Coro/Coro/State.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#if 1
# define CHK(x) (void *)0
#else
# define CHK(x) if (!(x)) croak("FATAL, CHK: " #x)
#endif

#define MAY_FLUSH /* increases codesize */

#define SAVE_DEFAV      0x00000001
#define SAVE_DEFSV      0x00000002
#define SAVE_ERRSV      0x00000004

#define SAVE_ALL        -1

struct coro {
  /* optionally saved, might be zero */
  AV *defav;
  SV *defsv;
  SV *errsv;
  
  /* saved global state not related to stacks */
  U8 dowarn;

  /* the stacks and related info (callchain etc..) */
  PERL_SI *curstackinfo;
  AV *curstack;
  AV *mainstack;
  SV **stack_sp;
  OP *op;
  SV **curpad;
  SV **stack_base;
  SV **stack_max;
  SV **tmps_stack;
  I32 tmps_floor;
  I32 tmps_ix;
  I32 tmps_max;
  I32 *markstack;
  I32 *markstack_ptr;
  I32 *markstack_max;
  I32 *scopestack;
  I32 scopestack_ix;
  I32 scopestack_max;
  ANY *savestack;
  I32 savestack_ix;
  I32 savestack_max;
  OP **retstack;
  I32 retstack_ix;
  I32 retstack_max;
  COP *curcop;

  /* data associated with this coroutine (initial args) */
  AV *args;
};

typedef struct coro *Coro__State;
typedef struct coro *Coro__State_or_hashref;

static HV *padlist_cache;

/* mostly copied from op.c:cv_clone2 */
STATIC AV *
clone_padlist (AV *protopadlist)
{
  AV *av;
  I32 ix;
  AV *protopad_name = (AV *) * av_fetch (protopadlist, 0, FALSE);
  AV *protopad = (AV *) * av_fetch (protopadlist, 1, FALSE);
  SV **pname = AvARRAY (protopad_name);
  SV **ppad = AvARRAY (protopad);
  I32 fname = AvFILLp (protopad_name);
  I32 fpad = AvFILLp (protopad);
  AV *newpadlist, *newpad_name, *newpad;
  SV **npad;

  newpad_name = newAV ();
  for (ix = fname; ix >= 0; ix--)
    av_store (newpad_name, ix, SvREFCNT_inc (pname[ix]));

  newpad = newAV ();
  av_fill (newpad, AvFILLp (protopad));
  npad = AvARRAY (newpad);

  newpadlist = newAV ();
  AvREAL_off (newpadlist);
  av_store (newpadlist, 0, (SV *) newpad_name);
  av_store (newpadlist, 1, (SV *) newpad);

  av = newAV ();                /* will be @_ */
  av_extend (av, 0);
  av_store (newpad, 0, (SV *) av);
  AvFLAGS (av) = AVf_REIFY;

  for (ix = fpad; ix > 0; ix--)
    {
      SV *namesv = (ix <= fname) ? pname[ix] : Nullsv;
      if (namesv && namesv != &PL_sv_undef)
        {
          char *name = SvPVX (namesv);        /* XXX */
          if (SvFLAGS (namesv) & SVf_FAKE || *name == '&')
            {                        /* lexical from outside? */
              npad[ix] = SvREFCNT_inc (ppad[ix]);
            }
          else
            {                        /* our own lexical */
              SV *sv;
              if (*name == '&')
                sv = SvREFCNT_inc (ppad[ix]);
              else if (*name == '@')
                sv = (SV *) newAV ();
              else if (*name == '%')
                sv = (SV *) newHV ();
              else
                sv = NEWSV (0, 0);
              if (!SvPADBUSY (sv))
                SvPADMY_on (sv);
              npad[ix] = sv;
            }
        }
      else if (IS_PADGV (ppad[ix]) || IS_PADCONST (ppad[ix]))
        {
          npad[ix] = SvREFCNT_inc (ppad[ix]);
        }
      else
        {
          SV *sv = NEWSV (0, 0);
          SvPADTMP_on (sv);
          npad[ix] = sv;
        }
    }

#if 0 /* return -ENOTUNDERSTOOD */
    /* Now that vars are all in place, clone nested closures. */

    for (ix = fpad; ix > 0; ix--) {
        SV* namesv = (ix <= fname) ? pname[ix] : Nullsv;
        if (namesv
            && namesv != &PL_sv_undef
            && !(SvFLAGS(namesv) & SVf_FAKE)
            && *SvPVX(namesv) == '&'
            && CvCLONE(ppad[ix]))
        {
            CV *kid = cv_clone((CV*)ppad[ix]);
            SvREFCNT_dec(ppad[ix]);
            CvCLONE_on(kid);
            SvPADMY_on(kid);
            npad[ix] = (SV*)kid;
        }
    }
#endif

  return newpadlist;
}

#ifdef MAY_FLUSH
STATIC AV *
free_padlist (AV *padlist)
{
  /* may be during global destruction */
  if (SvREFCNT(padlist))
    {
      I32 i = AvFILLp(padlist);
      while (i >= 0)
        {
          SV **svp = av_fetch(padlist, i--, FALSE);
          SV *sv = svp ? *svp : Nullsv;
          if (sv)
            SvREFCNT_dec(sv);
        }

