don't use object sharing inside I/O threads, as a fix for a well known instability of VM introduced with the new object sharing code

This commit is contained in:
antirez 2010-07-22 13:08:02 +02:00
parent 1a71fb9669
commit 0e5441d816
3 changed files with 11 additions and 2 deletions

View File

@ -213,8 +213,15 @@ robj *tryObjectEncoding(robj *o) {
/* Check if we can represent this string as a long integer */
if (isStringRepresentableAsLong(s,&value) == REDIS_ERR) return o;
/* Ok, this object can be encoded */
if (value >= 0 && value < REDIS_SHARED_INTEGERS) {
/* Ok, this object can be encoded...
*
* Can I use a shared object? Only if the object is inside a given
* range and if this is the main thread, sinc when VM is enabled we
* have the constraint that I/O thread should only handle non-shared
* objects, in order to avoid race conditions (we don't have per-object
* locking). */
if (value >= 0 && value < REDIS_SHARED_INTEGERS &&
pthread_equal(pthread_self(),server.mainthread)) {
decrRefCount(o);
incrRefCount(shared.integers[value]);
return shared.integers[value];

View File

@ -760,6 +760,7 @@ void initServer() {
signal(SIGPIPE, SIG_IGN);
setupSigSegvAction();
server.mainthread = pthread_self();
server.devnull = fopen("/dev/null","w");
if (server.devnull == NULL) {
redisLog(REDIS_WARNING, "Can't open /dev/null: %s", server.neterr);

View File

@ -327,6 +327,7 @@ struct sharedObjectsStruct {
/* Global server state structure */
struct redisServer {
pthread_t mainthread;
int port;
int fd;
redisDb *db;