Pthread Programming in VS2010

For Pthread Programming in VS2010, you will need the following:
1) pthreadVC2.lib
2) pthreadVC2.dll
3) semaphore.h, sched.h, pthread.h

All pthread source codes, *.lib, *.dll, *.h will be available in a link from -> https://sourceware.org/pthreads-win32/#download
(Download according to you system architecture i.e. x86 or x64)

Now, let us try a hello world program;

• Paste *.h files in C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include\
• *.dll files will be required in the ...\Debug\ folded inside projects file structure.
• Open VS2010
• File -> New -> Project
• Visual C++ -> General -> Empty Project
• In the solution explorer,
• right click 'source files' -> add -> new item
• Visual C++ -> Code -> C++ File (.cpp)
• Enter 'name' -> Add
• Now type the following code in the *.cpp file:

#include<iostream>

#include<pthread.h>

#include<errno.h>

#include<string.h>

using namespace std;

void* thread_func(void* arg)

{

cout<<endl<<" Thread created with "<<(long) arg<<" as ID\n";

return NULL;

}

void printError(char* msg,int status,char* filename,int lineno)

{

cout<<endl<<" Error msg: "<<msg<<" : "<<strerror(status)<<" in file "<<filename<<" at line "<<lineno;

}

int main()

{

cout<<endl<<"hello world"<<endl;

pthread_t th;

pthread_attr_t th_attr;

int status=pthread_attr_init(&th_attr);

if(status)

{

printError("Attribute initiation error",status,__FILE__,__LINE__);

exit(EXIT_FAILURE);

}

status=pthread_attr_setscope(&th_attr,PTHREAD_SCOPE_SYSTEM);

if(status)

{

printError("Attribute Scope setting error",status,__FILE__,__LINE__);

exit(EXIT_FAILURE);

}

status=pthread_create(&th,&th_attr,thread_func,(void*)1L);

if(status)

{

printError("Thread Creation error",status,__FILE__,__LINE__);

exit(EXIT_FAILURE);

}

status=pthread_attr_destroy(&th_attr);

if(status)

{

printError("Attribute Destroy error",status,__FILE__,__LINE__);

exit(EXIT_FAILURE);

}

status=pthread_join(th,(void**)NULL);

if(status)

{

printError("Thread joining error",status,__FILE__,__LINE__);

exit(EXIT_FAILURE);

}

cout<<endl<<"Now control passed into main(), exiting..."<<endl;

return 0;

}

• right click project name -> Properties -> Configuration Properties -> Linker
• Input -> Additional Dependencies
• Pop down menu -> Edit -> type 'pthreadVC2.lib' -> Ok -> Ok

__FILE__ is a preprocessor macro that expands to full path to the current file. __FILE__ is useful when generating log statements, error messages intended for programmers, when throwing exceptions, or when writing debugging code.

(Ref: http://www.cprogramming.com/reference/preprocessor/__FILE__.html )

Possible Errors:

-----------------------

• error LNK2019: unresolved external symbol __imp_ pthread_attr_destroy referenced in function
• This error is because we are using a x64 architecture library and building x32 solution or vice-versa
• This can be rectified by either downloading library files for the solution intended or changing the output solution type according to the library files we have
• symbol__imp_pthread -> x86
• symbol__imp__pthread -> x64

\

• error LNK1104: cannot open file 'pthreadVC2.lib'
• sometimes, even after linking pthreadVC2.lib in Additional Dependencies, we will get this error
• this can be rectified by going to 'Configuration Properties' -> 'VC++ Directories' -> 'Library Directories' -> pop down arrow -> Edit
• See the list of path by clicking on 'Macros'
• Try to pthreadVC2.lib in the path mention over there
• e.g:-
• $(VCInstallDir)lib\amd64 - C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC
• so add in 'C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\lib\amd64'

pthread_create, pthread_attr_init

pthread_attr_setscope

pthread_attr_destroy

pthread_join

mutex

pthread_self, pthread_equal

pthread_cancel, pthread_exit

pthread_detach

pthread_cond_signal()- awakens single thread in pthread_cond_wait()/pthread_cond_timewait(). But in case of multiple thread waiting, they are awakened according to scheduling priority + FIFO

pthread_cond_broadcast() - awakens all threads in waiting

the thread that issues signal/broadcast call, holds the mutex at time of call, but must release it after the call. It wakes up a waiting thread, which regains the control of the mutex.

mutex

conditional variables

Reader/Writer Locks