mariadb/innobase/usr/usr0sess.c
unknown 2662b59306 Added Innobase to source distribution
Docs/manual.texi:
  Added Innobase documentation
configure.in:
  Incremented version
include/my_base.h:
  Added option for Innobase
myisam/mi_check.c:
  cleanup
mysql-test/t/bdb.test:
  cleanup
mysql-test/t/innobase.test:
  Extended with new tests from bdb.test
mysql-test/t/merge.test:
  Added test of SHOW create
mysys/my_init.c:
  Fix for UNIXWARE 7
scripts/mysql_install_db.sh:
  Always write how to start mysqld
scripts/safe_mysqld.sh:
  Fixed type
sql/ha_innobase.cc:
  Update to new version
sql/ha_innobase.h:
  Update to new version
sql/handler.h:
  Added 'update_table_comment()' and 'append_create_info()'
sql/sql_delete.cc:
  Fixes for Innobase
sql/sql_select.cc:
  Fixes for Innobase
sql/sql_show.cc:
  Append create information (for MERGE tables)
sql/sql_update.cc:
  Fixes for Innobase
2001-02-17 14:19:19 +02:00

1174 lines
27 KiB
C

/******************************************************
Sessions
(c) 1996 Innobase Oy
Created 6/25/1996 Heikki Tuuri
*******************************************************/
#include "usr0sess.h"
#ifdef UNIV_NONINL
#include "usr0sess.ic"
#endif
#include "ut0rnd.h"
#include "mach0data.h"
#include "ha0ha.h"
#include "trx0trx.h"
#include "que0que.h"
#include "pars0pars.h"
#include "pars0sym.h"
#include "dict0dict.h"
#include "dict0mem.h"
#include "odbc0odbc.h"
#define SESS_ERR_BUF_SIZE 8192
/* The session system global data structure */
sess_sys_t* sess_sys = NULL;
/*************************************************************************
Communicates an error message to the client. If sess->client_waits is not
TRUE, puts the session to error state and does not try to send the error
message. */
static
void
sess_srv_msg_send_error(
/*====================*/
sess_t* sess); /* in: session object */
/*************************************************************************
Copies error info to a session. Sends to the transaction a signal which will
rollback the latest incomplete SQL statement and then send the error message
to the client. NOTE: This function will take care of the freeing of the error
string, thus the caller must supply a copy of the error string. */
static
void
sess_error_low(
/*===========*/
sess_t* sess, /* in: session object */
ulint err_no, /* in: error number */
char* err_str);/* in, own: error string or NULL;
NOTE: the function will take care of freeing of the
string! */
/*************************************************************************
Folds a session id to a ulint. Because this function is used also in
calculating a checksum for the id to write in the message, it is performs
also a XOR operation to mix the values more thoroughly. */
UNIV_INLINE
ulint
sess_id_fold(
/*=========*/
/* out: folded value; can be used also as the checksum
for id */
dulint id) /* in: session id */
{
return(ut_fold_dulint(id) ^ 2945794411U);
}
/*************************************************************************
Sets the session id in a client message. */
void
sess_cli_msg_set_sess(
/*==================*/
byte* str, /* in/out: message string */
dulint sess_id)/* in: session id */
{
ulint fold;
mach_write_to_8(str + SESS_CLI_MSG_SESS_ID, sess_id);
fold = sess_id_fold(sess_id);
mach_write_to_4(str + SESS_CLI_MSG_SESS_ID_CHECK, fold);
}
/*************************************************************************
Returns the session to which a message from a client is addressed.
