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/* File generated by Beremiz (PlugGenerate_C method of Modbus plugin) */

     2

     3

/*

     4

 * Copyright (c) 2016 Mario de Sousa (msousa@fe.up.pt)

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 *

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 * This file is part of the Modbus library for Beremiz and matiec.

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 *

     8

 * This Modbus library is free software: you can redistribute it and/or modify

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 * it under the terms of the GNU Lesser General Public License as published by

    10

 * the Free Software Foundation, either version 2 of the License, or

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 * (at your option) any later version.

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 *

    13

 * This program is distributed in the hope that it will be useful, but

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 * WITHOUT ANY WARRANTY; without even the implied warranty of

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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser 

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 * General Public License for more details.

    17

 *

    18

 * You should have received a copy of the GNU Lesser General Public License

    19

 * along with this Modbus library.  If not, see <http://www.gnu.org/licenses/>.

    20

 *

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 * This code is made available on the understanding that it will not be

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 * used in safety-critical situations without a full and competent review.

    23

 */

    24

    25

    26

#include <stdio.h>

    27

#include <string.h>  /* required for memcpy() */

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#include <errno.h>

    29

#include <time.h>

    30

#include <signal.h>

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#include "mb_slave_and_master.h"

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#include "MB_%(locstr)s.h"

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    35

    36

#define MAX_MODBUS_ERROR_CODE 11

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static const char *modbus_error_messages[MAX_MODBUS_ERROR_CODE+1] = {

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    /* 0 */ "",                             /* un-used -> no error! */

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    /* 1 */ "illegal/unsuported function",

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    /* 2 */ "illegal data address",

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    /* 3 */ "illegal data value",

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    /* 4 */ "slave device failure",

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    /* 5 */ "acknowledge -> slave intends to reply later",

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    /* 6 */ "slave device busy",

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    /* 7 */ "negative acknowledge",

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    /* 8 */ "memory parity error",

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    /* 9 */ "",                             /* undefined by Modbus */

    48

    /* 10*/ "gateway path unavalilable",

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    /* 11*/ "gateway target device failed to respond"

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};    

    51

    52

    53

/* Execute a modbus client transaction/request */

    54

static int __execute_mb_request(int request_id){

    55

	switch (client_requests[request_id].mb_function){

    56

    57

	case  1: /* read coils */

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		return read_output_bits(client_requests[request_id].slave_id,

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					client_requests[request_id].address,

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					client_requests[request_id].count,

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					client_requests[request_id].coms_buffer,

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					(int) client_requests[request_id].count,

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					client_nodes[client_requests[request_id].client_node_id].mb_nd,

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					client_requests[request_id].retries,

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					&(client_requests[request_id].error_code),

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					&(client_requests[request_id].resp_timeout),

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					&(client_requests[request_id].coms_buf_mutex));

    68

    69

	case  2: /* read discrete inputs */

    70

		return read_input_bits( client_requests[request_id].slave_id,

    71

					client_requests[request_id].address,

    72

					client_requests[request_id].count,

    73

					client_requests[request_id].coms_buffer,

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					(int) client_requests[request_id].count,

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					client_nodes[client_requests[request_id].client_node_id].mb_nd,

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					client_requests[request_id].retries,

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					&(client_requests[request_id].error_code),

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					&(client_requests[request_id].resp_timeout),

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					&(client_requests[request_id].coms_buf_mutex));

    80

    81

	case  3: /* read holding registers */

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		return read_output_words(client_requests[request_id].slave_id,

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					client_requests[request_id].address,

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					client_requests[request_id].count,

    85

					client_requests[request_id].coms_buffer,

    86

					(int) client_requests[request_id].count,

    87

					client_nodes[client_requests[request_id].client_node_id].mb_nd,

    88

					client_requests[request_id].retries,

    89

					&(client_requests[request_id].error_code),

    90

					&(client_requests[request_id].resp_timeout),

    91

					&(client_requests[request_id].coms_buf_mutex));

