Commit 35c57a98 authored by Paul Bone's avatar Paul Bone
Browse files

Bug 1540670 - Forbid a nursery size of 0 r=jonco 

The nursery uses capacity_ == 0 to determine if it is disabled.  This patch
avoids setting the capacity to zero by requring the minimum size to be at
least ArenaSize (usually 1 page).

Differential Revision: https://phabricator.services.mozilla.com/D25717

--HG--
extra : moz-landing-system : lando
parent 1c472b4e

js/src/gc/GC.cpp

+2 −1
Original line number Diff line number Diff line
@@ -1403,7 +1403,8 @@ bool GCSchedulingTunables::setParameter(JSGCParamKey key, uint32_t value, 
      gcMaxBytes_ = value;

      break;

    case JSGC_MIN_NURSERY_BYTES:

      if (value > gcMaxNurseryBytes_ && gcMaxNurseryBytes_ != 0) {

      if ((value > gcMaxNurseryBytes_ && gcMaxNurseryBytes_ != 0) ||

          value < ArenaSize) {

        // We make an exception for gcMaxNurseryBytes_ == 0 since that special

        // value is used to disable generational GC.

        return false;

js/src/gc/Nursery.cpp

+5 −0
Original line number Diff line number Diff line
@@ -143,6 +143,7 @@ bool js::Nursery::init(uint32_t maxNurseryBytes, AutoLockGCBgAlloc& lock) { 
    return false;

  }

  capacity_ = roundSize(tunables().gcMinNurseryBytes());

  MOZ_ASSERT(capacity_ >= ArenaSize);

  /* After this point the Nursery has been enabled */



  setCurrentChunk(0, true);
@@ -195,6 +196,7 @@ void js::Nursery::enable() { 
      return;

    }

    capacity_ = roundSize(tunables().gcMinNurseryBytes());

    MOZ_ASSERT(capacity_ >= ArenaSize);

  }



  setCurrentChunk(0, true);
@@ -1193,6 +1195,7 @@ void js::Nursery::maybeResizeNursery(JS::GCReason reason) { 
  size_t newCapacity = size_t(float(capacity()) * factor);



  const size_t minNurseryBytes = roundSize(tunables().gcMinNurseryBytes());

  MOZ_ASSERT(minNurseryBytes >= ArenaSize);



  // If one of these conditions is true then we always shrink or grow the

  // nursery.  This way the thresholds still have an effect even if the goal
@@ -1252,6 +1255,7 @@ bool js::Nursery::maybeResizeExact(JS::GCReason reason) { 
  }



  const size_t minNurseryBytes = roundSize(tunables().gcMinNurseryBytes());

  MOZ_ASSERT(minNurseryBytes >= ArenaSize);



  if (minNurseryBytes > capacity()) {

    /*
@@ -1317,6 +1321,7 @@ void js::Nursery::shrinkAllocableSpace(size_t newCapacity) { 
  }



  capacity_ = newCapacity;

  MOZ_ASSERT(capacity_ >= ArenaSize);

  setCurrentEnd();

}