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Diffstat (limited to 'mysql/mysys/mf_iocache.c')
| -rw-r--r-- | mysql/mysys/mf_iocache.c | 1733 |
1 files changed, 0 insertions, 1733 deletions
diff --git a/mysql/mysys/mf_iocache.c b/mysql/mysys/mf_iocache.c deleted file mode 100644 index bc5f1bb..0000000 --- a/mysql/mysys/mf_iocache.c +++ /dev/null @@ -1,1733 +0,0 @@ -/* Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved. - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; version 2 of the License. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ - -/* - Cashing of files with only does (sequential) read or writes of fixed- - length records. A read isn't allowed to go over file-length. A read is ok - if it ends at file-length and next read can try to read after file-length - (and get a EOF-error). - Possibly use of asyncronic io. - macros for read and writes for faster io. - Used instead of FILE when reading or writing whole files. - This code makes mf_rec_cache obsolete (currently only used by ISAM) - One can change info->pos_in_file to a higher value to skip bytes in file if - also info->read_pos is set to info->read_end. - If called through open_cached_file(), then the temporary file will - only be created if a write exeeds the file buffer or if one calls - my_b_flush_io_cache(). - - If one uses SEQ_READ_APPEND, then two buffers are allocated, one for - reading and another for writing. Reads are first done from disk and - then done from the write buffer. This is an efficient way to read - from a log file when one is writing to it at the same time. - For this to work, the file has to be opened in append mode! - Note that when one uses SEQ_READ_APPEND, one MUST write using - my_b_append ! This is needed because we need to lock the mutex - every time we access the write buffer. - -TODO: - When one SEQ_READ_APPEND and we are reading and writing at the same time, - each time the write buffer gets full and it's written to disk, we will - always do a disk read to read a part of the buffer from disk to the - read buffer. - This should be fixed so that when we do a my_b_flush_io_cache() and - we have been reading the write buffer, we should transfer the rest of the - write buffer to the read buffer before we start to reuse it. -*/ - -#include "mysys_priv.h" -#include "my_sys.h" -#include <m_string.h> -#include <errno.h> -#include "my_thread_local.h" -#include "mysql/psi/mysql_file.h" - -PSI_file_key key_file_io_cache; - -#define lock_append_buffer(info) \ - mysql_mutex_lock(&(info)->append_buffer_lock) -#define unlock_append_buffer(info) \ - mysql_mutex_unlock(&(info)->append_buffer_lock) - -#define IO_ROUND_UP(X) (((X)+IO_SIZE-1) & ~(IO_SIZE-1)) -#define IO_ROUND_DN(X) ( (X) & ~(IO_SIZE-1)) - -/* - Setup internal pointers inside IO_CACHE - - SYNOPSIS - setup_io_cache() - info IO_CACHE handler - - NOTES - This is called on automaticly on init or reinit of IO_CACHE - It must be called externally if one moves or copies an IO_CACHE - object. -*/ - -void setup_io_cache(IO_CACHE* info) -{ - /* Ensure that my_b_tell() and my_b_bytes_in_cache works */ - if (info->type == WRITE_CACHE) - { - info->current_pos= &info->write_pos; - info->current_end= &info->write_end; - } - else - { - info->current_pos= &info->read_pos; - info->current_end= &info->read_end; - } -} - - -static void -init_functions(IO_CACHE* info) -{ - enum cache_type type= info->type; - switch (type) { - case READ_NET: - /* - Must be initialized by the caller. The problem is that - _my_b_net_read has to be defined in sql directory because of - the dependency on THD, and therefore cannot be visible to - programs that link against mysys but know nothing about THD, such - as myisamchk - */ - break; - case SEQ_READ_APPEND: - info->read_function = _my_b_seq_read; - info->write_function = 0; /* Force a core if used */ - break; - default: - info->read_function = info->share ? _my_b_read_r : _my_b_read; - info->write_function = _my_b_write; - } - - setup_io_cache(info); -} - - -/* - Initialize an IO_CACHE object - - SYNOPSIS - init_io_cache_ext() - info cache handler to initialize - file File that should be associated to to the handler - If == -1 then real_open_cached_file() - will be called when it's time to open file. - cachesize Size of buffer to allocate for read/write - If == 0 then use my_default_record_cache_size - type Type of cache - seek_offset Where cache should start reading/writing - use_async_io Set to 1 of we should use async_io (if avaiable) - cache_myflags Bitmap of different flags - MY_WME | MY_FAE | MY_NABP | MY_FNABP | - MY_DONT_CHECK_FILESIZE - file_key Instrumented file key for temporary cache file - - RETURN - 0 ok - # error -*/ - -int init_io_cache_ext(IO_CACHE *info, File file, size_t cachesize, - enum cache_type type, my_off_t seek_offset, - pbool use_async_io, myf cache_myflags, - PSI_file_key file_key) -{ - size_t min_cache; - my_off_t pos; - my_off_t end_of_file= ~(my_off_t) 0; - DBUG_ENTER("init_io_cache_ext"); - DBUG_PRINT("enter",("cache: 0x%lx type: %d pos: %ld", - (ulong) info, (int) type, (ulong) seek_offset)); - - info->file= file; - info->file_key= file_key; - info->type= TYPE_NOT_SET; /* Don't set it until mutex are created */ - info->pos_in_file= seek_offset; - info->pre_close = info->pre_read = info->post_read = 0; - info->arg = 0; - info->alloced_buffer = 0; - info->buffer=0; - info->seek_not_done= 0; - - if (file >= 0) - { - pos= mysql_file_tell(file, MYF(0)); - if ((pos == (my_off_t) -1) && (my_errno() == ESPIPE)) - { - /* - This kind of object doesn't support seek() or tell(). Don't set a - flag that will make us again try to seek() later and fail. - */ - info->seek_not_done= 0; - /* - Additionally, if we're supposed to start somewhere other than the - the beginning of whatever this file is, then somebody made a bad - assumption. - */ - DBUG_ASSERT(seek_offset == 0); - } - else - info->seek_not_done= MY_TEST(seek_offset != pos); - } - - info->disk_writes= 0; - info->share=0; - - if (!cachesize && !(cachesize= my_default_record_cache_size)) - DBUG_RETURN(1); /* No cache requested */ - min_cache=use_async_io ? IO_SIZE*4 : IO_SIZE*2; - if (type == READ_CACHE || type == SEQ_READ_APPEND) - { /* Assume file isn't growing */ - if (!