bool JSStack::growSlowCase(Register* newTopOfStack)
{
Register* newTopOfStackWithReservedZone = newTopOfStack - m_reservedZoneSizeInRegisters;
// If we have already committed enough memory to satisfy this request,
// just update the end pointer and return.
if (newTopOfStackWithReservedZone >= m_commitTop) {
setStackLimit(newTopOfStack);
return true;
}
// Compute the chunk size of additional memory to commit, and see if we
// have it is still within our budget. If not, we'll fail to grow and
// return false.
ptrdiff_t delta = reinterpret_cast<char*>(m_commitTop) - reinterpret_cast<char*>(newTopOfStackWithReservedZone);
delta = WTF::roundUpToMultipleOf(commitSize, delta);
Register* newCommitTop = m_commitTop - (delta / sizeof(Register));
if (newCommitTop < reservationTop())
return false;
// Otherwise, the growth is still within our budget. Go ahead and commit
// it and return true.
m_reservation.commit(newCommitTop, delta);
addToCommittedByteCount(delta);
m_commitTop = newCommitTop;
setStackLimit(newTopOfStack);
return true;
}
int
main(int argc, char *argv[]) {
int newlim = argc > 1 ? atoi(argv[1]) : 10;
printf("%d\n", getThreadLimit());
setThreadLimit(newlim);
printf("%d\n", getThreadLimit());
newlim = argc > 2 ? atoi(argv[2]) : 10;
printf("%d\n", getStackLimit());
setStackLimit(newlim);
printf("%d\n", getStackLimit());
return 0;
}
JSStack::JSStack(VM& vm)
: m_vm(vm)
, m_topCallFrame(vm.topCallFrame)
#if ENABLE(LLINT_C_LOOP)
, m_end(0)
, m_reservedZoneSizeInRegisters(0)
#endif
{
#if ENABLE(LLINT_C_LOOP)
size_t capacity = Options::maxPerThreadStackUsage();
ASSERT(capacity && isPageAligned(capacity));
m_reservation = PageReservation::reserve(WTF::roundUpToMultipleOf(commitSize, capacity), OSAllocator::JSVMStackPages);
setStackLimit(highAddress());
m_commitTop = highAddress();
m_lastStackTop = baseOfStack();
#endif // ENABLE(LLINT_C_LOOP)
m_topCallFrame = 0;
}
