initial version of VSAP

Signed-off-by: Yu Ping <ping.yu@intel.com>
Change-Id: I04d9150f0c7607ba20de9096b452476eff1622fc

1 files changed, 53 insertions, 0 deletions

diff --git a/nginx/src/core/ngx_spinlock.c b/nginx/src/core/ngx_spinlock.c
new file mode 100644
index 0000000..9c93afa
--- /dev/null
+++ b/nginx/src/core/ngx_spinlock.c
@@ -0,0 +1,53 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) Nginx, Inc.
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+
+
+void
+ngx_spinlock(ngx_atomic_t *lock, ngx_atomic_int_t value, ngx_uint_t spin)
+{
+
+#if (NGX_HAVE_ATOMIC_OPS)
+
+    ngx_uint_t  i, n;
+
+    for ( ;; ) {
+
+        if (*lock == 0 && ngx_atomic_cmp_set(lock, 0, value)) {
+            return;
+        }
+
+        if (ngx_ncpu > 1) {
+
+            for (n = 1; n < spin; n <<= 1) {
+
+                for (i = 0; i < n; i++) {
+                    ngx_cpu_pause();
+                }
+
+                if (*lock == 0 && ngx_atomic_cmp_set(lock, 0, value)) {
+                    return;
+                }
+            }
+        }
+
+        ngx_sched_yield();
+    }
+
+#else
+
+#if (NGX_THREADS)
+
+#error ngx_spinlock() or ngx_atomic_cmp_set() are not defined !
+
+#endif
+
+#endif
+
+}