PNG  IHDRxsBIT|d pHYs+tEXtSoftwarewww.inkscape.org<,tEXtComment File Manager

File Manager

Path: /opt/alt/alt-nodejs18/root/usr/include/node/

Viewing File: v8-embedder-heap.h

// Copyright 2021 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef INCLUDE_V8_EMBEDDER_HEAP_H_
#define INCLUDE_V8_EMBEDDER_HEAP_H_

#include <stddef.h>
#include <stdint.h>

#include <utility>
#include <vector>

#include "cppgc/common.h"
#include "v8-local-handle.h"   // NOLINT(build/include_directory)
#include "v8-traced-handle.h"  // NOLINT(build/include_directory)
#include "v8config.h"          // NOLINT(build/include_directory)

namespace v8 {

class Data;
class Isolate;
class Value;

namespace internal {
class LocalEmbedderHeapTracer;
}  // namespace internal

/**
 * Handler for embedder roots on non-unified heap garbage collections.
 */
class V8_EXPORT EmbedderRootsHandler {
 public:
  virtual ~EmbedderRootsHandler() = default;

  /**
   * Returns true if the |TracedReference| handle should be considered as root
   * for the currently running non-tracing garbage collection and false
   * otherwise. The default implementation will keep all |TracedReference|
   * references as roots.
   *
   * If this returns false, then V8 may decide that the object referred to by
   * such a handle is reclaimed. In that case, V8 calls |ResetRoot()| for the
   * |TracedReference|.
   *
   * Note that the `handle` is different from the handle that the embedder holds
   * for retaining the object. The embedder may use |WrapperClassId()| to
   * distinguish cases where it wants handles to be treated as roots from not
   * being treated as roots.
   */
  virtual bool IsRoot(const v8::TracedReference<v8::Value>& handle) = 0;

  /**
   * Used in combination with |IsRoot|. Called by V8 when an
   * object that is backed by a handle is reclaimed by a non-tracing garbage
   * collection. It is up to the embedder to reset the original handle.
   *
   * Note that the |handle| is different from the handle that the embedder holds
   * for retaining the object. It is up to the embedder to find the original
   * handle via the object or class id.
   */
  virtual void ResetRoot(const v8::TracedReference<v8::Value>& handle) = 0;
};

/**
 * Interface for tracing through the embedder heap. During a V8 garbage
 * collection, V8 collects hidden fields of all potential wrappers, and at the
 * end of its marking phase iterates the collection and asks the embedder to
 * trace through its heap and use reporter to report each JavaScript object
 * reachable from any of the given wrappers.
 */
class V8_EXPORT EmbedderHeapTracer {
 public:
  using EmbedderStackState = cppgc::EmbedderStackState;

  enum TraceFlags : uint64_t {
    kNoFlags = 0,
    kReduceMemory = 1 << 0,
    kForced = 1 << 2,
  };

  /**
   * Interface for iterating through |TracedReference| handles.
   */
  class V8_EXPORT TracedGlobalHandleVisitor {
   public:
    virtual ~TracedGlobalHandleVisitor() = default;
    virtual void VisitTracedReference(const TracedReference<Value>& handle) {}
  };

  /**
   * Summary of a garbage collection cycle. See |TraceEpilogue| on how the
   * summary is reported.
   */
  struct TraceSummary {
    /**
     * Time spent managing the retained memory in milliseconds. This can e.g.
     * include the time tracing through objects in the embedder.
     */
    double time = 0.0;

    /**
     * Memory retained by the embedder through the |EmbedderHeapTracer|
     * mechanism in bytes.
     */
    size_t allocated_size = 0;
  };

  virtual ~EmbedderHeapTracer() = default;

  /**
   * Iterates all |TracedReference| handles created for the |v8::Isolate| the
   * tracer is attached to.
   */
  void IterateTracedGlobalHandles(TracedGlobalHandleVisitor* visitor);

  /**
   * Called by the embedder to set the start of the stack which is e.g. used by
   * V8 to determine whether handles are used from stack or heap.
   */
  void SetStackStart(void* stack_start);

  /**
   * Called by v8 to register internal fields of found wrappers.
   *
   * The embedder is expected to store them somewhere and trace reachable
   * wrappers from them when called through |AdvanceTracing|.
   */
  virtual void RegisterV8References(
      const std::vector<std::pair<void*, void*>>& embedder_fields) = 0;

  void RegisterEmbedderReference(const BasicTracedReference<v8::Data>& ref);

  /**
   * Called at the beginning of a GC cycle.
   */
  virtual void TracePrologue(TraceFlags flags) {}

