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 SUB_INIT "Coro::State::_newcoro"

#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);
}

STATIC void
transfer(pTHX_ struct coro *prev, struct coro *next, int flags)
{
  dSP;

  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 */
        }
    }
}

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
        PROTOTYPE: @
        CODE:

        transfer (aTHX_ prev, next, flags);

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

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

# this is dirty and should be in it's own .xs

void
result(...)
        PROTOTYPE: @
        CODE:
        static SV *returnstk;
        SV *sv;
        AV *defav = GvAV (PL_defgv);
        struct coro *prev, *next;

        if (!returnstk)
          returnstk = SvRV (get_sv ("Coro::Cont::return", FALSE));

        /* set up @_ */
        av_clear (defav);
        av_fill (defav, items - 1);
        while (items--)
          av_store (defav, items, SvREFCNT_inc (ST(items)));

        mg_get (returnstk); /* isn't documentation wrong for mg_get? */
        sv = av_pop ((AV *)SvRV (returnstk));
        prev = (struct coro *)SvIV ((SV*)SvRV (*av_fetch ((AV *)SvRV (sv), 0, 0)));
        next = (struct coro *)SvIV ((SV*)SvRV (*av_fetch ((AV *)SvRV (sv), 1, 0)));
        SvREFCNT_dec (sv);
        transfer(prev, next, 0);

