Unless you want to write your own IO thread pool, the glibc implementation is an acceptable solution. It actually works surprisingly well for something that runs entirely in userland. The kernel implementation does not work with buffered IO at all in my experience (though I’ve seen other people say the opposite!). Which is fine if … Read more
Before Java 7: BufferedReader br = new BufferedReader(new FileReader(“foo.txt”)); String line; while ((line = br.readLine()) != null) { System.out.println(line); } add exception handling add closing the stream Since Java 7, there is no need to close the stream, because it implements autocloseable try (BufferedReader br = new BufferedReader(new FileReader(“foo.txt”))) { String line; while ((line = … Read more
It seems that your implementation is correct so far. The issue is with how you are printing the local array for the first processor. The local array is formed column-wise because of how the file is being read and the data is distributed among the processes. To print the local array for the first processor … Read more
While using the constructor with the empty String, you create a File instance that has two properties : It does not actually exists. Its absolute pathname is the “empty abstract pathname” When using File(“.”), you create a different file : It DOES exist on the file system Its absolute pathname contains the “.” character This … Read more
ReadBlock does not mean it is thread safe. If you use Reflector to look at the implementation of StreamReader.ReadBlock (which is inherited from TextReader.ReadBlock), all it does is make multiple calls to the “Read” method until either the “Read” method returns 0 or we have read as many bytes as requested. This is needed because … Read more
I got the same Exception with PostgreSQL 8.4, but I connect to a local db on the same host. The reason was the connection, which was not valid any more and so I needed to open it again. There is a ticket on postgresql.org which has a related topic. Their answer is pretty similar, by … Read more
Streams are blocking by default. TCP/IP streams, filesystem streams, pipe streams, they are all blocking. When you tell a stream to give you a chunk of bytes it will stop and wait till it has the given amout of bytes or till something else happens (an interrupt, an end of stream, an error). The operating … Read more
So you can signal EOF: “Notice that read() returns an int value. If the input is a stream of bytes, why doesn’t read() return a byte value? Using a int as a return type allows read() to use -1 to indicate that it has reached the end of the stream.” http://java.sun.com/docs/books/tutorial/essential/io/bytestreams.html
Yes, it’s a bug. Here’s a workaround to save folks clicking and scrolling: {-# LANGUAGE ForeignFunctionInterface #-} import Data.Char import Foreign.C.Types getHiddenChar = fmap (chr.fromEnum) c_getch foreign import ccall unsafe “conio.h getch” c_getch :: IO CInt So you can replace calls to getChar with calls to getHiddenChar. Note this is a workaround just for ghc/ghci … Read more
Editor’s note: This answer is out of date. As of Ruby 2.6, File.read is different in that it does not invoke external commands for filenames that start with a “|” character (issue, commit). since File is a subclass of IO and it does not have the read method, when you invoke File.read, you are actually … Read more