  /**
   * Called to advance tracing in the embedder.
   *
   * The embedder is expected to trace its heap starting from wrappers reported
   * by RegisterV8References method, and report back all reachable wrappers.
   * Furthermore, the embedder is expected to stop tracing by the given
   * deadline. A deadline of infinity means that tracing should be finished.
   *
   * Returns |true| if tracing is done, and false otherwise.
   */
  virtual bool AdvanceTracing(double deadline_in_ms) = 0;

  /*
   * Returns true if there no more tracing work to be done (see AdvanceTracing)
   * and false otherwise.
   */
  virtual bool IsTracingDone() = 0;

  /**
   * Called at the end of a GC cycle.
   *
   * Note that allocation is *not* allowed within |TraceEpilogue|. Can be
   * overriden to fill a |TraceSummary| that is used by V8 to schedule future
   * garbage collections.
   */
  virtual void TraceEpilogue(TraceSummary* trace_summary) {}

  /**
   * Called upon entering the final marking pause. No more incremental marking
   * steps will follow this call.
   */
  virtual void EnterFinalPause(EmbedderStackState stack_state) = 0;

  /*
   * Called by the embedder to request immediate finalization of the currently
   * running tracing phase that has been started with TracePrologue and not
   * yet finished with TraceEpilogue.
   *
   * Will be a noop when currently not in tracing.
   *
   * This is an experimental feature.
   */
  void FinalizeTracing();

  /**
   * See documentation on EmbedderRootsHandler.
   */
  virtual bool IsRootForNonTracingGC(
      const v8::TracedReference<v8::Value>& handle);

  /**
   * See documentation on EmbedderRootsHandler.
   */
  virtual void ResetHandleInNonTracingGC(
      const v8::TracedReference<v8::Value>& handle);

  /*
   * Called by the embedder to signal newly allocated or freed memory. Not bound
   * to tracing phases. Embedders should trade off when increments are reported
   * as V8 may consult global heuristics on whether to trigger garbage
   * collection on this change.
   */
  void IncreaseAllocatedSize(size_t bytes);
  void DecreaseAllocatedSize(size_t bytes);

  /*
   * Returns the v8::Isolate this tracer is attached too and |nullptr| if it
   * is not attached to any v8::Isolate.
   */
  v8::Isolate* isolate() const { return isolate_; }

 protected:
  v8::Isolate* isolate_ = nullptr;

  friend class internal::LocalEmbedderHeapTracer;
};