Revision:	1.8
Committed:	Thu Jul 19 04:13:22 2001 UTC (22 years, 10 months ago) by root
Branch:	MAIN
Changes since 1.7:	+95 -58 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	root	1.8	#define SUB_INIT "Coro::State::_newcoro"
14
15	root	1.7	#define SAVE_DEFAV 0x00000001
16			#define SAVE_DEFSV 0x00000002
17			#define SAVE_ERRSV 0x00000004
18
19			#define SAVE_ALL -1
20
21	root	1.1	struct coro {
22	root	1.7	/* optionally saved, might be zero */
23	root	1.3	AV *defav;
24	root	1.7	SV *defsv;
25			SV *errsv;
26	root	1.1
27	root	1.7	/* saved global state not related to stacks */
28			U8 dowarn;
29
30			/* the stacks and related info (callchain etc..) */
31	root	1.1	PERL_SI *curstackinfo;
32			AV *curstack;
33			AV *mainstack;
34			SV **stack_sp;
35			OP *op;
36			SV **curpad;
37			SV **stack_base;
38			SV **stack_max;
39			SV **tmps_stack;
40			I32 tmps_floor;
41			I32 tmps_ix;
42			I32 tmps_max;
43			I32 *markstack;
44			I32 *markstack_ptr;
45			I32 *markstack_max;
46			I32 *scopestack;
47			I32 scopestack_ix;
48			I32 scopestack_max;
49			ANY *savestack;
50			I32 savestack_ix;
51			I32 savestack_max;
52			OP **retstack;
53			I32 retstack_ix;
54			I32 retstack_max;
55			COP *curcop;
56
57	root	1.7	/* data associated with this coroutine (initial args) */
58	root	1.3	AV *args;
59	root	1.1	};
60
61			typedef struct coro *Coro__State;
62			typedef struct coro *Coro__State_or_hashref;
63
64	root	1.3	static HV *padlist_cache;
65
66			/* mostly copied from op.c:cv_clone2 */
67			STATIC AV *
68			clone_padlist (AV *protopadlist)
69			{
70			AV *av;
71			I32 ix;
72			AV protopad_name = (AV ) * av_fetch (protopadlist, 0, FALSE);
73			AV protopad = (AV ) * av_fetch (protopadlist, 1, FALSE);
74			SV **pname = AvARRAY (protopad_name);
75			SV **ppad = AvARRAY (protopad);
76			I32 fname = AvFILLp (protopad_name);
77			I32 fpad = AvFILLp (protopad);
78			AV newpadlist, newpad_name, *newpad;
79			SV **npad;
80
81			newpad_name = newAV ();
82			for (ix = fname; ix >= 0; ix--)
83			av_store (newpad_name, ix, SvREFCNT_inc (pname[ix]));
84
85			newpad = newAV ();
86			av_fill (newpad, AvFILLp (protopad));
87			npad = AvARRAY (newpad);
88
89			newpadlist = newAV ();
90			AvREAL_off (newpadlist);
91			av_store (newpadlist, 0, (SV *) newpad_name);
92			av_store (newpadlist, 1, (SV *) newpad);
93
94			av = newAV (); /* will be @_ */
95			av_extend (av, 0);
96			av_store (newpad, 0, (SV *) av);
97			AvFLAGS (av) = AVf_REIFY;
98
99			for (ix = fpad; ix > 0; ix--)
100			{
101			SV *namesv = (ix <= fname) ? pname[ix] : Nullsv;
102			if (namesv && namesv != &PL_sv_undef)
103			{
104			char name = SvPVX (namesv); / XXX */
105			if (SvFLAGS (namesv) & SVf_FAKE \|\| *name == '&')
106			{ /* lexical from outside? */
107			npad[ix] = SvREFCNT_inc (ppad[ix]);
108			}
109			else
110			{ /* our own lexical */
111			SV *sv;
112			if (*name == '&')
113			sv = SvREFCNT_inc (ppad[ix]);
114			else if (*name == '@')
115			sv = (SV *) newAV ();
116			else if (*name == '%')
117			sv = (SV *) newHV ();
118			else
119			sv = NEWSV (0, 0);
120			if (!SvPADBUSY (sv))
121			SvPADMY_on (sv);
122			npad[ix] = sv;
123			}
124			}
125			else if (IS_PADGV (ppad[ix]) \|\| IS_PADCONST (ppad[ix]))
126			{
127			npad[ix] = SvREFCNT_inc (ppad[ix]);
128			}
129			else
130			{
131			SV *sv = NEWSV (0, 0);
132			SvPADTMP_on (sv);
133			npad[ix] = sv;
134			}
135			}
136
137	root	1.7	#if 0 /* return -ENOTUNDERSTOOD */
138	root	1.3	/* Now that vars are all in place, clone nested closures. */
139
140			for (ix = fpad; ix > 0; ix--) {
141			SV* namesv = (ix <= fname) ? pname[ix] : Nullsv;
142			if (namesv
143			&& namesv != &PL_sv_undef
144			&& !(SvFLAGS(namesv) & SVf_FAKE)
145			&& *SvPVX(namesv) == '&'
146			&& CvCLONE(ppad[ix]))
147			{
148			CV kid = cv_clone((CV)ppad[ix]);
149			SvREFCNT_dec(ppad[ix]);
150			CvCLONE_on(kid);
151			SvPADMY_on(kid);
152			npad[ix] = (SV*)kid;
153			}
154			}
155			#endif
156
157			return newpadlist;
158			}
