Sponsored Content
Full Discussion: C program
Top Forums UNIX for Advanced & Expert Users C program Post 302240564 by kumars on Friday 26th of September 2008 04:47:49 AM
Old 09-26-2008
Thread prog

I have attached "C program". In the program I am trying to create shared memory. I am also trying to create multiple threads to read and write into shared memory. I am able to create shared memory and number of threads (reader and writer threads) but I am not able to perform read and write operations using the theads.

Could you please check the program and modify it.
 

10 More Discussions You Might Find Interesting

1. Programming

Please need help with C program!

My program only ouputs the correct magic square sum totals for the number 15.If I enter any odd number smaller than 15 my sum totals are incorrect. I have define "size" to 15. How or what do I change so that my program will output the magic square results for the odd numbers 1 through 15 without... (1 Reply)
Discussion started by: JJJ
1 Replies

2. Programming

executing a program within a program

Read the title: how do i do it? (4 Replies)
Discussion started by: Gekko
4 Replies

3. Programming

How to write to stdin of another program (program A -> [stdin]program B)

Hi, Program A: uses pipe() I am able to read the stdout of PROGAM B (stdout got through system() command) into PROGRAM A using: * child -> dup2(fd, STDOUT_FILENO); -> execl("/path/PROGRAM B", "PROGRAM B", NULL); * parent -> char line; -> read(fd, line, 100); Question: ---------... (1 Reply)
Discussion started by: vvaidyan
1 Replies

4. UNIX for Dummies Questions & Answers

How to write to stdin of another program (program A -> [stdin]program B)

Hi, Program A: uses pipe() I am able to read the stdout of PROGAM B (stdout got through system() command) into PROGRAM A using: * child -> dup2(fd, STDOUT_FILENO); -> execl("/path/PROGRAM B", "PROGRAM B", NULL); * parent -> char line; -> read(fd, line, 100); Question: ---------... (3 Replies)
Discussion started by: vvaidyan
3 Replies

5. Programming

A program to trace execution of another program

Hi, I wanted to know if i can write a program using switches and signals, etc to trace execution of other unix program which calls c program internally. If yes how? If not with signals and switches then are there any other methods apart from debugging with gdb/dbx. (3 Replies)
Discussion started by: jiten_hegde
3 Replies

6. UNIX for Dummies Questions & Answers

Script to open program and send/execute command in program

Hi, i want to write a script that executes a program (exec?) . this program then requires a filename as input. how do i give it this input in the script so the program will be complete run and close by the script. e.g. exec prog.exe program then asks for filename "enter filename:"... (1 Reply)
Discussion started by: tuathan
1 Replies

7. Programming

Python program faster than C++ program.

I wrote a simple program that generates a random word 10,000,000 times. I wrote it in python, then in C++ and compared the two completion times. The python script was faster! Is that normal? Why would the python script be faster? I was under the impression that C++ was faster. What are some of... (2 Replies)
Discussion started by: cbreiny
2 Replies

8. Programming

Calling c program from another c program

Hi All, Probably this is a repeated question. My knowledge in this is limited and i got confused on all those materials i got in google search. We use #include <> to include a predefined library like stdio.h i saw somewhere that #include "" includes a man made module(another C program). IS... (2 Replies)
Discussion started by: jisha
2 Replies

9. Homework & Coursework Questions

Calling compiled C program with Perl program

Long story short: I'm working inside of a Unix SSH under a bash shell. I have to code a C program that generates a random number. Then I have to call the compiled C program with a Perl program to run the C program 20 times and put all the generated random #s into a text file, then print that text... (1 Reply)
Discussion started by: jdkirby
1 Replies

10. Shell Programming and Scripting

Perl program get a response before the program quits

I created a program, so a kid can practice there math on it. It dispenses varies math problems and the kid must input an answer. I also want it to grade the work they have done, but I can't find the best place for it to print out the grade. I have: if ( $response =~ m/^/ ) { $user_wants_to_quit... (1 Reply)
Discussion started by: germany1517
1 Replies
pthread_rwlockattr_getpshared(3T)										 pthread_rwlockattr_getpshared(3T)

NAME
pthread_rwlockattr_getpshared(), pthread_rwlockattr_setpshared() - get or set the process-shared attribute SYNOPSIS
PARAMETERS
attr Pointer to the read-write lock attributes object whose attributes are to be set/retrieved. pshared This parameter either specifies the new value of the process-shared attribute (set function) or points to the memory loca- tion where the process-shared attribute of attr is to be returned (get function). DESCRIPTION
The attributes object attr must have been previously initialized with the function before these functions are called. Read-Write locks can be used only by threads within the process or shared by threads in multiple processes. The process-shared attribute in a read-write lock attributes object describes who may use the read-write lock. The legal values for the process-shared attribute are: This option permits a read-write lock to be operated upon by any thread that has access to the memory where the read-write lock is allocated. The application is responsible for allocating the read-write lock in memory that multiple processes can access. The read-write lock can only be operated upon by threads created within the same process as the thread that initialized the read-write lock. If threads of differing processes attempt to operate on such read-write lock, the behavior is undefined. The default value of process-shared is is used to set the process-shared attribute in the initialized attributes object attr. The new value of the process-shared attribute of attr is set to the value specified in the pshared parameter. retrieves the value of the process-shared attribute from the read-write lock attributes object attr. The value of the process-shared attribute of attr is returned in the pshared parameter. RETURN VALUE
Upon successful completion, and return zero. Otherwise, an error number is returned to indicate the error (the variable is not set). ERRORS
If any of the following occur, the and functions return the corresponding error number: is not defined and these functions are not supported. For each of the following conditions, if the condition is detected, the and functions return the corresponding error number: The value specified by attr is invalid. The value specified by pshared is not a legal value. The value pshared points to an illegal address. WARNINGS
If a read-write lock is created with the process-shared attribute defined as the cooperating processes should have access to the memory in which the read-write lock is allocated. AUTHOR
and were developed by X/Open. SEE ALSO
pthread_create(3T), pthread_rwlockattr_init(3T), pthread_rwlock_init(3T). STANDARDS CONFORMANCE
Pthread Library pthread_rwlockattr_getpshared(3T)
All times are GMT -4. The time now is 07:20 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy