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Refactor the use of atomics in netmgr

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Now that everything runs on their own loop and we don't cross the thread
boundaries (with few exceptions), most of the atomic_bool variables used
to track the socket state have been unatomicized because they are always
accessed from the matching thread.

The remaining few have been relaxed: a) the sock->active is now using
acquire/release memory ordering; b) the various global limits are now
using relaxed memory ordering - we don't really care about the
synchronization for those.
This commit is contained in:
Ondřej Surý
2023-03-24 13:37:19 +01:00
parent ea8e00e7a5
commit e1a4572fd6
7 changed files with 243 additions and 281 deletions
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41
lib/isc/netmgr/tlsstream.c
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@@ -107,10 +107,10 @@ tls_try_to_enable_tcp_nodelay(isc_nmsocket_t *tlssock);
*/
static bool
inactive(isc_nmsocket_t *sock) {
return (!isc__nmsocket_active(sock) || atomic_load(&sock->closing) ||
return (!isc__nmsocket_active(sock) || sock->closing ||
sock->outerhandle == NULL ||
!isc__nmsocket_active(sock->outerhandle->sock) ||
atomic_load(&sock->outerhandle->sock->closing) ||
sock->outerhandle->sock->closing ||
(sock->listener != NULL &&
!isc__nmsocket_active(sock->listener)) ||
isc__nm_closing(sock->worker));
@@ -424,7 +424,7 @@ tls_try_handshake(isc_nmsocket_t *sock, isc_result_t *presult) {
if (isc__nm_closing(sock->worker)) {
result = ISC_R_SHUTTINGDOWN;
} else if (isc__nmsocket_closing(sock) ||
atomic_load(&sock->listener->closing))
sock->listener->closing)
{
result = ISC_R_CANCELED;
} else {
@@ -544,13 +544,13 @@ tls_do_bio(isc_nmsocket_t *sock, isc_region_t *received_data,
INSIST(SSL_is_init_finished(
sock->tlsstream.tls) ==
1);
INSIST(!atomic_load(&sock->client));
INSIST(!sock->client);
finish = true;
} else if (sock->tlsstream.state == TLS_IO &&
hs_result == ISC_R_SUCCESS &&
!sock->tlsstream.server)
{
INSIST(atomic_load(&sock->client));
INSIST(sock->client);
}
}
} else if (send_data != NULL) {
@@ -867,7 +867,7 @@ tlslisten_acceptcb(isc_nmhandle_t *handle, isc_result_t result, void *cbarg) {
isc_tlsctx_attach(tlsctx, &tlssock->tlsstream.ctx);
tlssock->tlsstream.tls = isc_tls_create(tlssock->tlsstream.ctx);
if (tlssock->tlsstream.tls == NULL) {
atomic_store(&tlssock->closed, true);
tlssock->closed = true;
isc_tlsctx_free(&tlssock->tlsstream.ctx);
isc__nmsocket_detach(&tlssock);
return (ISC_R_TLSERROR);
@@ -877,7 +877,7 @@ tlslisten_acceptcb(isc_nmhandle_t *handle, isc_result_t result, void *cbarg) {
isc_nmhandle_attach(handle, &tlssock->outerhandle);
tlssock->peer = handle->sock->peer;
tlssock->read_timeout =
atomic_load(&handle->sock->worker->netmgr->init);
atomic_load_relaxed(&handle->sock->worker->netmgr->init);
/*
* Hold a reference to tlssock in the TCP socket: it will
@@ -932,7 +932,7 @@ isc_nm_listentls(isc_nm_t *mgr, uint32_t workers, isc_sockaddr_t *iface,
result = isc_nm_listentcp(mgr, workers, iface, tlslisten_acceptcb,
tlssock, backlog, quota, &tlssock->outer);
if (result != ISC_R_SUCCESS) {