      SvREFCNT_dec((SV*)padlist);
  }
}
#endif

/* the next two functions merely cache the padlists */
STATIC void
get_padlist (CV *cv)
{
  SV **he = hv_fetch (padlist_cache, (void *)&cv, sizeof (CV *), 0);

  if (he && AvFILLp ((AV *)*he) >= 0)
    CvPADLIST (cv) = (AV *)av_pop ((AV *)*he);
  else
    CvPADLIST (cv) = clone_padlist (CvPADLIST (cv));
}

STATIC void
put_padlist (CV *cv)
{
  SV **he = hv_fetch (padlist_cache, (void *)&cv, sizeof (CV *), 1);

  if (SvTYPE (*he) != SVt_PVAV)
    {
      SvREFCNT_dec (*he);
      *he = (SV *)newAV ();
    }

  av_push ((AV *)*he, (SV *)CvPADLIST (cv));
}

#ifdef MAY_FLUSH
STATIC void
flush_padlist_cache ()
{
  HV *hv = padlist_cache;
  padlist_cache = newHV ();

  if (hv_iterinit (hv))
    {
      HE *he;
      AV *padlist;

      while (!!(he = hv_iternext (hv)))
        {
          AV *av = (AV *)HeVAL(he);

          /* casting is fun. */
          while (&PL_sv_undef != (SV *)(padlist = (AV *)av_pop (av)))
            free_padlist (padlist);
        }
    }

  SvREFCNT_dec (hv);
}
#endif

#define SB do {
#define SE } while (0)

#define LOAD(state)       SB load_state(aTHX_ state); SPAGAIN;       SE
#define SAVE(state,flags) SB PUTBACK; save_state(aTHX_ state,flags); SE

#define REPLACE_SV(sv,val) SB SvREFCNT_dec(sv); (sv) = (val); SE

static void
load_state(pTHX_ Coro__State c)
{
  PL_dowarn = c->dowarn;

  PL_curstackinfo = c->curstackinfo;
  PL_curstack = c->curstack;
  PL_mainstack = c->mainstack;
  PL_stack_sp = c->stack_sp;
  PL_op = c->op;
  PL_curpad = c->curpad;
  PL_stack_base = c->stack_base;
  PL_stack_max = c->stack_max;
  PL_tmps_stack = c->tmps_stack;
  PL_tmps_floor = c->tmps_floor;
  PL_tmps_ix = c->tmps_ix;
  PL_tmps_max = c->tmps_max;
  PL_markstack = c->markstack;
  PL_markstack_ptr = c->markstack_ptr;
  PL_markstack_max = c->markstack_max;
  PL_scopestack = c->scopestack;
  PL_scopestack_ix = c->scopestack_ix;
  PL_scopestack_max = c->scopestack_max;
  PL_savestack = c->savestack;
  PL_savestack_ix = c->savestack_ix;
  PL_savestack_max = c->savestack_max;
  PL_retstack = c->retstack;
  PL_retstack_ix = c->retstack_ix;
  PL_retstack_max = c->retstack_max;
  PL_curcop = c->curcop;

  if (c->defav) REPLACE_SV (GvAV (PL_defgv), c->defav);
  if (c->defsv) REPLACE_SV (DEFSV          , c->defsv);
  if (c->errsv) REPLACE_SV (ERRSV          , c->errsv);

  {
    dSP;
    CV *cv;

    /* now do the ugly restore mess */
    while ((cv = (CV *)POPs))
      {
        AV *padlist = (AV *)POPs;

        if (padlist)
          {
            put_padlist (cv); /* mark this padlist as available */
            CvPADLIST(cv) = padlist;
#ifdef USE_THREADS
            /*CvOWNER(cv) = (struct perl_thread *)POPs;*/
#endif
          }

        ++CvDEPTH(cv);
      }

    PUTBACK;
  }
}

static void
save_state(pTHX_ Coro__State c, int flags)
{
  {
    dSP;
    I32 cxix = cxstack_ix;
    PERL_SI *top_si = PL_curstackinfo;
    PERL_CONTEXT *ccstk = cxstack;

    /*
     * the worst thing you can imagine happens first - we have to save
     * (and reinitialize) all cv's in the whole callchain :(
     */

