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pro*c multithreaded application has memory leak

From: Jaguk Ku <jkku_at_kynax.com>
Date: Sun, 7 Dec 2003 15:28:06 +0900
Message-ID: <bques6$7qi$1@news1.kornet.net> 





Hi there,



I posted this message a week ago, nobody answer me, and the message was
deleted.


I am really curious if my application has a bug or the pro*c has a bug.
Anyone can compile the sample code and test it easily.



I made multithreaded application which queries dynamic SQL, it works.
But the memory leaks when i query the SQL statement.
The more memory leaks, the more i query the SQL statement, even same SQL
statement.


I check it with top, shell command.



My machine is SUN E450, Solaris 8. Oracle 9.2.0.1
Compiler : gcc (GCC) 3.2.2



I changed source code which is from


$(ORACLE_HOME)/precomp/demo/proc/sample10.pc
the sample10 doesn't need to be multithreaded. But i think it has to work
correctly if i changed it to multithreaded application.
the make file and source code will be placed below.



I have to figure out the problem.


Please help



Thanks in advance,



the make file is below


######################################################################

HOME = /user/jkku


ORA = $(ORACLE_HOME)


CC = gcc


PROC = proc



LC_INCL = -I$(HOME)/work/dbmss/libs/include
lc_incl = include=$(HOME)/work/dbmss/libs/include

SYS_INCL =
sys_incl =
ORA_INCL = -I. \
-I$(ORA)/precomp/public \
-I$(ORA)/rdbms/public \
-I$(ORA)/rdbms/demo \
-I$(ORA)/rdbms/pbsql/public \




-I$(ORA)/network/public \


-DSLMXMX_ENABLE -DSLTS_ENABLE -D_SVID_GETTOD


INCLUDES = $(LC_INCL) $(SYS_INCL) $(ORA_INCL)

includes = $(lc_incl) $(sys_incl)



LC_LIBS =



SYS_LIBS = -lpthread -lsocket -lnsl -lrt
ORA_LIBS = -L$(ORA)/lib/ -lclntsh



LIBS = $(LC_LIBS) $(SYS_LIBS) $(ORA_LIBS)




# Define C Compiler flags



CFLAGS += -D_Solaris64_ -m64


CFLAGS += -g -D_REENTRANT



# Define pro*c Compiler flags



PROCFLAGS += THREADS=YES



PROCFLAGS += CPOOL=YES




# Our object files



PRECOMPS = sample10.c



OBJS = sample10.o



.SUFFIXES: .o .c .pc



.c.o:


$(CC) -c $(CFLAGS) $(INCLUDES) $*.c



.pc.c:


$(PROC) $(PROCFLAGS) $(includes) $*.pc $*.c



all: sample10



sample10: $(PRECOMPS) $(OBJS)


$(CC) $(CFLAGS) -o sample10 $(OBJS) $(LIBS)



clean:


rm -rf *.o sample10 sample10.c



######################################################################





the source code is below which i changed the oracle sample10.pc to
multithreaded application.


######################################################################


/*******************************************************************


Sample Program 10: Dynamic SQL Method 4



This program connects you to ORACLE using your username and
password, then prompts you for a SQL statement. You can enter
any legal SQL statement. Use regular SQL syntax, not embedded SQL.
Your statement will be processed. If it is a query, the rows
fetched are displayed.


You can enter multi-line statements. The limit is 1023 characters.
This sample program only processes up to MAX_ITEMS bind variables and
MAX_ITEMS select-list items. MAX_ITEMS is #defined to be 40.

*******************************************************************/



#include <stdio.h>

#include <string.h>

#include <setjmp.h>

#include <sqlda.h>



#include <stdlib.h>

#include <sqlcpr.h>




/* Maximum number of select-list items or bind variables. */


#define MAX_ITEMS 40




/* Maximum lengths of the _names_ of the
select-list items or indicator variables. */


#define MAX_VNAME_LEN 30

#define MAX_INAME_LEN 30




#ifndef NULL

#define NULL 0

#endif




/* Prototypes */


#if defined(__STDC__)



void sql_error(void);


int oracle_connect(void);


int alloc_descriptors(int, int, int);


int get_dyn_statement(void);


void set_bind_variables(void);


void process_select_list(void);


void help(void);


