forked from OSchip/llvm-project
[XRay][compiler-rt] Remove more STL dependenices from FDR mode
Summary:
This change removes dependencies on STL types:
- std::aligned_storage -- we're using manually-aligned character
buffers instead for metadata and function records.
- std::tuple -- use a plain old struct instead.
This is an incremental step in removing all STL references from the
compiler-rt implementation of XRay (llvm.org/PR32274).
Reviewers: dblaikie, pelikan, kpw
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39277
llvm-svn: 316816
This commit is contained in:
Dean Michael Berris
parent
d0c6cf2e8c
commit
e8fec1955a
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@ -15,15 +15,10 @@
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//
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//===----------------------------------------------------------------------===//
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#include "xray_fdr_logging.h"
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#include <algorithm>
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#include <bitset>
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#include <cerrno>
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#include <cstring>
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#include <sys/syscall.h>
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#include <sys/time.h>
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#include <time.h>
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#include <unistd.h>
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#include <unordered_map>
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#include "sanitizer_common/sanitizer_atomic.h"
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#include "sanitizer_common/sanitizer_common.h"
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@ -176,19 +171,22 @@ XRayLogInitStatus fdrLoggingReset() XRAY_NEVER_INSTRUMENT {
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return XRayLogInitStatus::XRAY_LOG_UNINITIALIZED;
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}
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static std::tuple<uint64_t, unsigned char>
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getTimestamp() XRAY_NEVER_INSTRUMENT {
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struct TSCAndCPU {
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uint64_t TSC;
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unsigned char CPU;
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};
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static TSCAndCPU getTimestamp() XRAY_NEVER_INSTRUMENT {
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// We want to get the TSC as early as possible, so that we can check whether
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// we've seen this CPU before. We also do it before we load anything else, to
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// allow for forward progress with the scheduling.
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unsigned char CPU;
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uint64_t TSC;
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TSCAndCPU Result;
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// Test once for required CPU features
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static bool TSCSupported = probeRequiredCPUFeatures();
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if (TSCSupported) {
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TSC = __xray::readTSC(CPU);
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Result.TSC = __xray::readTSC(Result.CPU);
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} else {
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// FIXME: This code needs refactoring as it appears in multiple locations
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timespec TS;
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@ -197,34 +195,32 @@ getTimestamp() XRAY_NEVER_INSTRUMENT {
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Report("clock_gettime(2) return %d, errno=%d", result, int(errno));
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TS = {0, 0};
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}
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CPU = 0;
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TSC = TS.tv_sec * __xray::NanosecondsPerSecond + TS.tv_nsec;
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Result.CPU = 0;
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Result.TSC = TS.tv_sec * __xray::NanosecondsPerSecond + TS.tv_nsec;
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}
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return std::make_tuple(TSC, CPU);
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return Result;
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}
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void fdrLoggingHandleArg0(int32_t FuncId,
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XRayEntryType Entry) XRAY_NEVER_INSTRUMENT {
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auto TSC_CPU = getTimestamp();
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__xray_fdr_internal::processFunctionHook(FuncId, Entry, std::get<0>(TSC_CPU),
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std::get<1>(TSC_CPU), 0,
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clock_gettime, *BQ);
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auto TC = getTimestamp();
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__xray_fdr_internal::processFunctionHook(FuncId, Entry, TC.TSC,
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TC.CPU, 0, clock_gettime, *BQ);
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}
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void fdrLoggingHandleArg1(int32_t FuncId, XRayEntryType Entry,
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uint64_t Arg) XRAY_NEVER_INSTRUMENT {
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auto TSC_CPU = getTimestamp();
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__xray_fdr_internal::processFunctionHook(FuncId, Entry, std::get<0>(TSC_CPU),
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std::get<1>(TSC_CPU), Arg,
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clock_gettime, *BQ);
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auto TC = getTimestamp();
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__xray_fdr_internal::processFunctionHook(
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FuncId, Entry, TC.TSC, TC.CPU, Arg, clock_gettime, *BQ);
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}
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void fdrLoggingHandleCustomEvent(void *Event,
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std::size_t EventSize) XRAY_NEVER_INSTRUMENT {
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using namespace __xray_fdr_internal;
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auto TSC_CPU = getTimestamp();
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auto &TSC = std::get<0>(TSC_CPU);
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auto &CPU = std::get<1>(TSC_CPU);
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auto TC = getTimestamp();
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auto &TSC = TC.TSC;
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auto &CPU = TC.CPU;
