RetroZilla/xpinstall/wizard/libxpnet/GUSI/include/GUSIContext.h

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// %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
// % Project : GUSI - Grand Unified Socket Interface
// % File : GUSIContext.nw - Thread and Process structures
// % Author : Matthias Neeracher
// % Language : C++
// %
// % $Log: GUSIContext.h,v $
// % Revision 1.1 2001/03/11 22:33:38 sgehani%netscape.com
// % First Checked In.
// %
// % Revision 1.22 2001/01/22 04:31:11 neeri
// % Last minute changes for 2.1.5
// %
// % Revision 1.21 2001/01/17 08:43:42 neeri
// % Tweak scheduling
// %
// % Revision 1.20 2000/12/23 06:09:21 neeri
// % May need to create context for IO completions
// %
// % Revision 1.19 2000/10/16 04:34:22 neeri
// % Releasing 2.1.2
// %
// % Revision 1.18 2000/06/01 06:31:09 neeri
// % Delete SigContext
// %
// % Revision 1.17 2000/05/23 06:56:19 neeri
// % Improve formatting, add socket closing queue, tune scheduling
// %
// % Revision 1.16 2000/03/15 07:11:50 neeri
// % Fix detached delete (again), switcher restore
// %
// % Revision 1.15 2000/03/06 08:10:09 neeri
// % Fix sleep in main thread
// %
// % Revision 1.14 2000/03/06 06:13:46 neeri
// % Speed up thread/process switching through minimal quotas
// %
// % Revision 1.13 1999/12/13 02:40:50 neeri
// % GUSISetThreadSwitcher had Boolean <-> bool inconsistency
// %
// % Revision 1.12 1999/11/15 07:25:32 neeri
// % Safe context setup. Check interrupts only in foreground.
// %
// % Revision 1.11 1999/09/09 07:18:06 neeri
// % Added support for foreign threads
// %
// % Revision 1.10 1999/08/26 05:44:59 neeri
// % Fixes for literate edition of source code
// %
// % Revision 1.9 1999/06/28 05:59:02 neeri
// % Add signal handling support
// %
// % Revision 1.8 1999/05/30 03:09:29 neeri
// % Added support for MPW compilers
// %
// % Revision 1.7 1999/03/17 09:05:05 neeri
// % Added GUSITimer, expanded docs
// %
// % Revision 1.6 1999/02/25 03:34:24 neeri
// % Introduced GUSIContextFactory, simplified wakeup
// %
// % Revision 1.5 1998/11/22 23:06:51 neeri
// % Releasing 2.0a4 in a hurry
// %
// % Revision 1.4 1998/10/11 16:45:11 neeri
// % Ready to release 2.0a2
// %
// % Revision 1.3 1998/08/01 21:26:18 neeri
// % Switch dynamically to threading model
// %
// % Revision 1.2 1998/02/11 12:57:11 neeri
// % PowerPC Build
// %
// % Revision 1.1 1998/01/25 21:02:41 neeri
// % Engine implemented, except for signals & scheduling
// %
// %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//
// \chapter{Thread and Process structures}
//
// This section defines the process and thread switching engine of GUSI.
//
// In some execution environments, completion routines execute at interrupt level.
// GUSI therefore is designed so all information needed to operate from interrupt
// level is accessible from a [[GUSISocket]]. This information is separated into
// per-process data, collected in [[GUSIProcess]], and per-thread data, collected
// in [[GUSIContext]]. [[GUSIProcess]] is always a singleton, while [[GUSIContext]]
// is a singleton if threading is disabled, and has multiple instances if threading
// is enabled. By delegating the [[GUSIContext]] creation process to an instance
// of a [[GUSIContextFactory]], we gain some extra flexibility.
//
// As soon as GUSI has started an asynchronous call, it calls the [[Wait]] member
// function of its context. [[msec]] will set a time limit after which the call will
// return in any case. Exceptional events may also cause [[GUSIWait]] to return, so
// it is not safe to assume that the call will have completed upon return.
