diff options
Diffstat (limited to 'mysys/mf_iocache2.c')
| -rw-r--r-- | mysys/mf_iocache2.c | 49 |
1 files changed, 26 insertions, 23 deletions
diff --git a/mysys/mf_iocache2.c b/mysys/mf_iocache2.c index c56022e93e8..b19ca391672 100644 --- a/mysys/mf_iocache2.c +++ b/mysys/mf_iocache2.c @@ -27,32 +27,36 @@ my_off_t my_b_append_tell(IO_CACHE* info) { - /* prevent optimizer from putting res in a register when debugging - we need this to be able to see the value of res when the assert fails + /* + Prevent optimizer from putting res in a register when debugging + we need this to be able to see the value of res when the assert fails */ dbug_volatile my_off_t res; -/* we need to lock the append buffer mutex to keep flush_io_cache() - from messing with the variables that we need in order to provide the - answer to the question. -*/ + + /* + We need to lock the append buffer mutex to keep flush_io_cache() + from messing with the variables that we need in order to provide the + answer to the question. + */ #ifdef THREAD pthread_mutex_lock(&info->append_buffer_lock); #endif - /* save the value of my_tell in res so we can see it when studying - coredump - */ #ifndef DBUG_OFF - /* make sure EOF is where we think it is. Note that we cannot just use - my_tell() because we have a reader thread that could have left the - file offset in a non-EOF location - */ + /* + Make sure EOF is where we think it is. Note that we cannot just use + my_tell() because we have a reader thread that could have left the + file offset in a non-EOF location + */ { - volatile my_off_t save_pos; - save_pos = my_tell(info->file,MYF(0)); - my_seek(info->file,(my_off_t)0,MY_SEEK_END,MYF(0)); - DBUG_ASSERT(info->end_of_file - (info->append_read_pos-info->write_buffer) - == (res=my_tell(info->file,MYF(0)))); - my_seek(info->file,save_pos,MY_SEEK_SET,MYF(0)); + volatile my_off_t save_pos; + save_pos = my_tell(info->file,MYF(0)); + my_seek(info->file,(my_off_t)0,MY_SEEK_END,MYF(0)); + /* + Save the value of my_tell in res so we can see it when studying coredump + */ + DBUG_ASSERT(info->end_of_file - (info->append_read_pos-info->write_buffer) + == (res=my_tell(info->file,MYF(0)))); + my_seek(info->file,save_pos,MY_SEEK_SET,MYF(0)); } #endif res = info->end_of_file + (info->write_pos-info->append_read_pos); @@ -74,10 +78,9 @@ void my_b_seek(IO_CACHE *info,my_off_t pos) DBUG_PRINT("enter",("pos: %lu", (ulong) pos)); /* - TODO: verify that it is OK to do seek in the non-append - area in SEQ_READ_APPEND cache - */ - /* TODO: + TODO: + Verify that it is OK to do seek in the non-append + area in SEQ_READ_APPEND cache a) see if this always works b) see if there is a better way to make it work */ |