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PIIODevice Class Referenceabstract

Base class for input/output classes. More...

+ Inheritance diagram for PIIODevice:

Public Types

enum  DeviceMode { ReadOnly = 0x01, WriteOnly = 0x02, ReadWrite = 0x03 }
 Open modes for PIIODevice. More...
 
- Public Types inherited from PIThread
enum  Priority {
  piHighest, piHigh, piNormal, piLow,
  piLowerst
}
 Priority of thread. More...
 

Public Member Functions

 PIIODevice ()
 Constructs a empty PIIODevice.
 
 PIIODevice (const PIString &path, DeviceMode mode=ReadWrite)
 Constructs a PIIODevice with path and mode. More...
 
DeviceMode mode () const
 Current open mode of device.
 
PIString path () const
 Current path of device.
 
void setPath (const PIString &path)
 Set path of device.
 
bool isReadable () const
 Return true if mode is ReadOnly or ReadWrite.
 
bool isWriteable () const
 Return true if mode is WriteOnly or ReadWrite.
 
bool isOpened () const
 Return true if device is successfully opened.
 
bool isClosed () const
 Return true if device is closed.
 
bool canRead () const
 Return true if device can read now.
 
bool canWrite () const
 Return true if device can write now.
 
void setReopenEnabled (bool yes=true)
 Set execution of open enabled while threaded read on closed device.
 
void setReopenTimeout (int msecs)
 Set timeout in milliseconds between open tryings if reopen is enabled.
 
bool isReopenEnabled () const
 Return reopen enable.
 
int reopenTimeout ()
 Return reopen timeout.
 
void setThreadedReadSlot (ReadRetFunc func)
 Set "threaded read slot". More...
 
void setThreadedReadData (void *d)
 Set custom data that will be passed to "threaded read slot".
 
void setThreadedReadBufferSize (int new_size)
 Set size of threaded read buffer. More...
 
int threadedReadBufferSize () const
 Return size of threaded read buffer.
 
const uchar * threadedReadBuffer () const
 Return content of threaded read buffer.
 
void * threadedReadData () const
 Return custom data that will be passed to "threaded read slot".
 
bool isThreadedRead () const
 Return true if threaded read is started.
 
void startThreadedRead ()
 Start threaded read.
 
void startThreadedRead (ReadRetFunc func)
 Start threaded read and assign "threaded read slot" to "func".
 
void stopThreadedRead ()
 Stop threaded read.
 
bool isThreadedWrite () const
 Return true if threaded write is started.
 
void startThreadedWrite ()
 Start threaded write.
 
void stopThreadedWrite ()
 Stop threaded write.
 
void clearThreadedWriteQueue ()
 Clear threaded write task queue.
 
void start ()
 Start both threaded read and threaded write.
 
void stop (bool wait=false)
 Stop both threaded read and threaded write and if "wait" block until both threads are stop.
 
virtual int read (void *read_to, int max_size)
 Reimplement this function to read from your device.
 
virtual int write (const void *data, int max_size)
 Reimplement this function to write to your device.
 
PIByteArray read (int max_size)
 Read from device maximum "max_size" bytes and return them as PIByteArray.
 
PIByteArray readForTime (double timeout_ms)
 Read from device for "timeout_ms" milliseconds and return readed data as PIByteArray. Timeout should to be greater than 0.
 
int write (const PIByteArray &data)
 Write "data" to device.
 
ullong writeThreaded (const void *data, int max_size)
 Add task to threaded write queue and return task ID.
 
ullong writeThreaded (const PIByteArray &data)
 Add task to threaded write queue and return task ID.
 
bool configure (const PIString &config_file, const PIString &section, bool parent_section=false)
 Configure device from section "section" of file "config_file", if "parent_section" parent section also will be read.
 
virtual PIString constructFullPath () const
 Reimplement to construct full unambiguous string, describes this device, default returns path()
 
- Public Member Functions inherited from PIThread
 PIThread (void *data, ThreadFunc func, bool startNow=false, int timer_delay=-1)
 Contructs thread with custom data "data", external function "func" and main cycle delay "timer_delay".
 
