llvm-project/lldb/source/Utility/Event.cpp

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//===-- Event.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
//
//===----------------------------------------------------------------------===//
#include "lldb/Utility/Event.h"
#include "lldb/Utility/Broadcaster.h"
#include "lldb/Utility/DataExtractor.h"
#include "lldb/Utility/Endian.h"
#include "lldb/Utility/Stream.h"
#include "lldb/Utility/StreamString.h"
#include "lldb/lldb-enumerations.h"
#include <algorithm>
#include <ctype.h>
using namespace lldb;
using namespace lldb_private;
#pragma mark -
#pragma mark Event
// Event functions
Event::Event(Broadcaster *broadcaster, uint32_t event_type, EventData *data)
Fix some long standing issues that caused tests to be flaky. The main issues were: - Listeners recently were converted over to used by getting a shared pointer to a listener. And when they listened to broadcasters they would get a strong reference added to them meaning the listeners would never go away. This caused memory usage to increase and would cause performance issue if many steps were done. - The lldb_private::Process private state thread had an issue where if a "stop" contol signal was attempted to be sent to that thread, it could end up not responding in 2 seconds and end up getting cancelled which might cause us to cancel a thread that had a mutex locked and it would deadlock the test. This change makes broadcasters hold onto weak references to listeners. It also fixes some bad threading code that had races inside of it by making the m_events_mutex be non-recursive and getting rid of fragile use of a Predicate<bool> to say that new events are available, and replacing it with using the m_events_mutex with a new m_events_condition to control access to the events in a safer way. The private state thread now uses a safer way to communicate that the control event has been received by the private state thread: it makes a EventDataReceipt instance that it attaches to the event that sends the control to the private state thread and used this to synchronize the fact that the private state thread has received the event instead of using a Predicate<bool> to convey the info. When the signal event is received, it will pull the event off of the queue in the private state thread and cause the EventData::DoOnRemoval() to be called, which will signal that the event has been received. This cleans up the signal delivery notification so it doesn't rely on a member variable of the process class to convey the info. std::shared_ptr<EventDataReceipt> event_receipt_sp(new EventDataReceipt()); m_private_state_control_broadcaster.BroadcastEvent(signal, event_receipt_sp); <rdar://problem/26256353> Listeners are being kept around longer than they should be due to recent changs <rdar://problem/26256258> Private process state thread can be cancelled and cause deadlocks in test suite llvm-svn: 269377
2016-05-13 06:58:52 +08:00
: m_broadcaster_wp(broadcaster->GetBroadcasterImpl()), m_type(event_type),
m_data_sp(data) {}
Event::Event(Broadcaster *broadcaster, uint32_t event_type,
const EventDataSP &event_data_sp)
: m_broadcaster_wp(broadcaster->GetBroadcasterImpl()), m_type(event_type),
m_data_sp(event_data_sp) {}
Event::Event(uint32_t event_type, EventData *data)
Fix some long standing issues that caused tests to be flaky. The main issues were: - Listeners recently were converted over to used by getting a shared pointer to a listener. And when they listened to broadcasters they would get a strong reference added to them meaning the listeners would never go away. This caused memory usage to increase and would cause performance issue if many steps were done. - The lldb_private::Process private state thread had an issue where if a "stop" contol signal was attempted to be sent to that thread, it could end up not responding in 2 seconds and end up getting cancelled which might cause us to cancel a thread that had a mutex locked and it would deadlock the test. This change makes broadcasters hold onto weak references to listeners. It also fixes some bad threading code that had races inside of it by