Common: Remove async logging

It provided a large increase in complexity of the logging system while
having a negligible performance impact: the usage patterns of the ring
buffer meant that each log contended with the logging thread, causing
it to effectively act as a synchronous extra buffering.

Also removed some broken code related to filtering of subclasses which
was broken since it was introduced. (Which means no one ever used that
feature anyway, since, 8 months later, no one ever complained.)
This commit is contained in:
Yuri Kunde Schlesner 2015-05-12 02:19:44 -03:00
parent cb2b2071a8
commit b88c91dd3d
9 changed files with 32 additions and 222 deletions

View file

@ -20,14 +20,8 @@
/// Application entry point
int main(int argc, char **argv) {
std::shared_ptr<Log::Logger> logger = Log::InitGlobalLogger();
Log::Filter log_filter(Log::Level::Debug);
Log::SetFilter(&log_filter);
std::thread logging_thread(Log::TextLoggingLoop, logger);
SCOPE_EXIT({
logger->Close();
logging_thread.join();
});
if (argc < 2) {
LOG_CRITICAL(Frontend, "Failed to load ROM: No ROM specified");

View file

@ -350,14 +350,8 @@ void GMainWindow::closeEvent(QCloseEvent* event)
int main(int argc, char* argv[])
{
std::shared_ptr<Log::Logger> logger = Log::InitGlobalLogger();
Log::Filter log_filter(Log::Level::Info);
Log::SetFilter(&log_filter);
std::thread logging_thread(Log::TextLoggingLoop, logger);
SCOPE_EXIT({
logger->Close();
logging_thread.join();
});
QApplication::setAttribute(Qt::AA_X11InitThreads);
QApplication app(argc, argv);

View file

@ -3,17 +3,17 @@
// Refer to the license.txt file included.
#include <algorithm>
#include <array>
#include <cstdio>
#include "common/assert.h"
#include "common/common_funcs.h" // snprintf compatibility define
#include "common/logging/backend.h"
#include "common/logging/filter.h"
#include "common/logging/log.h"
#include "common/logging/text_formatter.h"
namespace Log {
static std::shared_ptr<Logger> global_logger;
/// Macro listing all log classes. Code should define CLS and SUB as desired before invoking this.
#define ALL_LOG_CLASSES() \
CLS(Log) \
@ -55,28 +55,8 @@ static std::shared_ptr<Logger> global_logger;
SUB(Render, OpenGL) \
CLS(Loader)
Logger::Logger() {
// Register logging classes so that they can be queried at runtime
size_t parent_class;
all_classes.reserve((size_t)Class::Count);
#define CLS(x) \
all_classes.push_back(Class::x); \
parent_class = all_classes.size() - 1;
#define SUB(x, y) \
all_classes.push_back(Class::x##_##y); \
all_classes[parent_class].num_children += 1;
ALL_LOG_CLASSES()
#undef CLS
#undef SUB
// Ensures that ALL_LOG_CLASSES isn't missing any entries.
DEBUG_ASSERT(all_classes.size() == (size_t)Class::Count);
}
// GetClassName is a macro defined by Windows.h, grrr...
const char* Logger::GetLogClassName(Class log_class) {
const char* GetLogClassName(Class log_class) {
switch (log_class) {
#define CLS(x) case Class::x: return #x;
#define SUB(x, y) case Class::x##_##y: return #x "." #y;
@ -87,7 +67,7 @@ const char* Logger::GetLogClassName(Class log_class) {
return "Unknown";
}
const char* Logger::GetLevelName(Level log_level) {
const char* GetLevelName(Level log_level) {
#define LVL(x) case Level::x: return #x
switch (log_level) {
LVL(Trace);
@ -101,19 +81,6 @@ const char* Logger::GetLevelName(Level log_level) {
#undef LVL
}
void Logger::LogMessage(Entry entry) {
ring_buffer.Push(std::move(entry));
}
size_t Logger::GetEntries(Entry* out_buffer, size_t buffer_len) {
return ring_buffer.BlockingPop(out_buffer, buffer_len);
}
std::shared_ptr<Logger> InitGlobalLogger() {
global_logger = std::make_shared<Logger>();
return global_logger;
}
Entry CreateEntry(Class log_class, Level log_level,
const char* filename, unsigned int line_nr, const char* function,
const char* format, va_list args) {
@ -138,7 +105,7 @@ Entry CreateEntry(Class log_class, Level log_level,
return std::move(entry);
}
static Filter* filter;
static Filter* filter = nullptr;
void SetFilter(Filter* new_filter) {
filter = new_filter;
@ -147,7 +114,7 @@ void SetFilter(Filter* new_filter) {
void LogMessage(Class log_class, Level log_level,
const char* filename, unsigned int line_nr, const char* function,
const char* format, ...) {
if (!filter->CheckMessage(log_class, log_level))
if (filter != nullptr && !filter->CheckMessage(log_class, log_level))
return;
va_list args;
@ -156,12 +123,7 @@ void LogMessage(Class log_class, Level log_level,
filename, line_nr, function, format, args);
va_end(args);
if (global_logger != nullptr && !global_logger->IsClosed()) {
global_logger->LogMessage(std::move(entry));
} else {
// Fall back to directly printing to stderr
PrintMessage(entry);
}
PrintColoredMessage(entry);
}
}

