alpar@1: /* glpenv01.c (environment initialization/termination) */
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  This code is part of GLPK (GNU Linear Programming Kit).
alpar@1: *
alpar@1: *  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
alpar@1: *  2009, 2010 Andrew Makhorin, Department for Applied Informatics,
alpar@1: *  Moscow Aviation Institute, Moscow, Russia. All rights reserved.
alpar@1: *  E-mail: <mao@gnu.org>.
alpar@1: *
alpar@1: *  GLPK is free software: you can redistribute it and/or modify it
alpar@1: *  under the terms of the GNU General Public License as published by
alpar@1: *  the Free Software Foundation, either version 3 of the License, or
alpar@1: *  (at your option) any later version.
alpar@1: *
alpar@1: *  GLPK is distributed in the hope that it will be useful, but WITHOUT
alpar@1: *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
alpar@1: *  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
alpar@1: *  License for more details.
alpar@1: *
alpar@1: *  You should have received a copy of the GNU General Public License
alpar@1: *  along with GLPK. If not, see <http://www.gnu.org/licenses/>.
alpar@1: ***********************************************************************/
alpar@1: 
alpar@1: #include "glpapi.h"
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  glp_init_env - initialize GLPK environment
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  int glp_init_env(void);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine glp_init_env initializes the GLPK environment. Normally
alpar@1: *  the application program does not need to call this routine, because
alpar@1: *  it is called automatically on the first call to any API routine.
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  The routine glp_init_env returns one of the following codes:
alpar@1: *
alpar@1: *  0 - initialization successful;
alpar@1: *  1 - environment has been already initialized;
alpar@1: *  2 - initialization failed (insufficient memory);
alpar@1: *  3 - initialization failed (unsupported programming model). */
alpar@1: 
alpar@1: int glp_init_env(void)
alpar@1: {     ENV *env;
alpar@1:       int ok;
alpar@1:       /* check if the programming model is supported */
alpar@1:       ok = (CHAR_BIT == 8 && sizeof(char) == 1 &&
alpar@1:          sizeof(short) == 2 && sizeof(int) == 4 &&
alpar@1:          (sizeof(void *) == 4 || sizeof(void *) == 8));
alpar@1:       if (!ok) return 3;
alpar@1:       /* check if the environment is already initialized */
alpar@1:       if (tls_get_ptr() != NULL) return 1;
alpar@1:       /* allocate and initialize the environment block */
alpar@1:       env = malloc(sizeof(ENV));
alpar@1:       if (env == NULL) return 2;
alpar@1:       env->magic = ENV_MAGIC;
alpar@1:       sprintf(env->version, "%d.%d",
alpar@1:          GLP_MAJOR_VERSION, GLP_MINOR_VERSION);
alpar@1:       env->term_buf = malloc(TERM_BUF_SIZE);
alpar@1:       if (env->term_buf == NULL)
alpar@1:       {  free(env);
alpar@1:          return 2;
alpar@1:       }
alpar@1:       env->term_out = GLP_ON;
alpar@1:       env->term_hook = NULL;
alpar@1:       env->term_info = NULL;
alpar@1:       env->tee_file = NULL;
alpar@1:       env->err_file = "";
alpar@1:       env->err_line = 0;
alpar@1:       env->err_hook = NULL;
alpar@1:       env->err_info = NULL;
alpar@1:       env->mem_limit.hi = 0x7FFFFFFF, env->mem_limit.lo = 0xFFFFFFFF;
alpar@1:       env->mem_ptr = NULL;
alpar@1:       env->mem_count = env->mem_cpeak = 0;
alpar@1:       env->mem_total = env->mem_tpeak = xlset(0);
alpar@1:       env->file_ptr = NULL;
alpar@1:       env->ioerr_msg = malloc(IOERR_MSG_SIZE);
alpar@1:       if (env->ioerr_msg == NULL)
alpar@1:       {  free(env->term_buf);
alpar@1:          free(env);
alpar@1:          return 2;
alpar@1:       }
alpar@1:       strcpy(env->ioerr_msg, "No error");
alpar@1:       env->h_odbc = env->h_mysql = NULL;
alpar@1:       /* save pointer to the environment block */
alpar@1:       tls_set_ptr(env);
alpar@1:       /* initialization successful */
alpar@1:       return 0;
alpar@1: }
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  get_env_ptr - retrieve pointer to environment block
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpenv.h"
alpar@1: *  ENV *get_env_ptr(void);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine get_env_ptr retrieves and returns a pointer to the GLPK
alpar@1: *  environment block.
alpar@1: *
alpar@1: *  If the GLPK environment has not been initialized yet, the routine
alpar@1: *  performs initialization. If initialization fails, the routine prints
alpar@1: *  an error message to stderr and terminates the program.
