fixed unit test bug; logWriters may now return NULL when readers attempt to read before the beginning of the log

This commit is contained in:
Sears Russell 2009-10-15 18:48:58 +00:00
parent 4b2cfb2b23
commit 5df5512d91
3 changed files with 27 additions and 12 deletions

View file

@ -145,9 +145,15 @@ static const LogEntry * stasis_log_impl_in_memory_read_entry(stasis_log_t* log,
lsn_t lsn) {
stasis_log_impl_in_memory * impl = log->impl;
DEBUG("lsn: %ld\n", lsn);
if(lsn >= impl->nextAvailableLSN) { return 0; }
assert(lsn-impl->globalOffset >= 0 && lsn-impl->globalOffset< impl->bufferLen);
readlock(impl->globalOffset_lock, 0);
if(lsn >= impl->nextAvailableLSN) {
unlock(impl->globalOffset_lock);
return NULL;
}
if(!(lsn-impl->globalOffset >= 0 && lsn-impl->globalOffset< impl->bufferLen)) {
unlock(impl->globalOffset_lock);
return NULL;
}
LogEntry * ptr = impl->buffer[lsn - impl->globalOffset];
unlock(impl->globalOffset_lock);
assert(ptr);

View file

@ -501,7 +501,7 @@ static const LogEntry * readLSNEntry_LogWriter(stasis_log_t * log, const lsn_t L
if(LSN >= sw->nextAvailableLSN) {
pthread_mutex_unlock(&sw->nextAvailableLSN_mutex);
return 0;
return NULL;
}
pthread_mutex_unlock(&sw->nextAvailableLSN_mutex);
@ -514,7 +514,11 @@ static const LogEntry * readLSNEntry_LogWriter(stasis_log_t * log, const lsn_t L
assert(flushedLSNInternal(sw) > LSN);
}
assert(sw->global_offset <= LSN);
if(sw->global_offset > LSN) {
// Return NULL; the caller read before the beginning of the log.
pthread_mutex_unlock(&sw->read_mutex);
return NULL;
}
off_t newPosition = LSN - sw->global_offset;
newPosition = lseek(sw->ro_fd, newPosition, SEEK_SET);

View file

@ -312,11 +312,11 @@ static void* worker_thread(void * arg) {
if(threshold < 3) {
if(i > 10) {
needToTruncate = 1;
if(lsns[i - 10] > truncated_to) {
truncated_to = lsns[i - 10];
myTruncVal = truncated_to;
}
needToTruncate = 1;
if(lsns[i - 10] > truncated_to) {
truncated_to = lsns[i - 10];
myTruncVal = truncated_to;
}
}
}
@ -355,9 +355,14 @@ static void* worker_thread(void * arg) {
pthread_mutex_unlock(&random_mutex);
const LogEntry * e = stasis_log_file->read_entry(stasis_log_file, lsn);
assert(e->xid == entry+key);
freeLogEntry(e);
if(e == NULL) {
pthread_mutex_lock(&random_mutex);
assert(lsn < truncated_to);
pthread_mutex_unlock(&random_mutex);
} else {
assert(e->xid == entry+key);
freeLogEntry(e);
}
} else {
pthread_mutex_unlock(&random_mutex);
}