NOTE: this function does not assume that the message is uncorrupted. */
static
sess_t*
sess_cli_msg_get_sess(
/*==================*/
/* out: session, NULL if not found */
byte* str, /* in: message string */
ulint len) /* in: message string length */
{
sess_t* sess;
ulint fold;
dulint id;
ut_ad(mutex_own(&kernel_mutex));
if (len < SESS_CLI_MSG_SESS_ID_CHECK + 4) {
return(NULL);
}
id = mach_read_from_8(str + SESS_CLI_MSG_SESS_ID);
fold = sess_id_fold(id);
if (fold != mach_read_from_4(str + SESS_CLI_MSG_SESS_ID_CHECK)) {
return(NULL);
}
HASH_SEARCH(hash, sess_sys->hash, fold, sess,
UT_DULINT_EQ(id, sess->id));
return(sess);
}
/***************************************************************************
Decrements the reference count of a session and closes it, if desired. */
UNIV_INLINE
void
sess_refer_count_dec(
/*=================*/
sess_t* sess) /* in: session */
{
ut_ad(mutex_own(&kernel_mutex));
ut_ad(sess->refer_count > 0);
sess->refer_count--;
if (sess->disconnecting && (sess->refer_count == 0)) {
sess_close(sess);
}
}
/***************************************************************************
Increments the reference count of a session. */
UNIV_INLINE
void
sess_refer_count_inc(
/*=================*/
sess_t* sess) /* in: session */
{
ut_ad(mutex_own(&kernel_mutex));
sess->refer_count++;
}
/***************************************************************************
Creates a session system at a database start. */
void
sess_sys_init_at_db_start(void)
/*===========================*/
{
sess_sys = mem_alloc(sizeof(sess_sys_t));
sess_sys->state = SESS_SYS_RUNNING;
sess_sys->free_sess_id = ut_dulint_create(0, 1);
sess_sys->hash = hash_create(SESS_HASH_SIZE);
}
/***************************************************************************
Gets the message type of a message from client. */
UNIV_INLINE
ulint
sess_cli_msg_get_type(
/*==================*/
/* out: message type */
byte* str) /* in: message string */
{
ut_ad(mutex_own(&kernel_mutex));
return(mach_read_from_4(str + SESS_CLI_MSG_TYPE));
}
/***************************************************************************
Gets the message number of a message from client. */
UNIV_INLINE
dulint
sess_cli_msg_get_msg_no(
/*====================*/
/* out: message number */
byte* str) /* in: message string */
{
ut_ad(mutex_own(&kernel_mutex));
return(mach_read_from_8(str + SESS_CLI_MSG_NO));
}
/***************************************************************************
Gets the continue field of a message from client. */
UNIV_INLINE
ulint
sess_cli_msg_get_continue(
/*======================*/
/* out: SESS_MSG_SINGLE_PART, ... */
byte* str) /* in: message string */
{
ut_ad(mutex_own(&kernel_mutex));
return(mach_read_from_4(str + SESS_CLI_MSG_CONTINUE));
}
/***************************************************************************
Gets the size of a big message in kilobytes. */
UNIV_INLINE
ulint
sess_cli_msg_get_cont_size(
/*=======================*/
/* out: size in kilobytes */
byte* str) /* in: message string */
{
ut_ad(mutex_own(&kernel_mutex));
return(mach_read_from_4(str + SESS_CLI_MSG_CONT_SIZE));
}
/*************************************************************************
Checks the consistency of a message from a client. */
UNIV_INLINE
ibool
sess_cli_msg_check_consistency(
/*===========================*/
/* out: TRUE if ok */
byte* str, /* in: message string */
