From e2ab7ffd894a44d836019c62710c20c7ef5852b3 Mon Sep 17 00:00:00 2001
From: ranshid <88133677+ranshid@users.noreply.github.com>
Date: Tue, 20 Aug 2024 13:54:53 +0300
Subject: [PATCH] Make use of a single listNode pointer for blocking utility
lists (#919)
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Saves some memory (one pointer) in the client struct.
Since a client cannot be blocked multiple times, we can assume
it will be held in only one extra utility list, so it is ok to maintain
a union of these listNode references.
Signed-off-by: Ran Shidlansik <ranshid@amazon.com>
Signed-off-by: ranshid <88133677+ranshid@users.noreply.github.com>
Signed-off-by: Binbin <binloveplay1314@qq.com>
Co-authored-by: Viktor Söderqvist <viktor.soderqvist@est.tech>
Co-authored-by: Binbin <binloveplay1314@qq.com>
---
src/blocked.c | 10 ++++++----
src/networking.c | 1 -
src/server.h | 16 +++++++++++-----
3 files changed, 17 insertions(+), 10 deletions(-)
diff --git a/src/blocked.c b/src/blocked.c
index 5f3d8bf50..8e1974a70 100644
--- a/src/blocked.c
+++ b/src/blocked.c
@@ -81,7 +81,7 @@ void initClientBlockingState(client *c) {
c->bstate.numreplicas = 0;
c->bstate.numlocal = 0;
c->bstate.reploffset = 0;
- c->bstate.client_waiting_acks_list_node = NULL;
+ c->bstate.generic_blocked_list_node = NULL;
c->bstate.module_blocked_handle = NULL;
c->bstate.async_rm_call_handle = NULL;
}
@@ -194,8 +194,9 @@ void unblockClient(client *c, int queue_for_reprocessing) {
if (moduleClientIsBlockedOnKeys(c)) unblockClientWaitingData(c);
unblockClientFromModule(c);
} else if (c->bstate.btype == BLOCKED_POSTPONE) {
- listDelNode(server.postponed_clients, c->postponed_list_node);
- c->postponed_list_node = NULL;
+ serverAssert(c->bstate.postponed_list_node);
+ listDelNode(server.postponed_clients, c->bstate.postponed_list_node);
+ c->bstate.postponed_list_node = NULL;
} else if (c->bstate.btype == BLOCKED_SHUTDOWN) {
/* No special cleanup. */
} else {
@@ -613,7 +614,8 @@ void blockPostponeClient(client *c) {
c->bstate.timeout = 0;
blockClient(c, BLOCKED_POSTPONE);
listAddNodeTail(server.postponed_clients, c);
- c->postponed_list_node = listLast(server.postponed_clients);
+ serverAssert(c->bstate.postponed_list_node == NULL);
+ c->bstate.postponed_list_node = listLast(server.postponed_clients);
/* Mark this client to execute its command */
c->flag.pending_command = 1;
}
diff --git a/src/networking.c b/src/networking.c
index 8b6974353..27d81da49 100644
--- a/src/networking.c
+++ b/src/networking.c
@@ -212,7 +212,6 @@ client *createClient(connection *conn) {
c->peerid = NULL;
c->sockname = NULL;
c->client_list_node = NULL;
- c->postponed_list_node = NULL;
c->io_read_state = CLIENT_IDLE;
c->io_write_state = CLIENT_IDLE;
c->nwritten = 0;
diff --git a/src/server.h b/src/server.h
index 9dd7f8fef..7fb7b2a4e 100644
--- a/src/server.h
+++ b/src/server.h
@@ -1010,15 +1010,22 @@ typedef struct blockingState {
* is > timeout then the operation timed out. */
int unblock_on_nokey; /* Whether to unblock the client when at least one of the keys
is deleted or does not exist anymore */
+ union {
+ listNode *client_waiting_acks_list_node; /* list node in server.clients_waiting_acks list. */
+ listNode *postponed_list_node; /* list node in server.postponed_clients */
+ listNode *generic_blocked_list_node; /* generic placeholder for blocked clients utility lists.
+ Since a client cannot be blocked multiple times, we can assume
+ it will be held in only one extra utility list, so it is ok to maintain
+ a union of these listNode references. */
+ };
/* BLOCKED_LIST, BLOCKED_ZSET and BLOCKED_STREAM or any other Keys related blocking */
dict *keys; /* The keys we are blocked on */
/* BLOCKED_WAIT and BLOCKED_WAITAOF */
- int numreplicas; /* Number of replicas we are waiting for ACK. */
- int numlocal; /* Indication if WAITAOF is waiting for local fsync. */
- long long reploffset; /* Replication offset to reach. */
- listNode *client_waiting_acks_list_node; /* list node in server.clients_waiting_acks list. */
+ int numreplicas; /* Number of replicas we are waiting for ACK. */
+ int numlocal; /* Indication if WAITAOF is waiting for local fsync. */
+ long long reploffset; /* Replication offset to reach. */
/* BLOCKED_MODULE */
void *module_blocked_handle; /* ValkeyModuleBlockedClient structure.
@@ -1321,7 +1328,6 @@ typedef struct client {
sds peerid; /* Cached peer ID. */
sds sockname; /* Cached connection target address. */
listNode *client_list_node; /* list node in client list */
- listNode *postponed_list_node; /* list node within the postponed list */
void *module_blocked_client; /* Pointer to the ValkeyModuleBlockedClient associated with this
* client. This is set in case of module authentication before the
* unblocked client is reprocessed to handle reply callbacks. */