1 files changed, 169 insertions, 0 deletions
diff --git a/snmplib/mt_support.c b/snmplib/mt_support.c
new file mode 100644
index 0000000..d28ebe4
--- /dev/null
+++ b/snmplib/mt_support.c
@@ -0,0 +1,169 @@
+/*
+ * 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