View file

@ -4,17 +4,17 @@
#pragma once
#include <chrono>
#include <cstdarg>
#include <memory>
#include <vector>
#include <string>
#include <utility>
#include "common/concurrent_ring_buffer.h"
#include "common/logging/filter.h"
#include "common/logging/log.h"
namespace Log {
class Filter;
/**
* A log entry. Log entries are store in a structured format to permit more varied output
* formatting on different frontends, as well as facilitating filtering and aggregation.
@ -48,89 +48,21 @@ struct Entry {
}
};
struct ClassInfo {
Class log_class;
/**
* Total number of (direct or indirect) sub classes this class has. If any, they follow in
* sequence after this class in the class list.
*/
unsigned int num_children = 0;
ClassInfo(Class log_class) : log_class(log_class) {}
};
/**
* Logging management class. This class has the dual purpose of acting as an exchange point between
* the logging clients and the log outputter, as well as containing reflection info about available
* log classes.
*/
class Logger {
private:
using Buffer = Common::ConcurrentRingBuffer<Entry, 16 * 1024 / sizeof(Entry)>;
public:
static const size_t QUEUE_CLOSED = Buffer::QUEUE_CLOSED;
Logger();
/**
* Returns a list of all vector classes and subclasses. The sequence returned is a pre-order of
* classes and subclasses, which together with the `num_children` field in ClassInfo, allows
* you to recover the hierarchy.
*/
const std::vector<ClassInfo>& GetClasses() const { return all_classes; }
/**
* Returns the name of the passed log class as a C-string. Subclasses are separated by periods
* instead of underscores as in the enumeration.
*/
static const char* GetLogClassName(Class log_class);
const char* GetLogClassName(Class log_class);
/**
/**
* Returns the name of the passed log level as a C-string.
*/
static const char* GetLevelName(Level log_level);
/**
* Appends a messages to the log buffer.
* @note This function is thread safe.
*/
void LogMessage(Entry entry);
/**
* Retrieves a batch of messages from the log buffer, blocking until they are available.
* @note This function is thread safe.
*
* @param out_buffer Destination buffer that will receive the log entries.
* @param buffer_len The maximum size of `out_buffer`.
* @return The number of entries stored. In case the logger is shutting down, `QUEUE_CLOSED` is
* returned, no entries are stored and the logger should shutdown.
*/
size_t GetEntries(Entry* out_buffer, size_t buffer_len);
/**
* Initiates a shutdown of the logger. This will indicate to log output clients that they
* should shutdown.
*/
void Close() { ring_buffer.Close(); }
/**
* Returns true if Close() has already been called on the Logger.
*/
bool IsClosed() const { return ring_buffer.IsClosed(); }
private:
Buffer ring_buffer;
std::vector<ClassInfo> all_classes;
};
const char* GetLevelName(Level log_level);
/// Creates a log entry by formatting the given source location, and message.
Entry CreateEntry(Class log_class, Level log_level,
const char* filename, unsigned int line_nr, const char* function,
const char* format, va_list args);
/// Initializes the default Logger.
std::shared_ptr<Logger> InitGlobalLogger();
void SetFilter(Filter* filter);

