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reader_concurrency_semaphore: get rid of struct permit_list

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struct permit_list exists so the intrusive list declaration which needs
the definition of reader_permit can be hidden in the .cc. But it turns
out that if the hook type is fully spelled out, the intrusive list
declaration doesn't need T to be defined. Exploit this to get rid of
this extra indirection.

Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20210720073121.63027-2-bdenes@scylladb.com>
This commit is contained in:
Botond Dénes
2021-07-20 10:31:21 +03:00
committed by Avi Kivity
parent 11b39cbc23
commit 8fc55fa5bf
2 changed files with 13 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
reader_concurrency_semaphore.cc
View File

@@ -303,12 +303,6 @@ public:
}
};
struct reader_concurrency_semaphore::permit_list {
using list_type = boost::intrusive::list<reader_permit::impl, boost::intrusive::constant_time_size<false>>;
list_type permits;
};
reader_permit::reader_permit(shared_ptr<impl> impl) : _impl(std::move(impl))
{
}
@@ -494,10 +488,10 @@ static permit_stats do_dump_reader_permit_diagnostics(std::ostream& os, const pe
}
static void do_dump_reader_permit_diagnostics(std::ostream& os, const reader_concurrency_semaphore& semaphore,
const reader_concurrency_semaphore::permit_list& list, std::string_view problem, unsigned max_lines = 20) {
const reader_concurrency_semaphore::permit_list_type& list, std::string_view problem, unsigned max_lines = 20) {
permit_groups permits;
for (const auto& permit : list.permits) {
for (const auto& permit : list) {
permits[permit_group_key(permit.get_schema(), permit.get_op_name(), permit.get_state())].add(permit);
}
@@ -515,7 +509,7 @@ static void do_dump_reader_permit_diagnostics(std::ostream& os, const reader_con
fmt::print(os, "Total: {} permits with {} count and {} memory resources\n", total.permits, total.resources.count, utils::to_hr_size(total.resources.memory));
}
static void maybe_dump_reader_permit_diagnostics(const reader_concurrency_semaphore& semaphore, const reader_concurrency_semaphore::permit_list& list,
static void maybe_dump_reader_permit_diagnostics(const reader_concurrency_semaphore& semaphore, const reader_concurrency_semaphore::permit_list_type& list,
std::string_view problem) {
static thread_local logger::rate_limit rate_limit(std::chrono::seconds(30));
@@ -531,7 +525,7 @@ static void maybe_dump_reader_permit_diagnostics(const reader_concurrency_semaph
void reader_concurrency_semaphore::expiry_handler::operator()(entry& e) noexcept {
e.pr.set_exception(named_semaphore_timed_out(_semaphore._name));
maybe_dump_reader_permit_diagnostics(_semaphore, *_semaphore._permit_list, "timed out");
maybe_dump_reader_permit_diagnostics(_semaphore, _semaphore._permit_list, "timed out");
}
reader_concurrency_semaphore::inactive_read::~inactive_read() {
@@ -595,7 +589,7 @@ reader_concurrency_semaphore::reader_concurrency_semaphore(int count, ssize_t me
, _ready_list(max_queue_length)
, _name(std::move(name))
, _max_queue_length(max_queue_length)
, _permit_list(std::make_unique<permit_list>()) {}
{ }
reader_concurrency_semaphore::reader_concurrency_semaphore(no_limits, sstring name)
: reader_concurrency_semaphore(
@@ -773,7 +767,7 @@ bool reader_concurrency_semaphore::all_used_permits_are_stalled() const {
std::exception_ptr reader_concurrency_semaphore::check_queue_size(std::string_view queue_name) {
if ((_wait_list.size() + _ready_list.size()) >= _max_queue_length) {
_stats.total_reads_shed_due_to_overload++;
maybe_dump_reader_permit_diagnostics(*this, *_permit_list, fmt::format("{} queue overload", queue_name));
maybe_dump_reader_permit_diagnostics(*this, _permit_list, fmt::format("{} queue overload", queue_name));
return std::make_exception_ptr(std::runtime_error(format("{}: {} queue overload", _name, queue_name)));
}
return {};
@@ -849,7 +843,7 @@ void reader_concurrency_semaphore::maybe_admit_waiters() noexcept {
void reader_concurrency_semaphore::on_permit_created(reader_permit::impl& permit) {
_permit_gate.enter();
_permit_list->permits.push_back(permit);
_permit_list.push_back(permit);
++_stats.total_permits;
++_stats.current_permits;
}
@@ -933,7 +927,7 @@ void reader_concurrency_semaphore::broken(std::exception_ptr ex) {
std::string reader_concurrency_semaphore::dump_diagnostics(unsigned max_lines) const {
std::ostringstream os;
do_dump_reader_permit_diagnostics(os, *this, *_permit_list, "user request", max_lines);
do_dump_reader_permit_diagnostics(os, *this, _permit_list, "user request", max_lines);
return os.str();
}

7
reader_concurrency_semaphore.hh
View File

@@ -96,7 +96,10 @@ public:
uint64_t blocked_permits = 0;
};
struct permit_list;
using permit_list_type = bi::list<
reader_permit::impl,
bi::base_hook<bi::list_base_hook<bi::link_mode<bi::auto_unlink>>>,
bi::constant_time_size<false>>;
class inactive_read_handle;
@@ -188,7 +191,7 @@ private:
size_t _max_queue_length = std::numeric_limits<size_t>::max();
inactive_reads_type _inactive_reads;
stats _stats;
std::unique_ptr<permit_list> _permit_list;
permit_list_type _permit_list;
bool _stopped = false;
gate _close_readers_gate;
gate _permit_gate;