(cache_myflags & MY_DONT_CHECK_FILESIZE)) - { - /* Calculate end of file to avoid allocating oversized buffers */ - end_of_file= mysql_file_seek(file, 0L, MY_SEEK_END, MYF(0)); - /* Need to reset seek_not_done now that we just did a seek. */ - info->seek_not_done= end_of_file == seek_offset ? 0 : 1; - if (end_of_file < seek_offset) - end_of_file=seek_offset; - /* Trim cache size if the file is very small */ - if ((my_off_t) cachesize > end_of_file-seek_offset+IO_SIZE*2-1) - { - cachesize= (size_t) (end_of_file-seek_offset)+IO_SIZE*2-1; - use_async_io=0; /* No need to use async */ - } - } - } - cache_myflags &= ~MY_DONT_CHECK_FILESIZE; - if (type != READ_NET && type != WRITE_NET) - { - /* Retry allocating memory in smaller blocks until we get one */ - cachesize= ((cachesize + min_cache-1) & ~(min_cache-1)); - for (;;) - { - size_t buffer_block; - /* - Unset MY_WAIT_IF_FULL bit if it is set, to prevent conflict with - MY_ZEROFILL. - */ - myf flags= (myf) (cache_myflags & ~(MY_WME | MY_WAIT_IF_FULL)); - - if (cachesize < min_cache) - cachesize = min_cache; - buffer_block= cachesize; - if (type == SEQ_READ_APPEND) - buffer_block *= 2; - if (cachesize == min_cache) - flags|= (myf) MY_WME; - - if ((info->buffer= (uchar*) my_malloc(key_memory_IO_CACHE, - buffer_block, flags)) != 0) - { - info->write_buffer=info->buffer; - if (type == SEQ_READ_APPEND) - info->write_buffer = info->buffer + cachesize; - info->alloced_buffer=1; - break; /* Enough memory found */ - } - if (cachesize == min_cache) - DBUG_RETURN(2); /* Can't alloc cache */ - /* Try with less memory */ - cachesize= (cachesize*3/4 & ~(min_cache-1)); - } - } - - DBUG_PRINT("info",("init_io_cache: cachesize = %lu", (ulong) cachesize)); - info->read_length=info->buffer_length=cachesize; - info->myflags=cache_myflags & ~(MY_NABP | MY_FNABP); - info->request_pos= info->read_pos= info->write_pos = info->buffer; - if (type == SEQ_READ_APPEND) - { - info->append_read_pos = info->write_pos = info->write_buffer; - info->write_end = info->write_buffer + info->buffer_length; - mysql_mutex_init(key_IO_CACHE_append_buffer_lock, - &info->append_buffer_lock, MY_MUTEX_INIT_FAST); - } -#if defined(SAFE_MUTEX) - else - { - /* Clear mutex so that safe_mutex will notice that it's not initialized */ - memset(&info->append_buffer_lock, 0, sizeof(info->append_buffer_lock)); - } -#endif - - if (type == WRITE_CACHE) - info->write_end= - info->buffer+info->buffer_length- (seek_offset & (IO_SIZE-1)); - else - info->read_end=info->buffer; /* Nothing in cache */ - - /* End_of_file may be changed by user later */ - info->end_of_file= end_of_file; - info->error=0; - info->type= type; - init_functions(info); - DBUG_RETURN(0); -} /* init_io_cache_ext */ - -/* - Initialize an IO_CACHE object - - SYNOPSIS - init_io_cache() - Wrapper for init_io_cache_ext() - - NOTE - This function should be used if the IO_CACHE tempfile is not instrumented. -*/ - -int init_io_cache(IO_CACHE *info, File file, size_t cachesize, - enum cache_type type, my_off_t seek_offset, - pbool use_async_io, myf cache_myflags) -{ - return init_io_cache_ext(info, file, cachesize, type, seek_offset, - use_async_io, cache_myflags, key_file_io_cache); -} - -/* - Use this to reset cache to re-start reading or to change the type - between READ_CACHE <-> WRITE_CACHE - If we are doing a reinit of a cache where we have the start of the file - in the cache, we are reusing this memory without flushing it to disk. -*/ - -my_bool reinit_io_cache(IO_CACHE *info, enum cache_type type, - my_off_t seek_offset, - pbool use_async_io MY_ATTRIBUTE((unused)), - pbool clear_cache) -{ - DBUG_ENTER("reinit_io_cache"); - DBUG_PRINT("enter",("cache: 0x%lx type: %d seek_offset: %lu clear_cache: %d", - (ulong) info, type, (ulong) seek_offset, - (int) clear_cache)); - - /* One can't do reinit with the following types */ - DBUG_ASSERT(type != READ_NET && info->type != READ_NET && - type != WRITE_NET && info->type != WRITE_NET && - type != SEQ_READ_APPEND && info->type != SEQ_READ_APPEND); - - /* If the whole file is in memory, avoid flushing to disk */ - if (! clear_cache && - seek_offset >= info->pos_in_file && - seek_offset <= my_b_tell(info)) - { - /* Reuse current buffer without flushing it to disk */ - uchar *pos; - if (info->type == WRITE_CACHE && type == READ_CACHE) - { - info->read_end=info->write_pos; - info->end_of_file=my_b_tell(info); - /* - Trigger a new seek only if we have a valid - file handle. - */ - info->seek_not_done= (info->file != -1); - } - else if (type == WRITE_CACHE) - { - if (info->type == READ_CACHE) - { - info->write_end=info->write_buffer+info->buffer_length; - info->seek_not_done=1; - } - info->end_of_file = ~(my_off_t) 0; - } - pos=info->request_pos+(seek_offset-info->pos_in_file); - if (type == WRITE_CACHE) - info->write_pos=pos; - else - info->read_pos= pos; - } - else - { - /* - If we change from WRITE_CACHE to READ_CACHE, assume that everything - after the current positions should be ignored - */ - if (info->type == WRITE_CACHE && type == READ_CACHE) - info->end_of_file=my_b_tell(info); - /* flush cache if we want to reuse it */ - if (!clear_cache && my_b_flush_io_cache(info,1)) - DBUG_RETURN(1); - info->pos_in_file=seek_offset; - /* Better to do always do a seek */ - info->seek_not_done=1; - info->request_pos=info->read_pos=info->write_pos=info->buffer; - if (type == READ_CACHE) - { - info->read_end=info->buffer; /* Nothing in cache */ - } - else - { - info->write_end=(info->buffer + info->buffer_length - - (seek_offset & (IO_SIZE-1))); - info->end_of_file= ~(my_off_t) 0; - } - } - info->type=type; - info->error=0; - init_functions(info); - - DBUG_RETURN(0); -} /* reinit_io_cache */ - - - -/* - Read buffered. - - SYNOPSIS - _my_b_read() - info IO_CACHE pointer - Buffer Buffer to retrieve count bytes from file - Count Number of bytes to read into Buffer - - NOTE - This function is only called from the my_b_read() macro when there - isn't enough characters in the buffer to satisfy the request. - - WARNING - - When changing this function, be careful with handling file offsets - (end-of_file, pos_in_file). Do not cast them to possibly smaller - types than my_off_t unless you can be sure that their value fits. - Same applies to differences of file offsets. - - When changing this function, check _my_b_read_r(). It might need the - same change. - - RETURN - 0 we succeeded in reading all data - 1 Error: couldn't read requested