aboutsummaryrefslogtreecommitdiff
path: root/pthreads/ptw32_getprocessors.c
diff options
context:
space:
mode:
Diffstat (limited to 'pthreads/ptw32_getprocessors.c')
-rw-r--r--pthreads/ptw32_getprocessors.c91
1 files changed, 91 insertions, 0 deletions
diff --git a/pthreads/ptw32_getprocessors.c b/pthreads/ptw32_getprocessors.c
new file mode 100644
index 000000000..e60c3143f
--- /dev/null
+++ b/pthreads/ptw32_getprocessors.c
@@ -0,0 +1,91 @@
+/*
+ * ptw32_getprocessors.c
+ *
+ * Description:
+ * This translation unit implements routines which are private to
+ * the implementation and may be used throughout it.
+ *
+ * --------------------------------------------------------------------------
+ *
+ * Pthreads-win32 - POSIX Threads Library for Win32
+ * Copyright(C) 1998 John E. Bossom
+ * Copyright(C) 1999,2005 Pthreads-win32 contributors
+ *
+ * Contact Email: rpj@callisto.canberra.edu.au
+ *
+ * The current list of contributors is contained
+ * in the file CONTRIBUTORS included with the source
+ * code distribution. The list can also be seen at the
+ * following World Wide Web location:
+ * http://sources.redhat.com/pthreads-win32/contributors.html
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library in the file COPYING.LIB;
+ * if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include "pthread.h"
+#include "implement.h"
+
+
+/*
+ * ptw32_getprocessors()
+ *
+ * Get the number of CPUs available to the process.
+ *
+ * If the available number of CPUs is 1 then pthread_spin_lock()
+ * will block rather than spin if the lock is already owned.
+ *
+ * pthread_spin_init() calls this routine when initialising
+ * a spinlock. If the number of available processors changes
+ * (after a call to SetProcessAffinityMask()) then only
+ * newly initialised spinlocks will notice.
+ */
+int
+ptw32_getprocessors (int *count)
+{
+ DWORD_PTR vProcessCPUs;
+ DWORD_PTR vSystemCPUs;
+ int result = 0;
+
+#if defined(NEED_PROCESS_AFFINITY_MASK)
+
+ *count = 1;
+
+#else
+
+ if (GetProcessAffinityMask (GetCurrentProcess (),
+ &vProcessCPUs, &vSystemCPUs))
+ {
+ DWORD_PTR bit;
+ int CPUs = 0;
+
+ for (bit = 1; bit != 0; bit <<= 1)
+ {
+ if (vProcessCPUs & bit)
+ {
+ CPUs++;
+ }
+ }
+ *count = CPUs;
+ }
+ else
+ {
+ result = EAGAIN;
+ }
+
+#endif
+
+ return (result);
+}