    PUSHs (Nullsv);
    /* this loop was inspired by pp_caller */
    for (;;)
      {
       do
          {
            PERL_CONTEXT *cx = &ccstk[cxix--];

            if (CxTYPE(cx) == CXt_SUB)
              {
                CV *cv = cx->blk_sub.cv;
                if (CvDEPTH(cv))
                  {
#ifdef USE_THREADS
                    /*XPUSHs ((SV *)CvOWNER(cv));*/
                    /*CvOWNER(cv) = 0;*/
                    /*error must unlock this cv etc.. etc...*/
#endif
                    EXTEND (SP, CvDEPTH(cv)*2);

                    while (--CvDEPTH(cv))
                      {
                        /* this tells the restore code to increment CvDEPTH */
                        PUSHs (Nullsv);
                        PUSHs ((SV *)cv);
                      }

                    PUSHs ((SV *)CvPADLIST(cv));
                    PUSHs ((SV *)cv);

                    get_padlist (cv); /* this is a monster */
                  }
              }
            else if (CxTYPE(cx) == CXt_FORMAT)
              {
                /* I never used formats, so how should I know how these are implemented? */
                /* my bold guess is as a simple, plain sub... */
                croak ("CXt_FORMAT not yet handled. Don't switch coroutines from within formats");
              }
          }
        while (cxix >= 0);

        if (top_si->si_type == PERLSI_MAIN)
          break;

        top_si = top_si->si_prev;
        ccstk = top_si->si_cxstack;
        cxix = top_si->si_cxix;
      }

    PUTBACK;
  }

  c->defav = flags & SAVE_DEFAV ? (AV *)SvREFCNT_inc (GvAV (PL_defgv)) : 0;
  c->defsv = flags & SAVE_DEFSV ?       SvREFCNT_inc (DEFSV)           : 0;
  c->errsv = flags & SAVE_ERRSV ?       SvREFCNT_inc (ERRSV)           : 0;

  c->dowarn = PL_dowarn;

  c->curstackinfo = PL_curstackinfo;
  c->curstack = PL_curstack;
  c->mainstack = PL_mainstack;
  c->stack_sp = PL_stack_sp;
  c->op = PL_op;
  c->curpad = PL_curpad;
  c->stack_base = PL_stack_base;
  c->stack_max = PL_stack_max;
  c->tmps_stack = PL_tmps_stack;
  c->tmps_floor = PL_tmps_floor;
  c->tmps_ix = PL_tmps_ix;
  c->tmps_max = PL_tmps_max;
  c->markstack = PL_markstack;
  c->markstack_ptr = PL_markstack_ptr;
  c->markstack_max = PL_markstack_max;
  c->scopestack = PL_scopestack;
  c->scopestack_ix = PL_scopestack_ix;
  c->scopestack_max = PL_scopestack_max;
  c->savestack = PL_savestack;
  c->savestack_ix = PL_savestack_ix;
  c->savestack_max = PL_savestack_max;
  c->retstack = PL_retstack;
  c->retstack_ix = PL_retstack_ix;
  c->retstack_max = PL_retstack_max;
  c->curcop = PL_curcop;
}

/*
 * destroy the stacks, the callchain etc...
 * still there is a memleak of 128 bytes...
 */
STATIC void
destroy_stacks(pTHX)
{
  /* is this ugly, I ask? */
  while (PL_scopestack_ix)
    LEAVE;

  /* sure it is, but more important: is it correct?? :/ */
  while (PL_tmps_ix > PL_tmps_floor) /* should only ever be one iteration */
    FREETMPS;

  while (PL_curstackinfo->si_next)
    PL_curstackinfo = PL_curstackinfo->si_next;

  while (PL_curstackinfo)
    {
      PERL_SI *p = PL_curstackinfo->si_prev;

      {
        dSP;
        SWITCHSTACK (PL_curstack, PL_curstackinfo->si_stack);
        PUTBACK; /* possibly superfluous */
      }

      dounwind(-1);

      SvREFCNT_dec(PL_curstackinfo->si_stack);
      Safefree(PL_curstackinfo->si_cxstack);
      Safefree(PL_curstackinfo);
      PL_curstackinfo = p;
  }

  Safefree(PL_tmps_stack);
  Safefree(PL_markstack);
  Safefree(PL_scopestack);
  Safefree(PL_savestack);
  Safefree(PL_retstack);
}

#define SUB_INIT "Coro::State::_newcoro"

MODULE = Coro::State                PACKAGE = Coro::State

PROTOTYPES: ENABLE

BOOT:
        HV * stash = gv_stashpvn("Coro::State", 10, TRUE);

        newCONSTSUB (stash, "SAVE_DEFAV", newSViv (SAVE_DEFAV));
        newCONSTSUB (stash, "SAVE_DEFSV", newSViv (SAVE_DEFSV));
        newCONSTSUB (stash, "SAVE_ERRSV", newSViv (SAVE_ERRSV));

        if (!padlist_cache)
          padlist_cache = newHV ();