    92

    93

	case  4: /* read input registers */

    94

		return read_input_words(client_requests[request_id].slave_id,

    95

					client_requests[request_id].address,

    96

					client_requests[request_id].count,

    97

					client_requests[request_id].coms_buffer,

    98

					(int) client_requests[request_id].count,

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					client_nodes[client_requests[request_id].client_node_id].mb_nd,

   100

					client_requests[request_id].retries,

   101

					&(client_requests[request_id].error_code),

   102

					&(client_requests[request_id].resp_timeout),

   103

					&(client_requests[request_id].coms_buf_mutex));

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   105

	case  5: /* write single coil */

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		return write_output_bit(client_requests[request_id].slave_id,

   107

					client_requests[request_id].address,

   108

					client_requests[request_id].coms_buffer[0],

   109

					client_nodes[client_requests[request_id].client_node_id].mb_nd,

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					client_requests[request_id].retries,

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					&(client_requests[request_id].error_code),

   112

					&(client_requests[request_id].resp_timeout),

   113

					&(client_requests[request_id].coms_buf_mutex));

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   115

	case  6: /* write single register */

   116

		return write_output_word(client_requests[request_id].slave_id,

   117

					client_requests[request_id].address,

   118

					client_requests[request_id].coms_buffer[0],

   119

					client_nodes[client_requests[request_id].client_node_id].mb_nd,

   120

					client_requests[request_id].retries,

   121

					&(client_requests[request_id].error_code),

   122

					&(client_requests[request_id].resp_timeout),

   123

					&(client_requests[request_id].coms_buf_mutex));

   124

   125

	case  7: break; /* function not yet supported */

   126

	case  8: break; /* function not yet supported */

   127

	case  9: break; /* function not yet supported */

   128

	case 10: break; /* function not yet supported */

   129

	case 11: break; /* function not yet supported */

   130

	case 12: break; /* function not yet supported */

   131

	case 13: break; /* function not yet supported */

   132

	case 14: break; /* function not yet supported */

   133

   134

	case 15: /* write multiple coils */

   135

		return write_output_bits(client_requests[request_id].slave_id,

   136

					 client_requests[request_id].address,

   137

					 client_requests[request_id].count,

   138

					 client_requests[request_id].coms_buffer,

   139

					 client_nodes[client_requests[request_id].client_node_id].mb_nd,

   140

					 client_requests[request_id].retries,

   141

					 &(client_requests[request_id].error_code),

   142

					 &(client_requests[request_id].resp_timeout),

   143

					 &(client_requests[request_id].coms_buf_mutex));

   144

   145

	case 16: /* write multiple registers */

   146

		return write_output_words(client_requests[request_id].slave_id,

   147

					client_requests[request_id].address,

   148

					client_requests[request_id].count,

   149

					client_requests[request_id].coms_buffer,

   150

					client_nodes[client_requests[request_id].client_node_id].mb_nd,

   151

					client_requests[request_id].retries,

   152

					&(client_requests[request_id].error_code),

   153

					&(client_requests[request_id].resp_timeout),

   154

					&(client_requests[request_id].coms_buf_mutex));

   155

   156

	default: break;  /* should never occur, if file generation is correct */

   157

	}

   158

   159

	fprintf(stderr, "Modbus plugin: Modbus function %%d not supported\n", request_id); /* should never occur, if file generation is correct */

   160

	return -1;

   161

}

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   163

   164

   165

/* pack bits from unpacked_data to packed_data */

   166

static inline int __pack_bits(u16 *unpacked_data, u16 start_addr, u16 bit_count,  u8  *packed_data) {

   167

  u8 bit;

   168

  u16 byte, coils_processed;

   169

   170

  if ((0 == bit_count) || (65535-start_addr < bit_count-1))

   171

    return -ERR_ILLEGAL_DATA_ADDRESS; /* ERR_ILLEGAL_DATA_ADDRESS defined in mb_util.h */