View file

@ -22,16 +22,6 @@ void Filter::SetClassLevel(Class log_class, Level level) {
class_levels[static_cast<size_t>(log_class)] = level;
}
void Filter::SetSubclassesLevel(const ClassInfo& log_class, Level level) {
const size_t log_class_i = static_cast<size_t>(log_class.log_class);
const size_t begin = log_class_i + 1;
const size_t end = begin + log_class.num_children;
for (size_t i = begin; begin < end; ++i) {
class_levels[i] = level;
}
}
void Filter::ParseFilterString(const std::string& filter_str) {
auto clause_begin = filter_str.cbegin();
while (clause_begin != filter_str.cend()) {
@ -53,7 +43,7 @@ void Filter::ParseFilterString(const std::string& filter_str) {
template <typename It>
static Level GetLevelByName(const It begin, const It end) {
for (u8 i = 0; i < static_cast<u8>(Level::Count); ++i) {
const char* level_name = Logger::GetLevelName(static_cast<Level>(i));
const char* level_name = GetLevelName(static_cast<Level>(i));
if (Common::ComparePartialString(begin, end, level_name)) {
return static_cast<Level>(i);
}
@ -64,7 +54,7 @@ static Level GetLevelByName(const It begin, const It end) {
template <typename It>
static Class GetClassByName(const It begin, const It end) {
for (ClassType i = 0; i < static_cast<ClassType>(Class::Count); ++i) {
const char* level_name = Logger::GetLogClassName(static_cast<Class>(i));
const char* level_name = GetLogClassName(static_cast<Class>(i));
if (Common::ComparePartialString(begin, end, level_name)) {
return static_cast<Class>(i);
}
@ -72,20 +62,6 @@ static Class GetClassByName(const It begin, const It end) {
return Class::Count;
}
template <typename InputIt, typename T>
static InputIt find_last(InputIt begin, const InputIt end, const T& value) {
auto match = end;
while (begin != end) {
auto new_match = std::find(begin, end, value);
if (new_match != end) {
match = new_match;
++new_match;
}
begin = new_match;
}
return match;
}
bool Filter::ParseFilterRule(const std::string::const_iterator begin,
const std::string::const_iterator end) {
auto level_separator = std::find(begin, end, ':');
@ -106,22 +82,13 @@ bool Filter::ParseFilterRule(const std::string::const_iterator begin,
return true;
}
auto class_name_end = find_last(begin, level_separator, '.');
if (class_name_end != level_separator &&
!Common::ComparePartialString(class_name_end + 1, level_separator, "*")) {
class_name_end = level_separator;
}
const Class log_class = GetClassByName(begin, class_name_end);
const Class log_class = GetClassByName(begin, level_separator);
if (log_class == Class::Count) {
LOG_ERROR(Log, "Unknown log class in filter: %s", std::string(begin, end).c_str());
return false;
}
if (class_name_end == level_separator) {
SetClassLevel(log_class, level);
}
SetSubclassesLevel(log_class, level);
return true;
}

