diff options
| -rw-r--r-- | ChangeLog | 14 | ||||
| -rw-r--r-- | NEWS | 2 | ||||
| -rw-r--r-- | lib/nproc.c | 236 | ||||
| -rw-r--r-- | lib/nproc.h | 21 | ||||
| -rw-r--r-- | m4/nproc.m4 | 32 | ||||
| -rw-r--r-- | modules/nproc | 2 |
6 files changed, 286 insertions, 21 deletions
@@ -1,3 +1,17 @@ +2009-11-04 Bruno Haible <bruno@clisp.org> + + Make num_processors more flexible and consistent. + * lib/nproc.h (enum nproc_query): New type. + (num_processors): Add a 'query' argument. + * lib/nproc.c: Include <stdlib.h>, <sched.h>, c-ctype.h. + (num_processors): Add a 'query' argument. Test the value of the + OMP_NUM_THREADS environment variable if requested. On Linux, NetBSD, + mingw, count the number of CPUs available for the current process. + * m4/nproc.m4 (gl_PREREQ_NPROC): Require AC_USE_SYSTEM_EXTENSIONS. + Check for sched_getaffinity and sched_getaffinity_np. + * modules/nproc (Depends-on): Add c-ctype, extensions. + * NEWS: Mention the change. + 2009-11-03 Bruno Haible <bruno@clisp.org> * NEWS: Document the new library dependencies of inet_ntop, inet_pton. @@ -6,6 +6,8 @@ User visible incompatible changes Date Modules Changes +2009-11-04 nproc The num_processors function now takes an argument. + 2009-11-02 inet_pton The use of this module now requires linking with $(INET_PTON_LIB). diff --git a/lib/nproc.c b/lib/nproc.c index b5a70b193a..7c9be94ae0 100644 --- a/lib/nproc.c +++ b/lib/nproc.c @@ -16,13 +16,22 @@ along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ -/* Written by Glen Lenker. */ +/* Written by Glen Lenker and Bruno Haible. */ #include <config.h> #include "nproc.h" +#include <stdlib.h> #include <unistd.h> +#if HAVE_PTHREAD_AFFINITY_NP && 0 +# include <pthread.h> +# include <sched.h> +#endif +#if HAVE_SCHED_GETAFFINITY_LIKE_GLIBC || HAVE_SCHED_GETAFFINITY_NP +# include <sched.h> +#endif + #include <sys/types.h> #if HAVE_SYS_PSTAT_H @@ -46,42 +55,235 @@ # include <windows.h> #endif +#include "c-ctype.h" + #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0])) -/* Return the total number of processors. The result is guaranteed to - be at least 1. */ unsigned long int -num_processors (void) +num_processors (enum nproc_query query) { + if (query == NPROC_CURRENT_OVERRIDABLE) + { + /* Test the environment variable OMP_NUM_THREADS, recognized also by all + programs that are based on OpenMP. The OpenMP spec says that the + value assigned to the environment variable "may have leading and + trailing white space". */ + const char *envvalue = getenv ("OMP_NUM_THREADS"); + + if (envvalue != NULL) + { + while (*envvalue != '\0' && c_isspace (*envvalue)) + envvalue++; + /* Convert it from decimal to 'unsigned long'. */ + if (c_isdigit (*envvalue)) + { + char *endptr = NULL; + unsigned long int value = strtoul (envvalue, &endptr, 10); + + if (endptr != NULL) + { + while (*endptr != '\0' && c_isspace (*endptr)) + endptr++; + if (*endptr == '\0') + return (value > 0 ? value : 1); + } + } + } + + query = NPROC_CURRENT; + } + /* Here query is one of NPROC_ALL, NPROC_CURRENT. */ + + if (query == NPROC_CURRENT) + { + /* glibc >= 2.3.3 with NPTL and NetBSD 5 have pthread_getaffinity_np, + but with different APIs. Also it requires linking with -lpthread. + Therefore this code is not enabled. + glibc >= 2.3.4 has sched_getaffinity whereas NetBSD 5 has + sched_getaffinity_np. */ +#if HAVE_PTHREAD_AFFINITY_NP && defined __GLIBC__ && 0 + { + cpu_set_t set; + + if (pthread_getaffinity_np (pthread_self (), sizeof (set), &set) == 0) + { + unsigned long count; + +# ifdef