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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
#include "mozilla/ProcInfo.h"
#include "mozilla/ProcInfo_linux.h"
#include "mozilla/Sprintf.h"
#include "mozilla/Logging.h"
#include "mozilla/ScopeExit.h"
#include "mozilla/ipc/GeckoChildProcessHost.h"
#include "nsMemoryReporterManager.h"
#include "nsWhitespaceTokenizer.h"
#include <cstdio>
#include <cstring>
#include <unistd.h>
#include <dirent.h>
#define NANOPERSEC 1000000000.
namespace mozilla {
int GetCycleTimeFrequencyMHz() { return 0; }
// StatReader can parse and tokenize a POSIX stat file.
//
// Its usage is quite simple:
//
// StatReader reader(pid);
// ProcInfo info;
// rv = reader.ParseProc(info);
// if (NS_FAILED(rv)) {
// // the reading of the file or its parsing failed.
// }
//
class StatReader {
public:
explicit StatReader(const base::ProcessId aPid)
: mPid(aPid), mMaxIndex(15), mTicksPerSec(sysconf(_SC_CLK_TCK)) {}
nsresult ParseProc(ProcInfo& aInfo) {
nsAutoString fileContent;
nsresult rv = ReadFile(fileContent);
NS_ENSURE_SUCCESS(rv, rv);
// We first extract the file or thread name
int32_t startPos = fileContent.RFindChar('(');
if (startPos == -1) {
return NS_ERROR_FAILURE;
}
int32_t endPos = fileContent.RFindChar(')');
if (endPos == -1) {
return NS_ERROR_FAILURE;
}
int32_t len = endPos - (startPos + 1);
mName.Assign(Substring(fileContent, startPos + 1, len));
// now we can use the tokenizer for the rest of the file
nsWhitespaceTokenizer tokenizer(Substring(fileContent, endPos + 2));
int32_t index = 2; // starting at third field
while (tokenizer.hasMoreTokens() && index < mMaxIndex) {
const nsAString& token = tokenizer.nextToken();
rv = UseToken(index, token, aInfo);
NS_ENSURE_SUCCESS(rv, rv);
index++;
}
return NS_OK;
}
protected:
// Called for each token found in the stat file.
nsresult UseToken(int32_t aIndex, const nsAString& aToken, ProcInfo& aInfo) {
// We're using a subset of what stat has to offer for now.
nsresult rv = NS_OK;
// see the proc documentation for fields index references.
switch (aIndex) {
case 13:
// Amount of time that this process has been scheduled
// in user mode, measured in clock ticks
aInfo.cpuTime += GetCPUTime(aToken, &rv);
NS_ENSURE_SUCCESS(rv, rv);
break;
case 14:
// Amount of time that this process has been scheduled
// in kernel mode, measured in clock ticks
aInfo.cpuTime += GetCPUTime(aToken, &rv);
NS_ENSURE_SUCCESS(rv, rv);
break;
}
return rv;
}
// Converts a token into a int64_t
uint64_t Get64Value(const nsAString& aToken, nsresult* aRv) {
// We can't use aToken.ToInteger64() since it returns a signed 64.
// and that can result into an overflow.
nsresult rv = NS_OK;
uint64_t out = 0;
if (sscanf(NS_ConvertUTF16toUTF8(aToken).get(), "%" PRIu64, &out) == 0) {
rv = NS_ERROR_FAILURE;
}
*aRv = rv;
return out;
}
// Converts a token into CPU time in nanoseconds.
uint64_t GetCPUTime(const nsAString& aToken, nsresult* aRv) {
nsresult rv;
uint64_t value = Get64Value(aToken, &rv);
*aRv = rv;
if (NS_FAILED(rv)) {
return 0;
}
if (value) {
value = (value * NANOPERSEC) / mTicksPerSec;
}
return value;
}
base::ProcessId mPid;
int32_t mMaxIndex;
nsCString mFilepath;
nsString mName;
private:
// Reads the stat file and puts its content in a nsString.
nsresult ReadFile(nsAutoString& aFileContent) {
if (mFilepath.IsEmpty()) {
if (mPid == 0) {
mFilepath.AssignLiteral("/proc/self/stat");
} else {
mFilepath.AppendPrintf("/proc/%u/stat", unsigned(mPid));
}
}
FILE* fstat = fopen(mFilepath.get(), "r");
if (!fstat) {
return NS_ERROR_FAILURE;
}
// /proc is a virtual file system and all files are
// of size 0, so GetFileSize() and related functions will
// return 0 - so the way to read the file is to fill a buffer
// of an arbitrary big size and look for the end of line char.
char buffer[2048];
char* end;
char* start = fgets(buffer, 2048, fstat);
fclose(fstat);
if (start == nullptr) {
return NS_ERROR_FAILURE;
}
// let's find the end
end = strchr(buffer, '\n');
if (!end) {
return NS_ERROR_FAILURE;
}
aFileContent.AssignASCII(buffer, size_t(end - start));
return NS_OK;
}
int64_t mTicksPerSec;
};
// Threads have the same stat file. The only difference is its path
// and we're getting less info in the ThreadInfo structure.
