I'm doing memory-mapped IO in Java. The FileChannel class allows you to map a ByteBuffer to a particular part of a file. I'm doing that with a file opened read only. The problem I am having is that I'm getting an exception when I attempt to call the .array() method on the resulting ByteBuffer. Perhaps that's because the .array() return...
I am writing a routine to compare two files using memory-mapped file. In case files are too big to be mapped at one go. I split the files and map them part by part. For example, to map a 1049MB file, I split it into 512MB + 512MB + 25MB. Every thing works fine except one thing: it always take much, much longer to compare the remainder (...
When we map a file to memory, a system call is required. Do subsequent accesses to the file require system calls or is the virtual memory page of the process mapped to the actual page cache in memory? update: what i also want to know is that if multiple processes are accessing the same file through mmap. they will be accessing the same ...
I'm using and x86 based core to manipulate a 32-bit memory mapped register. My hardware behaves correctly only if the CPU generates 32-bit wide reads and writes to this register. The register is aligned on a 32-bit address and is not addressable at byte granularity. What can I do to guarantee that my C (or C99) compiler will only gene...
I am working on embedded code and attempting to convert a lot of memory-mapped register assignments to get()/set() function calls. I was wondering if it would be possible to maintain the address assignments sprinkled throughout the code, but change the #defines so they take the assignment in as a function argument. Old Way: #define MOT...