ulint len) /* in: message string length */
{
ulint fold;
ut_ad(mutex_own(&kernel_mutex));
if (len < SESS_CLI_MSG_DATA) {
return(FALSE);
}
ut_ad(SESS_CLI_MSG_CHECKSUM == 0);
fold = ut_fold_binary(str + 4, len - 4);
if (mach_read_from_4(str + SESS_CLI_MSG_CHECKSUM) != fold) {
return(FALSE);
}
return(TRUE);
}
/*************************************************************************
Opens a session. */
sess_t*
sess_open(
/*======*/
/* out, own: session object */
com_endpoint_t* endpoint, /* in: communication endpoint used
for receiving messages from the client,
or NULL if no client */
byte* addr_buf, /* in: client address (= user name) */
ulint addr_len) /* in: client address length */
{
sess_t* sess;
ulint fold;
ut_ad(mutex_own(&kernel_mutex));
sess = mem_alloc(sizeof(sess_t));
sess->id = sess_sys->free_sess_id;
UT_DULINT_INC(sess_sys->free_sess_id);
sess->state = SESS_ACTIVE;
sess->disconnecting = FALSE;
sess->msgs_sent = ut_dulint_zero;
sess->msgs_recv = ut_dulint_zero;
sess->client_waits = TRUE;
sess->err_no = 0;
sess->err_str = NULL;
sess->error_count = ut_dulint_zero;
sess->big_msg = NULL;
sess->trx = trx_create(sess);
sess->next_graph_id = 0;
UT_LIST_INIT(sess->graphs);
fold = sess_id_fold(sess->id);
HASH_INSERT(sess_t, hash, sess_sys->hash, fold, sess);
sess->endpoint = endpoint;
sess->addr_buf = mem_alloc(addr_len);
ut_memcpy(sess->addr_buf, addr_buf, addr_len);
sess->addr_len = addr_len;
return(sess);
}
/*************************************************************************
Closes a session, freeing the memory occupied by it. */
void
sess_close(
/*=======*/
sess_t* sess) /* in, own: session object */
{
ulint fold;
ut_ad(mutex_own(&kernel_mutex));
ut_ad(sess->disconnecting);
ut_ad(sess->trx == NULL);
ut_ad(sess->refer_count == 0);
fold = ut_fold_dulint(sess->id);
HASH_DELETE(sess_t, hash, sess_sys->hash, fold, sess);
/* sess_reply_to_client_rel_kernel(sess); */
if (sess->err_str != NULL) {
mem_free(sess->err_str);
}
mem_free(sess->addr_buf);
mem_free(sess);
}
/*************************************************************************
Closes a session, freeing the memory occupied by it, if it is in a state
where it should be closed. */
ibool
sess_try_close(
/*===========*/
/* out: TRUE if closed */
sess_t* sess) /* in, own: session object */
{
ut_ad(mutex_own(&kernel_mutex));
if (sess->disconnecting && (UT_LIST_GET_LEN(sess->graphs) == 0)
&& (sess->refer_count == 0)) {
sess_close(sess);
return(TRUE);
}
return(FALSE);
}
/*************************************************************************
Initializes the first fields of a message to client. */
void
sess_srv_msg_init(
/*==============*/
sess_t* sess, /* in: session object */
byte* buf, /* in: message buffer, must be at least of size
SESS_SRV_MSG_DATA */
ulint type) /* in: message type */
{
ut_ad(mutex_own(&kernel_mutex));
sess->msgs_sent = ut_dulint_add(sess->msgs_sent, 1);
mach_write_to_8(buf + SESS_SRV_MSG_SESS_ID, sess->id);
mach_write_to_4(buf + SESS_SRV_MSG_TYPE, type);
mach_write_to_8(buf + SESS_SRV_MSG_NO, sess->msgs_sent);
ut_ad(com_endpoint_get_max_size(sess->endpoint) >= SESS_SRV_MSG_DATA);
}
/*************************************************************************
Sends a message to the client. */
static
ulint
sess_srv_msg_send_low(
/*==================*/
/* out: 0 if success, else error number */
sess_t* sess, /* in: session object */
