Advanced guard of DeallocationChecker

Advanced guard of DeallocationChecker
potatotips #66 at Yappli

Referenced URLs:
- https://github.com/fastred/DeallocationChecker
- https://speakerdeck.com/corin8823/iosdc-2018-memory-leak

Transcript

1. "EWBODFE
   HVBSE
   PG
   DeallocationChecker 11/11 potatotips #66 taiki komaba(@r_plus)
2. UBJLJ
   LPNBCB
   !S@QMVT
3. DeallocationChecker HJUIVCDPNGBTUSFE%FBMMPDBUJPO$IFDLFS
   EJTQBUDI
   BGUFS
   <XFBL
   TFMG>
   ͯ͠TFMG͕ੜ͖࢒͍ͬͯΔ͔ʢϦʔ Ϋ͍ͯ͠Δ͔ʣνΣοΫͯ͠4*("#35౤͛ͯ͘ΕΔϝιουΛఏ ڙͯ͘͠ΕΔ
   viewDidDisappear(_:)
   ࣌ʹͦΕΛ࣮ߦ͢ΔͱϦʔΫνΣοΫग़དྷΔ
4. DeallocationChecker viewDidDisappear(_:)
   ࣌ʹͦΕΛ࣮ߦ͢ΔͱϦʔΫνΣοΫग़དྷΔ ˠνΣοΫ͍ͨ͠WJFX
   DPOUSPMMFSຖʹݸผʹ࣮ߦ͢Δඞཁ͕͋Δ
5. ΊΜͲ͍
6. ࣗಈνΣοΫ΁ J04%$ͷ
   !DPSJO
   ͞Μͷૉ੖Β͍͠-5ʮ໌೔͔Β࢖͑Δ 7JFX$POUSPMMFSͷ
   .FNPSZ
   -FBLݕग़ʯΛࢀর
   IUUQTTQFBLFSEFDLDPNDPSJOJPTEDNFNPSZMFBL
   ʮviewDidDisappear(_:)
   Λ.FUIPE
   4XJ[[MJOHͯ͠શͯͷWJFX
   DPOUSPMMFSΛࣗ ಈͰ%FBMMPDBUJPO$IFDLFSͷνΣοΫର৅ʹ͠Α͏ʂʯͱ͍͏࿩
7. White list view controllers Ͱ΋ɺେମ͍͔ͭ͘ྫ֎తͳWJFX
   DPOUSPMMFS͕ग़ͯ͘Δ
   ্λϒతͳ΍ͭͷWJFX
   DPOUSPMMFSͱ͔
   Α͘Θ͔ΒΜ4ZTUFN͕࢖ͬͯΔͬΆ͍6*,JUͷ΋ͷͱ͔
8. White list view controllers ˣͷ༷ʹνΣοΫલʹHVBSEΛೖΕΔ͜ͱʹͳΔ
9. ର৅͕૿͑Δ౓ λϒ͕૿͑Δ౓
   ʹϝϯς͢Δͷ͕ΊΜͲ͍
   ʢ௥Ճ͢Δͷ͕ɺͱ͍͏ΑΓ͸ͦΕΛઆ໌ͨ͠Γ
   ஌Βͳͯͭ͘·ͬͯ͠·͍ແବͳ࣌ؒΛ࢖Θͤͯ͠·ͬͨΓ͢Δࣄ͕ɻʣ
10. White list view controllers ͜ͷ΁ΜͷHVBSE
    XIJUF
    MJTU
    Λ͏·͍ࣄ΍Γ͍ͨ
    ΋ͷʹΑͬͯ͸QSPUPDPM࢖͏ํ๏΋͋Δ͚Ͳࠓճ͸ผख๏
11. "EWBODFE
    HVBSE
    PG
    DeallocationChecker
12. Pattern of white list λϒత7$ͷ࣮૷͸λϒ੾ସͯ͠΋࠶࡞੒͠ͳͯ͘ྑ͍༷ʹอ༗ͯ͠ Δˡ͜Ε͕νΣοΫʹͻ͔͔ͬΔݪҼͰ΋͋Δ
    େମͷ࣮૷͸DPOUBJOFS
    WJFX
    DPOUSPMMFSͷparent͕ࣗ෼Λอ༗ͯ͠ Δߏ੒
    $POUBJOFS
    WJFX
    DPOUSPMMFS͕ϦʔΫνΣοΫʹೖΔલʹparent͕ࣗ ෼Λอ༗͍ͯͨ͠Βର৅֎ʹ͍ͨ͠
    ͔͠͠ viewDidDisappear(_:)
    ͷͱ͖ʹ͸طʹparentϓϩύςΟ͸OJM
13. Pattern of white list ද͕ࣔ੾ΓସΘΔ࣌ʹparent͕ࣗ਎Λอ༗͍ͯ͠Δ͔อଘ͍ͨ͠
    ͦΕΛ΋ͬͯνΣοΫର৅֎ʹ͢Ε͹λϒͷ7$Λ໢ཏͰ͖Δ
14. Pattern of white list ද͕ࣔ੾ΓସΘΔ࣌ʹ parent͕OJMͰ͸ͳ͍λΠϛϯάͰ͋Δ
    removeFromParent(:_) ΛTXJ[[MF
    parent͕ࣗ਎Λอ༗͍ͯ͠Δ͔อଘ͍ͨ͠ Mirror
    
    objc_{get,set}AssociatedObject
15. Swizzle
16. objc_{get,set}AssociatedObject
17. Mirror parent
    QSPQFSUZͷܕ͸
    UIViewController? Ͱ͋ΔͷͰɺͲΜͳܗ ࣜͰTUPSFE
    QSPQFSUZʹอଘ͞Ε͍ͯΔ͔Θ͔Βͳ͍
    ͦ͜ͰMirrorΛར༻͠ϦϑϨΫγϣϯͰTUPSFE
    QSPQFSUZΛ૸ࠪ ͢Δ
18. Mirror ୯७ͳTUPSFE
    QSPQFSUZ
19. Mirror "SSBZͰอ༗ ͜Ε͕ຆͲ
20. Mirror %JDUͰอ༗ ݟͨ͜ͱͳ͍
21. Simplified guard Ҏ্Swizzling
    AssociatedObject
    MirrorͷͭΛ
    ૊Έ߹ΘͤΔͱʜ
22. Simplified guard ͜ͷHVBSEୡ͕ʜ
23. Simplified guard ߦͰεοΩϦʂλϒͷ૿ݮʹ΋ࣗಈతʹରԠ
24. Recap ▸ λϒతͳview controllerͰchild view controllerΛอ༗ ͯ͠Δέʔεʹ͓͍ͯɺλϒ੾ସ࣌ʹdeinit͞Ε͍ͯͳ ͍ͷ͸ϝϞϦϦʔΫͰ͸ͳ͍ʢద੾ʹͳ͍ͬͯΕ͹ʣ ▸ Swizzling, AssociatedObject, MirrorΛ૊Έ߹ΘͤΕ͹ parentͷܕ͕ෆ໌Ͱ΋stored propertyʹࣗ਎Λอ༗͠ ͍ͯΕ͹แׅతʹϦʔΫνΣοΫର৅֎ͱग़དྷΔ
25. ͓ΘΓ