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ircd:Ⓜ️:vm: Add inner lock around write commitment.

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This commit is contained in:
Jason Volk 2019-09-08 18:11:45 -07:00
parent c01a816582
commit a35328f384
3 changed files with 22 additions and 8 deletions
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1
include/ircd/m/vm.h
View file

@ -37,6 +37,7 @@ namespace ircd::m::vm
namespace ircd::m::vm::sequence namespace ircd::m::vm::sequence
{ {
extern ctx::dock dock; extern ctx::dock dock;
extern ctx::mutex mutex;
extern uint64_t retired; // already written; always monotonic extern uint64_t retired; // already written; always monotonic
extern uint64_t committed; // pending write; usually monotonic extern uint64_t committed; // pending write; usually monotonic
extern uint64_t uncommitted; // evaluating; not monotonic extern uint64_t uncommitted; // evaluating; not monotonic

3
ircd/m.cc
View file

@ -1536,6 +1536,9 @@ ircd::m::vm::eval::operator()(const event &event)
// sequence // sequence
// //
decltype(ircd::m::vm::sequence::mutex)
ircd::m::vm::sequence::mutex;
decltype(ircd::m::vm::sequence::dock) decltype(ircd::m::vm::sequence::dock)
ircd::m::vm::sequence::dock; ircd::m::vm::sequence::dock;

26
modules/m_vm.cc
View file

@ -868,13 +868,7 @@ ircd::m::vm::execute_pdu(eval &eval,
at<"type"_>(event) at<"type"_>(event)
}; };
const bool already_exists if(m::exists(event_id) && !opts.replays)
{
exists(event_id)
};
//TODO: ABA
if(already_exists && !opts.replays)
throw error throw error
{ {
fault::EXISTS, "Event has already been evaluated." fault::EXISTS, "Event has already been evaluated."
@ -954,7 +948,20 @@ ircd::m::vm::execute_pdu(eval &eval,
// Commit the transaction to database iff this eval is at the stack base. // Commit the transaction to database iff this eval is at the stack base.
if(opts.write && !eval.sequence_shared[0]) if(opts.write && !eval.sequence_shared[0])
{
const std::lock_guard lock
{
sequence::mutex
};
if(m::exists(event_id) && !opts.replays)
throw error
{
fault::EXISTS, "Write commit rejected :Event has already been evaluated."
};
write_commit(eval); write_commit(eval);
}
// Wait for sequencing only if this is the stack base, otherwise we'll // Wait for sequencing only if this is the stack base, otherwise we'll
// never return back to that stack base. // never return back to that stack base.
@ -1106,7 +1113,10 @@ ircd::m::vm::write_commit(eval &eval)
assert(eval.txn); assert(eval.txn);
assert(eval.txn.use_count() == 1); assert(eval.txn.use_count() == 1);
assert(eval.sequence_shared[0] == 0); assert(eval.sequence_shared[0] == 0);
auto &txn(*eval.txn); auto &txn
{
*eval.txn
};
#ifdef RB_DEBUG #ifdef RB_DEBUG
const auto db_seq_before(db::sequence(*m::dbs::events)); const auto db_seq_before(db::sequence(*m::dbs::events));