Add API tracing to gRPC core

1 files changed, 65 insertions, 0 deletions

diff --git a/src/core/surface/api_trace.h b/src/core/surface/api_trace.h
new file mode 100644
index 0000000000..7769b191ef
--- /dev/null
+++ b/src/core/surface/api_trace.h
@@ -0,0 +1,65 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_SURFACE_API_TRACE_H
+#define GRPC_INTERNAL_CORE_SURFACE_API_TRACE_H
+
+#include "src/core/debug/trace.h"
+#include <grpc/support/log.h>
+
+extern int grpc_api_trace;
+
+/* Provide unwrapping macros because we're in C89 and variadic macros weren't
+   introduced until C99... */
+#define GRPC_API_TRACE_UNWRAP0()
+#define GRPC_API_TRACE_UNWRAP1(a) , a
+#define GRPC_API_TRACE_UNWRAP2(a, b) , a, b
+#define GRPC_API_TRACE_UNWRAP3(a, b, c) , a, b, c
+#define GRPC_API_TRACE_UNWRAP4(a, b, c, d) , a, b, c, d
+#define GRPC_API_TRACE_UNWRAP5(a, b, c, d, e) , a, b, c, d, e
+#define GRPC_API_TRACE_UNWRAP6(a, b, c, d, e, f) , a, b, c, d, e, f
+#define GRPC_API_TRACE_UNWRAP7(a, b, c, d, e, f, g) , a, b, c, d, e, f, g
+#define GRPC_API_TRACE_UNWRAP8(a, b, c, d, e, f, g, h) , a, b, c, d, e, f, g, h
+#define GRPC_API_TRACE_UNWRAP9(a, b, c, d, e, f, g, h, i) \
+    , a, b, c, d, e, f, g, h, i
+#define GRPC_API_TRACE_UNWRAP10(a, b, c, d, e, f, g, h, i, j) \
+    , a, b, c, d, e, f, g, h, i, j
+
+/* Due to the limitations of C89's preprocessor, the arity of the var-arg list
+   'nargs' must be specified. */
+#define GRPC_API_TRACE(fmt, nargs, args)                          \
+    if (grpc_api_trace) {                                         \
+      gpr_log(GPR_INFO, fmt GRPC_API_TRACE_UNWRAP##nargs args ); \
+    }
+
+#endif /* GRPC_INTERNAL_CORE_SURFACE_API_TRACE_H */