FX::FXProcess Class Reference

#include <FXProcess.h>

List of all members.

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Detailed Description

Provides process-wide information and control.

Where FXApp initialises the GUI subsystem, FXProcess initialises just those parts sufficient for command-line operation. Probably one of its most useful facilities is FXProcess_StaticInit which is used by a number of internal classes already.

FXProcess should be initialised first thing into main():

int main(int argc, char *argv[])
{
    FXProcess myprocess(argc, argv);
    FXApp app("name");      // Only for GUI apps
    app.init(argc, argv);   // Only for GUI apps
    ...
    app.create();           // Only for GUI apps
    ...
    return app.run();       // Only for GUI apps
}

Dynamic library facilities

You should use dllLoad() to load dynamic libraries - this loads and runs any FXProcess_StaticInit's the newly loaded library may have. If you manage your own loading, call runPendingStaticInits(). The search behaviour on POSIX is different than that for dlopen() - if a relative path, it emulates Windows by searching around where the executable is, then the current directory, then dlopen()'s default. It also tries appending .so if one isn't present already as well as prepending lib - this behaviour ensures that equivalent behaviour occurs both on Windows and POSIX. Watch out for calling DLL's the same as executables - on POSIX, there is no .exe extension to differentiate.

Once loaded you can resolve symbols using dllHandle::dllResolve() which returns a functor for that API. Note that C++ mangles its API names so you will have to specify extern "C" before their declaration in your DLL.

Free system resources

hostOSProcessorLoad(), hostOSMemoryLoad() and hostOSDiscIOLoad() allow your code to determine how free the system is in those areas. This can be used to dynamically adjust whether to use lots of memory and a fast algorithm or little memory and a slow algorithm.

A few parts of TnFOX use the convenience functions processorFull(), memoryFull() and discIOFull() but this facility is mostly intended for Tn. These functions return an integer index whereby zero is not full, one is getting full, two is nearly full and three is full and over. These numbers can be included in calculations as divisors of buffer sizes etc.

Note:

hostOSProcessLoad() and hostDiscIOLoad() are currently unimplemented. At some stage I'll do like FXSecure and maintain a shared memory region with the last five seconds of data from which meaningful values can be constructed.

Process-wide thread pool

A process-wide thread pool consisting of four threads is available at FXProcess::threadPool() and is created on first use. FX::QThreadPool offers timed callback facilities which are used by other code such as FX::FXFSMonitor. Once created, the thread pool lasts until the process terminates.

Security:

On POSIX, there is the weird and wonderful world of real and effective user ids and groups. Basically the real id of a process is under which user's shell it is running whereas the effective id is which user the process is impersonating. It gets more complex again on Linux because a process can impersonate someone different again only when accessing the file system. This does not in my mind make for easy security - and worst of all, you can't change these impersonation settings on a per-thread basis, only on a per-process one.

Hence we are substantially limited in what we can do whilst keeping semantics similar between NT and POSIX - unfortunately we need the ability to run as root but act like someone else because the Tn kernel can run as a daemon/service and the secure heap needs to be able to lock memory pages. I've decided that if the filing system is accessed like the real uid and TnFOX's ACL based security support forces the owner on all things it touches to be the real uid, it's safe to run the process with the suid bit set (ie; acting like root). Of course, users may not agree with this :)

Note:

userHandedness() is currently only implemented for Windows

Definition at line 134 of file FXProcess.h.

Public Types
typedef QValueList< MappedFileInfo >	MappedFileInfoList
typedef Generic::Functor< Generic::TL::create< void, bool >::value >	FatalExitUpcallSpec
	UNKNOWN_HANDED
	LEFT_HANDED
	RIGHT_HANDED
enum	UserHandedness { UNKNOWN_HANDED, LEFT_HANDED, RIGHT_HANDED }
Public Member Functions
	FXProcess ()
	FXProcess (int &argc, char *argv[])
	~FXProcess ()
bool	runPendingStaticInits (int &argc, char *argv[], FXStream &txtout)
Static Public Member Functions
static void	exit (FXint code=0)
static bool	isAutomatedTest () throw ()
static FXProcess *	instance ()
static FXuint	getMsCount ()
static void	getTimeOfDay (struct timeval *ts)
static FXulong	getNsCount ()
static FXuint	id ()
static FXuint	noOfProcessors ()
static FXuint	pageSize ()
static MappedFileInfoList	mappedFiles (bool forceRefresh=false)
static const FXString &	execpath ()
static FXString	dllPath (void *addr, void **dllstart=0, void **dllend=0)
static dllHandle	dllLoad (const FXString &path)
static void *	dllResolveBase (const dllHandle &h, const char *apiname)
static void	dllUnload (dllHandle &h)
static FXString	hostOS (FXString *myos=0, FXString *architecture=0)
static FXString	hostOSDescription (FXString *myapi=0, FXString *kernelname=0, FXString *kernelversion=0, FXString *apiversion=0, FXString *architecture=0)
static void	buildInfo (int *svnrev=0)
static FXfloat	hostOSProcessorLoad ()
static FXuint	processorFull ()
static FXfloat	hostOSMemoryLoad (FXuval *totalPhysMem=0)
static FXuint	memoryFull ()
static MemoryUsageInfo	processMemoryUsage (FXuint processId=FXProcess::id())
static FXfloat	hostOSDiscIOLoad (const FXString &path)
static FXfloat	hostOSDiskIOLoad (const FXString &path)
static FXuint	discIOFull (const FXString &path)
static FXuint	diskIOFull (const FXString &path)
static void	overrideFreeResources (FXfloat memory=-1, FXfloat processor=-1, FXfloat discio=-1)
static FXuval	virtualAddrSpaceLeft (FXuval chunk=1)
static QValueList< MountablePartition >	mountablePartitions ()
static void	mountPartition (const FXString &partitionName, const FXString &location=FXString::nullStr(), const FXString &fstype=FXString::nullStr(), bool readWrite=true)
static void	unmountPartition (const FXString &location)
static QThreadPool &	threadPool ()
static UserHandedness	userHandedness ()
static void	overrideUserHandedness (UserHandedness val)
static FXuint	screenScale (FXuint value)
static void	overrideScreenScale (FXuint percent)
static void	overrideScreenSize (FXint w, FXint h)
static void	addFatalExitUpcall (FatalExitUpcallSpec upcallv)
static bool	removeFatalExitUpcall (FatalExitUpcallSpec upcallv)
static QMemArray< void * >	lockedPages ()
static void	int_addStaticInit (FXProcess_StaticInitBase *o)
static void	int_removeStaticInit (FXProcess_StaticInitBase *o)
static void	int_addStaticDepend (FXProcess_StaticDepend *d)
Friends
class	FXProcess_MemLock
class	FXWindow
class	FXShell
Classes
class	dllHandle
struct	MappedFileInfo
	A structure containing information about a mapped file. More...
struct	MemoryUsageInfo
	Holds information about a process' memory usage. More...
struct	MountablePartition
	Information about a mountable partition. More...

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The documentation for this class was generated from the following file:

• FXProcess.h

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(C) 2002-2009 Niall Douglas. Some parts (C) to assorted authors.