CPU_COUNT + /* glibc >= 2.6 has the CPU_COUNT macro. */ + count = CPU_COUNT (&set); +# else + size_t i; + + count = 0; + for (i = 0; i < CPU_SETSIZE; i++) + if (CPU_ISSET (i, &set)) + count++; +# endif + if (count > 0) + return count; + } + } +#elif HAVE_PTHREAD_AFFINITY_NP && defined __NetBSD__ && 0 + { + cpuset_t *set; + + set = cpuset_create (); + if (set != NULL) + { + unsigned long count = 0; + + if (pthread_getaffinity_np (pthread_self (), cpuset_size (set), set) + == 0) + { + cpuid_t i; + + for (i = 0;; i++) + { + int ret = cpuset_isset (i, set); + if (ret < 0) + break; + if (ret > 0) + count++; + } + } + cpuset_destroy (set); + if (count > 0) + return count; + } + } +#elif HAVE_SCHED_GETAFFINITY_LIKE_GLIBC /* glibc >= 2.3.4 */ + { + cpu_set_t set; + + if (sched_getaffinity (0, sizeof (set), &set) == 0) + { + unsigned long count; + +# ifdef CPU_COUNT + /* glibc >= 2.6 has the CPU_COUNT macro. */ + count = CPU_COUNT (&set); +# else + size_t i; + + count = 0; + for (i = 0; i < CPU_SETSIZE; i++) + if (CPU_ISSET (i, &set)) + count++; +# endif + if (count > 0) + return count; + } + } +#elif HAVE_SCHED_GETAFFINITY_NP /* NetBSD >= 5 */ + { + cpuset_t *set; + + set = cpuset_create (); + if (set != NULL) + { + unsigned long count = 0; + + if (sched_getaffinity_np (getpid (), cpuset_size (set), set) == 0) + { + cpuid_t i; + + for (i = 0;; i++) + { + int ret = cpuset_isset (i, set); + if (ret < 0) + break; + if (ret > 0) + count++; + } + } + cpuset_destroy (set); + if (count > 0) + return count; + } + } +#endif + +#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ + { /* This works on native Windows platforms. */ + DWORD_PTR process_mask; + DWORD_PTR system_mask; + + if (GetProcessAffinityMask (GetCurrentProcess (), + &process_mask, &system_mask)) + { + DWORD_PTR mask = process_mask; + unsigned long count = 0; + + for (; mask != 0; mask = mask >> 1) + if (mask & 1) + count++; + if (count > 0) + return count; + } + } +#endif + #if defined _SC_NPROCESSORS_ONLN - { /* This works on glibc, MacOS X 10.5, FreeBSD, AIX, OSF/1, Solaris, Cygwin, - Haiku. */ - long int nprocs = sysconf (_SC_NPROCESSORS_ONLN); - if (0 < nprocs) - return nprocs; - } + { /* This works on glibc, MacOS X 10.5, FreeBSD, AIX, OSF/1, Solaris, + Cygwin, Haiku. */ + long int nprocs = sysconf (_SC_NPROCESSORS_ONLN); + if (nprocs > 0) + return nprocs; + } +#endif + } + else /* query == NPROC_ALL */ + { +#if defined _SC_NPROCESSORS_CONF + { /* This works on glibc, MacOS X 10.5, FreeBSD, AIX, OSF/1, Solaris, + Cygwin, Haiku. */ + long int nprocs = sysconf (_SC_NPROCESSORS_CONF); + if (nprocs > 0) + return nprocs; + } #endif + } #if HAVE_PSTAT_GETDYNAMIC { /* This works on HP-UX. */ struct pst_dynamic psd; - if (0 <= pstat_getdynamic (&psd, sizeof psd, 1, 0) - && 0 < psd.psd_proc_cnt) - return psd.psd_proc_cnt; + if (pstat_getdynamic (&psd, sizeof psd, 1, 0) >= 0) + { + /* The field psd_proc_cnt contains the number of active processors. + In newer releases of HP-UX 11, the field psd_max_proc_cnt includes + deactivated processors. */ + if (query == NPROC_CURRENT) + { + if (psd.psd_proc_cnt > 0) + return psd.psd_proc_cnt; + } + else + { + if (psd.psd_max_proc_cnt > 0) + return psd.psd_max_proc_cnt; + } + } } #endif -#if HAVE_SYSMP && defined MP_NAPROCS +#if HAVE_SYSMP && defined MP_NAPROCS && defined MP_NPROCS { /* This works on IRIX. */ /* MP_NPROCS yields the number of installed processors. MP_NAPROCS yields the number of processors available to unprivileged - processes. We need the latter. */ - int