}  // namespace v8

#endif  // INCLUDE_V8_EMBEDDER_HEAP_H_
b IDATxytVսϓ22 A@IR :hCiZ[v*E:WũZA ^dQeQ @ !jZ'>gsV仿$|?g)&x-EIENT ;@xT.i%-X}SvS5.r/UHz^_$-W"w)Ɗ/@Z &IoX P$K}JzX:;` &, ŋui,e6mX ԵrKb1ԗ)DADADADADADADADADADADADADADADADADADADADADADADADADADADADADADADADADADADADADADADADADADA݀!I*]R;I2$eZ#ORZSrr6mteffu*((Pu'v{DIߔ4^pIm'77WEEE;vƎ4-$]'RI{\I&G :IHJ DWBB=\WR޽m o$K(V9ABB.}jѢv`^?IOȅ} ڶmG}T#FJ`56$-ھ}FI&v;0(h;Б38CӧOWf!;A i:F_m9s&|q%=#wZprrrla A &P\\СC[A#! {olF} `E2}MK/vV)i{4BffV\|ۭX`b@kɶ@%i$K z5zhmX[IXZ` 'b%$r5M4º/l ԃߖxhʔ)[@=} K6IM}^5k㏷݆z ΗÿO:gdGBmyT/@+Vɶ纽z񕏵l.y޴it뭷zV0[Y^>Wsqs}\/@$(T7f.InݺiR$푔n.~?H))\ZRW'Mo~v Ov6oԃxz! S,&xm/yɞԟ?'uaSѽb,8GלKboi&3t7Y,)JJ c[nzӳdE&KsZLӄ I?@&%ӟ۶mSMMњ0iؐSZ,|J+N ~,0A0!5%Q-YQQa3}$_vVrf9f?S8`zDADADADADADADADADAdqP,تmMmg1V?rSI꒟]u|l RCyEf٢9 jURbztѰ!m5~tGj2DhG*{H9)꒟ר3:(+3\?/;TUݭʴ~S6lڧUJ*i$d(#=Yݺd{,p|3B))q:vN0Y.jkק6;SɶVzHJJЀ-utѹսk>QUU\޲~]fFnK?&ߡ5b=z9)^|u_k-[y%ZNU6 7Mi:]ۦtk[n X(e6Bb."8cۭ|~teuuw|ήI-5"~Uk;ZicEmN/:]M> cQ^uiƞ??Ңpc#TUU3UakNwA`:Y_V-8.KKfRitv޲* 9S6ֿj,ՃNOMߤ]z^fOh|<>@Å5 _/Iu?{SY4hK/2]4%it5q]GGe2%iR| W&f*^]??vq[LgE_3f}Fxu~}qd-ږFxu~I N>\;͗O֊:̗WJ@BhW=y|GgwܷH_NY?)Tdi'?խwhlmQi !SUUsw4kӺe4rfxu-[nHtMFj}H_u~w>)oV}(T'ebʒv3_[+vn@Ȭ\S}ot}w=kHFnxg S 0eޢm~l}uqZfFoZuuEg `zt~? b;t%>WTkķh[2eG8LIWx,^\thrl^Ϊ{=dž<}qV@ ⠨Wy^LF_>0UkDuʫuCs$)Iv:IK;6ֲ4{^6եm+l3>݆uM 9u?>Zc }g~qhKwڭeFMM~pМuqǿz6Tb@8@Y|jx](^]gf}M"tG -w.@vOqh~/HII`S[l.6nØXL9vUcOoB\xoǤ'T&IǍQw_wpv[kmO{w~>#=P1Pɞa-we:iǏlHo׈꒟f9SzH?+shk%Fs:qVhqY`jvO'ρ?PyX3lх]˾uV{ݞ]1,MzYNW~̈́ joYn}ȚF߾׮mS]F z+EDxm/d{F{-W-4wY듏:??_gPf ^3ecg ҵs8R2מz@TANGj)}CNi/R~}c:5{!ZHӋӾ6}T]G]7W6^n 9*,YqOZj:P?Q DFL|?-^.Ɵ7}fFh׶xe2Pscz1&5\cn[=Vn[ĶE鎀uˌd3GII k;lNmشOuuRVfBE]ۣeӶu :X-[(er4~LHi6:Ѻ@ԅrST0trk%$Č0ez" *z"T/X9|8.C5Feg}CQ%͞ˣJvL/?j^h&9xF`њZ(&yF&Iݻfg#W;3^{Wo^4'vV[[K';+mӍִ]AC@W?1^{එyh +^]fm~iԵ]AB@WTk̏t uR?l.OIHiYyԶ]Aˀ7c:q}ힽaf6Z~қm(+sK4{^6}T*UUu]n.:kx{:2 _m=sAߤU@?Z-Vކеz왍Nэ{|5 pڶn b p-@sPg]0G7fy-M{GCF'%{4`=$-Ge\ eU:m+Zt'WjO!OAF@ik&t݆ϥ_ e}=]"Wz_.͜E3leWFih|t-wZۍ-uw=6YN{6|} |*={Ѽn.S.z1zjۻTH]흾 DuDvmvK.`V]yY~sI@t?/ϓ. m&["+P?MzovVЫG3-GRR[(!!\_,^%?v@ҵő m`Y)tem8GMx.))A]Y i`ViW`?