From 99e8ecc5759668fd3af379eaddd70b4ae50ecd7f Mon Sep 17 00:00:00 2001
From: rpj <rpj>
Date: Thu, 5 Jul 2001 11:57:32 +0000
Subject: Added new routines from POSIX 1003.1j. This is alpha level code.

        * spin.c: New module implementing spin locks.
        * barrier.c: New module implementing barriers.
        * pthread.h (_POSIX_SPIN_LOCKS): defined.
        (_POSIX_BARRIERS): Defined.
        (pthread_spin_*): Defined.
        (pthread_barrier*): Defined.
        (PTHREAD_BARRIER_SERIAL_THREAD): Defined.
        * implement.h (pthread_spinlock_t_): Defined.
        (pthread_barrier_t_): Defined.
        (pthread_barrierattr_t_): Defined.

        * mutex.c (pthread_mutex_lock): Return with the error
        if an auto-initialiser initialisation fails.

        * nonportable.c (pthread_getprocessors_np): New; gets the
        number of available processors for the current process.
---
 nonportable.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

(limited to 'nonportable.c')

diff --git a/nonportable.c b/nonportable.c
index 150b0c0..5fcb1b8 100644
--- a/nonportable.c
+++ b/nonportable.c
@@ -134,6 +134,51 @@ pthread_delay_np (struct timespec * interval)
 }
 
 
+/*
+ * pthread_getprocessors_np()
+ *
+ * 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
+pthread_getprocessors_np(int * count)
+{
+  DWORD vProcessCPUs;
+  DWORD vSystemCPUs;
+  int result = 0;
+
+  if (GetProcessAffinityMask(GetCurrentProcess(),
+                             &vProcessCPUs,
+                             &vSystemCPUs))
+    {
+      DWORD bit;
+      int CPUs = 0;
+
+      for (bit = 1; bit != 0; bit <<= 1)
+        {
+          if (vProcessCPUs & bit)
+            {
+              CPUs++;
+            }
+        }
+      *count = CPUs;
+    }
+  else
+    {
+      result = EAGAIN;
+    }
+
+  return(result);
+}
+
+
 BOOL
 pthread_win32_process_attach_np ()
 {
-- 
cgit v1.2.3