Modbus

use writev() in RTU layer -> extra bytes no longer needed

2022-10-16, Mario de Sousa
b9f302d97b18
Parents 89333b3746d9
Children 330ac0b37846
use writev() in RTU layer -> extra bytes no longer needed
9 files changed, 32 insertions(+), 124 deletions(-)
  • +4 -20
    mb_ascii.c
  • +1 -2
    mb_layer1_prototypes.h
  • +4 -12
    mb_master.c
  • +1 -1
    mb_master_private.h
  • +5 -32
    mb_rtu.c
  • +4 -18
    mb_slave.c
  • +5 -13
    mb_slave_and_master.c
  • +1 -1
    mb_slave_private.h
  • +7 -25
    mb_tcp.c
    • --- a/mb_ascii.c Sun Oct 16 19:40:53 2022 +0100
    +++ b/mb_ascii.c Sun Oct 16 21:23:11 2022 +0100
    @@ -1610,8 +1610,7 @@
    /******************************/
    int modbus_ascii_init(int nd_count,
    - optimization_t opt,
    - int *extra_bytes)
    + optimization_t opt)
    {
    #ifdef DEBUG
    printf("modbus_asc_init(): called...\n");
    @@ -1623,22 +1622,12 @@
    #endif
    /* check input parameters...*/
    - if (0 == nd_count) {
    - if (extra_bytes != NULL)
    - // Not the corect value for this layer.
    - // What we set it to in case this layer is not used!
    - *extra_bytes = 0;
    - return 0;
    - }
    - if (nd_count <= 0)
    - goto error_exit_0;
    -
    - if (extra_bytes == NULL)
    - goto error_exit_0;
    + if (0 == nd_count) return 0;
    + if (nd_count <= 0) return -1;
    /* initialise nd table... */
    if (nd_table_init(&nd_table_, nd_count) < 0)
    - goto error_exit_0;
    + return -1;
    /* remember the optimization choice for later reference... */
    optimization_ = opt;
    @@ -1647,11 +1636,6 @@
    printf("modbus_asc_init(): returning succesfuly...\n");
    #endif
    return 0;
    -
    -error_exit_0:
    - if (extra_bytes != NULL)
    - *extra_bytes = 0; // The value we set this to in case of error.
    - return -1;
    }
    --- a/mb_layer1_prototypes.h Sun Oct 16 19:40:53 2022 +0100
    +++ b/mb_layer1_prototypes.h Sun Oct 16 21:23:11 2022 +0100
    @@ -103,8 +103,7 @@
    /* init the library */
    int modbus_init(int nd_count, /* maximum number of nodes... */
    - optimization_t opt,
    - int *extra_bytes);
    + optimization_t opt);
    /* shutdown the library...*/
    int modbus_done(void);
    --- a/mb_master.c Sun Oct 16 19:40:53 2022 +0100
    +++ b/mb_master.c Sun Oct 16 21:23:11 2022 +0100
    @@ -65,20 +65,13 @@
    /** **/
    /******************************************/
    /******************************************/
    - /* The layer 1 (RTU, ASCII, TCP) implementation will be adding some headers and CRC (at the end)
    - * of the packet we build here (actually currently it is only at the end). Since we want to
    - * re-use the same buffer so as not to continuosly copy the same info from buffer to buffer,
    - * we need tp allocate more bytes than the ones we need for this layer. Therefore, the
    - * extra_bytes parameter.
    - *
    - * Note that we add one more extra byte. This is because some packets will not be
    + /* Note that we add one more extra byte. This is because some packets will not be
    * starting off at byte 0, but rather at byte 1 of the buffer. This is in order to guarantee
    * that the data that is sent on the buffer is aligned on even bytes (the 16 bit words!).
    * This will allow us to reference this memory as an u16 *, without producing 'bus error'
    * messages in some embedded devices that do not allow acessing u16 on odd numbered addresses.