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RecursionGuard Guard{Running};
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if (!Guard) {
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assert(Running && "RecursionGuard is buggy!");
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@ -261,7 +257,7 @@ void fdrLoggingHandleCustomEvent(void *Event,
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CustomEvent.Type = uint8_t(RecordType::Metadata);
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CustomEvent.RecordKind =
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uint8_t(MetadataRecord::RecordKinds::CustomEventMarker);
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constexpr auto TSCSize = sizeof(std::get<0>(TSC_CPU));
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constexpr auto TSCSize = sizeof(TC.TSC);
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std::memcpy(&CustomEvent.Data, &ReducedEventSize, sizeof(int32_t));
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std::memcpy(&CustomEvent.Data[sizeof(int32_t)], &TSC, TSCSize);
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std::memcpy(TLD.RecordPtr, &CustomEvent, sizeof(CustomEvent));
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@ -18,16 +18,17 @@
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#define XRAY_XRAY_FDR_LOGGING_IMPL_H
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#include <cassert>
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#include <cstdint>
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#include <cstddef>
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#include <cstring>
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#include <limits>
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#include <memory>
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#include <pthread.h>
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#include <string>
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#include <sys/syscall.h>
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#include <time.h>
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#include <unistd.h>
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// FIXME: Implement analogues to std::shared_ptr and std::weak_ptr
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#include <memory>
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#include "sanitizer_common/sanitizer_common.h"
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#include "xray/xray_log_interface.h"
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#include "xray_buffer_queue.h"
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@ -96,7 +97,7 @@ static void writeTSCWrapMetadata(uint64_t TSC);
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// call so that it can be initialized on first use instead of as a global. We
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// force the alignment to 64-bytes for x86 cache line alignment, as this
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// structure is used in the hot path of implementation.
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struct ALIGNED(64) ThreadLocalData {
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struct alignas(64) ThreadLocalData {
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BufferQueue::Buffer Buffer;
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char *RecordPtr = nullptr;
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// The number of FunctionEntry records immediately preceding RecordPtr.
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@ -176,8 +177,8 @@ static ThreadLocalData &getThreadLocalData() {
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// We need aligned, uninitialized storage for the TLS object which is
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// trivially destructible. We're going to use this as raw storage and
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// placement-new the ThreadLocalData object into it later.
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thread_local std::aligned_storage<sizeof(ThreadLocalData),
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alignof(ThreadLocalData)>::type TLSBuffer;
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alignas(alignof(ThreadLocalData)) thread_local unsigned char
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TLSBuffer[sizeof(ThreadLocalData)];
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// Ensure that we only actually ever do the pthread initialization once.
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thread_local bool UNUSED Unused = [] {
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@ -215,7 +216,7 @@ static ThreadLocalData &getThreadLocalData() {
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return true;
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}();
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return *reinterpret_cast<ThreadLocalData *>(&TLSBuffer);
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return *reinterpret_cast<ThreadLocalData *>(TLSBuffer);
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}
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//-----------------------------------------------------------------------------|
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@ -255,14 +256,15 @@ public:
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inline void writeNewBufferPreamble(pid_t Tid, timespec TS,
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char *&MemPtr) XRAY_NEVER_INSTRUMENT {
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static constexpr int InitRecordsCount = 2;
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std::aligned_storage<sizeof(MetadataRecord)>::type Records[InitRecordsCount];
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alignas(alignof(MetadataRecord)) unsigned char
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Records[InitRecordsCount * MetadataRecSize];
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{
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// Write out a MetadataRecord to signify that this is the start of a new
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// buffer, associated with a particular thread, with a new CPU. For the
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// data, we have 15 bytes to squeeze as much information as we can. At this
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// point we only write down the following bytes:
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// - Thread ID (pid_t, 4 bytes)
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auto &NewBuffer = *reinterpret_cast<MetadataRecord *>(&Records[0]);
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auto &NewBuffer = *reinterpret_cast<MetadataRecord *>(Records);
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NewBuffer.Type = uint8_t(RecordType::Metadata);
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NewBuffer.RecordKind = uint8_t(MetadataRecord::RecordKinds::NewBuffer);
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std::memcpy(&NewBuffer.Data, &Tid, sizeof(pid_t));
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@ -270,7 +272,8 @@ inline void writeNewBufferPreamble(pid_t Tid, timespec TS,
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// Also write the WalltimeMarker record.
