Add reference counting to library initialization and deinitialization.

include/cconfigspace/base.h

@@ -701,17 +701,25 @@ extern const ccs_datum_t ccs_false;
 #endif
 
 /**
- * The library initialization function. Should be called before any operation
- * using the library are performed.
- * @return #CCS_RESULT_SUCCESS
+ * The library initialization function. The library usage is ref counted, so
+ * this function can be called several times.
+ * @return #CCS_RESULT_SUCCESS on success
+ * @return #CCS_RESULT_ERROR_INVALID_VALUE if the library reference count is
+ * found to be invalid
+ * @remarks
+ * This function is thread-safe
  */
 extern ccs_result_t
 ccs_init();
 
 /**
- * The library deinitialization function. Should be called after all operations
- * using the library are performed.
- * @return #CCS_RESULT_SUCCESS
+ * The library deinitialization function. When done using the library, should
+ * be called once for each time #ccs_init was called.
+ * @return #CCS_RESULT_SUCCESS on success
+ * @return #CCS_RESULT_ERROR_INVALID_VALUE if the library reference count is
+ * found to be invalid
+ * @remarks
+ * This function is thread-safe
  */
 extern ccs_result_t
 ccs_fini();

src/cconfigspace.c

@@ -16,17 +16,38 @@ const ccs_version_t ccs_version = {
  CCS_VERSION_REVISION, CCS_VERSION_PATCH, CCS_VERSION_MINOR,
  CCS_VERSION_MAJOR};
 
+static pthread_mutex_t _ccs_mutex = PTHREAD_MUTEX_INITIALIZER;
+static int32_t _ccs_refcount = 0;
+
 ccs_result_t
 ccs_init()
 {
- gsl_rng_env_setup();
- return CCS_RESULT_SUCCESS;
+ ccs_result_t err = CCS_RESULT_SUCCESS;
+ pthread_mutex_lock(&_ccs_mutex);
+
+ CCS_REFUTE_ERR_GOTO(
+ err, _ccs_refcount < 0 || _ccs_refcount == INT32_MAX,
+ CCS_RESULT_ERROR_INVALID_VALUE, end);
+ if (_ccs_refcount == 0)
+ gsl_rng_env_setup();
+ _ccs_refcount += 1;
+end:
+ pthread_mutex_unlock(&_ccs_mutex);
+ return err;
 }
 
 ccs_result_t
 ccs_fini()
 {
- return CCS_RESULT_SUCCESS;
+ ccs_result_t err = CCS_RESULT_SUCCESS;
+ pthread_mutex_lock(&_ccs_mutex);
+
+ CCS_REFUTE_ERR_GOTO(
+ err, _ccs_refcount < 1, CCS_RESULT_ERROR_INVALID_VALUE, end);
+ _ccs_refcount -= 1;
+end:
+ pthread_mutex_unlock(&_ccs_mutex);
+ return err;
 }
 
 ccs_version_t