blob: 9512a87cf98e401dafcf7f1761bf5fd965e04e61 [file] [log] [blame]
//===-- memprof_thread.cpp -----------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of MemProfiler, a memory profiler.
//
// Thread-related code.
//===----------------------------------------------------------------------===//
#include "memprof_thread.h"
#include "memprof_allocator.h"
#include "memprof_interceptors.h"
#include "memprof_mapping.h"
#include "memprof_stack.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_placement_new.h"
#include "sanitizer_common/sanitizer_stackdepot.h"
#include "sanitizer_common/sanitizer_tls_get_addr.h"
namespace __memprof {
// MemprofThreadContext implementation.
void MemprofThreadContext::OnCreated(void *arg) {
CreateThreadContextArgs *args = static_cast<CreateThreadContextArgs *>(arg);
if (args->stack)
stack_id = StackDepotPut(*args->stack);
thread = args->thread;
thread->set_context(this);
}
void MemprofThreadContext::OnFinished() {
// Drop the link to the MemprofThread object.
thread = nullptr;
}
static ALIGNED(16) char thread_registry_placeholder[sizeof(ThreadRegistry)];
static ThreadRegistry *memprof_thread_registry;
static Mutex mu_for_thread_context;
static LowLevelAllocator allocator_for_thread_context;
static ThreadContextBase *GetMemprofThreadContext(u32 tid) {
Lock lock(&mu_for_thread_context);
return new (allocator_for_thread_context) MemprofThreadContext(tid);
}
ThreadRegistry &memprofThreadRegistry() {
static bool initialized;
// Don't worry about thread_safety - this should be called when there is
// a single thread.
if (!initialized) {
// Never reuse MemProf threads: we store pointer to MemprofThreadContext
// in TSD and can't reliably tell when no more TSD destructors will
// be called. It would be wrong to reuse MemprofThreadContext for another
// thread before all TSD destructors will be called for it.
memprof_thread_registry = new (thread_registry_placeholder)
ThreadRegistry(GetMemprofThreadContext);
initialized = true;
}
return *memprof_thread_registry;
}
MemprofThreadContext *GetThreadContextByTidLocked(u32 tid) {
return static_cast<MemprofThreadContext *>(
memprofThreadRegistry().GetThreadLocked(tid));
}
// MemprofThread implementation.
MemprofThread *MemprofThread::Create(thread_callback_t start_routine, void *arg,
u32 parent_tid, StackTrace *stack,
bool detached) {
uptr PageSize = GetPageSizeCached();
uptr size = RoundUpTo(sizeof(MemprofThread), PageSize);
MemprofThread *thread = (MemprofThread *)MmapOrDie(size, __func__);
thread->start_routine_ = start_routine;
thread->arg_ = arg;
MemprofThreadContext::CreateThreadContextArgs args = {thread, stack};
memprofThreadRegistry().CreateThread(0, detached, parent_tid, &args);
return thread;
}
void MemprofThread::TSDDtor(void *tsd) {
MemprofThreadContext *context = (MemprofThreadContext *)tsd;
VReport(1, "T%d TSDDtor\n", context->tid);
if (context->thread)
context->thread->Destroy();
}
void MemprofThread::Destroy() {
int tid = this->tid();
VReport(1, "T%d exited\n", tid);
malloc_storage().CommitBack();
memprofThreadRegistry().FinishThread(tid);
FlushToDeadThreadStats(&stats_);
uptr size = RoundUpTo(sizeof(MemprofThread), GetPageSizeCached());
UnmapOrDie(this, size);
DTLS_Destroy();
}
inline MemprofThread::StackBounds MemprofThread::GetStackBounds() const {
if (stack_bottom_ >= stack_top_)
return {0, 0};
return {stack_bottom_, stack_top_};
}
uptr MemprofThread::stack_top() { return GetStackBounds().top; }
uptr MemprofThread::stack_bottom() { return GetStackBounds().bottom; }
uptr MemprofThread::stack_size() {
const auto bounds = GetStackBounds();
return bounds.top - bounds.bottom;
}
void MemprofThread::Init(const InitOptions *options) {
CHECK_EQ(this->stack_size(), 0U);
SetThreadStackAndTls(options);
if (stack_top_ != stack_bottom_) {
CHECK_GT(this->stack_size(), 0U);
CHECK(AddrIsInMem(stack_bottom_));
CHECK(AddrIsInMem(stack_top_ - 1));
}
int local = 0;
VReport(1, "T%d: stack [%p,%p) size 0x%zx; local=%p\n", tid(),
(void *)stack_bottom_, (void *)stack_top_, stack_top_ - stack_bottom_,
(void *)&local);
}
thread_return_t
MemprofThread::ThreadStart(tid_t os_id,
atomic_uintptr_t *signal_thread_is_registered) {
Init();
memprofThreadRegistry().StartThread(tid(), os_id, ThreadType::Regular,
nullptr);
if (signal_thread_is_registered)
atomic_store(signal_thread_is_registered, 1, memory_order_release);
if (!start_routine_) {
// start_routine_ == 0 if we're on the main thread or on one of the
// OS X libdispatch worker threads. But nobody is supposed to call
// ThreadStart() for the worker threads.
CHECK_EQ(tid(), 0);
return 0;
}
return start_routine_(arg_);
}
MemprofThread *CreateMainThread() {
MemprofThread *main_thread = MemprofThread::Create(
/* start_routine */ nullptr, /* arg */ nullptr, /* parent_tid */ kMainTid,
/* stack */ nullptr, /* detached */ true);
SetCurrentThread(main_thread);
main_thread->ThreadStart(internal_getpid(),
/* signal_thread_is_registered */ nullptr);
return main_thread;
}
// This implementation doesn't use the argument, which is just passed down
// from the caller of Init (which see, above). It's only there to support
// OS-specific implementations that need more information passed through.
void MemprofThread::SetThreadStackAndTls(const InitOptions *options) {
DCHECK_EQ(options, nullptr);
uptr tls_size = 0;
uptr stack_size = 0;
GetThreadStackAndTls(tid() == kMainTid, &stack_bottom_, &stack_size,
&tls_begin_, &tls_size);
stack_top_ = stack_bottom_ + stack_size;
tls_end_ = tls_begin_ + tls_size;
dtls_ = DTLS_Get();
if (stack_top_ != stack_bottom_) {
int local;
CHECK(AddrIsInStack((uptr)&local));
}
}
bool MemprofThread::AddrIsInStack(uptr addr) {
const auto bounds = GetStackBounds();
return addr >= bounds.bottom && addr < bounds.top;
}
MemprofThread *GetCurrentThread() {
MemprofThreadContext *context =
reinterpret_cast<MemprofThreadContext *>(TSDGet());
if (!context)
return nullptr;
return context->thread;
}
void SetCurrentThread(MemprofThread *t) {
CHECK(t->context());
VReport(2, "SetCurrentThread: %p for thread %p\n", (void *)t->context(),
(void *)GetThreadSelf());
// Make sure we do not reset the current MemprofThread.
CHECK_EQ(0, TSDGet());
TSDSet(t->context());
CHECK_EQ(t->context(), TSDGet());
}
u32 GetCurrentTidOrInvalid() {
MemprofThread *t = GetCurrentThread();
return t ? t->tid() : kInvalidTid;
}
void EnsureMainThreadIDIsCorrect() {
MemprofThreadContext *context =
reinterpret_cast<MemprofThreadContext *>(TSDGet());
if (context && (context->tid == kMainTid))
context->os_id = GetTid();
}
} // namespace __memprof