How stable is ocilib

Question

I have this code, which uses OCIlib:

int HoleInstrumentenDiffListeDB(GTree *tree)
{

  OCI_Connection* cn;
  OCI_Statement* st;
  OCI_Resultset* rs;
  if (!OCI_Initialize(err_handler, NULL, OCI_ENV_DEFAULT))
        return EXIT_FAILURE;
  char query[500];
  query[0] ='\0';
  cn = OCI_ConnectionCreate( "db", "user",  "pass", OCI_SESSION_DEFAULT);
  st = OCI_StatementCreate(cn);
  strcat(query, "SELECT...");
  OCI_ExecuteStmt(st, query);
  rs = OCI_GetResultset(st);
  int i = 1;
  int j = 0;
  char *symbolp;
  while (OCI_FetchNext(rs)){

    const char * symbolp = OCI_GetString(rs,2);
    switch ( * OCI_GetString(rs,3))
    {
      case 'N':
        insertQot(tree, symbolp, OCI_GetInt(rs, 1) );
        printf("new \n");
        break;
      case 'U':
        insertQot(tree, symbolp, OCI_GetInt(rs, 1) );
        printf("upd \n");
        break;
      case 'D':
        deleteQot(tree, symbolp);
        printf("del \n");
        break;
     }
  }
  OCI_Cleanup();
  return 1;
}

The connection is made, the select seems to work. But while checking it with valgrind I'm getting a lot of errorrs. Here few of them:

==21085== Source and destination overlap in memcpy(0x742dc80, 0x742dc80, 1)
==21085==    at 0x4A24F66: _intel_fast_memcpy (mc_replace_strmem.c:894)
==21085==    by 0x562E6D7: kpufprow (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x562BFDE: kpufch0 (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x562ACB6: kpufch (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x5520A2F: OCIStmtFetch2 (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x4CDAF6E: OCI_FetchData (resultset.c:506)
==21085==    by 0x4CDB405: OCI_FetchNext (resultset.c:1117)
==21085==    by 0x401B95: HoleInstrumentenDiffListeDB (unzipper_m.c:221)
==21085==    by 0x402AA9: main (unzipper_m.c:691)


==21085== Conditional jump or move depends on uninitialised value(s)
==21085==    at 0x5EC79DF: slpmloclfv (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x5EC771E: slpmloc (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x5EC4C44: lpmloadpkg (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x5EAAA8E: lfvLoadPkg (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x5EAA719: lfvSetShlMode (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x5EAA518: lfvini1 (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x5EAA234: lfvinit (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x5ACD1C9: kpummpin (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x547EED8: kpuenvcr (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x551FCD5: OCIEnvCreate (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x4CE311B: OCI_Initialize (library.c:1140)
==21085==    by 0x401942: HoleInstrumentenDiffListeDB (unzipper_m.c:207)



==21085== Use of uninitialised value of size 8
==21085==    at 0x56DFE05: ztceadecbk (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x56DC6BC: ztceb_decblk (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x56DC3BE: ztcebf (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x56DBB8A: ztcef (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x56DBC6E: ztcedec (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x57341A3: ztvo5ed (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x5734FA5: ztvo5ver (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x54C899D: kpu8lgn (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x54C649C: kpuauthxa (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x54C5EA5: kpuauth (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x551FF1A: OCISessionBegin (in /opt/oracle/product/10.2/lib/libclntsh.so.10.1)
==21085==    by 0x4CD45EA: OCI_ConnectionLogon (connection.c:598)

Can I improve my code? If not - how safe is it to leave it like it is ?

Answer 1

first, you should call OCI_Initialize() and OCI_Cleanup() once per application and preferably from the main thread.

Regarding the Valgrind traces you have, you can see that it concerns internal code from Oracle client shared library shipped by Oracle. You'll get the same with an application coded using pure OCI code. These traces are not related to OCILIB code that is build on top OCI.

Create an app that is just calling the OCI call OCIEnvCreate() and look at the Valgrind traces. You'll have similar traces.

Regards,

Vincent