characters. In this case: - If info->error == -1, we got a read error. - Otherwise info->error contains the number of bytes in Buffer. -*/ - -int _my_b_read(IO_CACHE *info, uchar *Buffer, size_t Count) -{ - size_t length,diff_length,left_length, max_length; - my_off_t pos_in_file; - DBUG_ENTER("_my_b_read"); - - /* If the buffer is not empty yet, copy what is available. */ - if ((left_length= (size_t) (info->read_end-info->read_pos))) - { - DBUG_ASSERT(Count >= left_length); /* User is not using my_b_read() */ - memcpy(Buffer,info->read_pos, left_length); - Buffer+=left_length; - Count-=left_length; - } - - /* pos_in_file always point on where info->buffer was read */ - pos_in_file=info->pos_in_file+ (size_t) (info->read_end - info->buffer); - - /* - Whenever a function which operates on IO_CACHE flushes/writes - some part of the IO_CACHE to disk it will set the property - "seek_not_done" to indicate this to other functions operating - on the IO_CACHE. - */ - if (info->seek_not_done) - { - if ((mysql_file_seek(info->file, pos_in_file, MY_SEEK_SET, MYF(0)) - != MY_FILEPOS_ERROR)) - { - /* No error, reset seek_not_done flag. */ - info->seek_not_done= 0; - } - else - { - /* - If the seek failed and the error number is ESPIPE, it is because - info->file is a pipe or socket or FIFO. We never should have tried - to seek on that. See Bugs#25807 and #22828 for more info. - */ - DBUG_ASSERT(my_errno() != ESPIPE); - info->error= -1; - DBUG_RETURN(1); - } - } - - /* - Calculate, how much we are within a IO_SIZE block. Ideally this - should be zero. - */ - diff_length= (size_t) (pos_in_file & (IO_SIZE-1)); - - /* - If more than a block plus the rest of the current block is wanted, - we do read directly, without filling the buffer. - */ - if (Count >= (size_t) (IO_SIZE+(IO_SIZE-diff_length))) - { /* Fill first intern buffer */ - size_t read_length; - if (info->end_of_file <= pos_in_file) - { - /* End of file. Return, what we did copy from the buffer. */ - info->error= (int) left_length; - DBUG_RETURN(1); - } - /* - Crop the wanted count to a multiple of IO_SIZE and subtract, - what we did already read from a block. That way, the read will - end aligned with a block. - */ - length=(Count & (size_t) ~(IO_SIZE-1))-diff_length; - if ((read_length= mysql_file_read(info->file,Buffer, length, info->myflags)) - != length) - { - /* - If we didn't get, what we wanted, we either return -1 for a read - error, or (it's end of file), how much we got in total. - */ - info->error= (read_length == (size_t) -1 ? -1 : - (int) (read_length+left_length)); - DBUG_RETURN(1); - } - Count-=length; - Buffer+=length; - pos_in_file+=length; - left_length+=length; - diff_length=0; - } - - /* - At this point, we want less than one and a partial block. - We will read a full cache, minus the number of bytes, we are - within a block already. So we will reach new alignment. - */ - max_length= info->read_length-diff_length; - /* We will not read past end of file. */ - if (info->type != READ_FIFO && - max_length > (info->end_of_file - pos_in_file)) - max_length= (size_t) (info->end_of_file - pos_in_file); - /* - If there is nothing left to read, - we either are done, or we failed to fulfill the request. - Otherwise, we read max_length into the cache. - */ - if (!max_length) - { - if (Count) - { - /* We couldn't fulfil the request. Return, how much we got. */ - info->error= (int)left_length; - DBUG_RETURN(1); - } - length=0; /* Didn't read any chars */ - } - else if ((length= mysql_file_read(info->file,info->buffer, max_length, - info->myflags)) < Count || - length == (size_t) -1) - { - /* - We got an read error, or less than requested (end of file). - If not a read error, copy, what we got. - */ - if (length != (size_t) -1) - memcpy(Buffer, info->buffer, length); - info->pos_in_file= pos_in_file; - /* For a read error, return -1, otherwise, what we got in total. */ - info->error= length == (size_t) -1 ? -1 : (int) (length+left_length); - info->read_pos=info->read_end=info->buffer; - DBUG_RETURN(1); - } - /* - Count is the remaining number of bytes requested. - length is the amount of data in the cache. - Read Count bytes from the cache. - */ - info->read_pos=info->buffer+Count; - info->read_end=info->buffer+length; - info->pos_in_file=pos_in_file; - memcpy(Buffer, info->buffer, Count); - DBUG_RETURN(0); -} - - -/* - Prepare IO_CACHE for shared use. - - SYNOPSIS - init_io_cache_share() - read_cache A read cache. This will be copied for - every thread after setup. - cshare The share. - write_cache If non-NULL a write cache that is to be - synchronized with the read caches. - num_threads Number of threads sharing the cache - including the write thread if any. - - DESCRIPTION - - The shared cache is used so: One IO_CACHE is initialized with - init_io_cache(). This includes the allocation of a buffer. Then a - share is allocated and init_io_cache_share() is called with the io - cache and the share. Then the io cache is copied for each thread. So - every thread has its own copy of IO_CACHE. But the allocated buffer - is shared because cache->buffer is the same for all caches. - - One thread reads data from the file into the buffer. All threads - read from the buffer, but every thread maintains its own set of - pointers into the buffer. When all threads have used up the buffer - contents, one of the threads reads the next block of data into the - buffer. To accomplish this, each thread enters the cache lock before - accessing the buffer. They wait in lock_io_cache() until all threads - joined the lock. The last thread entering the lock is in charge of - reading from file to buffer. It wakes all threads when done. - - Synchronizing a write cache to the read caches works so: Whenever - the write buffer needs a flush, the write thread enters the lock and - waits for all other threads to enter the lock too. They do this when - they have used up the read buffer. When all threads are in the lock, - the write thread copies the write buffer to the read buffer and - wakes all threads. - - share->running_threads is the number of threads not being in the - cache lock. When entering lock_io_cache() the number is decreased. - When the thread that fills the buffer enters unlock_io_cache() the - number is reset to the number of threads. The condition - running_threads == 0 means that all