": " << p;
return false;
}
} else if (msg.type == THREAD_INFO) {
uint64_t time;
uint32_t tid;
MoveFromBinaryFormat(time, p);
MoveFromBinaryFormat(tid, p);
CommRecord r(attr_, pid_, tid, p, Id(), time);
if (!record_callback_(&r)) {
return false;
}
} else if (msg.type == MAP_INFO) {
uint64_t time;
uint64_t start;
uint64_t len;
uint64_t pgoff;
MoveFromBinaryFormat(time, p);
MoveFromBinaryFormat(start, p);
MoveFromBinaryFormat(len, p);
MoveFromBinaryFormat(pgoff, p);
MmapRecord r(attr_, false, pid_, pid_, start, len, pgoff, p, Id(), time);
if (!record_callback_(&r)) {
return false;
}
} else if (msg.type == SAMPLE_INFO) {
uint64_t time;
uint32_t tid;
uint32_t period;
uint32_t ip_nr;
MoveFromBinaryFormat(time, p);
MoveFromBinaryFormat(tid, p);
MoveFromBinaryFormat(period, p);
MoveFromBinaryFormat(ip_nr, p);
std::vector<uint64_t> ips(ip_nr);
MoveFromBinaryFormat(ips.data(), ip_nr, p);
// Don't know which cpu tid is running on, use cpu 0.
SampleRecord r(attr_, Id(), ips[0], pid_, tid, time, 0, period, ips, {}, 0);
if (!record_callback_(&r)) {
return false;
}
} else {
LOG(ERROR) << "Unexpected msg type: " << msg.type;
return false;
}
return true;
}
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