From c1c9d551da6dd534c8dae051a3a7e64bf7db6bfb Mon Sep 17 00:00:00 2001 From: antirez Date: Mon, 20 Jun 2011 17:07:18 +0200 Subject: [PATCH] Fix for bug 561 and other related problems --- src/networking.c | 25 ++++++++++++++++ src/redis.h | 1 + src/t_list.c | 48 ++++++++++++++++++++++++------- src/t_set.c | 17 ++++------- tests/integration/replication.tcl | 18 ++++++++++++ tests/unit/type/list.tcl | 8 ++++++ 6 files changed, 96 insertions(+), 21 deletions(-) diff --git a/src/networking.c b/src/networking.c index c7b56ca4..8f2e6d8f 100644 --- a/src/networking.c +++ b/src/networking.c @@ -947,3 +947,28 @@ void clientCommand(redisClient *c) { addReplyError(c, "Syntax error, try CLIENT (LIST | KILL ip:port)"); } } + +void rewriteClientCommandVector(redisClient *c, int argc, ...) { + va_list ap; + int j; + robj **argv; /* The new argument vector */ + + argv = zmalloc(sizeof(robj*)*argc); + va_start(ap,argc); + for (j = 0; j < argc; j++) { + robj *a; + + a = va_arg(ap, robj*); + argv[j] = a; + incrRefCount(a); + } + /* We free the objects in the original vector at the end, so we are + * sure that if the same objects are reused in the new vector the + * refcount gets incremented before it gets decremented. */ + for (j = 0; j < c->argc; j++) decrRefCount(c->argv[j]); + zfree(c->argv); + /* Replace argv and argc with our new versions. */ + c->argv = argv; + c->argc = argc; + va_end(ap); +} diff --git a/src/redis.h b/src/redis.h index 27131e5d..cab7607e 100644 --- a/src/redis.h +++ b/src/redis.h @@ -819,6 +819,7 @@ void addReplyMultiBulkLen(redisClient *c, long length); void *dupClientReplyValue(void *o); void getClientsMaxBuffers(unsigned long *longest_output_list, unsigned long *biggest_input_buffer); +void rewriteClientCommandVector(redisClient *c, int argc, ...); #ifdef __GNUC__ void addReplyErrorFormat(redisClient *c, const char *fmt, ...) diff --git a/src/t_list.c b/src/t_list.c index 7c1b848a..d8827726 100644 --- a/src/t_list.c +++ b/src/t_list.c @@ -640,7 +640,9 @@ void lremCommand(redisClient *c) { * as well. This command was originally proposed by Ezra Zygmuntowicz. */ -void rpoplpushHandlePush(redisClient *c, robj *dstkey, robj *dstobj, robj *value) { +void rpoplpushHandlePush(redisClient *origclient, redisClient *c, robj *dstkey, robj *dstobj, robj *value) { + robj *aux; + if (!handleClientsWaitingListPush(c,dstkey,value)) { /* Create the list if the key does not exist */ if (!dstobj) { @@ -648,9 +650,25 @@ void rpoplpushHandlePush(redisClient *c, robj *dstkey, robj *dstobj, robj *value dbAdd(c->db,dstkey,dstobj); } else { signalModifiedKey(c->db,dstkey); - server.dirty++; } listTypePush(dstobj,value,REDIS_HEAD); + /* If we are pushing as a result of LPUSH against a key + * watched by BLPOPLPUSH, we need to rewrite the command vector. + * But if this is called directly by RPOPLPUSH (either directly + * or via a BRPOPLPUSH where the popped list exists) + * we should replicate the BRPOPLPUSH command itself. */ + if (c != origclient) { + aux = createStringObject("LPUSH",5); + rewriteClientCommandVector(origclient,3,aux,dstkey,value); + decrRefCount(aux); + } else { + /* Make sure to always use RPOPLPUSH in the replication / AOF, + * even if the original command was BRPOPLPUSH. */ + aux = createStringObject("RPOPLPUSH",9); + rewriteClientCommandVector(origclient,3,aux,c->argv[1],c->argv[2]); + decrRefCount(aux); + } + server.dirty++; } /* Always send the pushed value to the client. */ @@ -666,16 +684,22 @@ void rpoplpushCommand(redisClient *c) { addReply(c,shared.nullbulk); } else { robj *dobj = lookupKeyWrite(c->db,c->argv[2]); + robj *touchedkey = c->argv[1]; + if (dobj && checkType(c,dobj,REDIS_LIST)) return; value = listTypePop(sobj,REDIS_TAIL); - rpoplpushHandlePush(c,c->argv[2],dobj,value); + /* We saved touched key, and protect it, since rpoplpushHandlePush + * may change the client command argument vector. */ + incrRefCount(touchedkey); + rpoplpushHandlePush(c,c,c->argv[2],dobj,value); /* listTypePop