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/*
* mt_support.c - multi-thread resource locking support
*/
/*
* Author: Markku Laukkanen
* Created: 6-Sep-1999
* History:
* 8-Sep-1999 M. Slifcak method names changed;
* use array of resource locking structures.
*/
#include <net-snmp/net-snmp-config.h>
#include <errno.h>
#include <net-snmp/library/mt_support.h>
#ifdef __cplusplus
extern "C" {
#endif
#ifdef NETSNMP_REENTRANT
static mutex_type s_res[MT_MAX_IDS][MT_LIB_MAXIMUM]; /* locking structures */
static mutex_type *
_mt_res(int groupID, int resourceID)
{
if (groupID < 0) {
return 0;
}
if (groupID >= MT_MAX_IDS) {
return 0;
}
if (resourceID < 0) {
return 0;
}
if (resourceID >= MT_LIB_MAXIMUM) {
return 0;
}
return (&s_res[groupID][resourceID]);
}
static int
snmp_res_init_mutex(mutex_type *mutex)
{
int rc = 0;
#if HAVE_PTHREAD_H
pthread_mutexattr_t attr;
pthread_mutexattr_init(&attr);
pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
rc = pthread_mutex_init(mutex, &attr);
pthread_mutexattr_destroy(&attr);
#elif defined(WIN32)
InitializeCriticalSection(mutex);
#endif
return rc;
}
int
snmp_res_init(void)
{
int ii, jj, rc = 0;
mutex_type *mutex;
for (jj = 0; (0 == rc) && (jj < MT_MAX_IDS); jj++) {
for (ii = 0; (0 == rc) && (ii < MT_LIB_MAXIMUM); ii++) {
mutex = _mt_res(jj, ii);
if (!mutex) {
continue;
}
rc = snmp_res_init_mutex(mutex);
}
}
return rc;
}
int
snmp_res_destroy_mutex(int groupID, int resourceID)
{
int rc = 0;
mutex_type *mutex = _mt_res(groupID, resourceID);
if (!mutex) {
return EFAULT;
}
#if HAVE_PTHREAD_H
rc = pthread_mutex_destroy(mutex);
#elif defined(WIN32)
DeleteCriticalSection(mutex);
#endif
return rc;
}
int
snmp_res_lock(int groupID, int resourceID)
{
int rc = 0;
mutex_type *mutex = _mt_res(groupID, resourceID);
if (!mutex) {
return EFAULT;
}
#if HAVE_PTHREAD_H
rc = pthread_mutex_lock(mutex);
#elif defined(WIN32)
EnterCriticalSection(mutex);
#endif
return rc;
}
int
snmp_res_unlock(int groupID, int resourceID)
{
int rc = 0;
mutex_type *mutex = _mt_res(groupID, resourceID);
if (!mutex) {
return EFAULT;
}
#if HAVE_PTHREAD_H
rc = pthread_mutex_unlock(mutex);
#elif defined(WIN32)
LeaveCriticalSection(mutex);
#endif
return rc;
}
#else /* NETSNMP_REENTRANT */
#ifdef WIN32
/*
* Provide "do nothing" targets for Release (.DLL) builds.
*/
int
snmp_res_init(void)
{
return 0;
}
int
snmp_res_lock(int groupID, int resourceID)
{
return 0;
}
int
snmp_res_unlock(int groupID, int resourceID)
{
return 0;
}
int
snmp_res_destroy_mutex(int groupID, int resourceID)
{
return 0;
}
#endif /* WIN32 */
#endif /* NETSNMP_REENTRANT */
#ifdef __cplusplus
}
#endif
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