libloadplay.cpp File Reference

Implements a library intended to be injected into a clock frequency deamon via LD_PRELOAD. More...

#include "utility.hpp"
#include "constants.hpp"
#include "version.hpp"
#include "sys/env.hpp"
#include "sys/io.hpp"
#include <unordered_map>
#include <map>
#include <string>
#include <regex>
#include <memory>
#include <thread>
#include <exception>
#include <mutex>
#include <chrono>
#include <vector>
#include <algorithm>
#include <cstring>
#include <cassert>
#include <csignal>
#include <sys/types.h>
#include <sys/sysctl.h>
#include <sys/resource.h>
#include <libutil.h>
#include <dlfcn.h>
#include <unistd.h>

Include dependency graph for libloadplay.cpp:

Classes
struct	anonymous_namespace{libloadplay.cpp}::mib_t
	Represents MIB, but wraps it to provide the necessary operators to use it as an std::map key. More...
class	anonymous_namespace{libloadplay.cpp}::Callback< FunctionArgs >
	Implements a recursion safe std::function wrapper. More...
class	anonymous_namespace{libloadplay.cpp}::SysctlValue
	Instances of this class represents a specific sysctl value. More...
class	anonymous_namespace{libloadplay.cpp}::Sysctls
	Singleton class representing the sysctl table for this library. More...
struct	anonymous_namespace{libloadplay.cpp}::CoreReport
	The reported state of a single CPU pipeline. More...
struct	anonymous_namespace{libloadplay.cpp}::CoreFrameReport
	The report frame information for a single CPU pipeline. More...
class	anonymous_namespace{libloadplay.cpp}::Report
	Provides a mechanism to provide frame wise per core load information. More...
class	anonymous_namespace{libloadplay.cpp}::Report::Frame
	Represents a frame of the report. More...
class	anonymous_namespace{libloadplay.cpp}::Emulator
	Instances of this class represent an emulator session. More...
struct	anonymous_namespace{libloadplay.cpp}::Emulator::Core
	Per core information. More...
class	anonymous_namespace{libloadplay.cpp}::Main
	Singleton class representing the main execution environment. More...
class	anonymous_namespace{libloadplay.cpp}::Hold< T >
	Sets a referenced variable to a given value and restores it when going out of context. More...

Namespaces
	anonymous_namespace{libloadplay.cpp}
	File local scope.

Typedefs
using	anonymous_namespace{libloadplay.cpp}::cycles_t = uint64_t
	Clock cycle counting type.
template<auto Ownership>
using	anonymous_namespace{libloadplay.cpp}::ofile = io::file< Ownership, io::write >
	Output file type alias. More...
template<auto Ownership>
using	anonymous_namespace{libloadplay.cpp}::ifile = io::file< Ownership, io::read >
	Input file type alias. More...

Functions
template<size_t Size>
int	anonymous_namespace{libloadplay.cpp}::strcmp (char const *const s1, char const (&s2)[Size])
	Safe wrapper around strncmp, which automatically determines the buffer size of s2. More...
std::regex	anonymous_namespace{libloadplay.cpp}::operator""_r (char const *const str, size_t const len)
	User defined literal for regular expressions. More...
template<typename ... ArgTs>
constexpr void	anonymous_namespace{libloadplay.cpp}::dprintf (ArgTs &&... args)
	Calls io::ferr.printf(...) if built with -DEBUG. More...
template<>
std::string	anonymous_namespace{libloadplay.cpp}::SysctlValue::get< std::string > () const
	Returns a copy of the value string. More...
template<typename... MsgTs>
ofile< io::link >	anonymous_namespace{libloadplay.cpp}::debug (MsgTs &&... msg)
	Print a debugging message if built with -DEBUG. More...
template<typename... MsgTs>
ofile< io::link >	anonymous_namespace{libloadplay.cpp}::warn (MsgTs &&... msg)
	Print a warning. More...
int	anonymous_namespace{libloadplay.cpp}::sys_result (int const result)
	Combine sys_results with a computed result. More...
template<typename... MsgTs>
ofile< io::link >	anonymous_namespace{libloadplay.cpp}::fail (MsgTs &&... msg)
	This prints an error message and sets sys_results to make the hijacked process fail. More...
ofile< io::link >	anonymous_namespace{libloadplay.cpp}::operator<< (ofile< io::link > fout, CoreFrameReport const &frame)
	Print recorded and running clock frequency and load for a frame. More...
int	sysctl (const int *name, u_int namelen, void *oldp, size_t *oldlenp, const void *newp, size_t newlen)
	Functions to intercept. More...
int	sysctlnametomib (const char *name, int *mibp, size_t *sizep)
	Intercept calls to sysctlnametomib(). More...
int	daemon (int, int)
	Intercept calls to daemon(). More...
uid_t	geteuid (void)
	Intercept calls to geteuid(). More...
pidfh *	pidfile_open (const char *, mode_t, pid_t *)
	Intercept calls to pidfile_open(). More...
int	pidfile_write (pidfh *)
	Intercept calls to pidfile_write(). More...
int	pidfile_close (pidfh *)
	Intercept calls to pidfile_close(). More...
int	pidfile_remove (pidfh *)
	Intercept calls to pidfile_remove(). More...
int	pidfile_fileno (pidfh const *)
	Intercept calls to pidfile_fileno(). More...