byte* buf, /* in: message buffer */
ulint len, /* in: message length */
ulint rel_ker)/* in: SESS_RELEASE_KERNEL if the kernel mutex should
be temporarily released in the call; otherwise
SESS_NOT_RELEASE_KERNEL */
{
ulint ret;
ut_ad((rel_ker == SESS_NOT_RELEASE_KERNEL)
|| (rel_ker == SESS_RELEASE_KERNEL));
ut_ad(mutex_own(&kernel_mutex));
ut_ad(len <= com_endpoint_get_max_size(sess->endpoint));
ut_ad(len >= SESS_SRV_MSG_DATA);
if (sess->client_waits == FALSE) {
sess_error_low(sess, SESS_ERR_EXTRANEOUS_SRV_MSG, NULL);
return(1);
}
/* The client will now receive an error message: if the session is
in the error state, we can reset it to the normal state */
if (sess->state == SESS_ERROR) {
sess->state = SESS_ACTIVE;
}
/* We reset the client_waits flag to FALSE, regardless of whether the
message gets delivered to the client or not. This convention makes
things simpler. */
sess->client_waits = FALSE;
if (rel_ker == SESS_RELEASE_KERNEL) {
mutex_exit(&kernel_mutex);
}
ret = com_sendto(sess->endpoint, buf, len, sess->addr_buf,
sess->addr_len);
if (rel_ker == SESS_RELEASE_KERNEL) {
mutex_enter(&kernel_mutex);
}
if (ret != 0) {
sess_error_low(sess, SESS_ERR_REPLY_FAILED, NULL);
}
return(ret);
}
/*************************************************************************
Sends a message to the client. If the session is in the error state, sends
the error message instead of buf. */
static
ulint
sess_srv_msg_send(
/*==============*/
/* out: 0 if success, else error number */
sess_t* sess, /* in: session object */
byte* buf, /* in: message buffer */
ulint len, /* in: message length */
ulint rel_ker)/* in: SESS_RELEASE_KERNEL if the kernel mutex should
be temporarily released in the call; otherwise
SESS_NOT_RELEASE_KERNEL */
{
ulint ret;
ut_ad(mutex_own(&kernel_mutex));
if (sess->state == SESS_ERROR) {
sess_srv_msg_send_error(sess);
return(2);
}
ret = sess_srv_msg_send_low(sess, buf, len, rel_ker);
return(ret);
}
/*************************************************************************
Sends a simple message to client. */
void
sess_srv_msg_send_simple(
/*=====================*/
sess_t* sess, /* in: session object */
ulint type, /* in: message type */
ulint rel_kernel) /* in: SESS_RELEASE_KERNEL or
SESS_NOT_RELEASE_KERNEL */
{
byte buf[SESS_SRV_MSG_DATA];
ut_ad(mutex_own(&kernel_mutex));
sess_srv_msg_init(sess, buf, type);
sess_srv_msg_send(sess, buf, SESS_SRV_MSG_DATA, rel_kernel);
}
/*************************************************************************
Communicates an error message to the client. If sess->client_waits is not
TRUE, puts the session to error state and does not try to send the error
message. */
static
void
sess_srv_msg_send_error(
/*====================*/
sess_t* sess) /* in: session object */
{
ulint err_no;
byte* err_str;
ulint err_len;
ulint max_len;
byte buf[SESS_ERR_BUF_SIZE];
ulint ret;
ut_ad(sess->client_waits);
ut_ad(mutex_own(&kernel_mutex));
ut_ad(sess->state == SESS_ERROR);
ut_ad(!UT_LIST_GET_FIRST((sess->trx)->signals));
if (!sess->client_waits) {
/* Cannot send the error message now: leave the session to
the error state and send it later */
return;
}
err_no = sess->err_no;
err_str = (byte*)sess->err_str;
err_len = sess->err_len;
max_len = ut_min(SESS_ERR_BUF_SIZE,
com_endpoint_get_max_size(sess->endpoint));
sess_srv_msg_init(sess, buf, SESS_SRV_ERROR);
if (err_len + SESS_SRV_MSG_DATA > max_len) {