nprocs = sysmp (MP_NAPROCS); - if (0 < nprocs) + processes. */ + int nprocs = + sysmp (query == NPROC_CURRENT && getpid () != 0 + ? MP_NAPROCS + : MP_NPROCS); + if (nprocs > 0) return nprocs; } #endif + /* Finally, as fallback, use the APIs that don't distinguish between + NPROC_CURRENT and NPROC_ALL. */ + #if HAVE_SYSCTL && defined HW_NCPU { /* This works on MacOS X, FreeBSD, NetBSD, OpenBSD. */ int nprocs; diff --git a/lib/nproc.h b/lib/nproc.h index e9d65b9518..52e148cecc 100644 --- a/lib/nproc.h +++ b/lib/nproc.h @@ -16,14 +16,31 @@ along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ -/* Written by Glen Lenker. */ +/* Written by Glen Lenker and Bruno Haible. */ /* Allow the use in C++ code. */ #ifdef __cplusplus extern "C" { #endif -unsigned long int num_processors (void); +/* A "processor" in this context means a thread execution unit, that is either + - an execution core in a (possibly multi-core) chip, in a (possibly multi- + chip) module, in a single computer, or + - a thread execution unit inside a core + (hyper-threading, see <http://en.wikipedia.org/wiki/Hyper-threading>). + Which of the two definitions is used, is unspecified. */ + +enum nproc_query +{ + NPROC_ALL, /* total number of processors */ + NPROC_CURRENT, /* processors available to the current process */ + NPROC_CURRENT_OVERRIDABLE /* likewise, but overridable through the + OMP_NUM_THREADS environment variable */ +}; + +/* Return the total number of processors. The result is guaranteed to + be at least 1. */ +extern unsigned long int num_processors (enum nproc_query query); #ifdef __cplusplus } diff --git a/m4/nproc.m4 b/m4/nproc.m4 index 5e80fa6939..2017e68dab 100644 --- a/m4/nproc.m4 +++ b/m4/nproc.m4 @@ -1,4 +1,4 @@ -# nproc.m4 serial 3 +# nproc.m4 serial 4 dnl Copyright (C) 2009 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -12,6 +12,9 @@ AC_DEFUN([gl_NPROC], # Prerequisites of lib/nproc.c. AC_DEFUN([gl_PREREQ_NPROC], [ + dnl Persuade glibc <sched.h> to declare CPU_SETSIZE, CPU_ISSET etc. + AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) + AC_CHECK_HEADERS([sys/pstat.h sys/sysmp.h sys/param.h],,, [AC_INCLUDES_DEFAULT]) dnl <sys/sysctl.h> requires <sys/param.h> on OpenBSD 4.0. @@ -21,5 +24,30 @@ AC_DEFUN([gl_PREREQ_NPROC], # include <sys/param.h> #endif ]) - AC_CHECK_FUNCS([pstat_getdynamic sysmp sysctl]) + + AC_CHECK_FUNCS([sched_getaffinity sched_getaffinity_np \ + pstat_getdynamic sysmp sysctl]) + + dnl Test whether sched_getaffinity has the expected declaration. + dnl glibc 2.3.[0-2]: + dnl int sched_getaffinity (pid_t, unsigned int, unsigned long int *); + dnl glibc 2.3.3: + dnl int sched_getaffinity (pid_t, cpu_set_t *); + dnl glibc >= 2.3.4: + dnl int sched_getaffinity (pid_t, size_t, cpu_set_t *); + if test $ac_cv_func_sched_getaffinity = yes; then + AC_CACHE_CHECK([for glibc compatible sched_getaffinity], + [gl_cv_func_sched_getaffinity3], + [AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM( + [[#include <sched.h>]], + [[sched_getaffinity (0, 0, (cpu_set_t *) 0);]])], + [gl_cv_func_sched_getaffinity3=yes], + [gl_cv_func_sched_getaffinity3=no]) + ]) + if test $gl_cv_func_sched_getaffinity3 = yes; then + AC_DEFINE([HAVE_SCHED_GETAFFINITY_LIKE_GLIBC], [1], + [Define to 1 if sched_getaffinity has a glibc compatible declaration.]) + fi + fi ]) diff --git a/modules/nproc b/modules/nproc index 7b24121c5e..c04d4cd66a 100644 --- a/modules/nproc +++ b/modules/nproc @@ -7,6 +7,8 @@ lib/nproc.c m4/nproc.m4 Depends-on: +c-ctype +extensions unistd configure.ac: |