//
//
// <GUSIContext.h>=
#ifndef _GUSIContext_
#define _GUSIContext_
#include <errno.h>
#include <sys/cdefs.h>
#include <sys/signal.h>
#include <MacTypes.h>
#include <Threads.h>
__BEGIN_DECLS
// To maintain correct state, we have to remain informed which thread is active, so
// we install all sorts of hooks. Clients have to use the C++ interface or call
// [[GUSINewThread]], [[GUSISetThreadSwitcher]], and [[GUSISetThreadTerminator]].
// instead of the thread manager routines.
//
// <Definition of thread manager hooks>=
OSErr GUSINewThread(
ThreadStyle threadStyle, ThreadEntryProcPtr threadEntry, void *threadParam,
Size stackSize, ThreadOptions options,
void **threadResult, ThreadID *threadMade);
OSErr GUSISetThreadSwitcher(ThreadID thread,
ThreadSwitchProcPtr threadSwitcher, void *switchProcParam, Boolean inOrOut);
OSErr GUSISetThreadTerminator(ThreadID thread,
ThreadTerminationProcPtr threadTerminator, void *terminationProcParam);
__END_DECLS
#ifndef GUSI_SOURCE
typedef struct GUSIContext GUSIContext;
#else
#include "GUSISpecific.h"
#include "GUSIBasics.h"
#include "GUSIContextQueue.h"
#include <Files.h>
#include <Processes.h>
#include <OSUtils.h>
// \section{Definition of completion handling}
//
// {\tt GUSIContext} is heavily circular both with classes declared herein and
// in other files. Therefore, we start by declaring a few class names.
//
// <Name dropping for file GUSIContext>=
class GUSISocket;
class GUSIContext;
class GUSIProcess;
class GUSISigProcess;
class GUSISigContext;
class GUSITimer;
#include <ConditionalMacros.h>
#if PRAGMA_STRUCT_ALIGN
#pragma options align=native
#endif
// Ultimately, we will call through to the thread manager, but if an application uses foreign
// sources of threads, we might have to go through indirections.
//
// <Definition of class [[GUSIThreadManagerProxy]]>=
class GUSIThreadManagerProxy {
public:
virtual OSErr NewThread(
ThreadStyle threadStyle, ThreadEntryProcPtr threadEntry, void *threadParam,
Size stackSize, ThreadOptions options, void **threadResult, ThreadID *threadMade);
virtual OSErr SetThreadSwitcher(
ThreadID thread, ThreadSwitchProcPtr threadSwitcher, void *switchProcParam,
Boolean inOrOut);
virtual OSErr SetThreadTerminator(
ThreadID thread, ThreadTerminationProcPtr threadTerminator, void *terminatorParam);
virtual ~GUSIThreadManagerProxy() {}
static GUSIThreadManagerProxy * Instance();
protected:
GUSIThreadManagerProxy() {}
static GUSIThreadManagerProxy * MakeInstance();
};
// A [[GUSIProcess]] contains all the data needed to wake up a process:
//
// \begin{itemize}
// \item The [[ProcessSerialNumber]] of the process.
// \item The [[ThreadTaskRef]] if threads are enabled.
// \item The contents of the A5 register.
// \end{itemize}
//
// The sole instance of [[GUSIProcess]] is obtained by calling the [[GUSIProcess::Instance]] static member
// function, which will create the instance if necessary. Interrupt level prcedures may access the application's
// A5 register either manually by calling [[GetA5]] or simply by declaring a [[GUSIProcess::A5Saver]] in a scope.