 PIThread (bool startNow=false, int timer_delay=-1)
 Contructs thread with main cycle delay "timer_delay".
 
void setData (void *d)
 Set common data passed to external function.
 
void setSlot (ThreadFunc func)
 Set external function that will be executed after every run()
 
void setPriority (PIThread::Priority prior)
 Set priority of thread.
 
PIThread::Priority priority () const
 Return priority of thread.
 
bool isRunning () const
 Return true if thread is running.
 
void needLockRun (bool need)
 Set necessity of lock every run with internal mutex.
 
PIMutexmutex ()
 Return internal mutex.
 
bool start (int timer_delay)
 Start thread. More...
 
bool start (ThreadFunc func, int timer_delay)
 Start thread. More...
 
bool startOnce ()
 Start thread without internal loop. More...
 
bool startOnce (ThreadFunc func)
 Start thread without internal loop. More...
 
void stop (bool wait)
 Stop thread. More...
 
void terminate ()
 Strongly stop thread. More...
 
bool waitForStart (int timeout_msecs)
 Wait for thread start. More...
 
bool waitForFinish (int timeout_msecs)
 Wait for thread finish. More...
 
void lock ()
 Lock internal mutex.
 
void unlock ()
 Unlock internal mutex.
 
void started ()
 Raise on thread start.
 
void stopped ()
 Raise on thread stop.
 
- Public Member Functions inherited from PIObject
 PIObject (const PIString &name=PIString())
 Contructs PIObject with name "name".
 
PIString name () const
 Returns object name.
 
virtual const char * className () const
 Returns object class name.
 
bool debug () const
 Return if debug of this object is active.
 
void setName (const PIString &name)
 Set object name.
 
void setDebug (bool debug)
 Set object debug active.
 
const PIMap< PIString,
PIVariant > & 
properties () const
 Returns properties of the object.
 
int propertiesCount () const
 Returns properties count of the object.
 
PIVariant property (const PIString &name) const
 Returns property with name "name".
 
void setProperty (const PIString &name, const PIVariant &value)
 Set property with name "name" to "value". If there is no such property in object it will be added.
 
bool isPropertyExists (const PIString &name) const
 Returns if property with name "name" exists.
 

Static Public Member Functions

static PIIODevicecreateFromFullPath (const PIString &full_path)
 Try to determine suitable device, create new one, configure it with configureFromFullPath() and returns it. More...
 
- Static Public Member Functions inherited from PIObject
static void piDisconnect (PIObject *src, const PIString &sig)
 Disconnect object "src" from all connections with event name "sig".
 
static void piDisconnect (PIObject *src)
 Disconnect object "src" from all connections, i.e. all connections where object "src" is emitter.
 
static PIObjectfindByName (const PIString &name)
 Returns PIObject* with name "name" or 0, if there is no object found.
 

Protected Member Functions

virtual bool init ()
 Function executed before first openDevice() or from constructor.
 
virtual bool configureDevice (const void *e_main, const void *e_parent=0)
 Reimplement to configure device from entries "e_main" and "e_parent", cast arguments to PIConfig::Entry*.
 
virtual bool openDevice ()=0
 Reimplement to open device, return value will be set to "opened_" variable.
 
virtual bool closeDevice ()
 Reimplement to close device, inverse return value will be set to "opened_" variable.
 
virtual bool threadedRead (uchar *readed, int size)
 Function executed when thread read some data, default implementation execute external slot "ret_func_".
 
virtual PIString fullPathPrefix () const
 Reimplement to construct full unambiguous string prefix. Creating devices by unambiguous string.
 
virtual void configureFromFullPath (const PIString &full_path)
 Reimplement to configure your device with parameters of full unambiguous string. Default implementation does nothing.
 
- Protected Member Functions inherited from PIObject
PIObjectemitter () const
 Returns PIObject* which has raised an event. This value is correct only in definition of some event handler.
 
virtual void propertyChanged (const PIString &name)
 Virtual function executes after property with name "name" has been changed.
 

Related Functions

(Note that these are not member functions.)

template<typename T >
readDeviceSetting (const PIString &name, const T &def, const PIConfig::Entry *em, const PIConfig::Entry *ep)
 Service function. useful for configuring devices. More...
 