making the m_events_mutex be non-recursive and getting rid of fragile use of a Predicate<bool> to say that new events are available, and replacing it with using the m_events_mutex with a new m_events_condition to control access to the events in a safer way. The private state thread now uses a safer way to communicate that the control event has been received by the private state thread: it makes a EventDataReceipt instance that it attaches to the event that sends the control to the private state thread and used this to synchronize the fact that the private state thread has received the event instead of using a Predicate<bool> to convey the info. When the signal event is received, it will pull the event off of the queue in the private state thread and cause the EventData::DoOnRemoval() to be called, which will signal that the event has been received. This cleans up the signal delivery notification so it doesn't rely on a member variable of the process class to convey the info. std::shared_ptr<EventDataReceipt> event_receipt_sp(new EventDataReceipt()); m_private_state_control_broadcaster.BroadcastEvent(signal, event_receipt_sp); <rdar://problem/26256353> Listeners are being kept around longer than they should be due to recent changs <rdar://problem/26256258> Private process state thread can be cancelled and cause deadlocks in test suite llvm-svn: 269377
2016-05-13 06:58:52 +08:00
: m_broadcaster_wp(), m_type(event_type), m_data_sp(data) {}
Event::Event(uint32_t event_type, const EventDataSP &event_data_sp)
: m_broadcaster_wp(), m_type(event_type), m_data_sp(event_data_sp) {}
Event::~Event() = default;
void Event::Dump(Stream *s) const {
Broadcaster *broadcaster;
Broadcaster::BroadcasterImplSP broadcaster_impl_sp(m_broadcaster_wp.lock());
if (broadcaster_impl_sp)
broadcaster = broadcaster_impl_sp->GetBroadcaster();
else
broadcaster = nullptr;
if (broadcaster) {
StreamString event_name;
if (broadcaster->GetEventNames(event_name, m_type, false))
s->Printf("%p Event: broadcaster = %p (%s), type = 0x%8.8x (%s), data = ",
static_cast<const void *>(this),
static_cast<void *>(broadcaster),
broadcaster->GetBroadcasterName().GetCString(), m_type,
event_name.GetData());
else
s->Printf("%p Event: broadcaster = %p (%s), type = 0x%8.8x, data = ",
static_cast<const void *>(this),
static_cast<void *>(broadcaster),
broadcaster->GetBroadcasterName().GetCString(), m_type);
} else
s->Printf("%p Event: broadcaster = NULL, type = 0x%8.8x, data = ",
static_cast<const void *>(this), m_type);
if (m_data_sp) {
s->PutChar('{');
Fix some long standing issues that caused tests to be flaky. The main issues were: - Listeners recently were converted over to used by getting a shared pointer to a listener. And when they listened to broadcasters they would get a strong reference added to them meaning the listeners would never go away. This caused memory usage to increase and would cause performance issue if many steps were done. - The lldb_private::Process private state thread had an issue where if a "stop" contol signal was attempted to be sent to that thread, it could end up not responding in 2 seconds and end up getting cancelled which might cause us to cancel a thread that had a mutex locked and it would deadlock the test. This change makes broadcasters hold onto weak references to listeners. It also fixes some bad threading code that had races inside of it by making the m_events_mutex be non-recursive and getting rid of fragile use of a Predicate<bool> to say that new events are available, and replacing it with using the m_events_mutex with a new m_events_condition to control access to the events in a safer way. The private state thread now uses a safer way to communicate that the control event has been received by the private state thread: it makes a EventDataReceipt instance that it attaches to the event that sends the control to the private state thread and used this to synchronize the fact that the private state thread has received the event instead of using a Predicate<bool> to convey the info. When the signal event is received, it will pull the event off of the queue in the private state thread and cause the EventData::DoOnRemoval() to be called, which will signal that the event has been received. This cleans up the signal delivery notification so it doesn't rely on a member variable of the process class to convey the info. std::shared_ptr<EventDataReceipt> event_receipt_sp(new EventDataReceipt()); m_private_state_control_broadcaster.BroadcastEvent(signal, event_receipt_sp); <rdar://problem/26256353> Listeners are being kept around longer than they should be due to recent changs <rdar://problem/26256258> Private process state thread can be cancelled and cause deadlocks in test suite llvm-svn: 269377
