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Cache session/[{cursor, config}] for reuse and spawn threads when needed. #9

Merged
gburd merged 30 commits from gsb-ctx-cache into master 2013-07-03 12:31:15 +00:00
Conversation 0 Commits 30 Files changed 18 +59 -55
3 changed files with 59 additions and 55 deletions
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Showing only changes of commit 0f180a6531 - Show all commits

37
c_src/wterl.c
View file

@ -46,8 +46,8 @@ struct wterl_ctx {
uint64_t sig;
size_t sig_len;
WT_SESSION *session;
const char *session_config;
uint32_t num_cursors;
const char *session_config;
struct cursor_info {
const char *uri;
const char *config;
@ -127,7 +127,7 @@ __str_hash(uint32_t in, const char *p, size_t len)
{
uint32_t h = in;
for (++p ; len > 0; ++p, --len)
h += (h << 5) + (h >> 27) + *p;
h += (h << 5) + (h >> 27) + *p;
return h;
}
@ -191,13 +191,16 @@ static inline uint32_t __log2(uint64_t x) {
static int
__ctx_cache_evict(WterlConnHandle *conn_handle)
{
uint32_t mean, log, num_evicted, i;
uint64_t now, elapsed;
struct wterl_ctx *c, *n;
uint32_t num_evicted = 0;
struct wterl_ctx *c;
if (conn_handle->cache_size < MAX_CACHE_SIZE)
return 0;
#if 0 // TODO: fixme once stats work again
uint32_t mean, log, num_evicted, i;
uint64_t now, elapsed;
struct wterl_ctx *c, *n;
now = cpu_clock_ticks();
// Find the mean of the recorded times that items stayed in cache.
@ -230,6 +233,16 @@ __ctx_cache_evict(WterlConnHandle *conn_handle)
}
c = n;
}
#else
c = STAILQ_FIRST(&conn_handle->cache);
if (c) {
STAILQ_REMOVE(&conn_handle->cache, c, wterl_ctx, entries);
DPRINTF("evicting: %llu", PRIuint64(c->sig));
c->session->close(c->session, NULL);
enif_free(c);
num_evicted++;
}
#endif
conn_handle->cache_size -= num_evicted;
return num_evicted;
}
@ -246,22 +259,20 @@ __ctx_cache_evict(WterlConnHandle *conn_handle)
static struct wterl_ctx *
__ctx_cache_find(WterlConnHandle *conn_handle, const uint64_t sig)
{
struct wterl_ctx *c, *n;
struct wterl_ctx *c;
enif_mutex_lock(conn_handle->cache_mutex);
c = STAILQ_FIRST(&conn_handle->cache);
while (c != NULL) {
n = STAILQ_NEXT(c, entries);
if (c->sig == sig) { // TODO: hash collisions *will* lead to SEGVs
// cache hit:
STAILQ_REMOVE_HEAD(&conn_handle->cache, entries);
STAILQ_REMOVE(&conn_handle->cache, c, wterl_ctx, entries);
conn_handle->histogram[__log2(cpu_clock_ticks() - c->tstamp)]++;
conn_handle->histogram_count++;
conn_handle->cache_size -= 1;
break;
} else {
c = n;
}
c = STAILQ_NEXT(c, entries);
}
enif_mutex_unlock(conn_handle->cache_mutex);
return c;
@ -369,7 +380,6 @@ __retain_ctx(WterlConnHandle *conn_handle, uint32_t worker_id,
*ctx = NULL;
do {
WMB_NEAR_CAS();
c = conn_handle->mru_ctx[worker_id];
if (CASPO(&conn_handle->mru_ctx[worker_id], c, 0) == c) {
if (c == 0) {
@ -457,7 +467,6 @@ __release_ctx(WterlConnHandle *conn_handle, uint32_t worker_id, struct wterl_ctx
cursor->reset(cursor);
}
WMB_NEAR_CAS();
c = conn_handle->mru_ctx[worker_id];
if (CASPO(&conn_handle->mru_ctx[worker_id], c, ctx) != c) {
__ctx_cache_add(conn_handle, ctx);
@ -486,7 +495,6 @@ __close_all_sessions(WterlConnHandle *conn_handle)
// clear out the mru
for (worker_id = 0; worker_id < ASYNC_NIF_MAX_WORKERS; worker_id++) {
do {
WMB_NEAR_CAS();
c = conn_handle->mru_ctx[worker_id];
} while(CASPO(&conn_handle->mru_ctx[worker_id], c, 0) != c);
@ -521,7 +529,6 @@ __close_cursors_on(WterlConnHandle *conn_handle, const char *uri)
// walk the mru first, look for open cursors on matching uri
for (worker_id = 0; worker_id < ASYNC_NIF_MAX_WORKERS; worker_id++) {
WMB_NEAR_CAS();
c = conn_handle->mru_ctx[worker_id];
if (CASPO(&conn_handle->mru_ctx[worker_id], c, 0) == c && c != 0) {
cnt = c->num_cursors;
@ -691,6 +698,7 @@ __strerror_term(ErlNifEnv* env, int rc)
and/or may be localized to any given language (i18n). Use the errno
atom rather than the message when matching in Erlang. You've been
warned. */
DPRINTF("error: %s", erl_errno_id(rc));
return enif_make_tuple2(env, ATOM_ERROR,
enif_make_tuple2(env,
enif_make_atom(env, erl_errno_id(rc)),
@ -1861,6 +1869,7 @@ ASYNC_NIF_DECL(
WT_CURSOR* cursor = args->cursor_handle->cursor;
ASYNC_NIF_REPLY(__cursor_value_ret(env, cursor, cursor->next(cursor)));
DPRINTF("env: %p cursor: %p", env, cursor);
},
{ // post

