Since the system subroutines are used by other library routines that
require reentrancy, libc.a provides cover routines (for example,
the reentrant version of fork is _fork_r). These cover
routines are consistent with the other reentrant subroutines in this
library, and achieve reentrancy by using a reserved global data block
(see Reentrancy).
_close_r—Reentrant version of close_execve_r—Reentrant version of execve_fork_r—Reentrant version of fork_wait_r—Reentrant version of wait_fstat_r—Reentrant version of fstat_link_r—Reentrant version of link_lseek_r—Reentrant version of lseek_open_r—Reentrant version of open_read_r—Reentrant version of read_sbrk_r—Reentrant version of sbrk_kill_r—Reentrant version of kill_getpid_r—Reentrant version of getpid_stat_r—Reentrant version of stat_times_r—Reentrant version of times_unlink_r—Reentrant version of unlink_write_r—Reentrant version of write