/********************************************************************
 *
 * Testing thread safety. Thread Cancellation safety
 * -------------------------------------------------
 *
 * The main thread spawns a child to perform a series of dataset writes
 * to a hdf5 file. The main thread and child thread synchronizes within
 * a callback function called during a H5Diterate call afterwhich the
 * main thread attempts to cancel the child thread.
 *
 * The cancellation should only work after the child thread has safely
 * left the H5Diterate call.
 * 
 * Temporary files generated:
 *   ttsafe_cancel.h5
 *
 * HDF5 APIs exercised in thread:
 * H5Screate_simple, H5Tcopy, H5Tset_order, H5Dcreate, H5Dclose,
 * H5Dwrite, H5Dread, H5Diterate, H5Tclose, H5Sclose.
 *
 * Created: May 15 2000
 * Programmer: Chee Wai LEE
 *
 * Modification History
 * --------------------
 *
 *	19 May 2000, Bill Wendling
 *	Changed so that it creates its own HDF5 file and removes it at cleanup
 *	time. Added num_errs flag.
 *
 ********************************************************************/
#include "ttsafe.h"

#ifndef H5_HAVE_THREADSAFE
static int dummy;	/* just to create a non-empty object file */
#else

#define FILENAME	"ttsafe_cancel.h5"
#define DATASETNAME	"commonname"

void *tts_cancel_thread(void *);
void tts_cancel_barrier(void);
herr_t tts_cancel_callback(void *, hid_t, hsize_t, hssize_t *, void *);
void cancellation_cleanup(void *);

hid_t cancel_file;
typedef struct cleanup_struct {
	hid_t dataset;
	hid_t datatype;
	hid_t dataspace;
} cancel_cleanup_t;

pthread_t childthread;
pthread_mutex_t mutex;
pthread_cond_t cond;

void tts_cancel(void)
{
	pthread_attr_t attribute;
	hid_t dataset;
	int buffer;

	/* make thread scheduling global */
	pthread_attr_init(&attribute);
	pthread_attr_setscope(&attribute, PTHREAD_SCOPE_SYSTEM);

	/*
	 * Create a hdf5 file using H5F_ACC_TRUNC access, default file
	 * creation plist and default file access plist
	 */
	cancel_file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
	pthread_create(&childthread, &attribute, tts_cancel_thread, NULL);
	tts_cancel_barrier();
	pthread_cancel(childthread);

	dataset = H5Dopen(cancel_file, DATASETNAME);
	H5Dread(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT,
		&buffer);

	if (buffer != 11) {
		fprintf(stderr,
			"operation unsuccessful with value at %d instead of 11\n",
			buffer);
		num_errs++;
	}

	H5Dclose(dataset);
	H5Fclose(cancel_file);

        /* Destroy the thread attribute */
        pthread_attr_destroy(&attribute);
}

void *tts_cancel_thread(void *arg)
{
	int datavalue;
	int *buffer;
	hid_t dataspace, datatype, dataset;
	hsize_t dimsf[1];	/* dataset dimensions */
	cancel_cleanup_t *cleanup_structure;

	/* define dataspace for dataset */
	dimsf[0] = 1;
	dataspace = H5Screate_simple(1,dimsf,NULL);

	/* define datatype for the data using native little endian integers */
	datatype = H5Tcopy(H5T_NATIVE_INT);
	H5Tset_order(datatype, H5T_ORDER_LE);

	/* create a new dataset within the file */
	dataset = H5Dcreate(cancel_file, DATASETNAME, datatype, dataspace,
			    H5P_DEFAULT);

	/* If thread is cancelled, make cleanup call */
	cleanup_structure = (cancel_cleanup_t*)malloc(sizeof(cancel_cleanup_t));
	cleanup_structure->dataset = dataset;
	cleanup_structure->datatype = datatype;
	cleanup_structure->dataspace = dataspace;
	pthread_cleanup_push(cancellation_cleanup, cleanup_structure);

	datavalue = 1;
	H5Dwrite(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT,
		 &datavalue);

	buffer = malloc(sizeof(int));
	H5Dread(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT,
		buffer);
	H5Diterate(buffer, H5T_NATIVE_INT, dataspace, tts_cancel_callback,
		   &dataset);

	sleep(3);

	datavalue = 100;
	H5Dwrite(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT,
		 &datavalue);
	H5Dclose(dataset);
	H5Tclose(datatype);
	H5Sclose(dataspace);

	/*
	 * Required by pthreads. The argument 0 pops the stack but does not
	 * execute the cleanup routine.
	 */
	pthread_cleanup_pop(0);
	return NULL;
}

herr_t tts_cancel_callback(void *elem, hid_t type_id, hsize_t ndim,
			   hssize_t *point, void *operator_data)
{
	int value = *(int *)elem;
	hid_t dataset = *(hid_t *)operator_data;

	tts_cancel_barrier();
	sleep(3);

	if (value != 1) {
		fprintf(stderr, "Error! Element value should be 1 and not %d\n",
			value);
		num_errs++;
		return -1;
	}

	value += 10;
	H5Dwrite(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT,
		 &value);
	return 0;
}

/*
 * Need to perform the dataset, datatype and dataspace close that was never
 * performed because of thread cancellation
 */
void cancellation_cleanup(void *arg)
{
	cancel_cleanup_t *cleanup_structure = (cancel_cleanup_t *)arg;
	H5Dclose(cleanup_structure->dataset);
	H5Tclose(cleanup_structure->datatype);
	H5Sclose(cleanup_structure->dataspace);

	/* retained for debugging */
	/*  print_func("cancellation noted, cleaning up ... \n"); */
}

/*
 * Artificial (and specific to this test) barrier to keep track of whether
 * both the main and child threads have reached a point in the program.
 */
void tts_cancel_barrier(void)
{
	static int count = 2;

	pthread_mutex_lock(&mutex);

	if (count != 1) {
		count--;
		pthread_cond_wait(&cond, &mutex);
	} else {
		pthread_cond_signal(&cond);
	}

	pthread_mutex_unlock(&mutex);
}

void cleanup_cancel(void)
{
	HDunlink(FILENAME);
}

#endif /*H5_HAVE_THREADSAFE*/