159
160	root	1.7	#ifdef MAY_FLUSH
161	root	1.3	STATIC AV *
162			free_padlist (AV *padlist)
163			{
164			/* may be during global destruction */
165			if (SvREFCNT(padlist))
166			{
167			I32 i = AvFILLp(padlist);
168			while (i >= 0)
169			{
170			SV **svp = av_fetch(padlist, i--, FALSE);
171			SV sv = svp ? svp : Nullsv;
172			if (sv)
173			SvREFCNT_dec(sv);
174			}
175
176			SvREFCNT_dec((SV*)padlist);
177			}
178			}
179	root	1.7	#endif
180	root	1.3
181	root	1.7	/* the next two functions merely cache the padlists */
182	root	1.4	STATIC void
183			get_padlist (CV *cv)
184	root	1.3	{
185	root	1.4	SV *he = hv_fetch (padlist_cache, (void )&cv, sizeof (CV *), 0);
186
187			if (he && AvFILLp ((AV )he) >= 0)
188			CvPADLIST (cv) = (AV )av_pop ((AV )*he);
189			else
190			CvPADLIST (cv) = clone_padlist (CvPADLIST (cv));
191			}
192
193			STATIC void
194			put_padlist (CV *cv)
195			{
196			SV *he = hv_fetch (padlist_cache, (void )&cv, sizeof (CV *), 1);
197
198			if (SvTYPE (*he) != SVt_PVAV)
199			{
200			SvREFCNT_dec (*he);
201			he = (SV )newAV ();
202			}
203
204			av_push ((AV )he, (SV *)CvPADLIST (cv));
205	root	1.3	}
206
207	root	1.7	#ifdef MAY_FLUSH
208			STATIC void
209			flush_padlist_cache ()
210			{
211			HV *hv = padlist_cache;
212			padlist_cache = newHV ();
213
214			if (hv_iterinit (hv))
215			{
216			HE *he;
217			AV *padlist;
218
219			while (!!(he = hv_iternext (hv)))
220			{
221			AV av = (AV )HeVAL(he);
222
223			/* casting is fun. */
224			while (&PL_sv_undef != (SV )(padlist = (AV )av_pop (av)))
225			free_padlist (padlist);
226			}
227			}
228
229			SvREFCNT_dec (hv);
230			}
231			#endif
232
233			#define SB do {
234			#define SE } while (0)
235
236			#define LOAD(state) SB load_state(aTHX_ state); SPAGAIN; SE
237			#define SAVE(state,flags) SB PUTBACK; save_state(aTHX_ state,flags); SE
238
239			#define REPLACE_SV(sv,val) SB SvREFCNT_dec(sv); (sv) = (val); SE
240
241			static void
242			load_state(pTHX_ Coro__State c)
243			{
244			PL_dowarn = c->dowarn;
245
246			PL_curstackinfo = c->curstackinfo;
247			PL_curstack = c->curstack;
248			PL_mainstack = c->mainstack;
249			PL_stack_sp = c->stack_sp;
250			PL_op = c->op;
251			PL_curpad = c->curpad;
252			PL_stack_base = c->stack_base;
253			PL_stack_max = c->stack_max;
254			PL_tmps_stack = c->tmps_stack;
255			PL_tmps_floor = c->tmps_floor;
256			PL_tmps_ix = c->tmps_ix;
257			PL_tmps_max = c->tmps_max;
258			PL_markstack = c->markstack;
259			PL_markstack_ptr = c->markstack_ptr;
260			PL_markstack_max = c->markstack_max;
261			PL_scopestack = c->scopestack;
262			PL_scopestack_ix = c->scopestack_ix;
263			PL_scopestack_max = c->scopestack_max;
264			PL_savestack = c->savestack;
265			PL_savestack_ix = c->savestack_ix;
266			PL_savestack_max = c->savestack_max;
267			PL_retstack = c->retstack;
268			PL_retstack_ix = c->retstack_ix;
269			PL_retstack_max = c->retstack_max;
270			PL_curcop = c->curcop;
271
272			if (c->defav) REPLACE_SV (GvAV (PL_defgv), c->defav);
273			if (c->defsv) REPLACE_SV (DEFSV , c->defsv);
274			if (c->errsv) REPLACE_SV (ERRSV , c->errsv);
275
276			{
277			dSP;
278			CV *cv;
279
280			/* now do the ugly restore mess */
281			while ((cv = (CV *)POPs))
282			{
283			AV padlist = (AV )POPs;
284
285			if (padlist)
286			{
287			put_padlist (cv); /* mark this padlist as available */
288			CvPADLIST(cv) = padlist;
289			#ifdef USE_THREADS
290			/CvOWNER(cv) = (struct perl_thread )POPs;*/
291			#endif
292			}
293
294			++CvDEPTH(cv);
295			}
296
297			PUTBACK;
298			}
299			}
300
301	root	1.3	static void
302	root	1.7	save_state(pTHX_ Coro__State c, int flags)
303	root	1.3	{
304			{
305			dSP;
306			I32 cxix = cxstack_ix;
307			PERL_SI *top_si = PL_curstackinfo;
308			PERL_CONTEXT *ccstk = cxstack;
309
310			/*
311			* the worst thing you can imagine happens first - we have to save
312			* (and reinitialize) all cv's in the whole callchain :(
313			*/
314
315			PUSHs (Nullsv);