Variables
constexpr const flag_t	anonymous_namespace{libloadplay.cpp}::FEATURES
	The set of supported features. More...
int	anonymous_namespace{libloadplay.cpp}::sys_results = 0
	The success return value of intercepted functions.
class anonymous_namespace{libloadplay.cpp}::Sysctls	anonymous_namespace{libloadplay.cpp}::sysctls
	Sole instance of Sysctls.
bool	anonymous_namespace{libloadplay.cpp}::sysctl_startup = true
	Set to activate fallback to the original sysctl functions. More...
class anonymous_namespace{libloadplay.cpp}::Main	anonymous_namespace{libloadplay.cpp}::main
	Sole instance of Main.

Detailed Description

Implements a library intended to be injected into a clock frequency deamon via LD_PRELOAD.

This library reads instructions from io::fin (stdin) and outputs statistics about the hijacked process on io::fout (stdout).

The following environment variables affect the operation of loadplay:

Variable	Description
LOADPLAY_IN	Alternative input file
LOADPLAY_OUT	Alternative output file

---

Class Documentation

anonymous_namespace{libloadplay.cpp}::CoreReport

struct anonymous_namespace{libloadplay.cpp}::CoreReport

The reported state of a single CPU pipeline.

Collaboration diagram for anonymous_namespace{libloadplay.cpp}::CoreReport:

Class Members
mhz_t	freq	The core clock frequency in [MHz].
double	load	The core load as a fraction.

anonymous_namespace{libloadplay.cpp}::CoreFrameReport

struct anonymous_namespace{libloadplay.cpp}::CoreFrameReport

The report frame information for a single CPU pipeline.

Collaboration diagram for anonymous_namespace{libloadplay.cpp}::CoreFrameReport:

Class Members
CoreReport	rec	The recorded core state.
CoreReport	run	The running core state.

anonymous_namespace{libloadplay.cpp}::Emulator::Core

struct anonymous_namespace{libloadplay.cpp}::Emulator::Core

Per core information.

Collaboration diagram for anonymous_namespace{libloadplay.cpp}::Emulator::Core:

Class Members
cycles_t	carryCycles[CPUSTATES]	The cycles carried over to the next frame in [cycles]. This is determined at the beginning of frame and used to calculated the simulation load at the beginning of the next frame.
SysctlValue *	freqCtl	The sysctl handler. The constructor ensures this points to a valid handler.
mhz_t	recFreq	The recorded clock frequency. If FREQ_TRACKING is enabled this is updated at during the preliminary stage and used at the beginning of frame stage.
mhz_t	runFreq	The clock frequency the simulation is running at. Updated at the end of frame and used in the next frame.
cycles_t	runLoadCycles	The load cycles simulated for this frame in [cycles]. This is determined at the beginning of frame and used to calculate the reported load at the end of frame.

Function Documentation

daemon()

int daemon	(	int	,
		int
	)

Intercept calls to daemon().

Prevents process from separating from the controlling terminal.

Returns

The value of sys_results

geteuid()

uid_t geteuid

(

void

)

Intercept calls to geteuid().

Tells the asking process that it is running as root.

Returns

Always returns 0

pidfile_close()

int pidfile_close

(

pidfh *

)

Intercept calls to pidfile_close().

Returns

The value of sys_results

pidfile_fileno()

int pidfile_fileno

(

pidfh const *

)

Intercept calls to pidfile_fileno().

Returns

The value of sys_results

pidfile_open()

pidfh* pidfile_open	(	const char *	,
		mode_t	,
		pid_t *
	)

Intercept calls to pidfile_open().

Prevents pidfile locking and creation by the hijacked process.

Returns

A dummy pointer

pidfile_remove()

int pidfile_remove

(

pidfh *

)

Intercept calls to pidfile_remove().

Returns

The value of sys_results

pidfile_write()

int pidfile_write

(

pidfh *

)

Intercept calls to pidfile_write().

Returns

The value of sys_results

sysctl()

int sysctl	(	const int *	name,
		u_int	namelen,
		void *	oldp,
		size_t *	oldlenp,
		const void *	newp,
		size_t	newlen
	)

Functions to intercept.

Intercept calls to sysctl().

Uses the local anonymous_namespace{libloadplay::cpp}::sysctls store.

Falls back to the original under the following conditions:

• sysctl_startup is set
• The mib is not known to the simulation

The call may fail for 3 reasons:

1. The fail() function was called and sys_results was assigned -1
2. A target buffer was too small (errno == ENOMEM)
3. The given sysctl is not in the sysctls store (errno == ENOENT)

Parameters

name,namelen,oldp,oldlenp,newp,newlen

Please refer to sysctl(3)

Return values

0	The call succeeded
-1	The call failed

sysctlnametomib()

int sysctlnametomib	(	const char *	name,
		int *	mibp,
		size_t *	sizep
	)

Intercept calls to sysctlnametomib().

Parameters

name,mibp,sizep

Please refer to sysctl(3)

Return values

0	The call succeeded
-1	The call failed