#define REGISTER_DEVICE(class)
 Use this macro to enable automatic creation instances of your class with createFromFullPath() function.
 
#define PIIODEVICE(class)
 Use this macro instead of PIOBJECT when describe your own PIIODevice.
 

Handlers

bool open ()
 Open device.
 
bool open (const PIString &_path)
 Open device with path "path".
 
bool open (const DeviceMode &_mode)
 Open device with mode "mode".
 
bool open (const PIString &_path, const DeviceMode &_mode)
 Open device with path "path" and mode "mode".
 
bool close ()
 Close device.
 
bool initialize ()
 Initialize device.
 

Virtual handlers

virtual void flush ()
 Immediate write all buffers.
 

Events

void opened ()
 Raise if succesfull open.
 
void closed ()
 Raise if succesfull close.
 
void threadedReadEvent (uchar *readed, int size)
 Raise if read thread succesfull read some data.
 
void threadedWriteEvent (ullong id, int written_size)
 Raise if write thread succesfull write some data of task with ID "id".
 

Configurable parameters

bool reopenEnabled
 setReopenEnabled, default "true"
 
int reopenTimeout
 setReopenTimeout in ms, default 1000
 
int threadedReadBufferSize
 setThreadedReadBufferSize in bytes, default 4096
 

Detailed Description

Base class for input/output classes.

Synopsis

This class provide open/close logic, threaded read/write and virtual input/output functions read() and write(). You should implement pure virtual function openDevice() in your subclass.

Open and close

PIIODevice have boolean variable indicated open status. Returns of functions openDevice() and closeDevice() change this variable.

Threaded read

PIIODevice based on PIThread, so it`s overload run() to exec read() in background thread. If read is successful virtual function threadedRead() is executed. Default implementation of this function execute external static function set by setThreadedReadSlot() with data set by setThreadedReadData(). Extrenal static function should have format
bool func_name(void * Threaded_read_data, uchar * readed_data, int readed_size)
Threaded read starts with function startThreadedRead().

Threaded write

PIIODevice aggregate another PIThread to perform a threaded write by function writeThreaded(). This function add task to internal queue and return queue entry ID. You should start write thread by function startThreadedWrite. On successful write event threadedWriteEvent is raised with two arguments - task ID and written bytes count.

Internal buffer

PIIODevice have internal buffer for threaded read, and threadedRead() function receive pointer to this buffer in first argument. You can adjust size of this buffer by function setThreadedReadBufferSize()
Default size of this buffer is 4096 bytes.

Reopen

When threaded read is begin its call open() if device is closed. While threaded read running PIIODevice check if device opened every read and if not call open() every reopen timeout if reopen enabled. Reopen timeout is set by setReopenTimeout(), reopen enable is set by setReopenEnabled().

Configuration

This is virtual function configureDevice() which executes when configure() executes. This function takes two arguments: "e_main" and "e_parent" as void*. There are pointers to PIConfig::Entry entries of section "section" and their parent. If there is no parent "e_parent" = 0. Function configure() set three parameters of device: "reopenEnabled", "reopenTimeout" and "threadedReadBufferSize", then execute function configureDevice().
Each ancestor of PIIODevice reimlements configureDevice() function to be able to be confured from configuration file. This parameters described at section "Configurable parameters" in the class reference.
Usage example:

// file example.conf
dev.reopenEnabled = false
dev.device = /dev/ttyS0
dev.speed = 9600
// end example.conf
// code
ser.configure("example.conf", "dev");

Implementation example:

class SomeIO: public PIIODevice {
...
bool configureDevice(const void * e_main, const void * e_parent) {
PIConfig::Entry * em = (PIConfig::Entry * )e_main;
PIConfig::Entry * ep = (PIConfig::Entry * )e_parent;
setStringParam(readDeviceSetting<PIString>("stringParam", stringParam(), em, ep));
setIntParam(readDeviceSetting<int>("intParam", intParam(), em, ep));
return true;
}
...
};

Creating devices by unambiguous string

There are some virtual functions to describe child class without its declaration.
fullPathPrefix() should returns unique prefix of device
constructFullPath() should returns full unambiguous string, contains prefix and all device parameters
configureFromFullPath() provide configuring device from full unambiguous string without prefix and "://"
Macro PIIODEVICE should be used instead of PIOBJECT
Macro REGISTER_DEVICE should be used after definition of class, i.e. at the last line of *.cpp file