    */
    -static int buff_extra_bytes_;
    -#define QUERY_BUFFER_SIZE (MAX_L2_FRAME_LENGTH + buff_extra_bytes_ + 1)
    +#define QUERY_BUFFER_SIZE (MAX_L2_FRAME_LENGTH + 1)
    /******************************************/
    @@ -1156,11 +1149,10 @@
    /* Initialise the Modbus Master Layer */
    -int mb_master_init__(int extra_bytes) {
    +int mb_master_init__() {
    #ifdef DEBUG
    - fprintf(stderr, "mb_master_init__(extra_bytes=%d), QUERY_BUFFER_SIZE=%d\n", extra_bytes, QUERY_BUFFER_SIZE);
    + fprintf(stderr, "mb_master_init__(), QUERY_BUFFER_SIZE=%d\n", QUERY_BUFFER_SIZE);
    #endif
    - buff_extra_bytes_ = extra_bytes;
    return 0;
    }
    --- a/mb_master_private.h Sun Oct 16 19:40:53 2022 +0100
    +++ b/mb_master_private.h Sun Oct 16 21:23:11 2022 +0100
    @@ -38,7 +38,7 @@
    #define DEF_OPTIMIZATION optimize_speed
    -int mb_master_init__(int extra_bytes);
    +int mb_master_init__(void);
    int mb_master_done__(void);
    --- a/mb_rtu.c Sun Oct 16 19:40:53 2022 +0100
    +++ b/mb_rtu.c Sun Oct 16 21:23:11 2022 +0100
    @@ -1957,8 +1957,7 @@
    /******************************/
    int modbus_rtu_init(int nd_count,
    - optimization_t opt,
    - int *extra_bytes)
    + optimization_t opt)
    {
    #ifdef DEBUG
    fprintf(stderr, "modbus_rtu_init(): called...\n");
    @@ -1970,38 +1969,19 @@
    #endif
    /* check input parameters...*/
    - if (0 == nd_count) {
    - if (extra_bytes != NULL)
    - // Not the corect value for this layer.
    - // What we set it to in case this layer is not used!
    - *extra_bytes = 0;
    - return 0;
    - }
    - if (nd_count <= 0)
    - goto error_exit_0;
    -
    - if (extra_bytes == NULL)
    - goto error_exit_0;
    + if (0 == nd_count) return 0;
    + if (nd_count <= 0) return -1;
    if (crc_init(opt) < 0) {
    #ifdef ERRMSG
    fprintf(stderr, ERRMSG_HEAD "Out of memory: error initializing crc buffers\n");
    #endif
    - goto error_exit_0;
    + return -1;
    }
    - /* set the extra_bytes value... */
    - /* Please see note before the modbus_rtu_write() function for a
    - * better understanding of this extremely ugly hack...
    - *
    - * The number of extra bytes that must be allocated to the data buffer
    - * before calling modbus_rtu_write()
    - */
    - *extra_bytes = 0;
    -
    /* initialise nd table... */
    if (nd_table_init(&nd_table_, nd_count) < 0)
    - goto error_exit_0;
    + return -1;
    /* remember the optimization choice for later reference... */
    optimization_ = opt;
    @@ -2010,13 +1990,6 @@
    fprintf(stderr, "modbus_rtu_init(): returning succesfuly...\n");
    #endif
    return 0;
    -
    -error_exit_0:
    - if (extra_bytes != NULL)
    - // Not the corect value for this layer.
    - // What we set it to in case of error!
    - *extra_bytes = 0;
    - return -1;
    }
    --- a/mb_slave.c Sun Oct 16 19:40:53 2022 +0100
    +++ b/mb_slave.c Sun Oct 16 21:23:11 2022 +0100
    @@ -65,14 +65,7 @@
    /** **/
    /******************************************/
    /******************************************/
    -/* The layer 1 (RTU, ASCII, TCP) implementations will be adding some
    - * header and tail bytes (e.g. CRC) to the packet we build here. Since
    - * layer1 will re-use the same buffer allocated in this slave layer
    - * (so as not to continuosly copy the same info from buffer to buffer),
    - * we need to allocate more bytes than those strictly required for this
    - * slave layer. Therefore, the extra_bytes parameter.
    - *
    - * Note that we add one more extra byte to the response buffer.
    +/* Note that we add one more extra byte to the response buffer.
    * This is because some response packets will not be starting off
    * at byte 0, but rather at byte 1 of the buffer. This is in order
    * to guarantee that the data that is sent on the buffer is aligned
    @@ -82,8 +75,7 @@
    * 'bus error' messages in some embedded devices that do not allow
    * acessing u16 on odd numbered addresses.