threads are in the lock. Bumping - up the number to the full count is non-intuitive. But increasing the - number by one for each thread that leaves the lock could lead to a - solo run of one thread. The last thread to join a lock reads from - file to buffer, wakes the other threads, processes the data in the - cache and enters the lock again. If no other thread left the lock - meanwhile, it would think it's the last one again and read the next - block... - - The share has copies of 'error', 'buffer', 'read_end', and - 'pos_in_file' from the thread that filled the buffer. We may not be - able to access this information directly from its cache because the - thread may be removed from the share before the variables could be - copied by all other threads. Or, if a write buffer is synchronized, - it would change its 'pos_in_file' after waking the other threads, - possibly before they could copy its value. - - However, the 'buffer' variable in the share is for a synchronized - write cache. It needs to know where to put the data. Otherwise it - would need access to the read cache of one of the threads that is - not yet removed from the share. - - RETURN - void -*/ - -void init_io_cache_share(IO_CACHE *read_cache, IO_CACHE_SHARE *cshare, - IO_CACHE *write_cache, uint num_threads) -{ - DBUG_ENTER("init_io_cache_share"); - DBUG_PRINT("io_cache_share", ("read_cache: 0x%lx share: 0x%lx " - "write_cache: 0x%lx threads: %u", - (long) read_cache, (long) cshare, - (long) write_cache, num_threads)); - - DBUG_ASSERT(num_threads > 1); - DBUG_ASSERT(read_cache->type == READ_CACHE); - DBUG_ASSERT(!write_cache || (write_cache->type == WRITE_CACHE)); - - mysql_mutex_init(key_IO_CACHE_SHARE_mutex, - &cshare->mutex, MY_MUTEX_INIT_FAST); - mysql_cond_init(key_IO_CACHE_SHARE_cond, &cshare->cond); - mysql_cond_init(key_IO_CACHE_SHARE_cond_writer, &cshare->cond_writer); - - cshare->running_threads= num_threads; - cshare->total_threads= num_threads; - cshare->error= 0; /* Initialize. */ - cshare->buffer= read_cache->buffer; - cshare->read_end= NULL; /* See function comment of lock_io_cache(). */ - cshare->pos_in_file= 0; /* See function comment of lock_io_cache(). */ - cshare->source_cache= write_cache; /* Can be NULL. */ - - read_cache->share= cshare; - read_cache->read_function= _my_b_read_r; - read_cache->current_pos= NULL; - read_cache->current_end= NULL; - - if (write_cache) - write_cache->share= cshare; - - DBUG_VOID_RETURN; -} - - -/* - Remove a thread from shared access to IO_CACHE. - - SYNOPSIS - remove_io_thread() - cache The IO_CACHE to be removed from the share. - - NOTE - - Every thread must do that on exit for not to deadlock other threads. - - The last thread destroys the pthread resources. - - A writer flushes its cache first. - - RETURN - void -*/ - -void remove_io_thread(IO_CACHE *cache) -{ - IO_CACHE_SHARE *cshare= cache->share; - uint total; - DBUG_ENTER("remove_io_thread"); - - /* If the writer goes, it needs to flush the write cache. */ - if (cache == cshare->source_cache) - flush_io_cache(cache); - - mysql_mutex_lock(&cshare->mutex); - DBUG_PRINT("io_cache_share", ("%s: 0x%lx", - (cache == cshare->source_cache) ? - "writer" : "reader", (long) cache)); - - /* Remove from share. */ - total= --cshare->total_threads; - DBUG_PRINT("io_cache_share", ("remaining threads: %u", total)); - - /* Detach from share. */ - cache->share= NULL; - - /* If the writer goes, let the readers know. */ - if (cache == cshare->source_cache) - { - DBUG_PRINT("io_cache_share", ("writer leaves")); - cshare->source_cache= NULL; - } - - /* If all threads are waiting for me to join the lock, wake them. */ - if (!--cshare->running_threads) - { - DBUG_PRINT("io_cache_share", ("the last running thread leaves, wake all")); - mysql_cond_signal(&cshare->cond_writer); - mysql_cond_broadcast(&cshare->cond); - } - - mysql_mutex_unlock(&cshare->mutex); - - if (!total) - { - DBUG_PRINT("io_cache_share", ("last thread removed, destroy share")); - mysql_cond_destroy (&cshare->cond_writer); - mysql_cond_destroy (&cshare->cond); - mysql_mutex_destroy(&cshare->mutex); - } - - DBUG_VOID_RETURN; -} - - -/* - Lock IO cache and wait for all other threads to join. - - SYNOPSIS - lock_io_cache() - cache The cache of the thread entering the lock. - pos File position of the block to read. - Unused for the write thread. - - DESCRIPTION - - Wait for all threads to finish with the current buffer. We want - all threads to proceed in concert. The last thread to join - lock_io_cache() will read the block from file and all threads start - to use it. Then they will join again for reading the next block. - - The waiting threads detect a fresh buffer by comparing - cshare->pos_in_file with the position they want to process next. - Since the first block may start at position 0, we take - cshare->read_end as an additional condition. This variable is - initialized to NULL and will be set after a block of data is written - to the buffer. - - RETURN - 1 OK, lock in place, go ahead and read. - 0 OK, unlocked, another thread did the read. -*/ - -static int lock_io_cache(IO_CACHE *cache, my_off_t pos) -{ - IO_CACHE_SHARE *cshare= cache->share; - DBUG_ENTER("lock_io_cache"); - - /* Enter the lock. */ - mysql_mutex_lock(&cshare->mutex); - cshare->running_threads--; - DBUG_PRINT("io_cache_share", ("%s: 0x%lx pos: %lu running: %u", - (cache == cshare->source_cache) ? - "writer" : "reader", (long) cache, (ulong) pos, - cshare->running_threads)); - - if (cshare->source_cache) - { - /* A write cache is synchronized to the read caches. */ - - if (cache == cshare->source_cache) - { - /* The writer waits until all readers are here. */ - while (cshare->running_threads) - { - DBUG_PRINT("io_cache_share", ("writer waits in lock")); - mysql_cond_wait(&cshare->cond_writer, &cshare->mutex); - } - DBUG_PRINT("io_cache_share", ("writer awoke, going to copy")); - - /* Stay locked. Leave the lock later by unlock_io_cache(). */ - DBUG_RETURN(1); - } - - /* The last thread wakes the writer. */ - if (!cshare->running_threads) - { - DBUG_PRINT("io_cache_share", ("waking writer")); - mysql_cond_signal(&cshare->cond_writer); - } - - /* - Readers wait until the data is copied from the writer. Another - reason to stop waiting is the removal of the write thread. If this - happens, we leave the lock with old data in the buffer. - */ - while ((!cshare->read_end || (cshare->pos_in_file < pos)) && - cshare->source_cache) - { - DBUG_PRINT("io_cache_share", ("reader waits in lock")); - mysql_cond_wait(&cshare->cond, &cshare->mutex); - } - - /* - If the writer was removed from the share while this thread was - asleep, we need to simulate an EOF condition. The writer cannot - reset the share variables as they might still be in use by readers - of the last block. When we awake here then because the last - joining thread signalled us. If the writer is not the last, it - will not signal. So it is safe to clear the buffer here. - */ - if (!cshare->read_end || (cshare->pos_in_file < pos)) - { - DBUG_PRINT("io_cache_share", ("reader found writer removed. EOF")); - cshare->read_end= cshare->buffer; /* Empty buffer. */ - cshare->error= 0; /* EOF is not an error. */ - } - } - else - { - /* - There are read caches only. The last thread arriving in - lock_io_cache() continues with a locked cache and reads the block. - */ - if (!cshare->running_threads) - { - DBUG_PRINT("io_cache_share", ("last thread joined, going to read")); - /* Stay locked. Leave the lock later by unlock_io_cache(). */ - DBUG_RETURN(1); - } - - /* - All other threads wait until the requested block is read by the - last thread arriving. Another reason to stop waiting is the - removal of a thread. If this leads to all threads being in the - lock, we have to continue also. The first of the awaken threads - will then do the read. - */ - while ((!cshare->read_end || (cshare->pos_in_file < pos)) && - cshare->running_threads) - { - DBUG_PRINT("io_cache_share", ("reader waits in lock")); - mysql_cond_wait(&cshare->cond, &cshare->mutex); - } - - /* If the block is not yet read, continue with a locked cache and read. */ - if (!cshare->read_end || (cshare->pos_in_file < pos)) - { - DBUG_PRINT("io_cache_share", ("reader awoke, going to read")); - /* Stay locked. Leave the lock later by unlock_io_cache(). */ - DBUG_RETURN(1); - } - - /* Another thread did read the block already. */ - } - DBUG_PRINT("io_cache_share", ("reader awoke, going to process %u bytes", - (uint) (cshare->read_end ? (size_t) - (cshare->read_end - cshare->buffer) : - 0))); - - /* - Leave the lock. Do not call unlock_io_cache() later. The thread that - filled the buffer did this and marked all threads as running. - */ - mysql_mutex_unlock(&cshare->mutex); - DBUG_RETURN(0); -} - - -/* - Unlock IO cache. - - SYNOPSIS - unlock_io_cache() - cache The cache of the thread leaving the lock. - - NOTE - This is called by the thread that filled the buffer. It marks all - threads as running and awakes them. This must not be done by any - other thread. - - Do not signal cond_writer. Either there is no writer or the writer - is the only one who can call this function. - - The reason for resetting running_threads to total_threads before - waking all other threads is that it could be possible that this - thread is so fast with processing the buffer that it enters the lock - before even one other thread has left it. If every awoken thread - would increase running_threads by one, this thread could think that - he is again the last to join and would not wait for the other - threads to process the data. - - RETURN - void -*/ - -static void unlock_io_cache(IO_CACHE *cache) -{ - IO_CACHE_SHARE *cshare= cache->share; - DBUG_ENTER("unlock_io_cache"); - DBUG_PRINT("io_cache_share", ("%s: 0x%lx pos: %lu running: %u", - (cache == cshare->source_cache) ? - "writer" : "reader", - (long) cache, (ulong) cshare->pos_in_file, - cshare->total_threads)); - - cshare->running_threads= cshare->total_threads; - mysql_cond_broadcast(&cshare->cond); - mysql_mutex_unlock(&cshare->mutex); - DBUG_VOID_RETURN; -} - - -/* - Read from IO_CACHE when it is shared between several threads. - - SYNOPSIS - _my_b_read_r() - cache IO_CACHE pointer - Buffer Buffer to retrieve count bytes from file - Count Number of bytes to read into Buffer - - NOTE - This function is only called from the my_b_read() macro when there - isn't enough characters in the buffer to satisfy the request. - - IMPLEMENTATION - - It works as follows: when a thread tries to read from a file (that - is, after using all the data from the (shared) buffer), it just - hangs on lock_io_cache(), waiting for other threads. When the very - last thread attempts a read, lock_io_cache() returns 1, the thread - does actual IO and unlock_io_cache(), which signals all the waiting - threads that data is in the buffer. - - WARNING - - When changing this function, be careful with handling file offsets - (end-of_file, pos_in_file). Do not cast them to possibly smaller - types than my_off_t unless you can be sure that their value fits. - Same applies to differences of file offsets. (Bug #11527) - - When changing this function, check _my_b_read(). It might need the - same change. - - RETURN - 0 we succeeded in reading all data - 1 Error: can't read requested characters -*/ - -int _my_b_read_r(IO_CACHE *cache, uchar *Buffer, size_t Count) -{ - my_off_t pos_in_file; - size_t length, diff_length, left_length; - IO_CACHE_SHARE *cshare= cache->share; - DBUG_ENTER("_my_b_read_r"); - - if ((left_length= (size_t) (cache->read_end - cache->read_pos))) - { - DBUG_ASSERT(Count >= left_length); /* User is not using my_b_read() */ - memcpy(Buffer, cache->read_pos, left_length); - Buffer+= left_length; - Count-= left_length; - } - while (Count) - { - size_t cnt, len; - - pos_in_file= cache->pos_in_file + (cache->read_end - cache->buffer); - diff_length= (size_t) (pos_in_file & (IO_SIZE-1)); - length=IO_ROUND_UP(Count+diff_length)-diff_length; - length= ((length <= cache->read_length) ? - length + IO_ROUND_DN(cache->read_length - length) : - length - IO_ROUND_UP(length - cache->read_length)); - if (cache->type != READ_FIFO && - (length > (cache->end_of_file - pos_in_file))) - length= (size_t) (cache->end_of_file - pos_in_file); - if (length == 0) - { - cache->error= (int) left_length; - DBUG_RETURN(1); - } - if (lock_io_cache(cache, pos_in_file)) - { - /* With a synchronized write/read cache we won't come here... */ - DBUG_ASSERT(!cshare->source_cache); - /* - ... unless the writer has gone before this thread entered the - lock. Simulate EOF in this case. It can be distinguished by - cache->file. - */ - if (cache->file < 0) - len= 0; - else - { - /* - Whenever a function which operates on IO_CACHE flushes/writes - some part of the IO_CACHE to disk it will set the property - "seek_not_done" to indicate this to other functions operating - on the IO_CACHE. - */ - if (cache->seek_not_done) - { - if (mysql_file_seek(cache->file, pos_in_file, MY_SEEK_SET, MYF(0)) - == MY_FILEPOS_ERROR) - { - cache->error= -1; - unlock_io_cache(cache); - DBUG_RETURN(1); - } - } - len= mysql_file_read(cache->file, cache->buffer, length, cache->myflags); - } - DBUG_PRINT("io_cache_share", ("read %lu bytes", (ulong) len)); - - cache->read_end= cache->buffer + (len == (size_t) -1 ? 