err_len = max_len - SESS_SRV_MSG_DATA;
}
ut_memcpy(buf + SESS_SRV_MSG_DATA, err_str, err_len);
ret = sess_srv_msg_send_low(sess, buf, SESS_SRV_MSG_DATA + err_len,
SESS_NOT_RELEASE_KERNEL);
}
/*************************************************************************
Copies error info to a session. Sends to the transaction a signal which will
rollback the latest incomplete SQL statement and then send the error message
to the client. NOTE: This function will take care of the freeing of the error
string, thus the caller must supply a copy of the error string. */
static
void
sess_error_low(
/*===========*/
sess_t* sess, /* in: session object */
ulint err_no, /* in: error number */
char* err_str)/* in, own: error string or NULL;
NOTE: the function will take care of freeing of the
string! */
{
ut_ad(mutex_own(&kernel_mutex));
UT_DULINT_INC(sess->error_count);
printf("Error string::: %s\n", err_str);
if (sess->state == SESS_ERROR) {
/* Ignore the error because the session is already in the
error state */
if (err_str) {
mem_free(err_str);
}
return;
}
sess->err_no = err_no;
if (sess->err_str) {
mem_free(sess->err_str);
}
sess->err_str = err_str;
sess->err_len = ut_strlen(err_str);
sess->state = SESS_ERROR;
if (sess->big_msg) {
mem_free(sess->big_msg);
}
/* Send a signal which will roll back the latest incomplete SQL
statement: the error message will be sent to the client by the error
handling mechanism after the rollback is completed. */
trx_sig_send(sess->trx, TRX_SIG_ERROR_OCCURRED, TRX_SIG_SELF, FALSE,
NULL, NULL, NULL);
}
/*************************************************************************
Raises an SQL error. */
void
sess_raise_error_low(
/*=================*/
trx_t* trx, /* in: transaction */
ulint err_no, /* in: error number */
ulint type, /* in: more info of the error, or 0 */
dict_table_t* table, /* in: dictionary table or NULL */
dict_index_t* index, /* in: table index or NULL */
dtuple_t* tuple, /* in: tuple to insert or NULL */
rec_t* rec, /* in: record or NULL */
char* err_str)/* in: arbitrary null-terminated error string,
or NULL */
{
char* str;
ulint len;
ut_ad(mutex_own(&kernel_mutex));
str = mem_alloc(64000);
len = 0;
len += sprintf(str + len, "Error number: %lu", err_no);
if (type) {
len += sprintf(str + len, ", type: %lu", type);
}
if (table) {
len += sprintf(str + len, ", table: %s", table->name);
}
if (index) {
len += sprintf(str + len, ", index: %s", index->name);
}
if (tuple) {
len += sprintf(str + len, ", tuple:");
len += dtuple_sprintf(str + len, 8192, tuple);
}
if (rec) {
len += sprintf(str + len, ", record:");
len += rec_sprintf(str + len, 8192, rec);
}
if (err_str) {
len += sprintf(str + len, ", %s", err_str);
}
str[len] = '\0';
ut_a(len < 64000);
if (trx->sess) {
sess_error_low(trx->sess, err_no, str);
} else {
mem_free(str);
}
}
/***************************************************************************
Processes a client message which is part of a bigger message. */
static
ibool
sess_receive_msg_part(
/*==================*/
/* TRUE if message completed */
sess_t* sess, /* in: session */
byte* str, /* in: message string */
ulint len) /* in: message length */
{
ulint cont;
cont = sess_cli_msg_get_continue(str);
ut_ad(cont != SESS_MSG_SINGLE_PART);
if (cont == SESS_MSG_FIRST_PART) {
if (sess->big_msg) {
sess_error_low(sess, SESS_ERR_MSG_LOST, NULL);
return(FALSE);
}
