| // Copyright 2018 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // |
| // The API for instrumenting drivers with trace events. |
| // |
| // This header defines macros which are used to record trace information during |
| // driver execution when tracing is enabled. Each trace event macro records |
| // an event of a given type together with the current time, a category, name, |
| // and named arguments containing additional information about the event. |
| // |
| // Where indicated, the category and name literal strings must point to |
| // null-terminated static string constants whose memory address can be |
| // cached by the string table for the lifetime of the trace session. |
| // |
| // Defining the NTRACE macro completely disables recording of trace events |
| // in the compilation unit. |
| // |
| // For more control over how trace events are written, see <trace-engine/context.h>. |
| // |
| |
| #ifndef DDK_TRACE_EVENT_H_ |
| #define DDK_TRACE_EVENT_H_ |
| |
| // While driver tracing support is under development, |
| // one must pass ENABLE_DRIVER_TRACING=true to make. |
| #if !ENABLE_DRIVER_TRACING |
| #undef NTRACE |
| #define NTRACE |
| #endif |
| |
| // For now userspace and DDK tracing share the same API and implementation. |
| #include <trace/internal/event_common.h> |
| |
| #endif // DDK_TRACE_EVENT_H_ |