316			/* this loop was inspired by pp_caller */
317			for (;;)
318			{
319	root	1.7	do
320	root	1.3	{
321	root	1.4	PERL_CONTEXT *cx = &ccstk[cxix--];
322	root	1.3
323			if (CxTYPE(cx) == CXt_SUB)
324			{
325			CV *cv = cx->blk_sub.cv;
326			if (CvDEPTH(cv))
327			{
328			#ifdef USE_THREADS
329	root	1.7	/XPUSHs ((SV )CvOWNER(cv));*/
330			/CvOWNER(cv) = 0;/
331			/error must unlock this cv etc.. etc.../
332	root	1.3	#endif
333	root	1.7	EXTEND (SP, CvDEPTH(cv)*2);
334
335			while (--CvDEPTH(cv))
336			{
337			/* this tells the restore code to increment CvDEPTH */
338			PUSHs (Nullsv);
339			PUSHs ((SV *)cv);
340			}
341
342	root	1.3	PUSHs ((SV *)CvPADLIST(cv));
343			PUSHs ((SV *)cv);
344
345	root	1.7	get_padlist (cv); /* this is a monster */
346	root	1.3	}
347			}
348			else if (CxTYPE(cx) == CXt_FORMAT)
349			{
350			/* I never used formats, so how should I know how these are implemented? */
351			/* my bold guess is as a simple, plain sub... */
352			croak ("CXt_FORMAT not yet handled. Don't switch coroutines from within formats");
353			}
354			}
355	root	1.7	while (cxix >= 0);
356	root	1.3
357			if (top_si->si_type == PERLSI_MAIN)
358			break;
359
360			top_si = top_si->si_prev;
361			ccstk = top_si->si_cxstack;
362			cxix = top_si->si_cxix;
363			}
364
365			PUTBACK;
366			}
367
368	root	1.7	c->defav = flags & SAVE_DEFAV ? (AV *)SvREFCNT_inc (GvAV (PL_defgv)) : 0;
369			c->defsv = flags & SAVE_DEFSV ? SvREFCNT_inc (DEFSV) : 0;
370			c->errsv = flags & SAVE_ERRSV ? SvREFCNT_inc (ERRSV) : 0;
371
372	root	1.3	c->dowarn = PL_dowarn;
373	root	1.7
374	root	1.3	c->curstackinfo = PL_curstackinfo;
375			c->curstack = PL_curstack;
376			c->mainstack = PL_mainstack;
377			c->stack_sp = PL_stack_sp;
378			c->op = PL_op;
379			c->curpad = PL_curpad;
380			c->stack_base = PL_stack_base;
381			c->stack_max = PL_stack_max;
382			c->tmps_stack = PL_tmps_stack;
383			c->tmps_floor = PL_tmps_floor;
384			c->tmps_ix = PL_tmps_ix;
385			c->tmps_max = PL_tmps_max;
386			c->markstack = PL_markstack;
387			c->markstack_ptr = PL_markstack_ptr;
388			c->markstack_max = PL_markstack_max;
389			c->scopestack = PL_scopestack;
390			c->scopestack_ix = PL_scopestack_ix;
391			c->scopestack_max = PL_scopestack_max;
392			c->savestack = PL_savestack;
393			c->savestack_ix = PL_savestack_ix;
394			c->savestack_max = PL_savestack_max;
395			c->retstack = PL_retstack;
396			c->retstack_ix = PL_retstack_ix;
397			c->retstack_max = PL_retstack_max;
398			c->curcop = PL_curcop;
399			}
400	root	1.1
401	root	1.7	/*
402			* destroy the stacks, the callchain etc...
403			* still there is a memleak of 128 bytes...
404			*/
405	root	1.1	STATIC void
406	root	1.4	destroy_stacks(pTHX)
407	root	1.1	{
408	root	1.4	/* is this ugly, I ask? */
409			while (PL_scopestack_ix)
410			LEAVE;
411
412	root	1.7	/* sure it is, but more important: is it correct?? :/ */
413			while (PL_tmps_ix > PL_tmps_floor) /* should only ever be one iteration */
414			FREETMPS;
415
416	root	1.4	while (PL_curstackinfo->si_next)
417			PL_curstackinfo = PL_curstackinfo->si_next;
418
419			while (PL_curstackinfo)
420			{
421			PERL_SI *p = PL_curstackinfo->si_prev;
422
423	root	1.7	{
424			dSP;
425			SWITCHSTACK (PL_curstack, PL_curstackinfo->si_stack);
426			PUTBACK; /* possibly superfluous */
427			}
428
429			dounwind(-1);
430
431	root	1.4	SvREFCNT_dec(PL_curstackinfo->si_stack);
432			Safefree(PL_curstackinfo->si_cxstack);
433			Safefree(PL_curstackinfo);
434			PL_curstackinfo = p;
435			}
436
437			Safefree(PL_tmps_stack);
438			Safefree(PL_markstack);
439			Safefree(PL_scopestack);
440			Safefree(PL_savestack);
441			Safefree(PL_retstack);
442	root	1.1	}
443
444	root	1.8	STATIC void
445			transfer(pTHX_ struct coro prev, struct coro next, int flags)
446			{
447			dSP;
448
449			if (prev != next)
450			{
451			/*
452			* this could be done in newprocess which would lead to
453			* extremely elegant and fast (just SAVE/LOAD)
454			* code here, but lazy allocation of stacks has also