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  The routine returns a pointer to the environment block. */
alpar@1: 
alpar@1: ENV *get_env_ptr(void)
alpar@1: {     ENV *env = tls_get_ptr();
alpar@1:       /* check if the environment has been initialized */
alpar@1:       if (env == NULL)
alpar@1:       {  /* not initialized yet; perform initialization */
alpar@1:          if (glp_init_env() != 0)
alpar@1:          {  /* initialization failed; display an error message */
alpar@1:             fprintf(stderr, "GLPK initialization failed\n");
alpar@1:             fflush(stderr);
alpar@1:             /* and abnormally terminate the program */
alpar@1:             abort();
alpar@1:          }
alpar@1:          /* initialization successful; retrieve the pointer */
alpar@1:          env = tls_get_ptr();
alpar@1:       }
alpar@1:       /* check if the environment block is valid */
alpar@1:       if (env->magic != ENV_MAGIC)
alpar@1:       {  fprintf(stderr, "Invalid GLPK environment\n");
alpar@1:          fflush(stderr);
alpar@1:          abort();
alpar@1:       }
alpar@1:       return env;
alpar@1: }
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  glp_version - determine library version
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  const char *glp_version(void);
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  The routine glp_version returns a pointer to a null-terminated
alpar@1: *  character string, which specifies the version of the GLPK library in
alpar@1: *  the form "X.Y", where X is the major version number, and Y is the
alpar@1: *  minor version number, for example, "4.16". */
alpar@1: 
alpar@1: const char *glp_version(void)
alpar@1: {     ENV *env = get_env_ptr();
alpar@1:       return env->version;
alpar@1: }
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  glp_free_env - free GLPK environment
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  int glp_free_env(void);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine glp_free_env frees all resources used by GLPK routines
alpar@1: *  (memory blocks, etc.) which are currently still in use.
alpar@1: *
alpar@1: *  Normally the application program does not need to call this routine,
alpar@1: *  because GLPK routines always free all unused resources. However, if
alpar@1: *  the application program even has deleted all problem objects, there
alpar@1: *  will be several memory blocks still allocated for the library needs.
alpar@1: *  For some reasons the application program may want GLPK to free this
alpar@1: *  memory, in which case it should call glp_free_env.
alpar@1: *
alpar@1: *  Note that a call to glp_free_env invalidates all problem objects as
alpar@1: *  if no GLPK routine were called.
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  0 - termination successful;
alpar@1: *  1 - environment is inactive (was not initialized). */
alpar@1: 
alpar@1: int glp_free_env(void)
alpar@1: {     ENV *env = tls_get_ptr();
alpar@1:       MEM *desc;
alpar@1:       /* check if the environment is active */
alpar@1:       if (env == NULL) return 1;
alpar@1:       /* check if the environment block is valid */
alpar@1:       if (env->magic != ENV_MAGIC)
alpar@1:       {  fprintf(stderr, "Invalid GLPK environment\n");
alpar@1:          fflush(stderr);
alpar@1:          abort();
alpar@1:       }
alpar@1:       /* close handles to shared libraries */
alpar@1:       if (env->h_odbc != NULL)
alpar@1:          xdlclose(env->h_odbc);
alpar@1:       if (env->h_mysql != NULL)
alpar@1:          xdlclose(env->h_mysql);
alpar@1:       /* close streams which are still open */
alpar@1:       while (env->file_ptr != NULL)
alpar@1:          xfclose(env->file_ptr);
alpar@1:       /* free memory blocks which are still allocated */
alpar@1:       while (env->mem_ptr != NULL)
alpar@1:       {  desc = env->mem_ptr;
alpar@1:          env->mem_ptr = desc->next;
alpar@1:          free(desc);
alpar@1:       }
alpar@1:       /* invalidate the environment block */
alpar@1:       env->magic = -1;
alpar@1:       /* free memory allocated to the environment block */
alpar@1:       free(env->term_buf);
alpar@1:       free(env->ioerr_msg);
alpar@1:       free(env);
alpar@1:       /* reset a pointer to the environment block */
alpar@1:       tls_set_ptr(NULL);
alpar@1:       /* termination successful */
alpar@1:       return 0;
alpar@1: }
alpar@1: 
alpar@1: /* eof */