atomic_store(&tlssock->closed, true);
tlssock->closed = true;
isc__nmsocket_detach(&tlssock);
return (result);
}
@@ -945,7 +945,7 @@ isc_nm_listentls(isc_nm_t *mgr, uint32_t workers, isc_sockaddr_t *iface,
/* wait for listen result */
isc__nmsocket_attach(tlssock->outer, &tsock);
tlssock->result = result;
atomic_store(&tlssock->active, true);
atomic_store_release(&tlssock->active, true);
INSIST(tlssock->outer->tlsstream.tlslistener == NULL);
isc__nmsocket_attach(tlssock, &tlssock->outer->tlsstream.tlslistener);
isc__nmsocket_detach(&tsock);
@@ -956,7 +956,7 @@ isc_nm_listentls(isc_nm_t *mgr, uint32_t workers, isc_sockaddr_t *iface,
atomic_init(&tlssock->rchildren, tlssock->nchildren);
if (result == ISC_R_SUCCESS) {
atomic_store(&tlssock->listening, true);
tlssock->listening = true;
*sockp = tlssock;
}
@@ -1086,8 +1086,8 @@ tls_close_direct(void *arg) {
}
/* Further cleanup performed in isc__nm_tls_cleanup_data() */
atomic_store(&sock->closed, true);
atomic_store(&sock->active, false);
sock->closed = true;
atomic_store_release(&sock->active, false);
sock->tlsstream.state = TLS_CLOSED;
}
@@ -1095,12 +1095,9 @@ void
isc__nm_tls_close(isc_nmsocket_t *sock) {
REQUIRE(VALID_NMSOCK(sock));
REQUIRE(sock->type == isc_nm_tlssocket);
REQUIRE(!sock->closing);
if (!atomic_compare_exchange_strong(&sock->closing, &(bool){ false },
true))
{
return;
}
sock->closing = true;
if (sock->tid == isc_tid()) {
/* no point in attempting to make the call asynchronous */
@@ -1144,7 +1141,7 @@ isc_nm_tlsconnect(isc_nm_t *mgr, isc_sockaddr_t *local, isc_sockaddr_t *peer,
nsock->connect_cbarg = cbarg;
nsock->connect_timeout = timeout;
isc_tlsctx_attach(ctx, &nsock->tlsstream.ctx);
atomic_init(&nsock->client, true);
nsock->client = true;
if (client_sess_cache != NULL) {
INSIST(isc_tlsctx_client_session_cache_getctx(
client_sess_cache) == ctx);
@@ -1194,7 +1191,7 @@ tcp_connected(isc_nmhandle_t *handle, isc_result_t result, void *cbarg) {
}
tlssock->peer = isc_nmhandle_peeraddr(handle);
isc_nmhandle_attach(handle, &tlssock->outerhandle);
atomic_store(&tlssock->active, true);
atomic_store_release(&tlssock->active, true);
if (tlssock->tlsstream.client_sess_cache != NULL) {
isc_tlsctx_client_session_cache_reuse_sockaddr(
@@ -1215,7 +1212,7 @@ tcp_connected(isc_nmhandle_t *handle, isc_result_t result, void *cbarg) {
return;
error:
tlshandle = isc__nmhandle_get(tlssock, NULL, NULL);
atomic_store(&tlssock->closed, true);
tlssock->closed = true;
tls_call_connect_cb(tlssock, tlshandle, result);
isc_nmhandle_detach(&tlshandle);
isc__nmsocket_detach(&tlssock);
@@ -1246,7 +1243,7 @@ isc__nm_tls_cleanup_data(isc_nmsocket_t *sock) {
isc_tlsctx_free(&sock->tlsstream.ctx);
}
if (sock->tlsstream.client_sess_cache != NULL) {
INSIST(atomic_load(&sock->client));
INSIST(sock->client);
isc_tlsctx_client_session_cache_detach(
&sock->tlsstream.client_sess_cache);
}
@@ -1468,7 +1465,7 @@ tls_keep_client_tls_session(isc_nmsocket_t *sock) {
if (sock->tlsstream.client_sess_cache != NULL &&
sock->tlsstream.client_session_saved == false)
{
INSIST(atomic_load(&sock->client));
INSIST(sock->client);
isc_tlsctx_client_session_cache_keep_sockaddr(
sock->tlsstream.client_sess_cache, &sock->peer,
sock->tlsstream.tls);