^~!S#^+ѽGZj?Vģ0.))A꨷lzL*]OXrY`DBBLOj{-MH'ii-ϰ ok7^ )쭡b]UXSְmռY|5*cֽk0B7镹%ڽP#8nȎq}mJr23_>lE5$iwui+ H~F`IjƵ@q \ @#qG0".0" l`„.0! ,AQHN6qzkKJ#o;`Xv2>,tێJJ7Z/*A .@fفjMzkg @TvZH3Zxu6Ra'%O?/dQ5xYkU]Rֽkق@DaS^RSּ5|BeHNN͘p HvcYcC5:y #`οb;z2.!kr}gUWkyZn=f Pvsn3p~;4p˚=ē~NmI] ¾ 0lH[_L hsh_ғߤc_њec)g7VIZ5yrgk̞W#IjӪv>՞y睝M8[|]\շ8M6%|@PZڨI-m>=k='aiRo-x?>Q.}`Ȏ:Wsmu u > .@,&;+!!˱tﭧDQwRW\vF\~Q7>spYw$%A~;~}6¾ g&if_=j,v+UL1(tWake:@Ș>j$Gq2t7S?vL|]u/ .(0E6Mk6hiۺzښOrifޱxm/Gx> Lal%%~{lBsR4*}{0Z/tNIɚpV^#Lf:u@k#RSu =S^ZyuR/.@n&΃z~B=0eg뺆#,Þ[B/?H uUf7y Wy}Bwegל`Wh(||`l`.;Ws?V@"c:iɍL֯PGv6zctM̠':wuW;d=;EveD}9J@B(0iհ bvP1{\P&G7D޴Iy_$-Qjm~Yrr&]CDv%bh|Yzni_ˆR;kg}nJOIIwyuL}{ЌNj}:+3Y?:WJ/N+Rzd=hb;dj͒suݔ@NKMԄ jqzC5@y°hL m;*5ezᕏ=ep XL n?מ:r`۵tŤZ|1v`V뽧_csج'ߤ%oTuumk%%%h)uy]Nk[n 'b2 l.=͜E%gf$[c;s:V-͞WߤWh-j7]4=F-X]>ZLSi[Y*We;Zan(ӇW|e(HNNP5[= r4tP &0<pc#`vTNV GFqvTi*Tyam$ߏWyE*VJKMTfFw>'$-ؽ.Ho.8c"@DADADADADADADADADA~j*֘,N;Pi3599h=goضLgiJ5փy~}&Zd9p֚ e:|hL``b/d9p? fgg+%%hMgXosج, ΩOl0Zh=xdjLmhݻoO[g_l,8a]٭+ӧ0$I]c]:粹:Teꢢ"5a^Kgh,&= =՟^߶“ߢE ܹS J}I%:8 IDAT~,9/ʃPW'Mo}zNƍ쨓zPbNZ~^z=4mswg;5 Y~SVMRXUյڱRf?s:w ;6H:ºi5-maM&O3;1IKeamZh͛7+##v+c ~u~ca]GnF'ټL~PPPbn voC4R,ӟgg %hq}@#M4IÇ Oy^xMZx ) yOw@HkN˖-Sǎmb]X@n+i͖!++K3gd\$mt$^YfJ\8PRF)77Wא!Cl$i:@@_oG I{$# 8磌ŋ91A (Im7֭>}ߴJq7ޗt^ -[ԩSj*}%]&' -ɓ'ꫯVzzvB#;a 7@GxI{j޼ƌ.LÇWBB7`O"I$/@R @eee@۷>}0,ɒ2$53Xs|cS~rpTYYY} kHc %&k.], @ADADADADADADADADA@lT<%''*Lo^={رc5h %$+CnܸQ3fҥK}vUVVs9G R,_{xˇ3o߾;TTTd}馛]uuuG~iԩ@4bnvmvfϞ /Peeeq}}za I~,誫{UWW뮻}_~YƍSMMMYχ֝waw\ďcxꩧtEƍկ_?۷5@u?1kNׯWzz/wy>}zj3 k(ٺuq_Zvf̘:~ ABQ&r|!%KҥKgԞ={<_X-z !CyFUUz~ ABQIIIjݺW$UXXDٳZ~ ABQƍecW$<(~<RSSvZujjjԧOZQu@4 8m&&&jԩg$ď1h ͟?_{768@g =@`)))5o6m3)ѣƌJ;wҿUTT /KZR{~a=@0o<*狔iFɶ[ˎ;T]]OX@?K.ۈxN pppppppppppppppppPfl߾] ,{ｧk۶mڿo5BTӦMӴiӴ|r DB2e|An!Dy'tkΝ[A $***t5' "!駟oaDnΝ:t֭[gDШQ06qD;@ x M6v(PiizmZ4ew"@̴ixf [~-Fٱc&IZ2|n!?$@{[HTɏ#@hȎI# _m(F /6Z3z'\r,r!;w2Z3j=~GY7"I$iI.p_"?pN`y DD?: _  Gÿab7J !Bx@0 Bo cG@`1C[@0G @`0C_u V1 aCX>W ` | `!<S `"<. `#c`?cAC4 ?c p#~@0?:08&_MQ1J h#?/`7;I  q 7a wQ A 1 Hp !#<8/#@1Ul7=S=K.4Z?E_$i@!1!E4?`P_  @Bă10#: "aU,xbFY1 [n|n #'vEH:`xb #vD4Y hi.i&EΖv#O H4IŶ}:Ikh @tZRF#(tXҙzZ ?I3l7q@õ|ۍ1,GpuY Ꮿ@hJv#xxk$ v#9 5 }_$c S#=+"K{F*m7`#%H:NRSp6I?sIՖ{Ap$I$I:QRv2$Z @UJ*$]<FO4IENDB`