Coro::State
_newprocess(args)
        SV *    args
        PROTOTYPE: $
        CODE:
        Coro__State coro;

        if (!SvROK (args) || SvTYPE (SvRV (args)) != SVt_PVAV)
          croak ("Coro::State::_newprocess expects an arrayref");
        
        New (0, coro, 1, struct coro);

        coro->mainstack = 0; /* actual work is done inside transfer */
        coro->args = (AV *)SvREFCNT_inc (SvRV (args));

        RETVAL = coro;
        OUTPUT:
        RETVAL

void
transfer(prev, next, flags = SAVE_DEFAV)
        Coro::State_or_hashref  prev
        Coro::State_or_hashref  next
        int                     flags
        CODE:

        if (prev != next)
          {
            /*
             * this could be done in newprocess which would lead to
             * extremely elegant and fast (just SAVE/LOAD)
             * code here, but lazy allocation of stacks has also
             * some virtues and the overhead of the if() is nil.
             */
            if (next->mainstack)
              {
                SAVE (prev, flags);
                LOAD (next);
                /* mark this state as in-use */
                next->mainstack = 0;
                next->tmps_ix = -2;
              }
            else if (next->tmps_ix == -2)
              {
                croak ("tried to transfer to running coroutine");
              }
            else
              {
                /*
                 * emulate part of the perl startup here.
                 */
                UNOP myop;

                SAVE (prev, -1); /* first get rid of the old state */

                init_stacks (); /* from perl.c */
                SPAGAIN;

                PL_op = (OP *)&myop;
                /*PL_curcop = 0;*/
                SvREFCNT_dec (GvAV (PL_defgv));
                GvAV (PL_defgv) = next->args;

                Zero(&myop, 1, UNOP);
                myop.op_next = Nullop;
                myop.op_flags = OPf_WANT_VOID;

                PUSHMARK(SP);
                XPUSHs ((SV*)get_cv(SUB_INIT, TRUE));
                /*
                 * the next line is slightly wrong, as PL_op->op_next
                 * is actually being executed so we skip the first op.
                 * that doesn't matter, though, since it is only
                 * pp_nextstate and we never return...
                 * ah yes, and I don't care anyways ;)
                 */
                PUTBACK;
                PL_op = pp_entersub(aTHX);
                SPAGAIN;

                ENTER; /* necessary e.g. for dounwind */
              }
          }

void
DESTROY(coro)
        Coro::State     coro
        CODE:

        if (coro->mainstack)
          {
            struct coro temp;

            SAVE(aTHX_ (&temp), SAVE_ALL);
            LOAD(aTHX_ coro);

            destroy_stacks ();

            LOAD((&temp)); /* this will get rid of defsv etc.. */
          }

        Safefree (coro);

void
flush()
        CODE:
#ifdef MAY_FLUSH
        flush_padlist_cache ();
#endif