0 : len); - cache->error= (len == length ? 0 : (int) len); - cache->pos_in_file= pos_in_file; - - /* Copy important values to the share. */ - cshare->error= cache->error; - cshare->read_end= cache->read_end; - cshare->pos_in_file= pos_in_file; - - /* Mark all threads as running and wake them. */ - unlock_io_cache(cache); - } - else - { - /* - With a synchronized write/read cache readers always come here. - Copy important values from the share. - */ - cache->error= cshare->error; - cache->read_end= cshare->read_end; - cache->pos_in_file= cshare->pos_in_file; - - len= ((cache->error == -1) ? (size_t) -1 : - (size_t) (cache->read_end - cache->buffer)); - } - cache->read_pos= cache->buffer; - cache->seek_not_done= 0; - if (len == 0 || len == (size_t) -1) - { - DBUG_PRINT("io_cache_share", ("reader error. len %lu left %lu", - (ulong) len, (ulong) left_length)); - cache->error= (int) left_length; - DBUG_RETURN(1); - } - cnt= (len > Count) ? Count : len; - memcpy(Buffer, cache->read_pos, cnt); - Count -= cnt; - Buffer+= cnt; - left_length+= cnt; - cache->read_pos+= cnt; - } - DBUG_RETURN(0); -} - - -/* - Copy data from write cache to read cache. - - SYNOPSIS - copy_to_read_buffer() - write_cache The write cache. - write_buffer The source of data, mostly the cache buffer. - write_length The number of bytes to copy. - - NOTE - The write thread will wait for all read threads to join the cache - lock. Then it copies the data over and wakes the read threads. - - RETURN - void -*/ - -static void copy_to_read_buffer(IO_CACHE *write_cache, - const uchar *write_buffer, size_t write_length) -{ - IO_CACHE_SHARE *cshare= write_cache->share; - - DBUG_ASSERT(cshare->source_cache == write_cache); - /* - write_length is usually less or equal to buffer_length. - It can be bigger if _my_b_write() is called with a big length. - */ - while (write_length) - { - size_t copy_length= MY_MIN(write_length, write_cache->buffer_length); - int MY_ATTRIBUTE((unused)) rc; - - rc= lock_io_cache(write_cache, write_cache->pos_in_file); - /* The writing thread does always have the lock when it awakes. */ - DBUG_ASSERT(rc); - - memcpy(cshare->buffer, write_buffer, copy_length); - - cshare->error= 0; - cshare->read_end= cshare->buffer + copy_length; - cshare->pos_in_file= write_cache->pos_in_file; - - /* Mark all threads as running and wake them. */ - unlock_io_cache(write_cache); - - write_buffer+= copy_length; - write_length-= copy_length; - } -} - - -/* - Do sequential read from the SEQ_READ_APPEND cache. - - We do this in three stages: - - first read from info->buffer - - then if there are still data to read, try the file descriptor - - afterwards, if there are still data to read, try append buffer - - RETURNS - 0 Success - 1 Failed to read -*/ - -int _my_b_seq_read(IO_CACHE *info, uchar *Buffer, size_t Count) -{ - size_t length, diff_length, left_length, save_count, max_length; - my_off_t pos_in_file; - save_count=Count; - - /* first, read the regular buffer */ - if ((left_length=(size_t) (info->read_end-info->read_pos))) - { - DBUG_ASSERT(Count > left_length); /* User is not using my_b_read() */ - memcpy(Buffer,info->read_pos, left_length); - Buffer+=left_length; - Count-=left_length; - } - lock_append_buffer(info); - - /* pos_in_file always point on where info->buffer was read */ - if ((pos_in_file=info->pos_in_file + - (size_t) (info->read_end - info->buffer)) >= info->end_of_file) - goto read_append_buffer; - - /* - With read-append cache we must always do a seek before we read, - because the write could have moved the file pointer astray - */ - if (mysql_file_seek(info->file, pos_in_file, MY_SEEK_SET, MYF(0)) == MY_FILEPOS_ERROR) - { - info->error= -1; - unlock_append_buffer(info); - return (1); - } - info->seek_not_done=0; - - diff_length= (size_t) (pos_in_file & (IO_SIZE-1)); - - /* now the second stage begins - read from file descriptor */ - if (Count >= (size_t) (IO_SIZE+(IO_SIZE-diff_length))) - { - /* Fill first intern buffer */ - size_t read_length; - - length=(Count & (size_t) ~(IO_SIZE-1))-diff_length; - if ((read_length= mysql_file_read(info->file,Buffer, length, - info->myflags)) == (size_t) -1) - { - info->error= -1; - unlock_append_buffer(info); - return 1; - } - Count-=read_length; - Buffer+=read_length; - pos_in_file+=read_length; - - if (read_length != length) - { - /* - We only got part of data; Read the rest of the data from the - write buffer - */ - goto read_append_buffer; - } - left_length+=length; - diff_length=0; - } - - max_length= info->read_length-diff_length; - if (max_length > (info->end_of_file - pos_in_file)) - max_length= (size_t) (info->end_of_file - pos_in_file); - if (!max_length) - { - if (Count) - goto read_append_buffer; - length=0; /* Didn't read any more chars */ - } - else - { - length= mysql_file_read(info->file,info->buffer, max_length, info->myflags); - if (length == (size_t) -1) - { - info->error= -1; - unlock_append_buffer(info); - return 1; - } - if (length < Count) - { - memcpy(Buffer, info->buffer, length); - Count -= length; - Buffer += length; - - /* - added the line below to make - DBUG_ASSERT(pos_in_file==info->end_of_file) pass. - otherwise this does not appear to be needed - */ - pos_in_file += length; - goto read_append_buffer; - } - } - unlock_append_buffer(info); - info->read_pos=info->buffer+Count; - info->read_end=info->buffer+length; - info->pos_in_file=pos_in_file; - memcpy(Buffer,info->buffer,(size_t) Count); - return 0; - -read_append_buffer: - - /* - Read data from the current write buffer. - Count should never be == 0 here (The code will work even if count is 0) - */ - - { - /* First copy the data to Count */ - size_t len_in_buff = (size_t) (info->write_pos - info->append_read_pos); - size_t copy_len; - size_t transfer_len; - - DBUG_ASSERT(info->append_read_pos <= info->write_pos); - /* - TODO: figure out if the assert below is needed or correct. - */ - DBUG_ASSERT(pos_in_file == info->end_of_file); - copy_len= MY_MIN(Count, len_in_buff); - memcpy(Buffer, info->append_read_pos, copy_len); - info->append_read_pos += copy_len; - Count -= copy_len; - if (Count) - info->error = (int)(save_count - Count); - - /* Fill read buffer with data from write buffer */ - memcpy(info->buffer, info->append_read_pos, - (size_t) (transfer_len=len_in_buff - copy_len)); - info->read_pos= info->buffer; - info->read_end= info->buffer+transfer_len; - info->append_read_pos=info->write_pos; - info->pos_in_file=pos_in_file+copy_len; - info->end_of_file+=len_in_buff; - } - unlock_append_buffer(info); - return Count ? 