#else



void sql_error(/*_ void _*/);


int oracle_connect(/*_ void _*/);


int alloc_descriptors(/*_ int, int, int _*/);
int get_dyn_statement(/* void _*/);


void set_bind_variables(/*_ void -*/);


void process_select_list(/*_ void _*/);


void help(/*_ void _*/);


#endif




char *dml_commands[] = {"SELECT", "select", "INSERT", "insert",
"UPDATE", "update", "DELETE", "delete"};



EXEC SQL INCLUDE sqlda;


EXEC SQL INCLUDE sqlca;



EXEC SQL BEGIN DECLARE SECTION;



char dyn_statement[1024];


EXEC SQL VAR dyn_statement IS STRING(1024);
EXEC SQL END DECLARE SECTION;


EXEC ORACLE OPTION (ORACA=YES);



EXEC ORACLE OPTION (RELEASE_CURSOR=YES);


SQLDA *bind_dp;


SQLDA *select_dp;



/* Define a buffer to hold longjmp state info. */
jmp_buf jmp_continue;




char *db_uid="dbmuser/dbmuser_at_dbmdb";


sql_context ctx;


int err_sql;



enum{

SQL_SUCC=0,
SQL_ERR,
SQL_NOTFOUND,
SQL_UNIQUE,
SQL_DISCONNECT,
SQL_NOTNULL




};




int main()


{


int i;



EXEC SQL ENABLE THREADS;


EXEC SQL WHENEVER SQLERROR DO sql_error();
EXEC SQL WHENEVER NOT FOUND DO sql_not_found();



/* Connect to the database. */


if (connect_database() < 0)


exit(1);



EXEC SQL CONTEXT USE :ctx;



/* Process SQL statements. */


for (;;)


{


/* Allocate memory for the select and bind descriptors. */
if (alloc_descriptors(MAX_ITEMS, MAX_VNAME_LEN, MAX_INAME_LEN) != 0)
exit(1);



(void) setjmp(jmp_continue);



/* Get the statement. Break on "exit". */
if (get_dyn_statement() != 0)


break;



EXEC SQL PREPARE S FROM :dyn_statement;



EXEC SQL DECLARE C CURSOR FOR S;


/* Set the bind variables for any placeholders in the
SQL statement. */


set_bind_variables();



/* Open the cursor and execute the statement.

* If the statement is not a query (SELECT), the
* statement processing is completed after the
* OPEN.
*/





EXEC SQL OPEN C USING DESCRIPTOR bind_dp;



/* Call the function that processes the select-list.

* If the statement is not a query, this function
* just returns, doing nothing.
*/




process_select_list();



/* Tell user how many rows processed. */
for (i = 0; i < 8; i++)


{


if (strncmp(dyn_statement, dml_commands, 6) == 0)
{


printf("\n\n%d row%c processed.\n", sqlca.sqlerrd[2],
sqlca.sqlerrd[2] == 1 ? '\0' : 's');


break;


}


}


/* Close the cursor. */


EXEC SQL CLOSE C;


/* When done, free the memory allocated for pointers in the bind and
select descriptors. */


for (i = 0; i < MAX_ITEMS; i++)


{


if (bind_dp->V != (char *) 0)


free(bind_dp->V);


free(bind_dp->I); /* MAX_ITEMS were allocated. */
if (select_dp->V != (char *) 0)


free(select_dp->V);


free(select_dp->I); /* MAX_ITEMS were allocated. */
}



/* Free space used by the descriptors themselves. */
SQLSQLDAFree(ctx, bind_dp);


SQLSQLDAFree(ctx, select_dp);


} /* end of for(;;) statement-processing loop */
disconnect_database();



EXEC SQL WHENEVER SQLERROR CONTINUE;


EXEC SQL COMMIT WORK RELEASE;



puts("\nHave a good day!\n");



return;


}



/*

* Allocate the BIND and SELECT descriptors using sqlald().
* Also allocate the pointers to indicator variables
* in each descriptor. The pointers to the actual bind
* variables and the select-list items are realloc'ed in
* the set_bind_variables() or process_select_list()
* routines. This routine allocates 1 byte for select_dp->V
* and bind_dp->V, so the realloc will work correctly.
*/





alloc_descriptors(size, max_vname_len, max_iname_len)
int size;


int max_vname_len;


int max_iname_len;


{


int i;