Revision:	1.7
Committed:	Thu Jul 19 02:45:09 2001 UTC (22 years, 10 months ago) by root
Branch:	MAIN
Changes since 1.6:	+181 -108 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#include "EXTERN.h"
2			#include "perl.h"
3			#include "XSUB.h"
4
5	root	1.7	#if 1
6	root	1.3	# define CHK(x) (void *)0
7			#else
8			# define CHK(x) if (!(x)) croak("FATAL, CHK: " #x)
9			#endif
10
11	root	1.7	#define MAY_FLUSH /* increases codesize */
12
13			#define SAVE_DEFAV 0x00000001
14			#define SAVE_DEFSV 0x00000002
15			#define SAVE_ERRSV 0x00000004
16
17			#define SAVE_ALL -1
18
19	root	1.1	struct coro {
20	root	1.7	/* optionally saved, might be zero */
21	root	1.3	AV *defav;
22	root	1.7	SV *defsv;
23			SV *errsv;
24	root	1.1
25	root	1.7	/* saved global state not related to stacks */
26			U8 dowarn;
27
28			/* the stacks and related info (callchain etc..) */
29	root	1.1	PERL_SI *curstackinfo;
30			AV *curstack;
31			AV *mainstack;
32			SV **stack_sp;
33			OP *op;
34			SV **curpad;
35			SV **stack_base;
36			SV **stack_max;
37			SV **tmps_stack;
38			I32 tmps_floor;
39			I32 tmps_ix;
40			I32 tmps_max;
41			I32 *markstack;
42			I32 *markstack_ptr;
43			I32 *markstack_max;
44			I32 *scopestack;
45			I32 scopestack_ix;
46			I32 scopestack_max;
47			ANY *savestack;
48			I32 savestack_ix;
49			I32 savestack_max;
50			OP **retstack;
51			I32 retstack_ix;
52			I32 retstack_max;
53			COP *curcop;
54
55	root	1.7	/* data associated with this coroutine (initial args) */
56	root	1.3	AV *args;
57	root	1.1	};
58
59			typedef struct coro *Coro__State;
60			typedef struct coro *Coro__State_or_hashref;
61
62	root	1.3	static HV *padlist_cache;
63
64			/* mostly copied from op.c:cv_clone2 */
65			STATIC AV *
66			clone_padlist (AV *protopadlist)
67			{
68			AV *av;
69			I32 ix;
70			AV protopad_name = (AV ) * av_fetch (protopadlist, 0, FALSE);
71			AV protopad = (AV ) * av_fetch (protopadlist, 1, FALSE);
72			SV **pname = AvARRAY (protopad_name);
73			SV **ppad = AvARRAY (protopad);
74			I32 fname = AvFILLp (protopad_name);
75			I32 fpad = AvFILLp (protopad);
76			AV newpadlist, newpad_name, *newpad;
77			SV **npad;
78
79			newpad_name = newAV ();
80			for (ix = fname; ix >= 0; ix--)
81			av_store (newpad_name, ix, SvREFCNT_inc (pname[ix]));
82
83			newpad = newAV ();
84			av_fill (newpad, AvFILLp (protopad));
85			npad = AvARRAY (newpad);
86
87			newpadlist = newAV ();
88			AvREAL_off (newpadlist);
89			av_store (newpadlist, 0, (SV *) newpad_name);
90			av_store (newpadlist, 1, (SV *) newpad);
91
92			av = newAV (); /* will be @_ */
93			av_extend (av, 0);
94			av_store (newpad, 0, (SV *) av);
95			AvFLAGS (av) = AVf_REIFY;
96
97			for (ix = fpad; ix > 0; ix--)
98			{
99			SV *namesv = (ix <= fname) ? pname[ix] : Nullsv;
100			if (namesv && namesv != &PL_sv_undef)
101			{
102			char name = SvPVX (namesv); / XXX */
103			if (SvFLAGS (namesv) & SVf_FAKE \|\| *name == '&')
104			{ /* lexical from outside? */
105			npad[ix] = SvREFCNT_inc (ppad[ix]);
106			}
107			else
108			{ /* our own lexical */
109			SV *sv;
110			if (*name == '&')
111			sv = SvREFCNT_inc (ppad[ix]);
112			else if (*name == '@')
113			sv = (SV *) newAV ();
114			else if (*name == '%')
115			sv = (SV *) newHV ();
116			else
117			sv = NEWSV (0, 0);
118			if (!SvPADBUSY (sv))
119			SvPADMY_on (sv);
120			npad[ix] = sv;
121			}
122			}
123			else if (IS_PADGV (ppad[ix]) \|\| IS_PADCONST (ppad[ix]))
124			{
125			npad[ix] = SvREFCNT_inc (ppad[ix]);
126			}
127			else
128			{
129			SV *sv = NEWSV (0, 0);
130			SvPADTMP_on (sv);
131			npad[ix] = sv;
132			}
133			}
134
135	root	1.7	#if 0 /* return -ENOTUNDERSTOOD */
136	root	1.3	/* Now that vars are all in place, clone nested closures. */
137
138			for (ix = fpad; ix > 0; ix--) {
139			SV* namesv = (ix <= fname) ? pname[ix] : Nullsv;
