--- mlutils/unix_utils-c.c | 15 +++++++++++++++ mlutils/unix_utils.ml | 5 +++++ mlutils/unix_utils.mli | 9 +++++++++ 3 files changed, 29 insertions(+) diff --git a/mlutils/unix_utils-c.c b/mlutils/unix_utils-c.c index 3309961..8acf039 100644 --- a/mlutils/unix_utils-c.c +++ b/mlutils/unix_utils-c.c @@ -77,6 +77,7 @@ extern value guestfs_int_mllib_mkdtemp (value val_pattern); extern value guestfs_int_mllib_realpath (value pathv); extern value guestfs_int_mllib_statvfs_statvfs (value pathv); extern value guestfs_int_mllib_statvfs_is_network_filesystem (value pathv); +extern value guestfs_int_mllib_sysconf_nr_processors_online (value unitv); /* NB: This is a "noalloc" call. */ value @@ -368,3 +369,17 @@ guestfs_int_mllib_statvfs_is_network_filesystem (value pathv) return Val_bool (0); #endif } + +/* NB: This is a "noalloc" call. */ +value +guestfs_int_mllib_sysconf_nr_processors_online (value unitv) +{ +#ifdef _SC_NPROCESSORS_ONLN + long n; + + n = sysconf (_SC_NPROCESSORS_ONLN); + if (n > 0) return Val_int (n); +#endif + /* Return a safe value so that callers don't need to deal with errors. */ + return Val_int (1); +} diff --git a/mlutils/unix_utils.ml b/mlutils/unix_utils.ml index 52eb824..2bdda12 100644 --- a/mlutils/unix_utils.ml +++ b/mlutils/unix_utils.ml @@ -84,3 +84,8 @@ module StatVFS = struct external is_network_filesystem : string -> bool = "guestfs_int_mllib_statvfs_is_network_filesystem" "noalloc" end + +module Sysconf = struct + external nr_processors_online : unit -> int = + "guestfs_int_mllib_sysconf_nr_processors_online" "noalloc" +end diff --git a/mlutils/unix_utils.mli b/mlutils/unix_utils.mli index 4fcea4a..aead4df 100644 --- a/mlutils/unix_utils.mli +++ b/mlutils/unix_utils.mli @@ -121,3 +121,12 @@ module StatVFS : sig (** [is_network_filesystem path] returns true if [path] is located on a network filesystem such as NFS or CIFS. *) end + +module Sysconf : sig + val nr_processors_online : unit -> int + (** [nr_processors_online ()] returns the number of processors + currently online, from [sysconf (_SC_NPROCESSORS_ONLN)]. + + Note this never fails. In case we cannot get the number of + cores it returns 1. *) +end -- 2.27.0