class ThreadInfoReader final : public StatReader {
public:
ThreadInfoReader(const base::ProcessId aPid, const base::ProcessId aTid)
: StatReader(aPid) {
mFilepath.AppendPrintf("/proc/%u/task/%u/stat", unsigned(aPid),
unsigned(aTid));
}
nsresult ParseThread(ThreadInfo& aInfo) {
ProcInfo info;
nsresult rv = StatReader::ParseProc(info);
NS_ENSURE_SUCCESS(rv, rv);
// Copying over the data we got from StatReader::ParseProc()
aInfo.cpuTime = info.cpuTime;
aInfo.name.Assign(mName);
return NS_OK;
}
};
nsresult GetCpuTimeSinceProcessStartInMs(uint64_t* aResult) {
timespec t;
if (clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &t) == 0) {
uint64_t cpuTime =
uint64_t(t.tv_sec) * 1'000'000'000u + uint64_t(t.tv_nsec);
*aResult = cpuTime / PR_NSEC_PER_MSEC;
return NS_OK;
}
StatReader reader(0);
ProcInfo info;
nsresult rv = reader.ParseProc(info);
if (NS_FAILED(rv)) {
return rv;
}
*aResult = info.cpuTime / PR_NSEC_PER_MSEC;
return NS_OK;
}
nsresult GetGpuTimeSinceProcessStartInMs(uint64_t* aResult) {
return NS_ERROR_NOT_IMPLEMENTED;
}
ProcInfoPromise::ResolveOrRejectValue GetProcInfoSync(
nsTArray<ProcInfoRequest>&& aRequests) {
ProcInfoPromise::ResolveOrRejectValue result;
HashMap<base::ProcessId, ProcInfo> gathered;
if (!gathered.reserve(aRequests.Length())) {
result.SetReject(NS_ERROR_OUT_OF_MEMORY);
return result;
}
for (const auto& request : aRequests) {
ProcInfo info;
timespec t;
clockid_t clockid = MAKE_PROCESS_CPUCLOCK(request.pid, CPUCLOCK_SCHED);
if (clock_gettime(clockid, &t) == 0) {
info.cpuTime = uint64_t(t.tv_sec) * 1'000'000'000u + uint64_t(t.tv_nsec);
} else {
// Fallback to parsing /proc/<pid>/stat
StatReader reader(request.pid);
nsresult rv = reader.ParseProc(info);
if (NS_FAILED(rv)) {
// Can't read data for this proc.
// Probably either a sandboxing issue or a race condition, e.g.
// the process has been just been killed. Regardless, skip process.
continue;
}
}
// The 'Memory' value displayed in the system monitor is resident -
// shared. statm contains more fields, but we're only interested in
// the first three.
static const int MAX_FIELD = 3;
size_t VmSize, resident, shared;
info.memory = 0;
FILE* f = fopen(nsPrintfCString("/proc/%u/statm", request.pid).get(), "r");
if (f) {
int nread = fscanf(f, "%zu %zu %zu", &VmSize, &resident, &shared);
fclose(f);
if (nread == MAX_FIELD) {
info.memory = (resident - shared) * getpagesize();
}
}
// Extra info
info.pid = request.pid;
info.childId = request.childId;
info.type = request.processType;
info.origin = request.origin;
info.windows = std::move(request.windowInfo);
info.utilityActors = std::move(request.utilityInfo);
// Let's look at the threads
nsCString taskPath;
taskPath.AppendPrintf("/proc/%u/task", unsigned(request.pid));
DIR* dirHandle = opendir(taskPath.get());
if (!dirHandle) {
// For some reason, we have no data on the threads for this process.
// Most likely reason is that we have just lost a race condition and
// the process is dead.
// Let's stop here and ignore the entire process.
continue;
}
auto cleanup = mozilla::MakeScopeExit([&] { closedir(dirHandle); });
// If we can't read some thread info, we ignore that thread.
dirent* entry;
while ((entry = readdir(dirHandle)) != nullptr) {
if (entry->d_name[0] == '.') {
continue;
}
nsAutoCString entryName(entry->d_name);
nsresult rv;
int32_t tid = entryName.ToInteger(&rv);
if (NS_FAILED(rv)) {
continue;
}
ThreadInfo threadInfo;
threadInfo.tid = tid;
timespec ts;
if (clock_gettime(MAKE_THREAD_CPUCLOCK(tid, CPUCLOCK_SCHED), &ts) == 0) {
threadInfo.cpuTime =
uint64_t(ts.tv_sec) * 1'000'000'000u + uint64_t(ts.tv_nsec);
nsCString path;
path.AppendPrintf("/proc/%u/task/%u/comm", unsigned(request.pid),
unsigned(tid));
FILE* fstat = fopen(path.get(), "r");
if (fstat) {
// /proc is a virtual file system and all files are
// of size 0, so GetFileSize() and related functions will
// return 0 - so the way to read the file is to fill a buffer
// of an arbitrary big size and look for the end of line char.
// The size of the buffer needs to be as least 16, which is the
// value of TASK_COMM_LEN in the Linux kernel.
char buffer[32];
char* start = fgets(buffer, sizeof(buffer), fstat);
fclose(fstat);
if (start) {
// The thread name should always be smaller than our buffer,
// so we should find a newline character.
char* end = strchr(buffer, '\n');
if (end) {
threadInfo.name.AssignASCII(buffer, size_t(end - start));
info.threads.AppendElement(threadInfo);
continue;
}
}
}
}
// Fallback to parsing /proc/<pid>/task/<tid>/stat
// This is needed for child processes, as access to the per-thread
// CPU clock is restricted to the process owning the thread.
ThreadInfoReader reader(request.pid, tid);
rv = reader.ParseThread(threadInfo);
if (NS_FAILED(rv)) {
continue;
}
info.threads.AppendElement(threadInfo);
}
if (!gathered.put(request.pid, std::move(info))) {
result.SetReject(NS_ERROR_OUT_OF_MEMORY);
return result;
}
}
// ... and we're done!
result.SetResolve(std::move(gathered));
return result;
}
} // namespace mozilla