2016-05-13 06:58:52 +08:00
m_data_sp->Dump(s);
s->PutChar('}');
} else
s->Printf("<NULL>");
}
void Event::DoOnRemoval() {
Fix some long standing issues that caused tests to be flaky. The main issues were: - Listeners recently were converted over to used by getting a shared pointer to a listener. And when they listened to broadcasters they would get a strong reference added to them meaning the listeners would never go away. This caused memory usage to increase and would cause performance issue if many steps were done. - The lldb_private::Process private state thread had an issue where if a "stop" contol signal was attempted to be sent to that thread, it could end up not responding in 2 seconds and end up getting cancelled which might cause us to cancel a thread that had a mutex locked and it would deadlock the test. This change makes broadcasters hold onto weak references to listeners. It also fixes some bad threading code that had races inside of it by making the m_events_mutex be non-recursive and getting rid of fragile use of a Predicate<bool> to say that new events are available, and replacing it with using the m_events_mutex with a new m_events_condition to control access to the events in a safer way. The private state thread now uses a safer way to communicate that the control event has been received by the private state thread: it makes a EventDataReceipt instance that it attaches to the event that sends the control to the private state thread and used this to synchronize the fact that the private state thread has received the event instead of using a Predicate<bool> to convey the info. When the signal event is received, it will pull the event off of the queue in the private state thread and cause the EventData::DoOnRemoval() to be called, which will signal that the event has been received. This cleans up the signal delivery notification so it doesn't rely on a member variable of the process class to convey the info. std::shared_ptr<EventDataReceipt> event_receipt_sp(new EventDataReceipt()); m_private_state_control_broadcaster.BroadcastEvent(signal, event_receipt_sp); <rdar://problem/26256353> Listeners are being kept around longer than they should be due to recent changs <rdar://problem/26256258> Private process state thread can be cancelled and cause deadlocks in test suite llvm-svn: 269377
2016-05-13 06:58:52 +08:00
if (m_data_sp)
m_data_sp->DoOnRemoval(this);
}
#pragma mark -
#pragma mark EventData
// EventData functions
EventData::EventData() = default;
EventData::~EventData() = default;
void EventData::Dump(Stream *s) const { s->PutCString("Generic Event Data"); }
#pragma mark -
#pragma mark EventDataBytes
// EventDataBytes functions
EventDataBytes::EventDataBytes() : m_bytes() {}
EventDataBytes::EventDataBytes(const char *cstr) : m_bytes() {
SetBytesFromCString(cstr);
}
EventDataBytes::EventDataBytes(llvm::StringRef str) : m_bytes() {
SetBytes(str.data(), str.size());
}
EventDataBytes::EventDataBytes(const void *src, size_t src_len) : m_bytes() {
SetBytes(src, src_len);
}
EventDataBytes::~EventDataBytes() = default;
ConstString EventDataBytes::GetFlavorString() {
static ConstString g_flavor("EventDataBytes");
return g_flavor;
}
ConstString EventDataBytes::GetFlavor() const {
return EventDataBytes::GetFlavorString();
}
void EventDataBytes::Dump(Stream *s) const {
size_t num_printable_chars =
std::count_if(m_bytes.begin(), m_bytes.end(), llvm::isPrint);
if (num_printable_chars == m_bytes.size())
s->Format("\"{0}\"", m_bytes);
else
s->Format("{0:$[ ]@[x-2]}", llvm::make_range(
