blob: 4b27bdddd64ab7c87fa67af85337e877628a84d0 [file] [log] [blame]
/*
* Copyright (C) 2013 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.
*/
#define LOG_TAG "ProcessCallStack"
// #define LOG_NDEBUG 0
#include <utils/ProcessCallStack.h>
#include <dirent.h>
#include <unistd.h>
#include <memory>
#include <utils/Printer.h>
namespace android {
enum {
// Max sizes for various dynamically generated strings
MAX_TIME_STRING = 64,
MAX_PROC_PATH = 1024,
// Dump related prettiness constants
IGNORE_DEPTH_CURRENT_THREAD = 2,
};
static const char* CALL_STACK_PREFIX = " ";
static const char* PATH_THREAD_NAME = "/proc/self/task/%d/comm";
static const char* PATH_SELF_TASK = "/proc/self/task";
static void dumpProcessHeader(Printer& printer, pid_t pid, const char* timeStr) {
if (timeStr == nullptr) {
ALOGW("%s: timeStr was NULL", __FUNCTION__);
return;
}
char path[PATH_MAX];
char procNameBuf[MAX_PROC_PATH];
char* procName = nullptr;
FILE* fp;
snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
if ((fp = fopen(path, "r"))) {
procName = fgets(procNameBuf, sizeof(procNameBuf), fp);
fclose(fp);
}
if (!procName) {
procName = const_cast<char*>("<unknown>");
}
printer.printLine();
printer.printLine();
printer.printFormatLine("----- pid %d at %s -----", pid, timeStr);
printer.printFormatLine("Cmd line: %s", procName);
}
static void dumpProcessFooter(Printer& printer, pid_t pid) {
printer.printLine();
printer.printFormatLine("----- end %d -----", pid);
printer.printLine();
}
static String8 getThreadName(pid_t tid) {
char path[PATH_MAX];
char* procName = nullptr;
char procNameBuf[MAX_PROC_PATH];
FILE* fp;
snprintf(path, sizeof(path), PATH_THREAD_NAME, tid);
if ((fp = fopen(path, "r"))) {
procName = fgets(procNameBuf, sizeof(procNameBuf), fp);
fclose(fp);
} else {
ALOGE("%s: Failed to open %s", __FUNCTION__, path);
}
if (procName == nullptr) {
// Reading /proc/self/task/%d/comm failed due to a race
return String8::format("[err-unknown-tid-%d]", tid);
}
// Strip ending newline
strtok(procName, "\n");
return String8(procName);
}
static String8 getTimeString(struct tm tm) {
char timestr[MAX_TIME_STRING];
// i.e. '2013-10-22 14:42:05'
strftime(timestr, sizeof(timestr), "%F %T", &tm);
return String8(timestr);
}
/*
* Implementation of ProcessCallStack
*/
ProcessCallStack::ProcessCallStack() {
}
ProcessCallStack::ProcessCallStack(const ProcessCallStack& rhs) :
mThreadMap(rhs.mThreadMap),
mTimeUpdated(rhs.mTimeUpdated) {
}
ProcessCallStack::~ProcessCallStack() {
}
void ProcessCallStack::clear() {
mThreadMap.clear();
mTimeUpdated = tm();
}
void ProcessCallStack::update() {
std::unique_ptr<DIR, decltype(&closedir)> dp(opendir(PATH_SELF_TASK), closedir);
if (dp == nullptr) {
ALOGE("%s: Failed to update the process's call stacks: %s",
__FUNCTION__, strerror(errno));
return;
}
pid_t selfPid = getpid();
clear();
// Get current time.
{
time_t t = time(nullptr);
struct tm tm;
localtime_r(&t, &tm);
mTimeUpdated = tm;
}
/*
* Each tid is a directory inside of /proc/self/task
* - Read every file in directory => get every tid
*/
dirent* ep;
while ((ep = readdir(dp.get())) != nullptr) {
pid_t tid = -1;
sscanf(ep->d_name, "%d", &tid);
if (tid < 0) {
// Ignore '.' and '..'
ALOGV("%s: Failed to read tid from %s/%s",
__FUNCTION__, PATH_SELF_TASK, ep->d_name);
continue;
}
ssize_t idx = mThreadMap.add(tid, ThreadInfo());
if (idx < 0) { // returns negative error value on error
ALOGE("%s: Failed to add new ThreadInfo: %s",
__FUNCTION__, strerror(-idx));
continue;
}
ThreadInfo& threadInfo = mThreadMap.editValueAt(static_cast<size_t>(idx));
/*
* Ignore CallStack::update and ProcessCallStack::update for current thread
* - Every other thread doesn't need this since we call update off-thread
*/
int ignoreDepth = (selfPid == tid) ? IGNORE_DEPTH_CURRENT_THREAD : 0;
// Update thread's call stacks
threadInfo.callStack.update(ignoreDepth, tid);
// Read/save thread name
threadInfo.threadName = getThreadName(tid);
ALOGV("%s: Got call stack for tid %d (size %zu)",
__FUNCTION__, tid, threadInfo.callStack.size());
}
}
void ProcessCallStack::log(const char* logtag, android_LogPriority priority,
const char* prefix) const {
LogPrinter printer(logtag, priority, prefix, /*ignoreBlankLines*/false);
print(printer);
}
void ProcessCallStack::print(Printer& printer) const {
/*
* Print the header/footer with the regular printer.
* Print the callstack with an additional two spaces as the prefix for legibility.
*/
PrefixPrinter csPrinter(printer, CALL_STACK_PREFIX);
printInternal(printer, csPrinter);
}
void ProcessCallStack::printInternal(Printer& printer, Printer& csPrinter) const {
dumpProcessHeader(printer, getpid(), getTimeString(mTimeUpdated).c_str());
for (size_t i = 0; i < mThreadMap.size(); ++i) {
pid_t tid = mThreadMap.keyAt(i);
const ThreadInfo& threadInfo = mThreadMap.valueAt(i);
const String8& threadName = threadInfo.threadName;
printer.printLine("");
printer.printFormatLine("\"%s\" sysTid=%d", threadName.c_str(), tid);
threadInfo.callStack.print(csPrinter);
}
dumpProcessFooter(printer, getpid());
}
void ProcessCallStack::dump(int fd, int indent, const char* prefix) const {
if (indent < 0) {
ALOGW("%s: Bad indent (%d)", __FUNCTION__, indent);
return;
}
FdPrinter printer(fd, static_cast<unsigned int>(indent), prefix);
print(printer);
}
String8 ProcessCallStack::toString(const char* prefix) const {
String8 dest;
String8Printer printer(&dest, prefix);
print(printer);
return dest;
}
size_t ProcessCallStack::size() const {
return mThreadMap.size();
}
}; //namespace android