If custom I/O device corresponds there rules, it can be returned by function createFromFullPath().
Each PIP I/O device has custom unambiguous string description:

  • PIFile: "file://<path>"
  • PIBinaryLog: "binlog://<logDir>[:<filePrefix>][:<defaultID>]"
  • PISerial: "ser://<device>:<speed(50|...|115200)>[:<dataBitsCount(6|7|8)>][:<parity(N|E|O)>][:<stopBits(1|2)>]"
  • PIEthernet: "eth://<type(UDP|TCP)>:<readIP>:<readPort>[:<multicast(mcast:<ip>)>]"
  • PIUSB: "usb://<vid>:<pid>[:<deviceNumber>][:<readEndpointNumber>][:<writeEndpointNumber>]"

    Examples:
  • PIFile: "file://../text.txt"
  • PIBinaryLog: "binlog://../logs/:mylog_:1"
  • PISerial: "ser:///dev/ttyUSB0:9600:8:N:1", equivalent "ser:///dev/ttyUSB0:9600"
  • PIEthernet: "eth://TCP:127.0.0.1:16666", "eth://UDP:192.168.0.5:16666:mcast:234.0.2.1:mcast:234.0.2.2"
  • PIUSB: "usb://0bb4:0c86:1:1:2"

    So, custom I/O device can be created with next call:
    * // creatring devices
    * PISerial * ser = (PISerial * )PIIODevice::createFromFullPath("ser://COM1:115200");
    * PIEthernet * eth = (PIEthernet * )PIIODevice::createFromFullPath("eth://UDP:127.0.0.1:4001");
    * // examine devices
    * piCout << ser << ser->properties();
    * piCout << eth << eth->properties();
    *

Example

class SomeIO: public PIIODevice {
PIIODEVICE(SomeIO)
public:
SomeIO(): PIIODevice() {}
protected:
bool openDevice() {
// open your device here
return if_success;
}
int read(void * read_to, int max_size) {
// read from your device here
return readed_bytes;
}
int write(const void * data, int max_size) {
// write to your device here
return written_bytes;
}
PIString fullPathPrefix() const {return "myio";}
void configureFromFullPath(const PIString & full_path) {
// parse full_path and configure device there
}
};

Member Enumeration Documentation

Open modes for PIIODevice.

Enumerator
ReadOnly 

Device can only read

WriteOnly 

Device can only write

ReadWrite 

Device can both read and write

Constructor & Destructor Documentation

PIIODevice::PIIODevice ( const PIString path,
PIIODevice::DeviceMode  mode = ReadWrite 
)

Constructs a PIIODevice with path and mode.

Parameters
pathpath to device
typemode for open

Member Function Documentation

void PIIODevice::setThreadedReadSlot ( ReadRetFunc  func)
inline

Set "threaded read slot".

Set external static function of threaded read that will be executed at every successful threaded read. Function should have format "bool func(void * data, uchar * readed, int size)"

void PIIODevice::setThreadedReadBufferSize ( int  new_size)
inline

Set size of threaded read buffer.

Default size is 4096 bytes. If your device can read at single read more than 4096 bytes you should use this function to adjust buffer size

PIIODevice * PIIODevice::createFromFullPath ( const PIString full_path)
static

Try to determine suitable device, create new one, configure it with configureFromFullPath() and returns it.

To function configureFromFullPath() "full_path" passed without fullPathPrefix() + "://". See Creating devices by unambiguous string

Friends And Related Function Documentation

template<typename T >
T readDeviceSetting ( const PIString name,
const T &  def,
const PIConfig::Entry em,
const PIConfig::Entry ep 
)
related

Service function. useful for configuring devices.

Function takes entry name "name", default value "def" and two PIConfig::Entry sections: "em" and their parent "ep". If there is no parent ep = 0. If "ep" is not null and entry "name" exists in "ep" function returns this value. Else returns value of entry "name" in section "em" or "def" if entry doesn`t exists.
This function useful to read settings from configuration file in implementation PIIODevice::configureDevice() function