254 lines
11 KiB
C
254 lines
11 KiB
C
/****************************************************************
|
|
* *
|
|
* Copyright 2006, 2012 Fidelity Information Services, Inc *
|
|
* *
|
|
* This source code contains the intellectual property *
|
|
* of its copyright holder(s), and is made available *
|
|
* under a license. If you do not know the terms of *
|
|
* the license, please stop and do not read further. *
|
|
* *
|
|
****************************************************************/
|
|
|
|
#include "mdef.h"
|
|
|
|
#include "gtm_string.h"
|
|
#include "gtm_socket.h"
|
|
#include "gtm_inet.h"
|
|
#include "gtm_fcntl.h"
|
|
#include "gtm_unistd.h"
|
|
#include "gtm_stat.h"
|
|
|
|
#include <sys/time.h>
|
|
#include <errno.h>
|
|
#ifdef VMS
|
|
#include <descrip.h> /* Required for gtmsource.h */
|
|
#endif
|
|
|
|
#include "gdsroot.h"
|
|
#include "gdsblk.h"
|
|
#include "gtm_facility.h"
|
|
#include "fileinfo.h"
|
|
#include "gdsbt.h"
|
|
#include "gdsfhead.h"
|
|
#include "filestruct.h"
|
|
#include "repl_msg.h"
|
|
#include "gtmsource.h"
|
|
#include "jnl.h"
|
|
#include "buddy_list.h"
|
|
#include "hashtab_mname.h" /* needed for muprec.h */
|
|
#include "hashtab_int4.h" /* needed for muprec.h */
|
|
#include "hashtab_int8.h" /* needed for muprec.h */
|
|
#include "muprec.h"
|
|
#include "repl_ctl.h"
|
|
#include "repl_errno.h"
|
|
#include "repl_dbg.h"
|
|
#include "memcoherency.h"
|
|
#include "repl_tr_good.h"
|
|
#include "min_max.h"
|
|
#include "repl_instance.h"
|
|
|
|
GBLREF jnlpool_addrs jnlpool;
|
|
GBLREF gtmsource_state_t gtmsource_state;
|
|
|
|
int gtmsource_readpool(uchar_ptr_t buff, int *data_len, int maxbufflen, boolean_t read_multiple, qw_num stop_read_at)
|
|
{
|
|
uint4 jnldata_len, read_size, read, jnlpool_size, avail_data;
|
|
uint4 first_tr_len, num_tr_read, tr_len;
|
|
int4 wrap_size;
|
|
uchar_ptr_t buf_top, tr_p;
|
|
jnlpool_ctl_ptr_t jctl;
|
|
gtmsource_local_ptr_t gtmsource_local;
|
|
sm_uc_ptr_t jnldata_base;
|
|
jnldata_hdr_ptr_t jnl_header;
|
|
qw_num read_addr, avail_data_qw;
|
|
seq_num read_jnl_seqno, jnl_seqno, next_read_seqno, next_histinfo_seqno;
|
|
|
|
jctl = jnlpool.jnlpool_ctl;
|
|
jnlpool_size = jctl->jnlpool_size;
|
|
DEBUG_ONLY(jnl_seqno = jctl->jnl_seqno;) /* jnl_seqno is used in an assert below. jnl_seqno is a local variable for
|
|
* debugging purposes since shared memory can change from the time the assert
|
|
* fails to the time the core gets created
|
|
*/
|
|
jnldata_base = jnlpool.jnldata_base;
|
|
gtmsource_local = jnlpool.gtmsource_local;
|
|
do
|
|
{
|
|
read = gtmsource_local->read;
|
|
read_addr = gtmsource_local->read_addr;
|
|
assert(stop_read_at > read_addr); /* there should be data to be read, if not how did we end up here? */
|
|
read_jnl_seqno = gtmsource_local->read_jnl_seqno;
|
|
assert(read_jnl_seqno <= gtmsource_local->next_histinfo_seqno);
|
|
if (read_jnl_seqno == gtmsource_local->next_histinfo_seqno)
|
|
{ /* Request a REPL_HISTREC message be sent first before sending any more seqnos across */
|
|
gtmsource_state = gtmsource_local->gtmsource_state = GTMSOURCE_SEND_NEW_HISTINFO;
|
|
return 0;
|
|
}
|
|
next_histinfo_seqno = gtmsource_local->next_histinfo_seqno;
|
|
next_read_seqno = read_jnl_seqno;
|
|
if (jnlpool_hasnt_overflowed(jctl, jnlpool_size, read_addr))
|
|
{ /* No overflow yet. Before we read the content (including the jnldata_len read below), we have to ensure
|
|
* we read up-to-date content. We rely on the memory barrier done in jnlpool_hasnt_overflowed for this.