   172

   173

  for( byte = 0, coils_processed = 0; coils_processed < bit_count; byte++) {

   174

    packed_data[byte] = 0;

   175

    for( bit = 0x01; (bit & 0xFF) && (coils_processed < bit_count); bit <<= 1, coils_processed++ ) {

   176

      if(unpacked_data[start_addr + coils_processed])

   177

            packed_data[byte] |=  bit; /*   set bit */

   178

      else  packed_data[byte] &= ~bit; /* reset bit */

   179

    }

   180

  }

   181

  return 0;

   182

}

   183

   184

   185

/* unpack bits from packed_data to unpacked_data */

   186

static inline int __unpack_bits(u16 *unpacked_data, u16 start_addr, u16 bit_count,  u8  *packed_data) {

   187

  u8  temp, bit;

   188

  u16 byte, coils_processed;

   189

   190

  if ((0 == bit_count) || (65535-start_addr < bit_count-1))

   191

    return -ERR_ILLEGAL_DATA_ADDRESS; /* ERR_ILLEGAL_DATA_ADDRESS defined in mb_util.h */

   192

   193

  for(byte = 0, coils_processed = 0; coils_processed < bit_count; byte++) {

   194

    temp = packed_data[byte] ;

   195

    for(bit = 0x01; (bit & 0xff) && (coils_processed < bit_count); bit <<= 1, coils_processed++) {

   196

      unpacked_data[start_addr + coils_processed] = (temp & bit)?1:0;

   197

    }

   198

  }

   199

  return 0;

   200

}

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   202

   203

static int __read_inbits   (void *mem_map, u16 start_addr, u16 bit_count, u8  *data_bytes)

   204

  {return   __pack_bits(((server_mem_t *)mem_map)->ro_bits, start_addr, bit_count, data_bytes);}

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static int __read_outbits  (void *mem_map, u16 start_addr, u16 bit_count, u8  *data_bytes)

   206

  {return   __pack_bits(((server_mem_t *)mem_map)->rw_bits, start_addr, bit_count, data_bytes);}

   207

static int __write_outbits (void *mem_map, u16 start_addr, u16 bit_count, u8  *data_bytes)

   208

  {return __unpack_bits(((server_mem_t *)mem_map)->rw_bits, start_addr, bit_count, data_bytes); }

   209

   210

   211

   212

static int __read_inwords  (void *mem_map, u16 start_addr, u16 word_count, u16 *data_words) {

   213

   214

  if ((start_addr + word_count) > MEM_AREA_SIZE)

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    return -ERR_ILLEGAL_DATA_ADDRESS; /* ERR_ILLEGAL_DATA_ADDRESS defined in mb_util.h */

   216

   217

  /* use memcpy() because loop with pointers (u16 *) caused alignment problems */

   218

  memcpy(/* dest */ (void *)data_words,

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         /* src  */ (void *)&(((server_mem_t *)mem_map)->ro_words[start_addr]),

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         /* size */ word_count * 2);

   221

  return 0;

   222

}

   223

   224

   225

   226

static int __read_outwords (void *mem_map, u16 start_addr, u16 word_count, u16 *data_words) {

   227

   228

  if ((start_addr + word_count) > MEM_AREA_SIZE)

   229

    return -ERR_ILLEGAL_DATA_ADDRESS; /* ERR_ILLEGAL_DATA_ADDRESS defined in mb_util.h */

   230

   231

  /* use memcpy() because loop with pointers (u16 *) caused alignment problems */

   232

  memcpy(/* dest */ (void *)data_words,

   233

         /* src  */ (void *)&(((server_mem_t *)mem_map)->rw_words[start_addr]),

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         /* size */ word_count * 2);

   235

  return 0;

   236

}

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   238

   239

   240

   241

static int __write_outwords(void *mem_map, u16 start_addr, u16 word_count, u16 *data_words) {

   242

   243

  if ((start_addr + word_count) > MEM_AREA_SIZE)

   244

    return -ERR_ILLEGAL_DATA_ADDRESS; /* ERR_ILLEGAL_DATA_ADDRESS defined in mb_util.h */

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   246

  /* WARNING: The data returned in the data_words[] array is not guaranteed to be 16 bit aligned.