sess->big_msg_size = 1024 * sess_cli_msg_get_cont_size(str);
sess->big_msg = mem_alloc(sess->big_msg_size);
if (sess->big_msg == NULL) {
sess_error_low(sess, SESS_ERR_OUT_OF_MEMORY, NULL);
return(FALSE);
}
ut_memcpy(sess->big_msg, str, len);
sess->big_msg_len = len;
return(FALSE);
} else {
if (sess->big_msg == NULL) {
sess_error_low(sess, SESS_ERR_MSG_LOST, NULL);
return(FALSE);
}
ut_memcpy(sess->big_msg + sess->big_msg_len,
str + SESS_CLI_MSG_DATA, len - SESS_CLI_MSG_DATA);
sess->big_msg_len += len - SESS_CLI_MSG_DATA;
if (cont == SESS_MSG_MIDDLE_PART) {
return(FALSE);
}
return(TRUE);
}
}
/***************************************************************************
Processes a client message which requires SQL parsing. This function decodes
the client message built in SQLPrepare. NOTE: The kernel mutex is temporarily
released within this function. */
static
void
sess_receive_prepare(
/*=================*/
sess_t* sess, /* in: session */
byte* cli_msg,/* in: client message */
ulint len) /* in: message length */
{
dulint error_count;
que_t* graph;
byte msg[ODBC_DATAGRAM_SIZE];
UT_NOT_USED(len);
ut_ad(mutex_own(&kernel_mutex));
error_count = sess->error_count;
/* Make sure the session object is not freed during the parsing */
sess_refer_count_inc(sess);
/* We release the kernel mutex before parsing the command: this is
to reduce contention on the kernel mutex */
mutex_exit(&kernel_mutex);
/* printf("To parse query %s\n", (char*)(cli_msg + SESS_CLI_MSG_DATA)); */
graph = pars_sql((char*)(cli_msg + SESS_CLI_MSG_DATA));
mutex_enter(&kernel_mutex);
if (graph == NULL) {
/* Error in parsing */
sess_error_low(sess, SESS_ERR_SQL_ERROR, NULL);
sess_refer_count_dec(sess);
ut_error;
return;
}
if (!UT_DULINT_EQ(error_count, sess->error_count)) {
/* An error, or an asyncronous signal on the session happened
when the kernel mutex was not reserved: discard graph */
graph->state = QUE_FORK_INVALID;
que_graph_try_free(graph);
sess_refer_count_dec(sess);
ut_error;
return;
}
UT_LIST_ADD_LAST(graphs, sess->graphs, graph);
graph->id = sess->next_graph_id;
sess->next_graph_id++;
/* Tell the client that the preparation succeeded and communicate info
about the possible query parameters: the message will be decoded in
SQLPrepare */
ut_ad(sess->client_waits);
sess_srv_msg_init(sess, msg, SESS_SRV_SUCCESS);
mach_write_to_4(msg + SESS_SRV_MSG_DATA, graph->id);
mutex_exit(&kernel_mutex);
len = pars_write_query_param_info(msg + SESS_SRV_MSG_DATA + 4, graph);
mutex_enter(&kernel_mutex);
sess_srv_msg_send(sess, msg, SESS_SRV_MSG_DATA + 4 + len,
SESS_RELEASE_KERNEL);
sess_refer_count_dec(sess);
}
/***************************************************************************
Processes a client message which does not require SQL parsing. This function
decodes the client message built in SQLExecute. */
static
void
sess_receive_command(
/*=================*/
sess_t* sess, /* in: session */
byte* cli_msg,/* in: client message */
ulint len, /* in: message length */
ulint type) /* in: message type */
{
proc_node_t* proc_node;
call_node_t* call_node;
dict_proc_t* dict_proc;
que_thr_t* thr;
que_t* graph;
ulint stat_id;
UT_NOT_USED(len);
UT_NOT_USED(type);
ut_ad(mutex_own(&kernel_mutex));
sess->client_waits = TRUE;
stat_id = mach_read_from_4(cli_msg + SESS_CLI_MSG_DATA);
/* Look for the statement from the list of query graphs */
graph = UT_LIST_GET_FIRST(sess->graphs);
