The direct NIO buffers use unmanaged memory. It means that they are allocated on the native heap, not on the Java heap. As a consequence, they are freed only when the JVM runs out of memory on the Java heap, not on the native heap. In other terms, it’s unmanaged = it’s up to you … Read more
You may also be limited by the OS, if it still doesn’t seem to be working. Check the values in: /proc/sys/net/core/rmem_default /proc/sys/net/core/rmem_max If it’s TCP as you say in your example, and not actually a raw socket, you can also check the values in: /proc/sys/net/ipv4/tcp_mem If you run cat on these files they’ll show you … Read more
For GNU glibc: SYNOPSIS #include <malloc.h> size_t malloc_usable_size (void *ptr); DESCRIPTION The malloc_usable_size() function returns the number of usable bytes in the block pointed to by ptr, a pointer to a block of memory allocated by malloc(3) or a related function.
If you want see your buffer size in terminal, you can take a look at: /proc/sys/net/ipv4/tcp_rmem (for read) /proc/sys/net/ipv4/tcp_wmem (for write) They contain three numbers, which are minimum, default and maximum memory size values (in byte), respectively.
Why can’t we write directly to this buffer? I’ll state the obvious point: because it’s const. And casting away a const value and then modifying that data is… rude. Now, why is it const? That goes back to the days when copy-on-write was considered a good idea, so std::basic_string had to allow implementations to support … Read more
This is possible by combining the built-in Window and Throttle methods of Observable. First, let’s solve the simpler problem where we ignore the maximum count condition: public static IObservable<IList<T>> BufferUntilInactive<T>(this IObservable<T> stream, TimeSpan delay) { var closes = stream.Throttle(delay); return stream.Window(() => closes).SelectMany(window => window.ToList()); } The powerful Window method did the heavy lifting. Now … Read more
To clear the terminal manually: ⌘+K Command+K for newer keyboards To clear the terminal from within a shell script; /usr/bin/osascript -e ‘tell application “System Events” to tell process “Terminal” to keystroke “k” using command down’
When an error occurs when reading from a stream, an error flag gets set and no more reading is possible until you clear the error flags. That’s why you get an infinite loop. cin.clear(); // clears the error flags // this line discards all the input waiting in the stream cin.ignore(std::numeric_limits<std::streamsize>::max(), ‘\n’); Also, it’s wrong … Read more
I posted two solutions for a similar requirement here Basically you have two options. 1- Get a graphics object for the desktop and start drawing to it. The problem is if you need to start clearing what you have previously drawn etc. Point pt = Cursor.Position; // Get the mouse cursor in screen coordinates using … Read more
The other answers tell you that the pipe size is 64 KB. The reason why PIPE_BUF is 4KB is that PIPE_BUF is the largest size for which writes are guaranteed to be atomic. See http://pubs.opengroup.org/onlinepubs/9699919799/functions/write.html