   247

   *           It is not therefore safe to cast it to an u16 data type.

   248

   *           The following code cannot be used. memcpy() is used instead.

   249

   */

   250

  /*

   251

  for (count = 0; count < word_count ; count++)

   252

    ((server_mem_t *)mem_map)->rw_words[count + start_addr] = data_words[count];

   253

  */

   254

  memcpy(/* dest */ (void *)&(((server_mem_t *)mem_map)->rw_words[start_addr]),

   255

         /* src  */ (void *)data_words,

   256

         /* size */ word_count * 2);

   257

  return 0;

   258

}

   259

   260

   261

   262

   263

#include <pthread.h>

   264

   265

static void *__mb_server_thread(void *_server_node)  {

   266

	server_node_t *server_node = _server_node;

   267

	mb_slave_callback_t callbacks = { 

   268

			&__read_inbits,

   269

			&__read_outbits,

   270

			&__write_outbits,

   271

			&__read_inwords,

   272

			&__read_outwords,

   273

			&__write_outwords,

   274

			(void *)&(server_node->mem_area)

   275

			};  

   276

   277

	// Enable thread cancelation. Enabled is default, but set it anyway to be safe.

   278

	pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);

   279

   280

	// mb_slave_run() should never return!

   281

	mb_slave_run(server_node->mb_nd /* nd */, callbacks, server_node->slave_id);

   282

	fprintf(stderr, "Modbus plugin: Modbus server for node %%s died unexpectedly!\n", server_node->location); /* should never occur */

   283

	return NULL;

   284

}

   285

   286

   287

#define timespec_add(ts, sec, nsec) {		\

   288

	ts.tv_sec  +=  sec;			\

   289

	ts.tv_nsec += nsec;			\

   290

	if (ts.tv_nsec >= 1000000000) {		\

   291

		ts.tv_sec  ++;			\

   292

		ts.tv_nsec -= 1000000000;	\

   293

	}					\

   294

}

   295

   296

   297

static void *__mb_client_thread(void *_index)  {

   298

	int client_node_id = (char *)_index - (char *)NULL; // Use pointer arithmetic (more portable than cast)

   299

   300

	// Enable thread cancelation. Enabled is default, but set it anyway to be safe.

   301

	pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);

   302

   303

    /* loop the communication with the client

   304

     * 

   305

         * When the client thread has difficulty communicating with remote client and/or server (network issues, for example),

   306

         * then the communications get delayed and we will fall behind in the period. 

   307

         * 

   308

         * This is OK. Note that if the condition variable were to be signaled multiple times while the client thread is inside the same

   309

         * Modbus transaction, then all those signals would be ignored.

   310

         * However, and since we keep the mutex locked during the communication cycle, it is not possible to signal the condition variable

   311

         * during that time (it is only possible while the thread is blocked during the call to pthread_cond_wait().

   312

         * 

   313

         * This means that when network issues eventually get resolved, we will NOT have a bunch of delayed activations to handle

   314

         * in quick succession (which would goble up CPU time). 

   315

         * 

   316

         * Notice that the above property is valid whether the communication cycle is run with the mutex locked, or unlocked.

   317

         * Since it makes it easier to implement the correct semantics for the other activation methods if the communication cycle

   318

         * is run with the mutex locked, then that is what we do.

   319

         * 

   320

     * Note that during all the communication cycle we will keep locked the mutex 

   321

     * (i.e. the mutex used together with the condition variable that will activate a new communication cycle)

   322

     * 

   323

     * Note that we never get to explicitly unlock this mutex. It will only be unlocked by the pthread_cond_wait()

   324

     * call at the end of the cycle.