|
|
*/
|
|
assert(read + SIZEOF(jnldata_hdr_struct) <= jnlpool_size);
|
|
jnl_header = (jnldata_hdr_ptr_t)(jnldata_base + read);
|
|
first_tr_len = jnldata_len = jnl_header->jnldata_len;
|
|
if (read_multiple)
|
|
{
|
|
assert(stop_read_at >= read_addr);
|
|
avail_data_qw = stop_read_at - read_addr;
|
|
assert(maxbufflen <= MAXPOSINT4); /* to catch the case of change in type of maxbufflen */
|
|
avail_data = (uint4)MIN(avail_data_qw, (qw_num)maxbufflen);
|
|
assert(next_read_seqno < next_histinfo_seqno);
|
|
read_multiple = (first_tr_len < avail_data) && ((next_read_seqno + 1) < next_histinfo_seqno);
|
|
if (read_multiple)
|
|
jnldata_len = avail_data;
|
|
}
|
|
if (SIZEOF(jnldata_hdr_struct) < jnldata_len && jnldata_len <= jnlpool_size)
|
|
{
|
|
read_size = jnldata_len - SIZEOF(jnldata_hdr_struct);
|
|
if (0 < read_size && read_size <= maxbufflen)
|
|
{
|
|
if (0 < (wrap_size = (int4)(read - (jnlpool_size - jnldata_len))))
|
|
read_size -= wrap_size;
|
|
memcpy(buff, (sm_uc_ptr_t)jnl_header + SIZEOF(jnldata_hdr_struct), read_size);
|
|
if (0 < wrap_size)
|
|
memcpy(buff + read_size, jnldata_base, wrap_size);
|
|
/* Now that we have read the content, we have to ensure that we haven't read content
|
|
* that may been overwritten. We rely on the memory barrier done in
|
|
* jnlpool_hasnt_overflowed for this
|
|
*/
|
|
if (jnlpool_hasnt_overflowed(jctl, jnlpool_size, read_addr))
|
|
{ /* No overflow. Only now are we guaranteed a good value of "first_tr_len". */
|
|
assert(first_tr_len % JNL_WRT_END_MODULUS == 0);
|
|
REPL_DEBUG_ONLY(
|
|
assert(repl_tr_good(buff, first_tr_len - SIZEOF(jnldata_hdr_struct),
|
|
read_jnl_seqno));
|
|
num_tr_read = 1;
|
|
)
|
|
next_read_seqno++;
|
|
assert(next_read_seqno <= next_histinfo_seqno);
|
|
if (read_multiple)
|
|
{ /* Although stop_read_at - read_addr contains no partial transaction, it
|
|
* is possible that stop_read_at - read_addr is more than maxbufflen, and
|
|
* hence we read fewer bytes than stop_read_at - read_addr; scan what we
|
|
* read to figure out if the tail is an incomplete transaction.
|
|
*/
|
|
assert(first_tr_len < jnldata_len); /* must hold if multiple transactions
|
|
were read */
|
|
tr_p = buff + first_tr_len - SIZEOF(jnldata_hdr_struct);
|
|
buf_top = buff + jnldata_len - SIZEOF(jnldata_hdr_struct);
|
|
while (SIZEOF(jnldata_hdr_struct) < (buf_top - tr_p))
|
|
{ /* more than hdr available */
|
|
tr_len = ((jnldata_hdr_ptr_t)tr_p)->jnldata_len;
|
|
assert(tr_len % JNL_WRT_END_MODULUS == 0);
|
|
assert(0 < tr_len);
|
|
assert(tr_len <= jnlpool_size);
|
|
if (tr_len <= (buf_top - tr_p)) /* transaction completely read */
|
|
{ /* The message type and len assignments are a violation of
|
|
* layering; ideally, this should be done in
|
|
* gtmsource_process(), but we choose to do it here for
|
|
* performance reasons. If we have to do it in
|
|
* gtmsource_process(), we have to scan the buffer again.