reinterpret_cast<const uint8_t *>(m_bytes.data()),
reinterpret_cast<const uint8_t *>(m_bytes.data() +
m_bytes.size())));
}
const void *EventDataBytes::GetBytes() const {
return (m_bytes.empty() ? nullptr : m_bytes.data());
}
size_t EventDataBytes::GetByteSize() const { return m_bytes.size(); }
void EventDataBytes::SetBytes(const void *src, size_t src_len) {
if (src != nullptr && src_len > 0)
m_bytes.assign(static_cast<const char *>(src), src_len);
else
m_bytes.clear();
}
void EventDataBytes::SetBytesFromCString(const char *cstr) {
if (cstr != nullptr && cstr[0])
m_bytes.assign(cstr);
else
m_bytes.clear();
}
const void *EventDataBytes::GetBytesFromEvent(const Event *event_ptr) {
const EventDataBytes *e = GetEventDataFromEvent(event_ptr);
if (e != nullptr)
return e->GetBytes();
return nullptr;
}
size_t EventDataBytes::GetByteSizeFromEvent(const Event *event_ptr) {
const EventDataBytes *e = GetEventDataFromEvent(event_ptr);
if (e != nullptr)
return e->GetByteSize();
return 0;
}
const EventDataBytes *
EventDataBytes::GetEventDataFromEvent(const Event *event_ptr) {
if (event_ptr != nullptr) {
const EventData *event_data = event_ptr->GetData();
if (event_data &&
event_data->GetFlavor() == EventDataBytes::GetFlavorString())
return static_cast<const EventDataBytes *>(event_data);
}
return nullptr;
}
void EventDataBytes::SwapBytes(std::string &new_bytes) {
m_bytes.swap(new_bytes);
}
#pragma mark -
#pragma mark EventStructuredData
// EventDataStructuredData definitions
EventDataStructuredData::EventDataStructuredData()
: EventData(), m_process_sp(), m_object_sp(), m_plugin_sp() {}
EventDataStructuredData::EventDataStructuredData(
const ProcessSP &process_sp, const StructuredData::ObjectSP &object_sp,
const lldb::StructuredDataPluginSP &plugin_sp)
: EventData(), m_process_sp(process_sp), m_object_sp(object_sp),
m_plugin_sp(plugin_sp) {}
EventDataStructuredData::~EventDataStructuredData() {}
// EventDataStructuredData member functions
ConstString EventDataStructuredData::GetFlavor() const {
return EventDataStructuredData::GetFlavorString();
}
void EventDataStructuredData::Dump(Stream *s) const {
if (!s)
return;
if (m_object_sp)
m_object_sp->Dump(*s);
}
const ProcessSP &EventDataStructuredData::GetProcess() const {
return m_process_sp;
}
const StructuredData::ObjectSP &EventDataStructuredData::GetObject() const {
return m_object_sp;
}
const lldb::StructuredDataPluginSP &
EventDataStructuredData::GetStructuredDataPlugin() const {
return m_plugin_sp;
}
void EventDataStructuredData::SetProcess(const ProcessSP &process_sp) {
m_process_sp = process_sp;
}
void EventDataStructuredData::SetObject(
const StructuredData::ObjectSP &object_sp) {
m_object_sp = object_sp;
}
void EventDataStructuredData::SetStructuredDataPlugin(
const lldb::StructuredDataPluginSP &plugin_sp) {
m_plugin_sp = plugin_sp;
}
// EventDataStructuredData static functions
const EventDataStructuredData *
EventDataStructuredData::GetEventDataFromEvent(const Event *event_ptr) {
if (event_ptr == nullptr)
return nullptr;
const EventData *event_data = event_ptr->GetData();
if (!event_data ||
event_data->GetFlavor() != EventDataStructuredData::GetFlavorString())
return nullptr;
return static_cast<const EventDataStructuredData *>(event_data);
}
ProcessSP EventDataStructuredData::GetProcessFromEvent(const Event *event_ptr) {
auto event_data = EventDataStructuredData::GetEventDataFromEvent(event_ptr);
if (event_data)
return event_data->GetProcess();
else
return ProcessSP();
}
StructuredData::ObjectSP
EventDataStructuredData::GetObjectFromEvent(const Event *event_ptr) {
auto event_data = EventDataStructuredData::GetEventDataFromEvent(event_ptr);
if (event_data)
return event_data->GetObject();
else
return StructuredData::ObjectSP();
}
lldb::StructuredDataPluginSP
EventDataStructuredData::GetPluginFromEvent(const Event *event_ptr) {
auto event_data = EventDataStructuredData::GetEventDataFromEvent(event_ptr);
if (event_data)
return event_data->GetStructuredDataPlugin();
else
return StructuredDataPluginSP();
}
ConstString EventDataStructuredData::GetFlavorString() {
static ConstString s_flavor("EventDataStructuredData");
return s_flavor;
}