fluencelabs/redis
1
0
Fork 0
mirror of https://github.com/fluencelabs/redis synced 2025-06-13 01:01:22 +00:00
Code Issues Projects Releases Wiki Activity

ZPOP: renaming to have explicit MIN/MAX score idea.

Browse Source 
This commit also adds a top comment about a subtle behavior of mixing
blocking operations of different types in the same key.
This commit is contained in:
antirez
2018-05-11 17:31:46 +02:00
parent 6b026b70a8
commit 6efb6c1e06
5 changed files with 111 additions and 100 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
src/blocked.c
View File

@ -204,14 +204,25 @@ void disconnectAllBlockedClients(void) {
/* This function should be called by Redis every time a single command,
* a MULTI/EXEC block, or a Lua script, terminated its execution after
* being called by a client.
* being called by a client. It handles serving clients blocked in
* lists, streams, and sorted sets, via a blocking commands.
*
* All the keys with at least one client blocked that received at least
* one new element via some PUSH/XADD operation are accumulated into
* one new element via some write operation are accumulated into
* the server.ready_keys list. This function will run the list and will
* serve clients accordingly. Note that the function will iterate again and
* again as a result of serving BRPOPLPUSH we can have new blocking clients
* to serve because of the PUSH side of BRPOPLPUSH. */
* to serve because of the PUSH side of BRPOPLPUSH.
*
* This function is normally "fair", that is, it will server clients
* using a FIFO behavior. However this fairness is violated in certain
* edge cases, that is, when we have clients blocked at the same time
* in a sorted set and in a list, for the same key (a very odd thing to
* do client side, indeed!). Because mismatching clients (blocking for
* a different type compared to the current key type) are moved in the
* other side of the linked list. However as long as the key starts to
* be used only for a single type, like virtually any Redis application will
* do, the function is already fair. */
void handleClientsBlockedOnKeys(void) {
while(listLength(server.ready_keys) != 0) {
list *l;
@ -316,14 +327,14 @@ void handleClientsBlockedOnKeys(void) {
continue;
}
int reverse = (receiver->lastcmd &&
receiver->lastcmd->proc == bzpopCommand) ?
0 : 1;
int where = (receiver->lastcmd &&
receiver->lastcmd->proc == bzpopminCommand)
? ZSET_MIN : ZSET_MAX;
unblockClient(receiver);
genericZpopCommand(receiver,&rl->key,1,reverse);
genericZpopCommand(receiver,&rl->key,1,where);
propagate(reverse ?
server.zrevpopCommand : server.zpopCommand,
propagate(where == ZSET_MIN ?
server.zpopminCommand : server.zpopmaxCommand,
receiver->db->id,receiver->argv,receiver->argc,
PROPAGATE_AOF|PROPAGATE_REPL);
}