1 files changed, 111 insertions, 0 deletions
diff --git a/src/core/ngx_shmtx.h b/src/core/ngx_shmtx.h
new file mode 100644
index 000000000..fdd62e192
--- /dev/null
+++ b/src/core/ngx_shmtx.h
@@ -0,0 +1,111 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#ifndef _NGX_SHMTX_H_INCLUDED_
+#define _NGX_SHMTX_H_INCLUDED_
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+
+
+typedef struct {
+#if (NGX_HAVE_ATOMIC_OPS)
+    ngx_atomic_t  *lock;
+#else
+    ngx_fd_t       fd;
+    u_char        *name;
+    ngx_log_t     *log;
+#endif
+} ngx_shmtx_t;
+
+
+ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, void *addr, u_char *name,
+    ngx_log_t *log);
+
+
+#if (NGX_HAVE_ATOMIC_OPS)
+
+static ngx_inline ngx_uint_t
+ngx_shmtx_trylock(ngx_shmtx_t *mtx)
+{
+    if (*mtx->lock == 0 && ngx_atomic_cmp_set(mtx->lock, 0, ngx_pid)) {
+        return 1;
+    }
+
+    return 0;
+}
+
+#define ngx_shmtx_lock(mtx)   ngx_spinlock((mtx)->lock, ngx_pid, 1024)
+
+#define ngx_shmtx_unlock(mtx) (void) ngx_atomic_cmp_set((mtx)->lock, ngx_pid, 0)
+
+#define ngx_shmtx_destory(mtx)
+
+
+#else
+
+static ngx_inline ngx_uint_t
+ngx_shmtx_trylock(ngx_shmtx_t *mtx)
+{
+    ngx_err_t  err;
+
+    err = ngx_trylock_fd(mtx->fd);
+
+    if (err == 0) {
+        return 1;
+    }
+
+    if (err == NGX_EAGAIN) {
+        return 0;
+    }
+
+    ngx_log_error(NGX_LOG_ALERT, mtx->log, err, ngx_trylock_fd_n " failed");
+
+    ngx_abort();
+}
+
+
+static ngx_inline void
+ngx_shmtx_lock(ngx_shmtx_t *mtx)
+{
+    ngx_err_t  err;
+
+    err = ngx_lock_fd(mtx->fd);
+
+    if (err == 0) {
+        return;
+    }
+
+    ngx_log_error(NGX_LOG_ALERT, mtx->log, err, ngx_lock_fd_n " failed");
+
+    ngx_abort();
+}
+
+
+static ngx_inline void
+ngx_shmtx_unlock(ngx_shmtx_t *mtx)
+{
+    ngx_err_t  err;
+
+    err = ngx_unlock_fd(mtx->fd);
+
+    if (err == 0) {
+        return;
+    }
+
+    ngx_log_error(NGX_LOG_ALERT, mtx->log, err, ngx_unlock_fd_n " failed");
+
+    ngx_abort();
+}
+
+
+void ngx_shmtx_destory(ngx_shmtx_t *mtx);
+
+#endif
+
+
+#endif /* _NGX_SHMTX_H_INCLUDED_ */