//
// <Definition of class [[GUSIProcess]]>=
enum GUSIYieldMode {
kGUSIPoll, // Busy wait for some unblockable condition
kGUSIBlock, // Wait for some blockable condition
kGUSIYield // Yield to some other eligible thread
};
class GUSIProcess {
public:
static GUSIProcess * Instance();
static void DeleteInstance();
void GetPSN(ProcessSerialNumber * psn);
void AcquireTaskRef();
ThreadTaskRef GetTaskRef();
long GetA5();
bool Threading();
void Yield(GUSIYieldMode wait);
void Wakeup();
GUSISigProcess * SigProcess() { return fSigProcess; }
void QueueForClose(GUSISocket * sock);
// A [[GUSIProcess::A5Saver]] is a class designed to restore the process A5
// register for the scope of its declaration.
//
// <Definition of class [[GUSIProcess::A5Saver]]>=
class A5Saver {
public:
A5Saver(long processA5);
A5Saver(GUSIContext * context);
A5Saver(GUSIProcess * process);
~A5Saver();
private:
long fSavedA5;
};
protected:
friend class GUSIContext;
GUSIProcess(bool threading);
~GUSIProcess();
int fReadyThreads;
int fExistingThreads;
GUSISigProcess * fSigProcess;
private:
// \section{Implementation of completion handling}
//
// [[Instance]] returns the sole instance of [[GUSIProcess]], creating it if
// necessary.
//
// <Privatissima of [[GUSIProcess]]>=
static GUSIProcess * sInstance;
// Much of the information stored in a [[GUSIProcess]] is static and read-only.
//
// <Privatissima of [[GUSIProcess]]>=
ProcessSerialNumber fProcess;
ThreadTaskRef fTaskRef;
long fA5;
// The exception is the [[fClosing]] socket queue and some yielding related flags.
//
// <Privatissima of [[GUSIProcess]]>=
GUSISocket * fClosing;
UInt32 fResumeTicks;
bool fWillSleep;
bool fDontSleep;
};
// A [[GUSIContext]] gathers thread related data. The central operation on a
// [[GUSIContext]] is [[Wakeup]]. If the process is not asleep when [[Wakeup]]
// is called, it is marked for deferred wakeup.
//
// A [[GUSIContext]] can either be created from an existing thread manager
// [[ThreadID]] or by specifying the parameters for a [[NewThread]] call.
//
// [[Current]] returns the current [[GUSIContext]]. [[Setup]] initializes the
// default context for either the threading or the non-threading model.
//
// [[Yield]] suspends the current process or thread until something interesting
// happens if [[wait]] is [[kGUSIBlock]. Otherwise, [[Yield]] switches,
// but does not suspend. For an ordinary thread context, [[Yield]] simply yields
// the thread. For the context in a non-threading application, [[Yield]] does a
// [[WaitNextEvent]]. For the main thread context, [[Yield]] does both.
//
// [[Done]] tests whether the thread has terminated yet. If [[join]] is set,
// the caller is willing to wait. [[Result]] returns the default location to store
// the thread result if no other is specified.
//
// By default, a context is joinable. Calling [[Detach]] will cause the context to
// be destroyed automatically upon thread termination, and joins are no longer allowed.
// A joinable context will not be destroyed automatically before the end of the
// program, so you will have to call [[Liquidate]] to do that.
//
// [[SetSwitchIn]], [[SetSwitchOut]], and [[SetTerminator]] set per-thread user
// switch and termination procedures. [[SwitchIn]], [[SwitchOut]], and [[Terminate]]
// call the user defined procedures then perform their own actions.