    */
    -static int buff_extra_bytes_;
    -#define RESP_BUFFER_SIZE (MAX_L2_FRAME_LENGTH + buff_extra_bytes_ + 1)
    +#define RESP_BUFFER_SIZE (MAX_L2_FRAME_LENGTH + 1)
    /******************************************/
    /******************************************/
    @@ -647,14 +639,8 @@
    /***********************************************/
    /***********************************************/
    -int mb_slave_init__(int extra_bytes) {
    - buff_extra_bytes_ = extra_bytes;
    - return 0;
    -}
    -
    -
    -int mb_slave_done__(void)
    - {return 0;}
    +int mb_slave_init__(void) {return 0;}
    +int mb_slave_done__(void) {return 0;}
    #if 0
    --- a/mb_slave_and_master.c Sun Oct 16 19:40:53 2022 +0100
    +++ b/mb_slave_and_master.c Sun Oct 16 21:23:11 2022 +0100
    @@ -106,7 +106,6 @@
    #define max(a,b) (((a)>(b))?(a):(b))
    int mb_slave_and_master_init(int nd_count_tcp, int nd_count_rtu, int nd_count_ascii) {
    - int extra_bytes, extra_bytes_tcp, extra_bytes_rtu, extra_bytes_ascii;
    #ifdef DEBUG
    fprintf( stderr, "mb_slave_and_master_init()\n");
    @@ -114,20 +113,13 @@
    #endif
    /* initialise layer 1 library */
    - if (modbus_tcp_init (nd_count_tcp, DEF_OPTIMIZATION, &extra_bytes_tcp ) < 0)
    - goto error_exit_0;
    - if (modbus_rtu_init (nd_count_rtu, DEF_OPTIMIZATION, &extra_bytes_rtu ) < 0)
    - goto error_exit_1;
    - if (modbus_ascii_init(nd_count_ascii, DEF_OPTIMIZATION, &extra_bytes_ascii) < 0)
    - goto error_exit_2;
    - extra_bytes= max(extra_bytes_tcp, extra_bytes_rtu);
    - extra_bytes= max(extra_bytes , extra_bytes_ascii);
    + if (modbus_tcp_init (nd_count_tcp, DEF_OPTIMIZATION) < 0) goto error_exit_0;
    + if (modbus_rtu_init (nd_count_rtu, DEF_OPTIMIZATION) < 0) goto error_exit_1;
    + if (modbus_ascii_init(nd_count_ascii, DEF_OPTIMIZATION) < 0) goto error_exit_2;
    /* initialise master and slave libraries... */
    - if (mb_slave_init__(extra_bytes) < 0)
    - goto error_exit_3;
    - if (mb_master_init__(extra_bytes) < 0)
    - goto error_exit_4;
    + if (mb_slave_init__ () < 0) goto error_exit_3;
    + if (mb_master_init__() < 0) goto error_exit_4;
    return 0;
    /*
    --- a/mb_slave_private.h Sun Oct 16 19:40:53 2022 +0100
    +++ b/mb_slave_private.h Sun Oct 16 21:23:11 2022 +0100
    @@ -38,7 +38,7 @@
    -int mb_slave_init__(int extra_bytes);
    +int mb_slave_init__(void);
    int mb_slave_done__(void);
    --- a/mb_tcp.c Sun Oct 16 19:40:53 2022 +0100
    +++ b/mb_tcp.c Sun Oct 16 21:23:11 2022 +0100
    @@ -1453,8 +1453,8 @@
    * returns -1 on error.
    */
    int modbus_tcp_init(int nd_count,
    - optimization_t opt /* ignored... */,
    - int *extra_bytes) {
    + optimization_t opt /* ignored... */
    + ) {
    #ifdef DEBUG
    printf("[%lu] modbus_tcp_init(): called...\n", pthread_self());
    printf("[%lu] creating %d nodes:\n", pthread_self(), nd_count);
    @@ -1462,27 +1462,12 @@
    modbus_tcp_init_counter++;
    - /* set the extra_bytes value... */
    - /* Please see note before the modbus_rtu_write() function for a
    - * better understanding of this extremely ugly hack... This will be
    - * in the mb_rtu.c file!!
    - *
    - * The number of extra bytes that must be allocated to the data buffer
    - * before calling modbus_tcp_write()
    - */
    - if (extra_bytes != NULL)
    - *extra_bytes = 0;
    -
    - if (0 == nd_count)
    - /* no need to initialise this layer! */
    - return 0;
    - if (nd_count <= 0)
    - /* invalid node count... */
    - goto error_exit_1;
    + if (0 == nd_count) return 0; /* no need to initialise this layer! */
    + if (nd_count <= 0) return -1; /* invalid node count... */
    /* initialise the node table... */
    if (nd_table_init(&nd_table_, nd_count) < 0)
    - goto error_exit_1;
    + return -1;
    #ifdef DEBUG
    printf("[%lu] modbus_tcp_init(): %d node(s) opened succesfully\n", pthread_self(), nd_count);
    @@ -1490,13 +1475,10 @@
    return nd_count; /* number of succesfully created nodes! */
    /*
    -error_exit_2:
    +error_exit_1:
    nd_table_done(&nd_table_);
    + return -1;
    */
    -error_exit_1:
    - if (extra_bytes != NULL)
    - *extra_bytes = 0;
    - return -1;
    }