/*

* The first sqlald parameter determines the maximum number of
* array elements in each variable in the descriptor. In
* other words, it determines the maximum number of bind
* variables or select-list items in the SQL statement.
*
* The second parameter determines the maximum length of
* strings used to hold the names of select-list items
* or placeholders. The maximum length of column
* names in ORACLE is 30, but you can allocate more or less
* as needed.
*
* The third parameter determines the maximum length of
* strings used to hold the names of any indicator
* variables. To follow ORACLE standards, the maximum
* length of these should be 30. But, you can allocate
* more or less as needed.
*/





if ((bind_dp =


SQLSQLDAAlloc(ctx, size, max_vname_len, max_iname_len)) ==
(SQLDA *) 0)



{


fprintf(stderr,


"Cannot allocate memory for bind descriptor.");
return -1; /* Have to exit in this case. */
}



if ((select_dp =


SQLSQLDAAlloc(ctx, size, max_vname_len, max_iname_len)) == (SQLDA *)
0)


{


fprintf(stderr,


"Cannot allocate memory for select descriptor.");
return -1;


}


select_dp->N = MAX_ITEMS;



/* Allocate the pointers to the indicator variables, and the
actual data. */


for (i = 0; i < MAX_ITEMS; i++) {


bind_dp->I = (short *) malloc(sizeof (short));
select_dp->I = (short *) malloc(sizeof(short));
bind_dp->V = (char *) malloc(1);


select_dp->V = (char *) malloc(1);


}



return 0;


}




int get_dyn_statement()


{


char *cp, linebuf[256];


int iter, plsql;




for (plsql = 0, iter = 1; ;)


{


if (iter == 1)


{


printf("\nSQL> ");


dyn_statement[0] = '\0';


}



fgets(linebuf, sizeof linebuf, stdin);



cp = strrchr(linebuf, '\n');


if (cp && cp != linebuf)


*cp = ' ';


else if (cp == linebuf)


continue;



if ((strncmp(linebuf, "EXIT", 4) == 0) ||
(strncmp(linebuf, "exit", 4) == 0))


{


return -1;


}


else if (linebuf[0] == '?' ||
(strncmp(linebuf, "HELP", 4) == 0) ||
(strncmp(linebuf, "help", 4) == 0))




{


help();


iter = 1;


continue;


}



if (strstr(linebuf, "BEGIN") ||


(strstr(linebuf, "begin")))


{


plsql = 1;


}



strcat(dyn_statement, linebuf);



if ((plsql && (cp = strrchr(dyn_statement, '/'))) ||
(!plsql && (cp = strrchr(dyn_statement, ';'))))
{


*cp = '\0';


break;


}


else


{


iter++;


printf("%3d ", iter);


}


}


return 0;


}





void set_bind_variables()


{


int i, n;


char bind_var[64];



/* Describe any bind variables (input host variables) */
EXEC SQL WHENEVER SQLERROR DO sql_error();



bind_dp->N = MAX_ITEMS; /* Initialize count of array elements. */
EXEC SQL DESCRIBE BIND VARIABLES FOR S INTO bind_dp;



/* If F is negative, there were more bind variables
than originally allocated by sqlald(). */
if (bind_dp->F < 0)


{


printf ("\nToo many bind variables (%d), maximum is %d\n.",
-bind_dp->F, MAX_ITEMS);


return;


}



/* Set the maximum number of array elements in the
descriptor to the number found. */


bind_dp->N = bind_dp->F;



/* Get the value of each bind variable as a

* character string.
*
* C contains the length of the bind variable
* name used in the SQL statement.
* S contains the actual name of the bind variable
* used in the SQL statement.
*
* L will contain the length of the data value
* entered.
*
* V will contain the address of the data value
* entered.
*
* T is always set to 1 because in this sample program
* data values for all bind variables are entered
* as character strings.
* ORACLE converts to the table value from CHAR.
*
* I will point to the indicator value, which is
* set to -1 when the bind variable value is "null".
*/




for (i = 0; i < bind_dp->F; i++)


{


printf ("\nEnter value for bind variable %.*s: ",
(int)bind_dp->C, bind_dp->S);


fgets(bind_var, sizeof bind_var, stdin);



/* Get length and remove the new line character. */
n = strlen(bind_var) - 1;



/* Set it in the descriptor. */


bind_dp->L = n;



/* (re-)allocate the buffer for the value.
sqlald() reserves a pointer location for
V but does not allocate the full space for
the pointer. */


bind_dp->V = (char *) realloc(bind_dp->V, (bind_dp->L + 1));