1 : 0; -} - - -/* Read one byte when buffer is empty */ - -int _my_b_get(IO_CACHE *info) -{ - uchar buff; - IO_CACHE_CALLBACK pre_read,post_read; - if ((pre_read = info->pre_read)) - (*pre_read)(info); - if ((*(info)->read_function)(info,&buff,1)) - return my_b_EOF; - if ((post_read = info->post_read)) - (*post_read)(info); - return (int) (uchar) buff; -} - -/* - Write a byte buffer to IO_CACHE and flush to disk - if IO_CACHE is full. - - RETURN VALUE - 1 On error on write - 0 On success - -1 On error; my_errno contains error code. -*/ - -int _my_b_write(IO_CACHE *info, const uchar *Buffer, size_t Count) -{ - size_t rest_length,length; - my_off_t pos_in_file= info->pos_in_file; - - DBUG_EXECUTE_IF("simulate_huge_load_data_file", - { - pos_in_file=(my_off_t)(5000000000ULL); - }); - if (pos_in_file+info->buffer_length > info->end_of_file) - { - errno=EFBIG; - set_my_errno(EFBIG); - return info->error = -1; - } - - rest_length= (size_t) (info->write_end - info->write_pos); - memcpy(info->write_pos,Buffer,(size_t) rest_length); - Buffer+=rest_length; - Count-=rest_length; - info->write_pos+=rest_length; - - if (my_b_flush_io_cache(info,1)) - return 1; - if (Count >= IO_SIZE) - { /* Fill first intern buffer */ - length=Count & (size_t) ~(IO_SIZE-1); - if (info->seek_not_done) - { - /* - Whenever a function which operates on IO_CACHE flushes/writes - some part of the IO_CACHE to disk it will set the property - "seek_not_done" to indicate this to other functions operating - on the IO_CACHE. - */ - if (mysql_file_seek(info->file, info->pos_in_file, MY_SEEK_SET, MYF(0))) - { - info->error= -1; - return (1); - } - info->seek_not_done=0; - } - if (mysql_file_write(info->file, Buffer, length, info->myflags | MY_NABP)) - return info->error= -1; - - /* - In case of a shared I/O cache with a writer we normally do direct - write cache to read cache copy. Simulate this here by direct - caller buffer to read cache copy. Do it after the write so that - the cache readers actions on the flushed part can go in parallel - with the write of the extra stuff. copy_to_read_buffer() - synchronizes writer and readers so that after this call the - readers can act on the extra stuff while the writer can go ahead - and prepare the next output. copy_to_read_buffer() relies on - info->pos_in_file. - */ - if (info->share) - copy_to_read_buffer(info, Buffer, length); - - Count-=length; - Buffer+=length; - info->pos_in_file+=length; - } - memcpy(info->write_pos,Buffer,(size_t) Count); - info->write_pos+=Count; - return 0; -} - - -/* - Append a block to the write buffer. - This is done with the buffer locked to ensure that we don't read from - the write buffer before we are ready with it. -*/ - -int my_b_append(IO_CACHE *info, const uchar *Buffer, size_t Count) -{ - size_t rest_length,length; - - /* - Assert that we cannot come here with a shared cache. If we do one - day, we might need to add a call to copy_to_read_buffer(). - */ - DBUG_ASSERT(!info->share); - - lock_append_buffer(info); - rest_length= (size_t) (info->write_end - info->write_pos); - if (Count <= rest_length) - goto end; - memcpy(info->write_pos, Buffer, rest_length); - Buffer+=rest_length; - Count-=rest_length; - info->write_pos+=rest_length; - if (my_b_flush_io_cache(info,0)) - { - unlock_append_buffer(info); - return 1; - } - if (Count >= IO_SIZE) - { /* Fill first intern buffer */ - length=Count & (size_t) ~(IO_SIZE-1); - if (mysql_file_write(info->file,Buffer, length, info->myflags | MY_NABP)) - { - unlock_append_buffer(info); - return info->error= -1; - } - Count-=length; - Buffer+=length; - info->end_of_file+=length; - } - -end: - memcpy(info->write_pos,Buffer,(size_t) Count); - info->write_pos+=Count; - unlock_append_buffer(info); - return 0; -} - - -int my_b_safe_write(IO_CACHE *info, const uchar *Buffer, size_t Count) -{ - /* - Sasha: We are not writing this with the ? operator to avoid hitting - a possible compiler bug. At least gcc 2.95 cannot deal with - several layers of ternary operators that evaluated comma(,) operator - expressions inside - I do have a test case if somebody wants it - */ - if (info->type == SEQ_READ_APPEND) - return my_b_append(info, Buffer, Count); - return my_b_write(info, Buffer, Count); -} - - -/* - Write a block to disk where part of the data may be inside the record - buffer. As all write calls to the data goes through the cache, - we will never get a seek over the end of the buffer -*/ - -int my_block_write(IO_CACHE *info, const uchar *Buffer, size_t Count, - my_off_t pos) -{ - size_t length; - int error=0; - - /* - Assert that we cannot come here with a shared cache. If we do one - day, we might need to add a call to copy_to_read_buffer(). - */ - DBUG_ASSERT(!info->share); - - if (pos < info->pos_in_file) - { - /* Of no overlap, write everything without buffering */ - if (pos + Count <= info->pos_in_file) - return (int)mysql_file_pwrite(info->file, Buffer, Count, pos, - info->myflags | MY_NABP); - /* Write the part of the block that is before buffer */ - length= (uint) (info->pos_in_file - pos); - if (mysql_file_pwrite(info->file, Buffer, length, pos, info->myflags | MY_NABP)) - info->error= error= -1; - Buffer+=length; - pos+= length; - Count-= length; -#ifdef _WIN32 - info->seek_not_done=1; -#endif - } - - /* Check if we want to write inside the used part of the buffer.