//
// <Definition of class [[GUSIContext]]>=
class GUSIContext : public GUSISpecificTable {
public:
friend class GUSIProcess;
friend class GUSIContextFactory;
ThreadID ID() { return fThreadID; }
virtual void Wakeup();
void ClearWakeups() { fWakeup = false; }
GUSIProcess * Process() { return fProcess; }
void Detach() { fFlags |= detached; }
void Liquidate();
OSErr Error() { return sError; }
bool Done(bool join);
void * Result() { return fResult; }
GUSISigContext * SigContext() { return fSigContext; }
static GUSIContext * Current() { return sCurrentContext; }
static GUSIContext * CreateCurrent(bool threading = false)
{ if (!sCurrentContext) Setup(threading); return sCurrentContext; }
static GUSIContext * Lookup(ThreadID id);
static void Setup(bool threading);
static bool Yield(GUSIYieldMode wait);
static void SigWait(sigset_t sigs);
static void SigSuspend();
static bool Raise(bool allSigs = false);
static sigset_t Pending();
static sigset_t Blocked();
void SetSwitchIn(ThreadSwitchProcPtr switcher, void *switchParam);
void SetSwitchOut(ThreadSwitchProcPtr switcher, void *switchParam);
void SetTerminator(ThreadTerminationProcPtr terminator, void *terminationParam);
static GUSIContextQueue::iterator begin() { return sContexts.begin(); }
static GUSIContextQueue::iterator end() { return sContexts.end(); }
static void LiquidateAll() { sContexts.LiquidateAll(); }
protected:
// <Friends of [[GUSIContext]]>=
friend class GUSIContextFactory;
// The thread switcher updates the pointer to the current context and switches
// the global error variables.
//
// <Friends of [[GUSIContext]]>=
friend pascal void GUSIThreadSwitchIn(ThreadID thread, GUSIContext * context);
friend pascal void GUSIThreadSwitchOut(ThreadID thread, GUSIContext * context);
// The terminator wakes up the joining thread if a join is pending.
//
// <Friends of [[GUSIContext]]>=
friend pascal void GUSIThreadTerminator(ThreadID thread, GUSIContext * context);
GUSIContext(ThreadID id);
GUSIContext(
ThreadEntryProcPtr threadEntry, void *threadParam,
Size stackSize, ThreadOptions options = kCreateIfNeeded,
void **threadResult = nil, ThreadID *threadMade = nil);
virtual void SwitchIn();
virtual void SwitchOut();
virtual void Terminate();
// At this point, we need to introduce all the private data of a [[GUSIContext]].
//
// \begin{itemize}
// \item [[fThreadID]] stores the thread manager thread ID.
// \item [[fProcess]] keeps a pointer to the process structure, so completion
// routines can get at it.
// \item [[sCurrentContext]] always points at the current context.
// \item [[sContexts]] contains a queue of all contexts.
// \item [[sHasThreads]] reminds us whether we are threading or not.
// \item We define our own switch-in and termination procedures. If the user specifies procedures
// we store them in [[fSwitchInProc]], [[fSwitchOutProc]], and [[fTerminateProc]] and their parameters
// in [[fSwitchInParam]], [[fSwitchOutParam]], and [[fTerminateParam]] so we can call through to them
// from our procedures.
// \item [[fJoin]] contains the context waiting for us to die;
// \item [[done]] reminds us if the thread is still alive. [[detached]] guarantees
// that we will never wait for that thread anymore.
// \item Last of all, we keep the global error variables [[errno]] and [[h_errno]]
// for each context in the [[fErrno]] and [[fHostErrno]] fields.
// \end{itemize}
//
//
// <Privatissima of [[GUSIContext]]>=
ThreadID fThreadID;
GUSIProcess * fProcess;
GUSIContext * fNext;
GUSISigContext * fSigContext;
ThreadSwitchProcPtr fSwitchInProc;
ThreadSwitchProcPtr fSwitchOutProc;
ThreadTerminationProcPtr fTerminateProc;
void * fSwitchInParam;
void * fSwitchOutParam;
void * fTerminateParam;
void * fResult;
GUSIContext * fJoin;
enum {
done = 1 << 0,
detached= 1 << 1,
asleep = 1 << 2
};
char fFlags;
bool fWakeup;
UInt32 fEntryTicks;
int fErrno;
int fHostErrno;
class Queue : public GUSIContextQueue {
public:
void LiquidateAll();
~Queue() { LiquidateAll(); }
};
static Queue sContexts;
static GUSIContext * sCurrentContext;
static bool sHasThreading;
static OSErr sError;
// The [[GUSIContext]] constructor links the context into the queue of existing
// contexts and installs the appropriate thread hooks. We split this into two
// routines: [[StartSetup]] does static setup before the thread id is determined,
// [[FinishSetup]] does the queueing.