returns an object with its refcount incremented */ decrRefCount(value); /* Delete the source list when it is empty */ - if (listTypeLength(sobj) == 0) dbDelete(c->db,c->argv[1]); - signalModifiedKey(c->db,c->argv[1]); + if (listTypeLength(sobj) == 0) dbDelete(c->db,touchedkey); + signalModifiedKey(c->db,touchedkey); + decrRefCount(touchedkey); server.dirty++; } } @@ -777,6 +801,7 @@ void unblockClientWaitingData(redisClient *c) { /* Cleanup the client structure */ zfree(c->bpop.keys); c->bpop.keys = NULL; + if (c->bpop.target) decrRefCount(c->bpop.target); c->bpop.target = NULL; c->flags &= ~REDIS_BLOCKED; c->flags |= REDIS_UNBLOCKED; @@ -820,6 +845,10 @@ int handleClientsWaitingListPush(redisClient *c, robj *key, robj *ele) { receiver = ln->value; dstkey = receiver->bpop.target; + /* Protect receiver->bpop.target, that will be freed by + * the next unblockClientWaitingData() call. */ + if (dstkey) incrRefCount(dstkey); + /* This should remove the first element of the "clients" list. */ unblockClientWaitingData(receiver); @@ -828,17 +857,16 @@ int handleClientsWaitingListPush(redisClient *c, robj *key, robj *ele) { addReplyMultiBulkLen(receiver,2); addReplyBulk(receiver,key); addReplyBulk(receiver,ele); - return 1; + return 1; /* Serve just the first client as in B[RL]POP semantics */ } else { /* BRPOPLPUSH, note that receiver->db is always equal to c->db. */ dstobj = lookupKeyWrite(receiver->db,dstkey); - if (dstobj && checkType(receiver,dstobj,REDIS_LIST)) { - decrRefCount(dstkey); - } else { - rpoplpushHandlePush(receiver,dstkey,dstobj,ele); + if (!(dstobj && checkType(receiver,dstobj,REDIS_LIST))) { + rpoplpushHandlePush(c,receiver,dstkey,dstobj,ele); decrRefCount(dstkey); return 1; } + decrRefCount(dstkey); } } diff --git a/src/t_set.c b/src/t_set.c index c7d05c2f..bffea3d4 100644 --- a/src/t_set.c +++ b/src/t_set.c @@ -332,7 +332,7 @@ void scardCommand(redisClient *c) { } void spopCommand(redisClient *c) { - robj *set, *ele; + robj *set, *ele, *aux; int64_t llele; int encoding; @@ -348,16 +348,11 @@ void spopCommand(redisClient *c) { setTypeRemove(set,ele); } - /* Change argv to replicate as SREM */ - c->argc = 3; - c->argv = zrealloc(c->argv,sizeof(robj*)*(c->argc)); - - /* Overwrite SREM with SPOP (same length) */ - redisAssert(sdslen(c->argv[0]->ptr) == 4); - memcpy(c->argv[0]->ptr, "SREM", 4); - - /* Popped element already has incremented refcount */ - c->argv[2] = ele; + /* Replicate/AOF this command as an SREM operation */ + aux = createStringObject("SREM",4); + rewriteClientCommandVector(c,3,aux,c->argv[1],ele); + decrRefCount(ele); + decrRefCount(aux); addReplyBulk(c,ele); if (setTypeSize(set) == 0) dbDelete(c->db,c->argv[1]); diff --git a/tests/integration/replication.tcl b/tests/integration/replication.tcl index 892fae03..227356b2 100644 --- a/tests/integration/replication.tcl +++ b/tests/integration/replication.tcl @@ -6,6 +6,24 @@ start_server {tags {"repl"}} { s -1 role } {slave} + test {BRPOPLPUSH replication, when blocking against empty list} { + set rd [redis_deferring_client] + $rd brpoplpush a b 5 + r lpush a foo + after 1000 + assert_equal [r debug digest] [r -1 debug digest] + } + + test {BRPOPLPUSH replication, list exists} { + set rd [redis_deferring_client] + r lpush c 1 + r lpush c 2 + r lpush c 3 + $rd brpoplpush c d 5 + after 1000 + assert_equal [r debug digest] [r -1 debug digest] + } + test {MASTER and SLAVE dataset should be identical after complex ops} { createComplexDataset r 10000 after 500 diff --git a/tests/unit/type/list.tcl b/tests/unit/type/list.tcl index b6055b26..616abd21 100644 --- a/tests/unit/type/list.tcl +++ b/tests/unit/type/list.tcl @@ -278,6 +278,14 @@ start_server { r exec } {foo bar {} {} {bar foo}} + test {BRPOPLPUSH timeout} { + set rd [redis_deferring_client] + + $rd brpoplpush foo_list bar_list 1 + after 2000 + $rd read + } {} + foreach {pop} {BLPOP BRPOP} { test "$pop: with single empty list argument" { set rd [redis_deferring_client] -- 2.45.2