*/ - length= (size_t) (info->write_end - info->buffer); - if (pos < info->pos_in_file + length) - { - size_t offset= (size_t) (pos - info->pos_in_file); - length-=offset; - if (length > Count) - length=Count; - memcpy(info->buffer+offset, Buffer, length); - Buffer+=length; - Count-= length; - /* Fix length of buffer if the new data was larger */ - if (info->buffer+length > info->write_pos) - info->write_pos=info->buffer+length; - if (!Count) - return (error); - } - /* Write at the end of the current buffer; This is the normal case */ - if (_my_b_write(info, Buffer, Count)) - error= -1; - return error; -} - - - /* Flush write cache */ - -#define LOCK_APPEND_BUFFER if (need_append_buffer_lock) \ - lock_append_buffer(info); -#define UNLOCK_APPEND_BUFFER if (need_append_buffer_lock) \ - unlock_append_buffer(info); - -int my_b_flush_io_cache(IO_CACHE *info, - int need_append_buffer_lock MY_ATTRIBUTE((unused))) -{ - size_t length; - my_off_t pos_in_file; - my_bool append_cache= (info->type == SEQ_READ_APPEND); - DBUG_ENTER("my_b_flush_io_cache"); - DBUG_PRINT("enter", ("cache: 0x%lx", (long) info)); - - DBUG_EXECUTE_IF("simulate_error_during_flush_cache_to_file", - { - DBUG_RETURN(TRUE); - }); - if (!append_cache) - need_append_buffer_lock= 0; - - if (info->type == WRITE_CACHE || append_cache) - { - if (info->file == -1) - { - if (real_open_cached_file(info)) - DBUG_RETURN((info->error= -1)); - } - LOCK_APPEND_BUFFER; - - if ((length=(size_t) (info->write_pos - info->write_buffer))) - { - /* - In case of a shared I/O cache with a writer we do direct write - cache to read cache copy. Do it before the write here so that - the readers can work in parallel with the write. - copy_to_read_buffer() relies on info->pos_in_file. - */ - if (info->share) - copy_to_read_buffer(info, info->write_buffer, length); - - pos_in_file=info->pos_in_file; - /* - If we have append cache, we always open the file with - O_APPEND which moves the pos to EOF automatically on every write - */ - if (!append_cache && info->seek_not_done) - { /* File touched, do seek */ - if (mysql_file_seek(info->file, pos_in_file, MY_SEEK_SET, MYF(0)) == - MY_FILEPOS_ERROR) - { - UNLOCK_APPEND_BUFFER; - DBUG_RETURN((info->error= -1)); - } - if (!append_cache) - info->seek_not_done=0; - } - if (!append_cache) - info->pos_in_file+=length; - info->write_end= (info->write_buffer+info->buffer_length- - ((pos_in_file+length) & (IO_SIZE-1))); - - if (mysql_file_write(info->file,info->write_buffer,length, - info->myflags | MY_NABP)) - info->error= -1; - else - info->error= 0; - if (!append_cache) - { - set_if_bigger(info->end_of_file,(pos_in_file+length)); - } - else - { - info->end_of_file+=(info->write_pos-info->append_read_pos); - DBUG_ASSERT(info->end_of_file == mysql_file_tell(info->file, MYF(0))); - } - - info->append_read_pos=info->write_pos=info->write_buffer; - ++info->disk_writes; - UNLOCK_APPEND_BUFFER; - DBUG_RETURN(info->error); - } - } - UNLOCK_APPEND_BUFFER; - DBUG_RETURN(0); -} - -/* - Free an IO_CACHE object - - SYNOPSOS - end_io_cache() - info IO_CACHE Handle to free - - NOTES - It's currently safe to call this if one has called init_io_cache() - on the 'info' object, even if init_io_cache() failed. - This function is also safe to call twice with the same handle. - - RETURN - 0 ok - # Error -*/ - -int end_io_cache(IO_CACHE *info) -{ - int error=0; - IO_CACHE_CALLBACK pre_close; - DBUG_ENTER("end_io_cache"); - DBUG_PRINT("enter",("cache: 0x%lx", (ulong) info)); - - /* - Every thread must call remove_io_thread(). The last one destroys - the share elements. - */ - DBUG_ASSERT(!info->share || !info->share->total_threads); - - if ((pre_close=info->pre_close)) - { - (*pre_close)(info); - info->pre_close= 0; - } - if (info->alloced_buffer) - { - info->alloced_buffer=0; - if (info->file != -1) /* File doesn't exist */ - error= my_b_flush_io_cache(info,1); - my_free(info->buffer); - info->buffer=info->read_pos=(uchar*) 0; - } - if (info->type == SEQ_READ_APPEND) - { - /* Destroy allocated mutex */ - info->type= TYPE_NOT_SET; - mysql_mutex_destroy(&info->append_buffer_lock); - } - DBUG_RETURN(error); -} /* end_io_cache */ - - -/********************************************************************** - Testing of MF_IOCACHE -**********************************************************************/ - -#ifdef MAIN - -#include <my_dir.h> - -void die(const char* fmt, ...) -{ - va_list va_args; - va_start(va_args,fmt); - fprintf(stderr,"Error:"); - vfprintf(stderr, fmt,va_args); - fprintf(stderr,", errno=%d\n", errno); - exit(1); -} - -int open_file(const char* fname, IO_CACHE* info, int cache_size) -{ - int fd; - if ((fd=my_open(fname,O_CREAT | O_RDWR,MYF(MY_WME))) < 0) - die("Could not open %s", fname); - if (init_io_cache(info, fd, cache_size, SEQ_READ_APPEND, 0,0,MYF(MY_WME))) - die("failed in init_io_cache()"); - return fd; -} - -void close_file(IO_CACHE* info) -{ - end_io_cache(info); - my_close(info->file, MYF(MY_WME)); -} - -int main(int argc, char** argv) -{ - IO_CACHE sra_cache; /* SEQ_READ_APPEND */ - MY_STAT status; - const char* fname="/tmp/iocache.test"; - int cache_size=16384; - char llstr_buf[22]; - int max_block,total_bytes=0; - int i,num_loops=100,error=0; - char *p; - char* block, *block_end; - MY_INIT(argv[0]); - max_block = cache_size*3; - if (!(block=(char*)my_malloc(PSI_NOT_INSTRUMENTED, - max_block,MYF(MY_WME)))) - die("Not enough memory to allocate test block"); - block_end = block + max_block; - for (p = block,i=0; p < block_end;i++) - { - *p++ = (char)i; - } - if (my_stat(fname,&status, MYF(0)) && - my_delete(fname,MYF(MY_WME))) - { - die("Delete of %s failed, aborting", fname); - } - open_file(fname,&sra_cache, cache_size); - for (i = 0; i < num_loops; i++) - { - char buf[4]; - int block_size = abs(rand() % max_block); - int4store(buf, block_size); - if (my_b_append(&sra_cache,buf,4) || - my_b_append(&sra_cache, block, block_size)) - die("write failed"); - total_bytes += 4+block_size; - } - close_file(&sra_cache); - my_free(block); - if (!my_stat(fname,&status,MYF(MY_WME))) - die("%s failed to stat, but I had just closed it,\ - wonder how that happened"); - printf("Final size of %s is %s, wrote %d bytes\n",fname, - llstr(status.st_size,llstr_buf), - total_bytes); - my_delete(fname, MYF(MY_WME)); - /* check correctness of tests */ - if (total_bytes != status.st_size) - { - fprintf(stderr,"Not the same number of bytes acutally in file as bytes \ -supposedly written\n"); - error=1; - } - exit(error); - return 0; -} -#endif |