140			if (namesv
141			&& namesv != &PL_sv_undef
142			&& !(SvFLAGS(namesv) & SVf_FAKE)
143			&& *SvPVX(namesv) == '&'
144			&& CvCLONE(ppad[ix]))
145			{
146			CV kid = cv_clone((CV)ppad[ix]);
147			SvREFCNT_dec(ppad[ix]);
148			CvCLONE_on(kid);
149			SvPADMY_on(kid);
150			npad[ix] = (SV*)kid;
151			}
152			}
153			#endif
154
155			return newpadlist;
156			}
157
158	root	1.7	#ifdef MAY_FLUSH
159	root	1.3	STATIC AV *
160			free_padlist (AV *padlist)
161			{
162			/* may be during global destruction */
163			if (SvREFCNT(padlist))
164			{
165			I32 i = AvFILLp(padlist);
166			while (i >= 0)
167			{
168			SV **svp = av_fetch(padlist, i--, FALSE);
169			SV sv = svp ? svp : Nullsv;
170			if (sv)
171			SvREFCNT_dec(sv);
172			}
173
174			SvREFCNT_dec((SV*)padlist);
175			}
176			}
177	root	1.7	#endif
178	root	1.3
179	root	1.7	/* the next two functions merely cache the padlists */
180	root	1.4	STATIC void
181			get_padlist (CV *cv)
182	root	1.3	{
183	root	1.4	SV *he = hv_fetch (padlist_cache, (void )&cv, sizeof (CV *), 0);
184
185			if (he && AvFILLp ((AV )he) >= 0)
186			CvPADLIST (cv) = (AV )av_pop ((AV )*he);
187			else
188			CvPADLIST (cv) = clone_padlist (CvPADLIST (cv));
189			}
190
191			STATIC void
192			put_padlist (CV *cv)
193			{
194			SV *he = hv_fetch (padlist_cache, (void )&cv, sizeof (CV *), 1);
195
196			if (SvTYPE (*he) != SVt_PVAV)
197			{
198			SvREFCNT_dec (*he);
199			he = (SV )newAV ();
200			}
201
202			av_push ((AV )he, (SV *)CvPADLIST (cv));
203	root	1.3	}
204
205	root	1.7	#ifdef MAY_FLUSH
206			STATIC void
207			flush_padlist_cache ()
208			{
209			HV *hv = padlist_cache;
210			padlist_cache = newHV ();
211
212			if (hv_iterinit (hv))
213			{
214			HE *he;
215			AV *padlist;
216
217			while (!!(he = hv_iternext (hv)))
218			{
219			AV av = (AV )HeVAL(he);
220
221			/* casting is fun. */
222			while (&PL_sv_undef != (SV )(padlist = (AV )av_pop (av)))
223			free_padlist (padlist);
224			}
225			}
226
227			SvREFCNT_dec (hv);
228			}
229			#endif
230
231			#define SB do {
232			#define SE } while (0)
233
234			#define LOAD(state) SB load_state(aTHX_ state); SPAGAIN; SE
235			#define SAVE(state,flags) SB PUTBACK; save_state(aTHX_ state,flags); SE
236
237			#define REPLACE_SV(sv,val) SB SvREFCNT_dec(sv); (sv) = (val); SE
238
239			static void
240			load_state(pTHX_ Coro__State c)
241			{
242			PL_dowarn = c->dowarn;
243
244			PL_curstackinfo = c->curstackinfo;
245			PL_curstack = c->curstack;
246			PL_mainstack = c->mainstack;
247			PL_stack_sp = c->stack_sp;
248			PL_op = c->op;
249			PL_curpad = c->curpad;
250			PL_stack_base = c->stack_base;
251			PL_stack_max = c->stack_max;
252			PL_tmps_stack = c->tmps_stack;
253			PL_tmps_floor = c->tmps_floor;
254			PL_tmps_ix = c->tmps_ix;
255			PL_tmps_max = c->tmps_max;
256			PL_markstack = c->markstack;
257			PL_markstack_ptr = c->markstack_ptr;
258			PL_markstack_max = c->markstack_max;
259			PL_scopestack = c->scopestack;
260			PL_scopestack_ix = c->scopestack_ix;
261			PL_scopestack_max = c->scopestack_max;
262			PL_savestack = c->savestack;
263			PL_savestack_ix = c->savestack_ix;
264			PL_savestack_max = c->savestack_max;
265			PL_retstack = c->retstack;
266			PL_retstack_ix = c->retstack_ix;
267			PL_retstack_max = c->retstack_max;
268			PL_curcop = c->curcop;
269
270			if (c->defav) REPLACE_SV (GvAV (PL_defgv), c->defav);
271			if (c->defsv) REPLACE_SV (DEFSV , c->defsv);
272			if (c->errsv) REPLACE_SV (ERRSV , c->errsv);
273
274			{
275			dSP;
276			CV *cv;
277
278			/* now do the ugly restore mess */
279			while ((cv = (CV *)POPs))
280			{
281			AV padlist = (AV )POPs;
282
283			if (padlist)
284			{
285			put_padlist (cv); /* mark this padlist as available */
286			CvPADLIST(cv) = padlist;
287			#ifdef USE_THREADS
288			/CvOWNER(cv) = (struct perl_thread )POPs;*/