   325

     */

   326

    pthread_mutex_lock(&(client_nodes[client_node_id].mutex));

   327

   328

	while (1) {

   329

		/*

   330

		struct timespec cur_time;

   331

		clock_gettime(CLOCK_MONOTONIC, &cur_time);

   333

		*/

   334

		int req;

   335

		for (req=0; req < NUMBER_OF_CLIENT_REQTS; req ++){

   336

			/* just do the requests belonging to the client */

   337

			if (client_requests[req].client_node_id != client_node_id)

   338

				continue;

   339

   340

            /* only do the request if:

   341

             *   - this request was explictly asked to be executed by the client program

   342

             *  OR

   343

             *   - the client thread was activated periodically

   344

             *     (in which case we execute all the requests belonging to the client node)

   345

             */

   346

            if ((client_requests[req].flag_exec_req == 0) && (client_nodes[client_requests[req].client_node_id].periodic_act == 0))

   347

                continue;

   348

   353

   354

			int res_tmp = __execute_mb_request(req);

   355

			switch (res_tmp) {

   356

			  case PORT_FAILURE: {

   357

				if (res_tmp != client_nodes[client_node_id].prev_error)

   358

					fprintf(stderr, "Modbus plugin: Error connecting Modbus client %%s to remote server.\n", client_nodes[client_node_id].location);

   359

				client_nodes[client_node_id].prev_error = res_tmp;

   360

				break;

   361

			  }

   362

			  case INVALID_FRAME: {

   363

				if ((res_tmp != client_requests[req].prev_error) && (0 == client_nodes[client_node_id].prev_error))

   364

					fprintf(stderr, "Modbus plugin: Modbus client request configured at location %%s was unsuccesful. Server/slave returned an invalid/corrupted frame.\n", client_requests[req].location);

   365

				client_requests[req].prev_error = res_tmp;

   366

				break;

   367

			  }

   368

			  case TIMEOUT: {

   369

				if ((res_tmp != client_requests[req].prev_error) && (0 == client_nodes[client_node_id].prev_error))

   370

					fprintf(stderr, "Modbus plugin: Modbus client request configured at location %%s timed out waiting for reply from server.\n", client_requests[req].location);

   371

				client_requests[req].prev_error = res_tmp;

   372

				break;

   373

			  }

   374

			  case MODBUS_ERROR: {

   375

				if (client_requests[req].prev_error != client_requests[req].error_code) {

   376

					fprintf(stderr, "Modbus plugin: Modbus client request configured at location %%s was unsuccesful. Server/slave returned error code 0x%%2x", client_requests[req].location, client_requests[req].error_code);

   377

					if (client_requests[req].error_code <= MAX_MODBUS_ERROR_CODE ) {

   378

						fprintf(stderr, "(%%s)", modbus_error_messages[client_requests[req].error_code]);

   379

						fprintf(stderr, ".\n");

   380

					}

   381

				}

   382

				client_requests[req].prev_error = client_requests[req].error_code;

   383

				break;

   384

			  }

   385

			  default: {

   386

				if ((res_tmp >= 0) && (client_nodes[client_node_id].prev_error != 0)) {

   387

					fprintf(stderr, "Modbus plugin: Modbus client %%s has reconnected to server/slave.\n", client_nodes[client_node_id].location);

   388

				}

   389

				if ((res_tmp >= 0) && (client_requests[req]        .prev_error != 0)) {

   390

					fprintf(stderr, "Modbus plugin: Modbus client request configured at location %%s has succesfully resumed comunication.\n", client_requests[req].location);

   391

				}

   392

				client_nodes[client_node_id].prev_error = 0;

   393

				client_requests[req]        .prev_error = 0;

   394

				break;

   395

			  }

   396

			}

   397

   398

            /* We have just finished excuting a client transcation request.

