NAME

       pmemblk_read(), pmemblk_write() - read or write a block from a block memory pool

SYNOPSIS

              #include <libpmemblk.h>

              int pmemblk_read(PMEMblkpool *pbp, void *buf, long long blockno);
              int pmemblk_write(PMEMblkpool *pbp, const void *buf, long long blockno);

DESCRIPTION

       The pmemblk_read() function reads the block with block number blockno from memory pool pbp
       into the buffer buf.  Reading a block that has never been written by pmemblk_write()  will
       return a block of zeroes.

       The pmemblk_write() function writes a block from buf to block number blockno in the memory
       pool pbp.  The write is atomic with respect to other reads and writes.  In  addition,  the
       write  cannot  be  torn  by  program  failure  or  system  crash; on recovery the block is
       guaranteed to contain either the old data or the new data, never a mixture of both.

RETURN VALUE

       On success, the pmemblk_read() and pmemblk_write() functions return  0.   On  error,  they
       return -1 and set errno appropriately.

SEE ALSO

       libpmemblk(7) and <http://pmem.io>