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{
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static_assert(sizeof(time_t) <= 8, "time_t needs to be at most 8 bytes");
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auto &WalltimeMarker = *reinterpret_cast<MetadataRecord *>(&Records[1]);
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auto &WalltimeMarker =
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*reinterpret_cast<MetadataRecord *>(Records + MetadataRecSize);
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WalltimeMarker.Type = uint8_t(RecordType::Metadata);
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WalltimeMarker.RecordKind =
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uint8_t(MetadataRecord::RecordKinds::WalltimeMarker);
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@ -382,10 +385,7 @@ static inline void writeCallArgumentMetadata(uint64_t A) XRAY_NEVER_INSTRUMENT {
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static inline void writeFunctionRecord(int FuncId, uint32_t TSCDelta,
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XRayEntryType EntryType,
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char *&MemPtr) XRAY_NEVER_INSTRUMENT {
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std::aligned_storage<sizeof(FunctionRecord), alignof(FunctionRecord)>::type
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AlignedFuncRecordBuffer;
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auto &FuncRecord =
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*reinterpret_cast<FunctionRecord *>(&AlignedFuncRecordBuffer);
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FunctionRecord FuncRecord;
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FuncRecord.Type = uint8_t(RecordType::Function);
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// Only take 28 bits of the function id.
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FuncRecord.FuncId = FuncId & ~(0x0F << 28);
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@ -439,7 +439,7 @@ static inline void writeFunctionRecord(int FuncId, uint32_t TSCDelta,
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}
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}
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std::memcpy(MemPtr, &AlignedFuncRecordBuffer, sizeof(FunctionRecord));
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std::memcpy(MemPtr, &FuncRecord, sizeof(FunctionRecord));
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MemPtr += sizeof(FunctionRecord);
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}
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@ -456,14 +456,10 @@ static uint64_t thresholdTicks() {
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// "Function Entry" record and any "Tail Call Exit" records after that.
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static void rewindRecentCall(uint64_t TSC, uint64_t &LastTSC,
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uint64_t &LastFunctionEntryTSC, int32_t FuncId) {
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using AlignedFuncStorage =
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std::aligned_storage<sizeof(FunctionRecord),
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alignof(FunctionRecord)>::type;
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auto &TLD = getThreadLocalData();
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TLD.RecordPtr -= FunctionRecSize;
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AlignedFuncStorage AlignedFuncRecordBuffer;
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const auto &FuncRecord = *reinterpret_cast<FunctionRecord *>(
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std::memcpy(&AlignedFuncRecordBuffer, TLD.RecordPtr, FunctionRecSize));
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FunctionRecord FuncRecord;
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std::memcpy(&FuncRecord, TLD.RecordPtr, FunctionRecSize);
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assert(FuncRecord.RecordKind ==
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uint8_t(FunctionRecord::RecordKinds::FunctionEnter) &&
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"Expected to find function entry recording when rewinding.");
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@ -485,20 +481,17 @@ static void rewindRecentCall(uint64_t TSC, uint64_t &LastTSC,
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auto RewindingTSC = LastTSC;
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auto RewindingRecordPtr = TLD.RecordPtr - FunctionRecSize;
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while (TLD.NumTailCalls > 0) {
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AlignedFuncStorage TailExitRecordBuffer;
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// Rewind the TSC back over the TAIL EXIT record.
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const auto &ExpectedTailExit =
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*reinterpret_cast<FunctionRecord *>(std::memcpy(
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&TailExitRecordBuffer, RewindingRecordPtr, FunctionRecSize));
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FunctionRecord ExpectedTailExit;
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std::memcpy(&ExpectedTailExit, RewindingRecordPtr, FunctionRecSize);
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assert(ExpectedTailExit.RecordKind ==
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uint8_t(FunctionRecord::RecordKinds::FunctionTailExit) &&
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"Expected to find tail exit when rewinding.");
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RewindingRecordPtr -= FunctionRecSize;
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RewindingTSC -= ExpectedTailExit.TSCDelta;
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AlignedFuncStorage FunctionEntryBuffer;
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const auto &ExpectedFunctionEntry = *reinterpret_cast<FunctionRecord *>(
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std::memcpy(&FunctionEntryBuffer, RewindingRecordPtr, FunctionRecSize));
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FunctionRecord ExpectedFunctionEntry;
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std::memcpy(&ExpectedFunctionEntry, RewindingRecordPtr, FunctionRecSize);
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assert(ExpectedFunctionEntry.RecordKind ==
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uint8_t(FunctionRecord::RecordKinds::FunctionEnter) &&
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"Expected to find function entry when rewinding tail call.");
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