File access from multiple processes or threads?


 
Thread Tools Search this Thread
Top Forums Programming File access from multiple processes or threads?
# 8  
Old 12-26-2009
Quote:
Originally Posted by sanzee
Thanks for the above replies guys, but I want a simple dummy example coe in linux for both scenarios. If you can provide it wud a gr8 help.
Beggars can't be choosers. Smilie

I'm not sure I would go with the fcntl.h interface, though. IIRC, ownership is based on PIDs, not TIDs, and although POSIX 1003.1d (previously 1003.4) changed that you might still find non-conforming implementations as 1003.1d compliance is optional.

In any other case (such as synchronization between processes) I would definitely go with the file locking API as it gets the most use on _any_ platform and will therefore be the most bug-free of the implementations. The biggest problem with most thread-based file-locking will be race conditions. Look at the pthread_condwait family of calls (again, IIRC).
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Script to access multiple file and operate on single file

We have three files as mentioned below: 1. main_file.txt: This is the file in which all operations will be done. Which means this file will be signed by using the below two files 2. signature_file.txt: This is a status file and contains two signatures. 3. command.txt:file contains two commands... (2 Replies)
Discussion started by: chetanojha
2 Replies

2. Shell Programming and Scripting

Need to create multiple threads

Hi , i need to run multiple scripts parallely ,on my server....i have 8 cpus . planning to run minimum of 6 scripts paralley ....could you please suggest someone . thanks in advance , (3 Replies)
Discussion started by: Huvan
3 Replies

3. Linux

Linux Processes, Threads, scheduling header files

Hello everyone i am new to Linux. could anyone help me with the names of the Linux processes, threads and scheduling header files. I need them to write a documentation on Linux processes and threads. Thanks (5 Replies)
Discussion started by: bee_in_toronto
5 Replies

4. UNIX for Advanced & Expert Users

Monitoring cpu usage of mysql processes/threads/queries without any tool

hi all, i want to monitor mysql processes/threads/queries with respect to cpu usage.how can i do it? show processlist is of no use as no information abt cpu usage is given. plz help (7 Replies)
Discussion started by: rohitmahambre
7 Replies

5. UNIX for Advanced & Expert Users

Multiple processes write to log file at the same time

If we have 3 process to write to same log file at the same time like below. will it cause the data outdated because the multiple process writing same time? It this a safe way to keep the log for multiple process? p1 >> test.log &; p2 >> test.log &; p3 >> test.log & Thanks, (1 Reply)
Discussion started by: casttree
1 Replies

6. UNIX for Dummies Questions & Answers

kernel giving access for multiple users to access files

hi all, i want to know y kernel is giving access for multiple users to access a file when one user may be the owner is executing that file. Because other user can manipulate that file when the other user is executing that file, it will give the unexpected result to owner . plz help me... (1 Reply)
Discussion started by: jimmyuk
1 Replies

7. Shell Programming and Scripting

Multiple processes writing on the same file simultaneously

Hi All, I have encountered a problem,please help me. I have a script in which multiple processes are writing on to the same file . How should I stop this , I mean lock mechanism can be implemented or we can write the at different files and then concatenate the files. What would be a better... (1 Reply)
Discussion started by: Sayantan
1 Replies

8. IP Networking

How to choose Multiple process or Multiple threads?

Hi All, Please explain me when i have to use multiple process and when I have to use Multiple threads? Please give me an example.It will be very helpful for me. Thanks in advance. (0 Replies)
Discussion started by: ashleykumar
0 Replies

9. Post Here to Contact Site Administrators and Moderators

access old threads

i would like to see some of my olds post and threads so i can compile them for future use but when i tried to search all of my post some of them were not present. how can i have access from these threads? thanks a lot! (1 Reply)
Discussion started by: inquirer
1 Replies

10. Programming

How to use pipe() in multiple threads?

Hi, I have a program that runs two threads in stead of two processes. I want to use pipe to redirect the output of the first thread to the input of the second thread. One thread is continuously writing to a pipe, and the other thread will read from the pipe. How do I do that? Is there... (2 Replies)
Discussion started by: wminghao
2 Replies
Login or Register to Ask a Question
Portable Threads Abstraction Classes(3)                                Coin                                Portable Threads Abstraction Classes(3)

NAME
Portable Threads Abstraction Classes - Classes class SbBarrier The SbBarrier class implements the 'barrier' multi-thread synchronization technique. A barrier is a synchronization mechanism that is used for blocking threads as they enter the barrier until a given number of threads are blocked, at which point all the threads are released again. " class SbCondVar A class for synchronizing access to global variables. Condition variables are used to protect global variables in an environment where multiple threads are running concurrently. " class SbFifo A class for managing a pointer first-in, first-out queue. class SbMutex A basic class for managing a mutex. This class provides a portable framework around the mutex interface of the underlying native thread-handling toolkit. " class SbThreadAutoLock Simple convenience class for locking access to a function. This class provides a simple convenience mechanism for automatically locking access to a function that is not re-entrant. " class SbRWMutex class SbStorage The SbStorage class manages thread-local memory. This class manages thread-local memory. When different threads access the memory an SbStorage object manages, they will receive different memory blocks back. " class SbTypedStorage< Type > The SbTypedStorage class manages generic thread-local memory. This class manages thread-local memory. When different threads access the memory an SbTypedStorage object manages, they will receive different memory blocks back. " class SbThread A class for managing threads. This class provides a portable framework around the tasks of instantiating, starting, stopping and joining threads. " Detailed Description Coin implements a set of abstractions over the native threads data types that can be portably used across all the platforms Coin has been ported to. Author Generated automatically by Doxygen for Coin from the source code. Version 3.1.3 Wed May 23 2012 Portable Threads Abstraction Classes(3)