289			#endif
290			}
291
292			++CvDEPTH(cv);
293			}
294
295			PUTBACK;
296			}
297			}
298
299	root	1.3	static void
300	root	1.7	save_state(pTHX_ Coro__State c, int flags)
301	root	1.3	{
302			{
303			dSP;
304			I32 cxix = cxstack_ix;
305			PERL_SI *top_si = PL_curstackinfo;
306			PERL_CONTEXT *ccstk = cxstack;
307
308			/*
309			* the worst thing you can imagine happens first - we have to save
310			* (and reinitialize) all cv's in the whole callchain :(
311			*/
312
313			PUSHs (Nullsv);
314			/* this loop was inspired by pp_caller */
315			for (;;)
316			{
317	root	1.7	do
318	root	1.3	{
319	root	1.4	PERL_CONTEXT *cx = &ccstk[cxix--];
320	root	1.3
321			if (CxTYPE(cx) == CXt_SUB)
322			{
323			CV *cv = cx->blk_sub.cv;
324			if (CvDEPTH(cv))
325			{
326			#ifdef USE_THREADS
327	root	1.7	/XPUSHs ((SV )CvOWNER(cv));*/
328			/CvOWNER(cv) = 0;/
329			/error must unlock this cv etc.. etc.../
330	root	1.3	#endif
331	root	1.7	EXTEND (SP, CvDEPTH(cv)*2);
332
333			while (--CvDEPTH(cv))
334			{
335			/* this tells the restore code to increment CvDEPTH */
336			PUSHs (Nullsv);
337			PUSHs ((SV *)cv);
338			}
339
340	root	1.3	PUSHs ((SV *)CvPADLIST(cv));
341			PUSHs ((SV *)cv);
342
343	root	1.7	get_padlist (cv); /* this is a monster */
344	root	1.3	}
345			}
346			else if (CxTYPE(cx) == CXt_FORMAT)
347			{
348			/* I never used formats, so how should I know how these are implemented? */
349			/* my bold guess is as a simple, plain sub... */
350			croak ("CXt_FORMAT not yet handled. Don't switch coroutines from within formats");
351			}
352			}
353	root	1.7	while (cxix >= 0);
354	root	1.3
355			if (top_si->si_type == PERLSI_MAIN)
356			break;
357
358			top_si = top_si->si_prev;
359			ccstk = top_si->si_cxstack;
360			cxix = top_si->si_cxix;
361			}
362
363			PUTBACK;
364			}
365
366	root	1.7	c->defav = flags & SAVE_DEFAV ? (AV *)SvREFCNT_inc (GvAV (PL_defgv)) : 0;
367			c->defsv = flags & SAVE_DEFSV ? SvREFCNT_inc (DEFSV) : 0;
368			c->errsv = flags & SAVE_ERRSV ? SvREFCNT_inc (ERRSV) : 0;
369
370	root	1.3	c->dowarn = PL_dowarn;
371	root	1.7
372	root	1.3	c->curstackinfo = PL_curstackinfo;
373			c->curstack = PL_curstack;
374			c->mainstack = PL_mainstack;
375			c->stack_sp = PL_stack_sp;
376			c->op = PL_op;
377			c->curpad = PL_curpad;
378			c->stack_base = PL_stack_base;
379			c->stack_max = PL_stack_max;
380			c->tmps_stack = PL_tmps_stack;
381			c->tmps_floor = PL_tmps_floor;
382			c->tmps_ix = PL_tmps_ix;
383			c->tmps_max = PL_tmps_max;
384			c->markstack = PL_markstack;
385			c->markstack_ptr = PL_markstack_ptr;
386			c->markstack_max = PL_markstack_max;
387			c->scopestack = PL_scopestack;
388			c->scopestack_ix = PL_scopestack_ix;
389			c->scopestack_max = PL_scopestack_max;
390			c->savestack = PL_savestack;
391			c->savestack_ix = PL_savestack_ix;
392			c->savestack_max = PL_savestack_max;
393			c->retstack = PL_retstack;
394			c->retstack_ix = PL_retstack_ix;
395			c->retstack_max = PL_retstack_max;
396			c->curcop = PL_curcop;
397			}
398	root	1.1
399	root	1.7	/*
400			* destroy the stacks, the callchain etc...
401			* still there is a memleak of 128 bytes...
402			*/
403	root	1.1	STATIC void
404	root	1.4	destroy_stacks(pTHX)
405	root	1.1	{
406	root	1.4	/* is this ugly, I ask? */
407			while (PL_scopestack_ix)
408			LEAVE;
409
410	root	1.7	/* sure it is, but more important: is it correct?? :/ */
411			while (PL_tmps_ix > PL_tmps_floor) /* should only ever be one iteration */
412			FREETMPS;
413
414	root	1.4	while (PL_curstackinfo->si_next)
415			PL_curstackinfo = PL_curstackinfo->si_next;
416
417			while (PL_curstackinfo)
418			{
419			PERL_SI *p = PL_curstackinfo->si_prev;
420
421	root	1.7	{
422			dSP;
423			SWITCHSTACK (PL_curstack, PL_curstackinfo->si_stack);
424			PUTBACK; /* possibly superfluous */
425			}
426