/* And copy it in. */


strncpy(bind_dp->V, bind_var, n);



/* Set the indicator variable's value. */
if ((strncmp(bind_dp->V, "NULL", 4) == 0) ||
(strncmp(bind_dp->V, "null", 4) == 0))


*bind_dp->I = -1;


else


*bind_dp->I = 0;



/* Set the bind datatype to 1 for CHAR. */
bind_dp->T = 1;


}



return;


}



void process_select_list()


{


int i, null_ok, precision, scale;



if ((strncmp(dyn_statement, "SELECT", 6) != 0) &&
(strncmp(dyn_statement, "select", 6) != 0))
{


select_dp->F = 0;


return;


}



/* If the SQL statement is a SELECT, describe the
select-list items. The DESCRIBE function returns
their names, datatypes, lengths (including precision
and scale), and NULL/NOT NULL statuses. */



select_dp->N = MAX_ITEMS;



EXEC SQL DESCRIBE SELECT LIST FOR S INTO select_dp;



/* If F is negative, there were more select-list
items than originally allocated by sqlald(). */
if (select_dp->F < 0)


{


printf ("\nToo many select-list items (%d), maximum is %d\n",
-(select_dp->F), MAX_ITEMS);


return;


}



/* Set the maximum number of array elements in the
descriptor to the number found. */


select_dp->N = select_dp->F;



/* Allocate storage for each select-list item.



sqlprc() is used to extract precision and scale
from the length (select_dp->L).



sqlnul() is used to reset the high-order bit of
the datatype and to check whether the column
is NOT NULL.



CHAR datatypes have length, but zero precision and
scale. The length is defined at CREATE time.



NUMBER datatypes have precision and scale only if
defined at CREATE time. If the column


definition was just NUMBER, the precision
and scale are zero, and you must allocate
the required maximum length.



DATE datatypes return a length of 7 if the default
format is used. This should be increased to
9 to store the actual date character string.
If you use the TO_CHAR function, the maximum
length could be 75, but will probably be less
(you can see the effects of this in SQL*Plus).



ROWID datatype always returns a fixed length of 18 if
coerced to CHAR.



LONG and


LONG RAW datatypes return a length of 0 (zero),
so you need to set a maximum. In this example,
it is 240 characters.



*/



printf ("\n");


for (i = 0; i < select_dp->F; i++)


{


char title[MAX_VNAME_LEN];


/* Turn off high-order bit of datatype (in this example,
it does not matter if the column is NOT NULL). */
sqlnul ((unsigned short *)&(select_dp->T), (unsigned short
*)&(select_dp->T), &null_ok);



switch (select_dp->T)


{


case 1 : /* CHAR datatype: no change in length
needed, except possibly for TO_CHAR


conversions (not handled here). */


break;


case 2 : /* NUMBER datatype: use sqlprc() to
extract precision and scale. */


sqlprc ((unsigned int *)&(select_dp->L), &precision,
&scale);


/* Allow for maximum size of NUMBER. */


if (precision == 0) precision = 40;


/* Also allow for decimal point and


possible sign. */


/* convert NUMBER datatype to FLOAT if scale > 0,
INT otherwise. */


if (scale > 0)


select_dp->L = sizeof(float);


else


select_dp->L = sizeof(int);


break;



case 8 : /* LONG datatype */


select_dp->L = 240;


break;



case 11 : /* ROWID datatype */


case 104 : /* Universal ROWID datatype */
select_dp->L = 18;


break;



case 12 : /* DATE datatype */


select_dp->L = 9;


break;



case 23 : /* RAW datatype */


break;



case 24 : /* LONG RAW datatype */


select_dp->L = 240;


break;


}


/* Allocate space for the select-list data values.
sqlald() reserves a pointer location for
V but does not allocate the full space for
the pointer. */



if (select_dp->T != 2)


select_dp->V = (char *) realloc(select_dp->V,
select_dp->L + 1);


else


select_dp->V = (char *) realloc(select_dp->V,
select_dp->L);



/* Print column headings, right-justifying number
column headings. */



/* Copy to temporary buffer in case name is null-terminated */
memset(title, ' ', MAX_VNAME_LEN);


strncpy(title, select_dp->S, select_dp->C);
if (select_dp->T == 2)


if (scale > 0)


printf ("%.*s ", select_dp->L+3, title);
else


printf ("%.*s ", select_dp->L, title);


else


printf("%-.*s ", select_dp->L, title);



