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/*******************************************************************/
/* sltdl: a surrogate ltdl implementation */
/* Copyright (C) 2019 Z. Gilboa */
/* Released under the Standard MIT License; see COPYING.SLTDL. */
/*******************************************************************/
#include <dlfcn.h>
#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <sltdl/sltdl.h>
#include "sltdl_core.h"
static const char * lt_dlerror_desc[] = {
[SLTDL_OK] = 0,
[SLTDL_SYSTEM_ERROR] = 0,
[SLTDL_DLFCN_ERROR] = 0,
[SLTDL_SLTDL_ERROR] = "sltdl internal error",
[SLTDL_DLEXIT_REF_COUNT] = "lt_dlexit() reference count already zero",
[SLTDL_MODULE_REF_COUNT] = "module reference count already zero",
[SLTDL_MODULE_PTR_INVALID] = "module handle invalid",
[SLTDL_PATH_INVALID_FIRST_CHAR] = "invalid path (does not begin with a forward slash)",
[SLTDL_PATH_INVALID_SEPARATTOR_CHAR] = "invalid path (separator character is not a colon)",
[SLTDL_PATH_INVALID_MARK] = "invalid path (mark not within range)",
[SLTDL_PATH_INVALID_LEN] = "invalid path (string too long)",
[SLTDL_PATH_NO_ENTRY] = "invalid path (not found)",
};
static int lt_refs = 0;
static int lt_error = 0;
static int lt_errno = 0;
static char * lt_dlerr = 0;
static pthread_mutex_t lt_lock = PTHREAD_MUTEX_INITIALIZER;
int lt_dlinit(void)
{
if (pthread_mutex_lock(<_lock))
return 1;
lt_refs++;
pthread_mutex_unlock(<_lock);
return 0;
}
int lt_dlexit(void)
{
if (pthread_mutex_lock(<_lock))
return 1;
if (!lt_refs) {
lt_error = SLTDL_DLEXIT_REF_COUNT;
pthread_mutex_unlock(<_lock);
return 1;
}
lt_refs--;
pthread_mutex_unlock(<_lock);
return 0;
}
void lt_slock(void)
{
int locked;
do {
locked = pthread_mutex_lock(<_lock);
} while (locked);
}
int lt_sunlock(int ret, int error)
{
if (error == 0) {
pthread_mutex_unlock(<_lock);
return 0;
}
if ((error < 0) || (error >= SLTDL_ERROR_CAP)) {
error = SLTDL_SLTDL_ERROR;
} else if (error == SLTDL_SYSTEM_ERROR) {
lt_errno = errno;
} else if (error == SLTDL_DLFCN_ERROR) {
if (lt_dlerr)
free(lt_dlerr);
lt_dlerr = strdup(dlerror());
}
lt_error = error;
pthread_mutex_unlock(<_lock);
return ret;
}
const char * lt_dlerror(void)
{
const char * errdesc;
lt_slock();
switch (lt_error) {
case SLTDL_OK:
errdesc = 0;
break;
case SLTDL_SYSTEM_ERROR:
errdesc = strerror(lt_errno);
break;
case SLTDL_DLFCN_ERROR:
errdesc = lt_dlerr;
break;
default:
errdesc = lt_dlerror_desc[lt_error];
break;
}
lt_error = 0;
lt_sunlock(0,0);
return errdesc;
}
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