427			dounwind(-1);
428
429	root	1.4	SvREFCNT_dec(PL_curstackinfo->si_stack);
430			Safefree(PL_curstackinfo->si_cxstack);
431			Safefree(PL_curstackinfo);
432			PL_curstackinfo = p;
433			}
434
435			Safefree(PL_tmps_stack);
436			Safefree(PL_markstack);
437			Safefree(PL_scopestack);
438			Safefree(PL_savestack);
439			Safefree(PL_retstack);
440	root	1.1	}
441
442	root	1.3	#define SUB_INIT "Coro::State::_newcoro"
443
444			MODULE = Coro::State PACKAGE = Coro::State
445	root	1.1
446			PROTOTYPES: ENABLE
447
448	root	1.3	BOOT:
449	root	1.7	HV * stash = gv_stashpvn("Coro::State", 10, TRUE);
450
451			newCONSTSUB (stash, "SAVE_DEFAV", newSViv (SAVE_DEFAV));
452			newCONSTSUB (stash, "SAVE_DEFSV", newSViv (SAVE_DEFSV));
453			newCONSTSUB (stash, "SAVE_ERRSV", newSViv (SAVE_ERRSV));
454
455	root	1.3	if (!padlist_cache)
456			padlist_cache = newHV ();
457
458	root	1.1	Coro::State
459	root	1.3	_newprocess(args)
460			SV * args
461			PROTOTYPE: $
462	root	1.1	CODE:
463			Coro__State coro;
464	root	1.3
465			if (!SvROK (args) \|\| SvTYPE (SvRV (args)) != SVt_PVAV)
466	root	1.7	croak ("Coro::State::_newprocess expects an arrayref");
467	root	1.1
468			New (0, coro, 1, struct coro);
469
470			coro->mainstack = 0; /* actual work is done inside transfer */
471	root	1.3	coro->args = (AV *)SvREFCNT_inc (SvRV (args));
472	root	1.1
473			RETVAL = coro;
474			OUTPUT:
475			RETVAL
476
477			void
478	root	1.7	transfer(prev, next, flags = SAVE_DEFAV)
479	root	1.3	Coro::State_or_hashref prev
480			Coro::State_or_hashref next
481	root	1.7	int flags
482	root	1.1	CODE:
483
484	root	1.2	if (prev != next)
485	root	1.1	{
486			/*
487	root	1.3	* this could be done in newprocess which would lead to
488	root	1.6	* extremely elegant and fast (just SAVE/LOAD)
489	root	1.2	* code here, but lazy allocation of stacks has also
490			* some virtues and the overhead of the if() is nil.
491	root	1.1	*/
492	root	1.2	if (next->mainstack)
493			{
494	root	1.7	SAVE (prev, flags);
495	root	1.6	LOAD (next);
496			/* mark this state as in-use */
497			next->mainstack = 0;
498			next->tmps_ix = -2;
499			}
500			else if (next->tmps_ix == -2)
501			{
502			croak ("tried to transfer to running coroutine");
503	root	1.2	}
504			else
505			{
506			/*
507			* emulate part of the perl startup here.
508			*/
509			UNOP myop;
510
511	root	1.7	SAVE (prev, -1); /* first get rid of the old state */
512
513	root	1.4	init_stacks (); /* from perl.c */
514	root	1.7	SPAGAIN;
515
516	root	1.2	PL_op = (OP *)&myop;
517			/PL_curcop = 0;/
518	root	1.7	SvREFCNT_dec (GvAV (PL_defgv));
519			GvAV (PL_defgv) = next->args;
520	root	1.2
521			Zero(&myop, 1, UNOP);
522			myop.op_next = Nullop;
523			myop.op_flags = OPf_WANT_VOID;
524
525	root	1.3	PUSHMARK(SP);
526			XPUSHs ((SV*)get_cv(SUB_INIT, TRUE));
527	root	1.2	/*
528			* the next line is slightly wrong, as PL_op->op_next
529	root	1.3	* is actually being executed so we skip the first op.
530			* that doesn't matter, though, since it is only
531	root	1.2	* pp_nextstate and we never return...
532	root	1.7	* ah yes, and I don't care anyways ;)
533	root	1.2	*/
534	root	1.7	PUTBACK;
535			PL_op = pp_entersub(aTHX);
536	root	1.2	SPAGAIN;
537	root	1.1
538	root	1.7	ENTER; /* necessary e.g. for dounwind */
539	root	1.2	}
540	root	1.1	}
541
542			void
543			DESTROY(coro)
544	root	1.3	Coro::State coro
545	root	1.1	CODE:
546
547			if (coro->mainstack)
548			{
549			struct coro temp;
550
551	root	1.7	SAVE(aTHX_ (&temp), SAVE_ALL);
552	root	1.3	LOAD(aTHX_ coro);
553	root	1.1
554	root	1.4	destroy_stacks ();
555	root	1.1
556	root	1.7	LOAD((&temp)); /* this will get rid of defsv etc.. */
557	root	1.1	}
558
559			Safefree (coro);
560	root	1.7
561			void
562			flush()
563			CODE:
564			#ifdef MAY_FLUSH
565			flush_padlist_cache ();
566			#endif
567	root	1.1
568