private static void InvokeSecondPassWasm(uint idxStart, uint idxTryLandingStart, ref EHClauseIterator clauseIter, uint idxLimit, void *shadowStack)
{
uint lastTryStart = 0, lastTryEnd = 0;
// Search the clauses for one that contains the current offset.
RhEHClauseWasm ehClause = new RhEHClauseWasm();
for (uint curIdx = 0; clauseIter.Next(ref ehClause) && curIdx < idxLimit; curIdx++)
{
//
// Skip to the starting try region. This is used by collided unwinds and rethrows to pickup where
// the previous dispatch left off.
//
if (idxStart != MaxTryRegionIdx)
{
if (curIdx <= idxStart)
{
lastTryStart = ehClause._tryStartOffset;
lastTryEnd = ehClause._tryEndOffset;
continue;
}
// Now, we continue skipping while the try region is identical to the one that invoked the
// previous dispatch.
if ((ehClause._tryStartOffset == lastTryStart) && (ehClause._tryEndOffset == lastTryEnd))
{
continue;
}
// We are done skipping. This is required to handle empty finally block markers that are used
// to separate runs of different try blocks with same native code offsets.
idxStart = MaxTryRegionIdx;
}
EHClauseIterator.RhEHClauseKindWasm clauseKind = ehClause._clauseKind;
if ((clauseKind != EHClauseIterator.RhEHClauseKindWasm.RH_EH_CLAUSE_FAULT) ||
!ehClause.TryStartsAt(idxTryLandingStart))
{
continue;
}
// Found a containing clause. Because of the order of the clauses, we know this is the
// most containing.
// N.B. -- We need to suppress GC "in-between" calls to finallys in this loop because we do
// not have the correct next-execution point live on the stack and, therefore, may cause a GC
// hole if we allow a GC between invocation of finally funclets (i.e. after one has returned
// here to the dispatcher, but before the next one is invoked). Once they are running, it's
// fine for them to trigger a GC, obviously.
//
// As a result, RhpCallFinallyFunclet will set this state in the runtime upon return from the
// funclet, and we need to reset it if/when we fall out of the loop and we know that the
// method will no longer get any more GC callbacks.
byte *pFinallyHandler = ehClause._handlerAddress;
InternalCalls.RhpCallFinallyFunclet(pFinallyHandler, shadowStack);
}
}
private static void InvokeSecondPass(ref ExInfo exInfo, uint idxStart, uint idxLimit)
{
EHEnum ehEnum;
byte * pbMethodStartAddress;
if (!InternalCalls.RhpEHEnumInitFromStackFrameIterator(ref exInfo._frameIter, &pbMethodStartAddress, &ehEnum))
{
return;
}
byte *pbControlPC = exInfo._frameIter.ControlPC;
uint codeOffset = (uint)(pbControlPC - pbMethodStartAddress);
uint lastTryStart = 0, lastTryEnd = 0;
// Search the clauses for one that contains the current offset.
RhEHClause ehClause;
for (uint curIdx = 0; InternalCalls.RhpEHEnumNext(&ehEnum, &ehClause) && curIdx < idxLimit; curIdx++)
{
//
// Skip to the starting try region. This is used by collided unwinds and rethrows to pickup where
// the previous dispatch left off.
//
if (idxStart != MaxTryRegionIdx)
{
if (curIdx <= idxStart)
{
lastTryStart = ehClause._tryStartOffset; lastTryEnd = ehClause._tryEndOffset;
continue;
}
// Now, we continue skipping while the try region is identical to the one that invoked the
// previous dispatch.
if ((ehClause._tryStartOffset == lastTryStart) && (ehClause._tryEndOffset == lastTryEnd))
{
continue;
}
}
RhEHClauseKind clauseKind = ehClause._clauseKind;
if ((clauseKind != RhEHClauseKind.RH_EH_CLAUSE_FAULT) ||
!ehClause.ContainsCodeOffset(codeOffset))
{
continue;
}
// Found a containing clause. Because of the order of the clauses, we know this is the
// most containing.
// N.B. -- We need to suppress GC "in-between" calls to finallys in this loop because we do
// not have the correct next-execution point live on the stack and, therefore, may cause a GC
// hole if we allow a GC between invocation of finally funclets (i.e. after one has returned
// here to the dispatcher, but before the next one is invoked). Once they are running, it's
// fine for them to trigger a GC, obviously.
//
// As a result, RhpCallFinallyFunclet will set this state in the runtime upon return from the
// funclet, and we need to reset it if/when we fall out of the loop and we know that the
// method will no longer get any more GC callbacks.
byte *pFinallyHandler = ehClause._handlerAddress;
exInfo._idxCurClause = curIdx;
InternalCalls.RhpCallFinallyFunclet(pFinallyHandler, exInfo._frameIter.RegisterSet);
exInfo._idxCurClause = MaxTryRegionIdx;
}
}
