Fix lock acquisition in shared memory functions

This commit is contained in:
Ian Barwick
2017-11-08 11:55:08 +09:00
parent 97471626b4
commit 4ef2b111da

View File

@@ -232,7 +232,7 @@ set_local_node_id(PG_FUNCTION_ARGS)
if (!shared_state) if (!shared_state)
PG_RETURN_NULL(); PG_RETURN_NULL();
LWLockAcquire(shared_state->lock, LW_SHARED); LWLockAcquire(shared_state->lock, LW_EXCLUSIVE);
/* only set local_node_id once, as it should never change */ /* only set local_node_id once, as it should never change */
if (shared_state->local_node_id == UNKNOWN_NODE_ID) if (shared_state->local_node_id == UNKNOWN_NODE_ID)
@@ -254,7 +254,7 @@ standby_set_last_updated(PG_FUNCTION_ARGS)
if (!shared_state) if (!shared_state)
PG_RETURN_NULL(); PG_RETURN_NULL();
LWLockAcquire(shared_state->lock, LW_SHARED); LWLockAcquire(shared_state->lock, LW_EXCLUSIVE);
shared_state->last_updated = last_updated; shared_state->last_updated = last_updated;
LWLockRelease(shared_state->lock); LWLockRelease(shared_state->lock);
@@ -272,7 +272,7 @@ standby_get_last_updated(PG_FUNCTION_ARGS)
if (!shared_state) if (!shared_state)
PG_RETURN_NULL(); PG_RETURN_NULL();
LWLockAcquire(shared_state->lock, LW_EXCLUSIVE); LWLockAcquire(shared_state->lock, LW_SHARED);
last_updated = shared_state->last_updated; last_updated = shared_state->last_updated;
LWLockRelease(shared_state->lock); LWLockRelease(shared_state->lock);
@@ -372,6 +372,9 @@ request_vote(PG_FUNCTION_ARGS)
elog(DEBUG1, "our LSN is %s", lsn_text); elog(DEBUG1, "our LSN is %s", lsn_text);
#endif #endif
LWLockRelease(shared_state->lock);
LWLockAcquire(shared_state->lock, LW_EXCLUSIVE);
/* indicate this node has responded to a vote request */ /* indicate this node has responded to a vote request */
shared_state->voting_status = VS_VOTE_REQUEST_RECEIVED; shared_state->voting_status = VS_VOTE_REQUEST_RECEIVED;
shared_state->current_electoral_term = current_electoral_term; shared_state->current_electoral_term = current_electoral_term;
@@ -427,6 +430,9 @@ set_voting_status_initiated(PG_FUNCTION_ARGS)
/* only do something if local_node_id is initialised */ /* only do something if local_node_id is initialised */
if (shared_state->local_node_id != UNKNOWN_NODE_ID) if (shared_state->local_node_id != UNKNOWN_NODE_ID)
{ {
LWLockRelease(shared_state->lock);
LWLockAcquire(shared_state->lock, LW_EXCLUSIVE);
shared_state->voting_status = VS_VOTE_INITIATED; shared_state->voting_status = VS_VOTE_INITIATED;
shared_state->current_electoral_term += 1; shared_state->current_electoral_term += 1;
@@ -469,6 +475,8 @@ other_node_is_candidate(PG_FUNCTION_ARGS)
} }
} }
LWLockRelease(shared_state->lock);
LWLockAcquire(shared_state->lock, LW_EXCLUSIVE);
shared_state->candidate_node_id = requesting_node_id; shared_state->candidate_node_id = requesting_node_id;
elog(INFO, "node %i is candidate", requesting_node_id); elog(INFO, "node %i is candidate", requesting_node_id);
} }
@@ -499,6 +507,8 @@ notify_follow_primary(PG_FUNCTION_ARGS)
shared_state->local_node_id, shared_state->local_node_id,
primary_node_id); primary_node_id);
LWLockRelease(shared_state->lock);
LWLockAcquire(shared_state->lock, LW_EXCLUSIVE);
/* Explicitly set the primary node id */ /* Explicitly set the primary node id */
shared_state->candidate_node_id = primary_node_id; shared_state->candidate_node_id = primary_node_id;
shared_state->follow_new_primary = true; shared_state->follow_new_primary = true;
@@ -542,6 +552,9 @@ reset_voting_status(PG_FUNCTION_ARGS)
/* only do something if local_node_id is initialised */ /* only do something if local_node_id is initialised */
if (shared_state->local_node_id != UNKNOWN_NODE_ID) if (shared_state->local_node_id != UNKNOWN_NODE_ID)
{ {
LWLockRelease(shared_state->lock);
LWLockAcquire(shared_state->lock, LW_EXCLUSIVE);
shared_state->voting_status = VS_NO_VOTE; shared_state->voting_status = VS_NO_VOTE;
shared_state->candidate_node_id = UNKNOWN_NODE_ID; shared_state->candidate_node_id = UNKNOWN_NODE_ID;
shared_state->follow_new_primary = false; shared_state->follow_new_primary = false;
@@ -566,6 +579,8 @@ am_bdr_failover_handler(PG_FUNCTION_ARGS)
if (shared_state->bdr_failover_handler == UNKNOWN_NODE_ID) if (shared_state->bdr_failover_handler == UNKNOWN_NODE_ID)
{ {
LWLockRelease(shared_state->lock);
LWLockAcquire(shared_state->lock, LW_EXCLUSIVE);
shared_state->bdr_failover_handler = node_id; shared_state->bdr_failover_handler = node_id;
am_handler = true; am_handler = true;
} }
@@ -586,11 +601,16 @@ unset_bdr_failover_handler(PG_FUNCTION_ARGS)
if (!shared_state) if (!shared_state)
PG_RETURN_NULL(); PG_RETURN_NULL();
LWLockAcquire(shared_state->lock, LW_SHARED);
/* only do something if local_node_id is initialised */ /* only do something if local_node_id is initialised */
if (shared_state->local_node_id != UNKNOWN_NODE_ID) if (shared_state->local_node_id != UNKNOWN_NODE_ID)
{ {
LWLockAcquire(shared_state->lock, LW_SHARED); LWLockRelease(shared_state->lock);
LWLockAcquire(shared_state->lock, LW_EXCLUSIVE);
shared_state->bdr_failover_handler = UNKNOWN_NODE_ID; shared_state->bdr_failover_handler = UNKNOWN_NODE_ID;
LWLockRelease(shared_state->lock); LWLockRelease(shared_state->lock);
} }