/* Coerce ALL datatypes except for LONG RAW and NUMBER to
character. */


if (select_dp->T != 24 && select_dp->T != 2)
select_dp->T = 1;



/* Coerce the datatypes of NUMBERs to float or int depending on
the scale. */


if (select_dp->T == 2)


if (scale > 0)


select_dp->T = 4; /* float */


else


select_dp->T = 3; /* int */


}


printf ("\n\n");



/* FETCH each row selected and print the column values. */
EXEC SQL WHENEVER NOT FOUND GOTO end_select_loop;



for (;;)


{


EXEC SQL FETCH C USING DESCRIPTOR select_dp;



/* Since each variable returned has been coerced to a
character string, int, or float very little processing
is required here. This routine just prints out the
values on the terminal. */


for (i = 0; i < select_dp->F; i++)


{


if (*select_dp->I < 0)


if (select_dp->T == 4)


printf ("%-*c ",(int)select_dp->L+3, ' ');
else


printf ("%-*c ",(int)select_dp->L, ' ');
else


if (select_dp->T == 3) /* int datatype */
printf ("%*d ", (int)select_dp->L,


*(int *)select_dp->V);


else if (select_dp->T == 4) /* float datatype */
printf ("%*.2f ", (int)select_dp->L,


*(float *)select_dp->V);


else /* character string */


printf ("%-*.*s ", (int)select_dp->L,


(int)select_dp->L, select_dp->V);


}


printf ("\n");


}


end_select_loop:



return;


}



void help()


{

puts("\n\nEnter a SQL statement or a PL/SQL block at the SQL> prompt.");
puts("Statements can be continued over several lines, except");
puts("within string literals.");
puts("Terminate a SQL statement with a semicolon.");
puts("Terminate a PL/SQL block (which can contain embedded


semicolons)");

puts("with a slash (/).");
puts("Typing \"exit\" (no semicolon needed) exits the program.");
puts("You typed \"?\" or \"help\" to get this message.\n\n");


}



int connect_database()


{


err_sql = SQL_SUCC;


EXEC SQL WHENEVER SQLERROR DO sql_error();
EXEC SQL WHENEVER NOT FOUND DO sql_not_found();
EXEC SQL CONTEXT ALLOCATE :ctx;


EXEC SQL CONTEXT USE :ctx;


EXEC SQL CONNECT :db_uid;



if(err_sql != SQL_SUCC){


printf("err => connect database(ctx:%ld, uid:%s) failed!\n", ctx, db_uid);
return -1;


}



return 1;


}



int disconnect_database()


{


err_sql = SQL_SUCC;


EXEC SQL WHENEVER SQLERROR DO sql_error();
EXEC SQL WHENEVER NOT FOUND DO sql_not_found();
EXEC SQL CONTEXT USE :ctx;


EXEC SQL COMMIT WORK RELEASE;



EXEC SQL CONTEXT FREE:ctx;



return 1;


}



void sql_error()


{

printf("err => %.*s", sqlca.sqlerrm.sqlerrml, sqlca.sqlerrm.sqlerrmc);
printf("in \"%.*s...\'\n", oraca.orastxt.orastxtl, oraca.orastxt.orastxtc);
printf("on line %d of %.*s.\n\n", oraca.oraslnr, oraca.orasfnm.orasfnml,


oraca.orasfnm.orasfnmc);



switch(sqlca.sqlcode) {


case -1: /* unique constraint violated */
err_sql = SQL_UNIQUE;


break;

case -1012: /* not logged on */
case -1089:
case -3133:
case -1041:
case -3114:
case -3113:
/* 오라클이 shutdown되거나 로그인 상태가 아닐때 재접속 시도 */
/* immediate shutdown in progress - no operations are permitted */


/* end-of-file on communication channel */
/* internal error. hostdef extension doesn't exist */
err_sql = SQL_DISCONNECT;


break;


case -1400:


err_sql = SQL_NOTNULL;


break;


default:


err_sql = SQL_ERR;


break;


}



EXEC SQL CONTEXT USE :ctx;


EXEC SQL WHENEVER SQLERROR CONTINUE;



EXEC SQL ROLLBACK WORK;



}



void sql_not_found()


{


err_sql = SQL_NOTFOUND;


}



######################################################################

Received on Sun Dec 07 2003 - 00:28:06 CST












Original text of this message













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