Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
Currently I am using a single thread and fseek/fwrite to save data into a large file in loop. But of course the saving is bottleneck. To remove this bottleneck, I think I can create a thread for asynchronous file write but this will block the file access in next iteration thread.
Is there any way to concurrently and asynchronously write into a file in Visual C/C++?
(OS is Windows)
Use CreateFile(), SetFilePointer(), and SetEndOfFile() to create and pre-size a file. Then use CreateFile() in your worker threads to open additional handles to the file, SetFilePointer() to seek to the desired offsets, and WriteFile() to write into it. As long as each call to CreateFile() grants FILE_SHARE_WRITE rights, you can open multiple handles with GENERIC_WRITE permissions at a time. Each handle maintains its own pointer in the file.