while (graph != NULL) {
if (graph->id == stat_id) {
break;
}
graph = UT_LIST_GET_NEXT(graphs, graph);
}
if (graph == NULL) {
/* Could not find the right graph: error */
sess_error_low(sess, SESS_ERR_STMT_NOT_FOUND, NULL);
return;
}
if (graph->state != QUE_FORK_COMMAND_WAIT) {
sess_error_low(sess, SESS_ERR_STMT_NOT_READY, NULL);
return;
}
/* printf("To execute stat %lu\n", stat_id); */
if (graph->fork_type == QUE_FORK_PROCEDURE_CALL) {
/* It is a stored procedure call: retrieve a parsed copy of
the procedure from the dictionary cache */
mutex_exit(&kernel_mutex);
call_node = que_fork_get_child(graph);
graph = dict_procedure_reserve_parsed_copy(
call_node->procedure_def);
graph->trx = sess->trx;
/* Retrieve the procedure input parameters from the message */
pars_proc_read_input_params_from_buf(graph,
cli_msg + SESS_CLI_MSG_DATA + 4);
mutex_enter(&kernel_mutex);
} else {
/* It is a create procedure command: add the procedure to the
dictionary cache */
ut_ad(graph->fork_type == QUE_FORK_PROCEDURE);
mutex_exit(&kernel_mutex);
proc_node = que_fork_get_child(graph);
dict_proc = dict_mem_procedure_create(proc_node->proc_id->name,
proc_node->sym_tab->sql_string,
graph);
dict_procedure_add_to_cache(dict_proc);
mutex_enter(&kernel_mutex);
sess_srv_msg_send_simple(sess, SESS_SRV_SUCCESS,
SESS_RELEASE_KERNEL);
return;
}
/* Choose a query thread for execution */
thr = que_fork_start_command(graph, SESS_COMM_EXECUTE, 0);
ut_ad(thr);
sess->trx->graph = graph;
mutex_exit(&kernel_mutex);
/* Run query threads with the kernel mutex released */
que_run_threads(thr);
mutex_enter(&kernel_mutex);
}
/***************************************************************************
When a command has been completed, this function sends the message about it
to the client. */
void
sess_command_completed_message(
/*===========================*/
sess_t* sess, /* in: session */
byte* msg, /* in: message buffer */
ulint len) /* in: message data length */
{
mutex_enter(&kernel_mutex);
sess_srv_msg_send(sess, msg, SESS_SRV_MSG_DATA + len,
SESS_RELEASE_KERNEL);
mutex_exit(&kernel_mutex);
}
/***************************************************************************
Processes a break message from the client. */
static
void
sess_receive_break(
/*===============*/
sess_t* sess) /* in: session */
{
ut_ad(mutex_own(&kernel_mutex));
/* Rollback the latest incomplete SQL statement */
sess_error_low(sess, SESS_ERR_BREAK_BY_CLIENT, NULL);
}
/***************************************************************************
Processes a message from a client. NOTE: Releases the kernel mutex temporarily
when parsing an SQL string. */
void
sess_receive_msg_rel_kernel(
/*========================*/
sess_t* sess, /* in: session */
byte* str, /* in: message string */
ulint len) /* in: message length */
{
dulint msg_no;
ulint msg_type;
ulint cont;
ibool is_big_msg = FALSE;
ibool client_waited;
ut_ad(mutex_own(&kernel_mutex));
ut_ad(!sess->disconnecting);
client_waited = sess->client_waits;
sess->client_waits = TRUE;
if (sess->state == SESS_ERROR) {
/* Send a buffered error message */
sess_srv_msg_send_error(sess);
return;
}
if (FALSE == sess_cli_msg_check_consistency(str, len)) {
/* Message from the client was corrupted */
sess_error_low(sess, SESS_ERR_MSG_CORRUPTED, NULL);
return;
}
msg_no = sess_cli_msg_get_msg_no(str);
UT_DULINT_INC(sess->msgs_recv);
if (!UT_DULINT_EQ(msg_no, sess->msgs_recv)) {
sess_error_low(sess, SESS_ERR_MSG_LOST, NULL);
sess->msgs_recv = msg_no;
return;
}
msg_type = sess_cli_msg_get_type(str);
if (msg_type == SESS_CLI_BREAK_EXECUTION) {
sess_receive_break(sess);
return;
}
if (client_waited) {
/* Client sent an extraneous message which is not a break
command: an error */
sess_error_low(sess, SESS_ERR_EXTRANEOUS_MSG, NULL);
return;
}
/*-----------------------------------------------------------*/
/* Handle big messages */
cont = sess_cli_msg_get_continue(str);
if (cont == SESS_MSG_SINGLE_PART) {
if (sess->big_msg) {
sess_error_low(sess, SESS_ERR_MSG_LOST, NULL);
return;
}
} else {
ut_error; /* Not in use */
is_big_msg = sess_receive_msg_part(sess, str, len);
if (is_big_msg) {
str = sess->big_msg;
len = sess->big_msg_len;
sess->big_msg = NULL;
} else {
return;
}
}
/*-----------------------------------------------------------*/
/* The session has received a complete message from the client */
ut_ad(!UT_LIST_GET_FIRST((sess->trx)->signals));
if (msg_type == SESS_CLI_PREPARE) {
/* Note that the kernel mutex is temporarily released when
the SQL string is parsed */
sess_receive_prepare(sess, str, len);
} else {
/* Note that the kernel mutex is temporarily released when the
command is executed */
sess_receive_command(sess, str, len, msg_type);
}
if (is_big_msg) {
mem_free(str);
}
}
/***********************************************************************
Opens a new connection and creates a session. */
static
ibool
sess_open_connection(
/*=================*/
byte* str, /* in: message string */
ulint len, /* in: string length */
byte* addr, /* in: user address string */
ulint alen) /* in: user address length */
{
dulint sess_id;
sess_t* sess;
sess_id = mach_read_from_8(str + SESS_CLI_MSG_SESS_ID);
if (!(UT_DULINT_EQ(sess_id, ut_dulint_zero))
|| !(sess_cli_msg_get_type(str) == SESS_CLI_CONNECT)) {
/* It is not a valid connect message */
return(FALSE);
}
ut_a(len == SESS_CLI_MSG_DATA);
sess = sess_open(srv_sys->endpoint, addr, alen);
sess_srv_msg_send_simple(sess, SESS_SRV_ACCEPT_CONNECT,
SESS_NOT_RELEASE_KERNEL);
return(TRUE);
}
/***********************************************************************
Starts a new connection and a session, or starts a query based on a client
message. This is called by a SRV_COM thread. */
void
sess_process_cli_msg(
/*=================*/
byte* str, /* in: message string */
ulint len, /* in: string length */
byte* addr, /* in: address string */
ulint alen) /* in: address length */
{
sess_t* sess;
ibool success;
UT_NOT_USED(addr);
UT_NOT_USED(alen);
mutex_enter(&kernel_mutex);
sess = sess_cli_msg_get_sess(str, len);
if (sess == NULL) {
/* There was no matching session */
if (sess_cli_msg_check_consistency(str, len)) {
/* As the message is consistent, it may be a connect
message */
/* printf("%s\n", addr); */
success = sess_open_connection(str, len, addr, alen);
if (success) {
mutex_exit(&kernel_mutex);
return;
}
}
/* Could not make sense of the message: write an error entry
to the system error log */
/* srv_err_log_insert(
"MESSAGE SENT TO AN UNKNOWN SESSION");*/
ut_error;
mutex_exit(&kernel_mutex);
return;
}
if (sess->disconnecting) {
/* srv_err_log_insert(
"MESSAGE SENT TO A DISCONNECTING SESSION");*/
ut_error;
mutex_exit(&kernel_mutex);
return;
}
sess_receive_msg_rel_kernel(sess, str, len);
mutex_exit(&kernel_mutex);
}