   399

             * If the current cycle was activated by user request we reset the flag used to ask to run it

   400

             */

   401

            if (0 != client_requests[req].flag_exec_req) {

   402

                client_requests[req].flag_exec_req     = 0;

   403

                client_requests[req].flag_exec_started = 0;   

   404

            }

   405

   406

            //fprintf(stderr, "Modbus plugin: RUNNING<---> of Modbus request %%d  (periodic = %%d  flag_exec_req = %%d)\n", 

   407

            //        req, client_nodes[client_requests[req].client_node_id].periodic_act, client_requests[req].flag_exec_req );

   408

        }

   409

   410

        // Wait for signal (from timer or explicit request from user program) before starting the next cycle

   411

        {

   412

            // No need to lock the mutex. Is is already locked just before the while(1) loop.

   413

            // Read the comment there to understand why.

   414

            // pthread_mutex_lock(&(client_nodes[client_node_id].mutex));

   415

   416

            /* the client thread has just finished a cycle, so all the flags used to signal an activation

   417

             * and specify the activation source (periodic, user request, ...)

   418

             * get reset here, before waiting for a new activation.

   419

             */

   420

            client_nodes[client_node_id].periodic_act = 0;            

   421

            client_nodes[client_node_id].execute_req  = 0;

   422

   423

            while (client_nodes[client_node_id].execute_req == 0)

   424

                pthread_cond_wait(&(client_nodes[client_node_id].condv),

   425

                                &(client_nodes[client_node_id].mutex)); 

   426

   427

            // We run the communication cycle with the mutex locked.

   428

            // Read the comment just above the while(1) to understand why.

   429

            // pthread_mutex_unlock(&(client_nodes[client_node_id].mutex));

   430

        }

   431

	}

   432

   433

	// humour the compiler.

   434

	return NULL;

   435

}

   436

   437

   438

   439

/* Function to activate a client node's thread */

   440

/* returns -1 if it could not send the signal */

   441

static int __signal_client_thread(int client_node_id) {

   442

    /* We TRY to signal the client thread.

   443

     * We do this because this function can be called at the end of the PLC scan cycle

   444

     * and we don't want it to block at that time.

   445

     */

   446

    if (pthread_mutex_trylock(&(client_nodes[client_node_id].mutex)) != 0)

   447

        return -1;

   448

    client_nodes[client_node_id].execute_req = 1; // tell the thread to execute

   449

    pthread_cond_signal (&(client_nodes[client_node_id].condv));

   450

    pthread_mutex_unlock(&(client_nodes[client_node_id].mutex));

   451

    return 0;

   452

}

   453

   454

   455

   456

/* Function that will be called whenever a client node's periodic timer expires. */

   457

/* The client node's thread will be waiting on a condition variable, so this function simply signals that 

   458

 * condition variable.

   459

 * 

   460

 * The same callback function is called by the timers of all client nodes. The id of the client node

   461

 * in question will be passed as a parameter to the call back function.

   462

 */

   463

void __client_node_timer_callback_function(int client_node_id) {

   464

    /* signal the client node's condition variable on which the client node's thread should be waiting... */

   465

    /* Since the communication cycle is run with the mutex locked, we use trylock() instead of lock() */

   466

    if (pthread_mutex_trylock (&(client_nodes[client_node_id].mutex)) != 0)

   467

        /* we never get to signal the thread for activation. But that is OK.

   468

         * If it still in the communication cycle (during which the mutex is kept locked)

   469

         * then that means that the communication cycle is falling behing in the periodic 

   470

         * communication cycle, and we therefore need to skip a period.

   471

         */

   472

        return;

   473

    client_nodes[client_node_id].execute_req  = 1; // tell the thread to execute

   474

    client_nodes[client_node_id].periodic_act = 1; // tell the thread the activation was done by periodic timer   

   475

    pthread_cond_signal (&(client_nodes[client_node_id].condv));

   476

    pthread_mutex_unlock(&(client_nodes[client_node_id].mutex));

   477

}

   478

   479

   480

   491

static void *__mb_client_timer_thread(void *_index) {

   492

	int client_node_id = (char *)_index - (char *)NULL; // Use pointer arithmetic (more portable than cast)