76
src/riak_kv_wterl_backend.erl
View file

@ -52,9 +52,7 @@
-record(state, {table :: string(),
type :: string(),
connection :: wterl:connection(),
is_empty_cursor :: wterl:cursor(),
status_cursor :: wterl:cursor()}).
connection :: wterl:connection()}).
-type state() :: #state{}.
-type config() :: [{atom(), term()}].
@ -135,15 +133,8 @@ start(Partition, Config) ->
end,
case wterl:create(Connection, Table, TableOpts) of
ok ->
case establish_utility_cursors(Connection, Table) of
{ok, IsEmptyCursor, StatusCursor} ->
{ok, #state{table=Table, type=Type,
connection=Connection,
is_empty_cursor=IsEmptyCursor,
status_cursor=StatusCursor}};
{error, Reason2} ->
{error, Reason2}
end;
{ok, #state{table=Table, type=Type,
connection=Connection}};
{error, Reason3} ->
{error, Reason3}
end
@ -329,25 +320,42 @@ drop(#state{connection=Connection, table=Table}=State) ->
%% @doc Returns true if this wterl backend contains any
%% non-tombstone values; otherwise returns false.
-spec is_empty(state()) -> boolean().
is_empty(#state{is_empty_cursor=Cursor}) ->
wterl:cursor_reset(Cursor),
case wterl:cursor_next(Cursor) of
not_found -> true;
{error, {eperm, _}} -> false; % TODO: review/fix this logic
_ -> false
is_empty(#state{connection=Connection, table=Table}) ->
case wterl:cursor_open(Connection, Table) of
{ok, Cursor} ->
IsEmpty =
case wterl:cursor_next(Cursor) of
not_found ->
true;
{error, {eperm, _}} ->
false; % TODO: review/fix this logic
_ ->
false
end,
wterl:cursor_close(Cursor),
IsEmpty;
{error, Reason2} ->
{error, Reason2}
end.
%% @doc Get the status information for this wterl backend
-spec status(state()) -> [{atom(), term()}].
status(#state{status_cursor=Cursor}) ->
wterl:cursor_reset(Cursor),
case fetch_status(Cursor) of
{ok, Stats} ->
Stats;
{error, {eperm, _}} -> % TODO: review/fix this logic
{ok, []};
_ ->
{ok, []}
status(#state{connection=Connection, table=Table}) ->
case wterl:cursor_open(Connection, Table) of
{ok, Cursor} ->
TheStats =
case fetch_status(Cursor) of
{ok, Stats} ->
Stats;
{error, {eperm, _}} -> % TODO: review/fix this logic
{ok, []};
_ ->
{ok, []}
end,
wterl:cursor_close(Cursor),
TheStats;
{error, Reason2} ->
{error, Reason2}
end.
%% @doc Register an asynchronous callback
@ -373,20 +381,6 @@ max_sessions(Config) ->
false -> Est
end.
%% @private
establish_utility_cursors(Connection, Table) ->
case wterl:cursor_open(Connection, Table) of
{ok, IsEmptyCursor} ->
case wterl:cursor_open(Connection, "statistics:" ++ Table, [{statistics_fast, true}]) of
{ok, StatusCursor} ->
{ok, IsEmptyCursor, StatusCursor};
{error, Reason1} ->
{error, Reason1}
end;
{error, Reason2} ->
{error, Reason2}
end.
%% @private
establish_connection(Config, Type) ->
%% Get the data root directory

1
src/wterl.erl
View file

@ -95,6 +95,7 @@ nif_stub_error(Line) ->
-spec init() -> ok | {error, any()}.
init() ->
Module <- [wterl, wterl_conn, wterl_app, wterl_sup, wterl_ets, riak_kv_wiredtiger_backend, temp_riak_kv_backend]],
erlang:load_nif(filename:join([priv_dir(), atom_to_list(?MODULE)]),
[{wterl_vsn, "53307e8"},
{wiredtiger_vsn, "1.6.2-0-g07cb0a5"}]).