//
// <Privatissima of [[GUSIContext]]>=
void StartSetup();
void FinishSetup();
// Destruction of a [[GUSIContext]] requires some cleanup.
//
// <Privatissima of [[GUSIContext]]>=
~GUSIContext();
};
// [[GUSIContext]] instances are created by instances of [[GUSIContextFactory]].
//
// <Definition of class [[GUSIContextFactory]]>=
class GUSIContextFactory {
public:
static GUSIContextFactory * Instance();
static void SetInstance(GUSIContextFactory * instance);
virtual GUSIContext * CreateContext(ThreadID id);
virtual GUSIContext * CreateContext(
ThreadEntryProcPtr threadEntry, void *threadParam,
Size stackSize, ThreadOptions options = kCreateIfNeeded,
void **threadResult = nil, ThreadID *threadMade = nil);
virtual ~GUSIContextFactory();
protected:
GUSIContextFactory();
};
// Many asynchronous calls take the same style of I/O parameter block and thus
// can be handled by the same completion procedure. [[StartIO]] prepares
// a parameter block for asynchronous I/O; [[FinishIO]] waits for the I/O
// to complete. The parameter block has to be wrapped in a [[GUSIIOPBWrapper]].
//
// <Definition of IO wrappers>=
void GUSIStartIO(IOParam * pb);
OSErr GUSIFinishIO(IOParam * pb);
OSErr GUSIControl(IOParam * pb);
template <class PB> struct GUSIIOPBWrapper {
GUSIContext * fContext;
PB fPB;
GUSIIOPBWrapper() {}
GUSIIOPBWrapper(const PB & pb) { memcpy(&fPB, &pb, sizeof(PB)); }
PB * operator->(){ return &fPB; }
void StartIO() { GUSIStartIO(reinterpret_cast<IOParam *>(&fPB)); }
OSErr FinishIO() { return GUSIFinishIO(reinterpret_cast<IOParam *>(&fPB)); }
OSErr Control() { return GUSIControl(reinterpret_cast<IOParam *>(&fPB)); }
};
#if PRAGMA_STRUCT_ALIGN
#pragma options align=reset
#endif
// <Inline member functions for file GUSIContext>=
inline GUSIProcess * GUSIProcess::Instance()
{
if (!sInstance)
sInstance = new GUSIProcess(GUSIContext::sHasThreading);
return sInstance;
}
inline void GUSIProcess::DeleteInstance()
{
delete sInstance;
sInstance = 0;
}
// <Inline member functions for file GUSIContext>=
inline void GUSIProcess::GetPSN(ProcessSerialNumber * psn)
{ *psn = fProcess; }
inline void GUSIProcess::AcquireTaskRef()
{ GetThreadCurrentTaskRef(&fTaskRef); }
inline ThreadTaskRef GUSIProcess::GetTaskRef()
{ return fTaskRef; }
inline long GUSIProcess::GetA5()
{ return fA5; }
inline bool GUSIProcess::Threading()
{ return fTaskRef!=0;}
// An [[A5Saver]] is trivially implemented but it simplifies bookkeeping.
//
// <Inline member functions for file GUSIContext>=
inline GUSIProcess::A5Saver::A5Saver(long processA5)
{ fSavedA5 = SetA5(processA5); }
inline GUSIProcess::A5Saver::A5Saver(GUSIProcess * process)
{ fSavedA5 = SetA5(process->GetA5()); }
inline GUSIProcess::A5Saver::A5Saver(GUSIContext * context)
{ fSavedA5 = SetA5(context->Process()->GetA5()); }
inline GUSIProcess::A5Saver::~A5Saver()
{ SetA5(fSavedA5); }
#endif /* GUSI_SOURCE */
#endif /* _GUSIContext_ */