View file

@ -11,8 +11,6 @@
namespace Log {
struct ClassInfo;
/**
* Implements a log message filter which allows different log classes to have different minimum
* severity levels. The filter can be changed at runtime and can be parsed from a string to allow
@ -27,29 +25,19 @@ public:
void ResetAll(Level level);
/// Sets the minimum level of `log_class` (and not of its subclasses) to `level`.
void SetClassLevel(Class log_class, Level level);
/**
* Sets the minimum level of all of `log_class` subclasses to `level`. The level of `log_class`
* itself is not changed.
*/
void SetSubclassesLevel(const ClassInfo& log_class, Level level);
/**
* Parses a filter string and applies it to this filter.
*
* A filter string consists of a space-separated list of filter rules, each of the format
* `<class>:<level>`. `<class>` is a log class name, with subclasses separated using periods.
* A rule for a given class also affects all of its subclasses. `*` wildcards are allowed and
* can be used to apply a rule to all classes or to all subclasses of a class without affecting
* the parent class. `<level>` a severity level name which will be set as the minimum logging
* level of the matched classes. Rules are applied left to right, with each rule overriding
* previous ones in the sequence.
* `*` is allowed as a class name and will reset all filters to the specified level. `<level>`
* a severity level name which will be set as the minimum logging level of the matched classes.
* Rules are applied left to right, with each rule overriding previous ones in the sequence.
*
* A few examples of filter rules:
* - `*:Info` -- Resets the level of all classes to Info.
* - `Service:Info` -- Sets the level of Service and all subclasses (Service.FS, Service.APT,
* etc.) to Info.
* - `Service.*:Debug` -- Sets the level of all Service subclasses to Debug, while leaving the
* level of Service unchanged.
* - `Service:Info` -- Sets the level of Service to Info.
* - `Service.FS:Trace` -- Sets the level of the Service.FS class to Trace.
*/
void ParseFilterString(const std::string& filter_str);

View file

@ -78,11 +78,7 @@ enum class Class : ClassType {
Count ///< Total number of logging classes
};
/**
* Logs a message to the global logger. This proxy exists to avoid exposing the details of the
* Logger class, including the ConcurrentRingBuffer template, to all files that desire to log
* messages, reducing unecessary recompilations.
*/
/// Logs a message to the global logger.
void LogMessage(Class log_class, Level log_level,
const char* filename, unsigned int line_nr, const char* function,
#ifdef _MSC_VER

View file

@ -46,8 +46,8 @@ void FormatLogMessage(const Entry& entry, char* out_text, size_t text_len) {
unsigned int time_seconds = static_cast<unsigned int>(entry.timestamp.count() / 1000000);
unsigned int time_fractional = static_cast<unsigned int>(entry.timestamp.count() % 1000000);
const char* class_name = Logger::GetLogClassName(entry.log_class);
const char* level_name = Logger::GetLevelName(entry.log_level);
const char* class_name = GetLogClassName(entry.log_class);
const char* level_name = GetLevelName(entry.log_level);
snprintf(out_text, text_len, "[%4u.%06u] %s <%s> %s: %s",
time_seconds, time_fractional, class_name, level_name,
@ -116,19 +116,4 @@ void PrintColoredMessage(const Entry& entry) {
#endif
}
void TextLoggingLoop(std::shared_ptr<Logger> logger) {
std::array<Entry, 256> entry_buffer;
while (true) {
size_t num_entries = logger->GetEntries(entry_buffer.data(), entry_buffer.size());
if (num_entries == Logger::QUEUE_CLOSED) {
break;
}
for (size_t i = 0; i < num_entries; ++i) {
const Entry& entry = entry_buffer[i];
PrintColoredMessage(entry);
}
}
}
}

View file

@ -5,11 +5,9 @@
#pragma once
#include <cstddef>
#include <memory>
namespace Log {
class Logger;
struct Entry;
/**
@ -31,10 +29,4 @@ void PrintMessage(const Entry& entry);
/// Prints the same message as `PrintMessage`, but colored acoording to the severity level.
void PrintColoredMessage(const Entry& entry);
/**
* Logging loop that repeatedly reads messages from the provided logger and prints them to the
* console. It is the baseline barebones log outputter.
*/
void TextLoggingLoop(std::shared_ptr<Logger> logger);
}