455			* some virtues and the overhead of the if() is nil.
456			*/
457			if (next->mainstack)
458			{
459			SAVE (prev, flags);
460			LOAD (next);
461			/* mark this state as in-use */
462			next->mainstack = 0;
463			next->tmps_ix = -2;
464			}
465			else if (next->tmps_ix == -2)
466			{
467			croak ("tried to transfer to running coroutine");
468			}
469			else
470			{
471			/*
472			* emulate part of the perl startup here.
473			*/
474			UNOP myop;
475
476			SAVE (prev, -1); /* first get rid of the old state */
477
478			init_stacks (); /* from perl.c */
479			SPAGAIN;
480
481			PL_op = (OP *)&myop;
482			/PL_curcop = 0;/
483			SvREFCNT_dec (GvAV (PL_defgv));
484			GvAV (PL_defgv) = next->args;
485
486			Zero(&myop, 1, UNOP);
487			myop.op_next = Nullop;
488			myop.op_flags = OPf_WANT_VOID;
489
490			PUSHMARK(SP);
491			XPUSHs ((SV*)get_cv(SUB_INIT, TRUE));
492			/*
493			* the next line is slightly wrong, as PL_op->op_next
494			* is actually being executed so we skip the first op.
495			* that doesn't matter, though, since it is only
496			* pp_nextstate and we never return...
497			* ah yes, and I don't care anyways ;)
498			*/
499			PUTBACK;
500			PL_op = pp_entersub(aTHX);
501			SPAGAIN;
502
503			ENTER; /* necessary e.g. for dounwind */
504			}
505			}
506			}
507	root	1.3
508			MODULE = Coro::State PACKAGE = Coro::State
509	root	1.1
510			PROTOTYPES: ENABLE
511
512	root	1.3	BOOT:
513	root	1.7	HV * stash = gv_stashpvn("Coro::State", 10, TRUE);
514
515			newCONSTSUB (stash, "SAVE_DEFAV", newSViv (SAVE_DEFAV));
516			newCONSTSUB (stash, "SAVE_DEFSV", newSViv (SAVE_DEFSV));
517			newCONSTSUB (stash, "SAVE_ERRSV", newSViv (SAVE_ERRSV));
518
519	root	1.3	if (!padlist_cache)
520			padlist_cache = newHV ();
521
522	root	1.1	Coro::State
523	root	1.3	_newprocess(args)
524			SV * args
525			PROTOTYPE: $
526	root	1.1	CODE:
527			Coro__State coro;
528	root	1.3
529			if (!SvROK (args) \|\| SvTYPE (SvRV (args)) != SVt_PVAV)
530	root	1.7	croak ("Coro::State::_newprocess expects an arrayref");
531	root	1.1
532			New (0, coro, 1, struct coro);
533
534			coro->mainstack = 0; /* actual work is done inside transfer */
535	root	1.3	coro->args = (AV *)SvREFCNT_inc (SvRV (args));
536	root	1.1
537			RETVAL = coro;
538			OUTPUT:
539			RETVAL
540
541			void
542	root	1.7	transfer(prev, next, flags = SAVE_DEFAV)
543	root	1.3	Coro::State_or_hashref prev
544			Coro::State_or_hashref next
545	root	1.7	int flags
546	root	1.8	PROTOTYPE: @
547	root	1.1	CODE:
548
549	root	1.8	transfer (aTHX_ prev, next, flags);
550	root	1.1
551			void
552			DESTROY(coro)
553	root	1.3	Coro::State coro
554	root	1.1	CODE:
555
556			if (coro->mainstack)
557			{
558			struct coro temp;
559
560	root	1.7	SAVE(aTHX_ (&temp), SAVE_ALL);
561	root	1.3	LOAD(aTHX_ coro);
562	root	1.1
563	root	1.4	destroy_stacks ();
564	root	1.1
565	root	1.7	LOAD((&temp)); /* this will get rid of defsv etc.. */
566	root	1.1	}
567
568			Safefree (coro);
569	root	1.7
570			void
571			flush()
572			CODE:
573			#ifdef MAY_FLUSH
574			flush_padlist_cache ();
575			#endif
576	root	1.1
577	root	1.8	MODULE = Coro::State PACKAGE = Coro::Cont
578
579			# this is dirty and should be in it's own .xs
580
581			void
582			result(...)
583			PROTOTYPE: @
584			CODE:
585			static SV *returnstk;
586			SV *sv;
587			AV *defav = GvAV (PL_defgv);
588			struct coro prev, next;
589
590			if (!returnstk)
591			returnstk = SvRV (get_sv ("Coro::Cont::return", FALSE));
592
593			/* set up @_ */
594			av_clear (defav);
595			av_fill (defav, items - 1);
596			while (items--)
597			av_store (defav, items, SvREFCNT_inc (ST(items)));
598
599			mg_get (returnstk); /* isn't documentation wrong for mg_get? */
600			sv = av_pop ((AV *)SvRV (returnstk));
601			prev = (struct coro )SvIV ((SV)SvRV (av_fetch ((AV )SvRV (sv), 0, 0)));
602			next = (struct coro )SvIV ((SV)SvRV (av_fetch ((AV )SvRV (sv), 1, 0)));
603			SvREFCNT_dec (sv);
604			transfer(prev, next, 0);
605	root	1.1