|
|
*/
|
|
((repl_msg_ptr_t)tr_p)->type = REPL_TR_JNL_RECS;
|
|
((repl_msg_ptr_t)tr_p)->len = tr_len;
|
|
REPL_DEBUG_ONLY(
|
|
assert(repl_tr_good(tr_p + REPL_MSG_HDRLEN,
|
|
tr_len - REPL_MSG_HDRLEN,
|
|
read_jnl_seqno + num_tr_read));
|
|
num_tr_read++;
|
|
)
|
|
next_read_seqno++;
|
|
tr_p += tr_len;
|
|
if (next_read_seqno >= next_histinfo_seqno)
|
|
{ /* Dont read more than boundary of next histinfo */
|
|
assert(next_read_seqno == next_histinfo_seqno);
|
|
break;
|
|
}
|
|
} else
|
|
{
|
|
REPL_DPRINT5("Partial transaction read since jnldata_len"
|
|
" %llu larger than maxbufflen %d, tr_len %d, "
|
|
"remaining buffer %d\n", avail_data_qw, maxbufflen,
|
|
tr_len, buf_top - tr_p);
|
|
break;
|
|
}
|
|
}
|
|
REPL_DEBUG_ONLY(
|
|
if (0 != (buf_top - tr_p))
|
|
{
|
|
REPL_DPRINT4("Partial tr header read since jnldata_len "
|
|
"%llu larger than maxbufflen %d, incomplete header"
|
|
" length %d\n", avail_data_qw, maxbufflen,
|
|
buf_top - tr_p);
|
|
}
|
|
)
|
|
jnldata_len = (uint4)((tr_p - buff) + SIZEOF(jnldata_hdr_struct));
|
|
wrap_size = (int4)(read - (jnlpool_size - jnldata_len));
|
|
}
|
|
REPL_DPRINT4("Pool read seqno : "INT8_FMT" Num Tr read : %d Total Tr len : %d\n",
|
|
INT8_PRINT(read_jnl_seqno), num_tr_read, jnldata_len);
|
|
REPL_DPRINT4("Read %u : Next read : %u : %s\n", read,
|
|
(0 > wrap_size) ? read + jnldata_len : wrap_size,
|
|
(0 > wrap_size) ? "" : " READ WRAPPED");
|
|
assert(next_read_seqno <= next_histinfo_seqno);
|
|
/* Before sending the seqnos, check if a new histinfo got concurrently written */
|
|
assert(gtmsource_local->next_histinfo_num <= gtmsource_local->num_histinfo);
|
|
if ((gtmsource_local->next_histinfo_num == gtmsource_local->num_histinfo)
|
|
&& (gtmsource_local->num_histinfo
|
|
!= jnlpool.repl_inst_filehdr->num_histinfo))
|
|
{ /* We are sending seqnos of the last histinfo (that is open-ended) and
|
|
* there has been at least one histinfo concurrently added to this instance
|
|
* file compared to what is in our private memory. Set the next histinfo's
|
|
* start_seqno and redo the read with the new "next_histinfo_seqno".
|
|
*/
|
|
assert(MAX_SEQNO == gtmsource_local->next_histinfo_seqno);
|
|
gtmsource_set_next_histinfo_seqno(TRUE);
|
|
/* Set the next histinfo's start_seqno and redo the read */
|
|
if (GTMSOURCE_WAITING_FOR_CONNECTION == gtmsource_state)
|
|
{ /* Connection reset in "gtmsource_set_next_histinfo_seqno" */
|
|
return 0;
|
|
}
|
|
continue;
|
|
}
|
|
read = ((0 > wrap_size) ? read + jnldata_len : wrap_size);
|
|
read_addr += jnldata_len;
|
|
read_jnl_seqno = next_read_seqno;
|
|
assert(read_jnl_seqno <= gtmsource_local->next_histinfo_seqno);
|
|
assert(stop_read_at >= read_addr);
|
|
assert(jnl_seqno >= read_jnl_seqno - 1);
|
|
/* In the rare case when we read the transaction read_jnl_seqno just as
|
|
* it becomes available and before the GTM process that wrote it updates
|
|
* jctl->jnl_seqno in t_end/tp_tend, we may return from this function
|
|
* with read_jnl_seqno one more than jctl->jnl_seqno. This is such a rare
|
|
* case that we don't want to add a wait loop for jctl->jnl_seqno to become
|
|
* equal to read_jnl_seqno. We expect that by the time we send the just read
|
|
* transaction(s) using socket I/O, jctl->jnl_seqno would have been updated.
|
|
* In any case, we prevent ourselves from misinterpreting this condition when
|
|
* read_jnl_seqno is compared against jctl->jnl_seqno in gtmsource_process(),
|
|
* gtmsource_get_jnlrecs() and gtmsource_showbacklog().
|
|
*/
|
|
assert(read == read_addr % jnlpool_size);
|
|
gtmsource_local->read = read;
|
|
gtmsource_local->read_addr = read_addr;
|
|
gtmsource_local->read_jnl_seqno = read_jnl_seqno;
|
|
*data_len = first_tr_len - SIZEOF(jnldata_hdr_struct);
|
|
return (jnldata_len);
|
|
} /* else overflow happened, or about to happen */
|
|
} else if (0 < read_size && jnlpool_hasnt_overflowed(jctl, jnlpool_size, read_addr))
|
|
{ /* Buffer cannot accommodate data */
|
|
*data_len = read_size;
|
|
return (-1);
|
|
} /* else
|
|
* We read a corrupt (overwritten) large value, or read_size == 0, both of which imply overflow.
|
|
* read_size == 0 => overflow because every transaction generates non-zero bytes of jnl data */
|
|
} /* else
|
|
* We read a corrupt (overwritten) large value, or read 0, both of which imply overflow.
|
|
* jnldata_len == 0 => overflow because every transaction generates non-zero bytes of jnl data */
|
|
} /* else overflow happened, or about to happen */
|
|
break;
|
|
} while (TRUE);
|
|
*data_len = -1;
|
|
return (-1); /* Error indication */
|
|
}
|