xref: /external/chromium_org/ppapi/api/dev/ppb_trace_event_dev.idl

/* Copyright (c) 2012 The Chromium Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

/**
 * This file defines the <code>PPB_Trace_Event</code> interface. It is meant
 * to be used in plugins as the API that trace macros from trace_event.h use.
 */

label Chrome {
  M25 = 0.1,
  M29 = 0.2
};

/**
 * A trace event timestamp.
 */
typedef int64_t PP_TraceEventTime;

interface PPB_Trace_Event_Dev {
  /**
   * Gets a pointer to a character for identifying a category name in the
   * tracing system as well as for being able to early exit in client-side
   * tracing code.
   *
   * NB: This mem_t return value should technically be const, but return values
   * for Pepper IDL of mem_t type are not const.  The same is true for the arg
   * |category_enabled| for AddTraceEvent.
   */
  mem_t GetCategoryEnabled([in] cstr_t category_name);

  /**
   * Adds a trace event to the platform tracing system. This function call is
   * usually the result of a TRACE_* macro from trace_event.h when tracing and
   * the category of the particular trace are enabled. It is not advisable to
   * call this function on its own; it is really only meant to be used by the
   * trace macros.
   */
  void AddTraceEvent(
      [in] int8_t phase,
      [in] mem_t category_enabled,
      [in] cstr_t name,
      [in] uint64_t id,
      [in] uint32_t num_args,
      [in, size_as=num_args] str_t[] arg_names,
      [in, size_as=num_args] uint8_t[] arg_types,
      [in, size_as=num_args] uint64_t[] arg_values,
      [in] uint8_t flags);

  /**
   * Version of the above interface that allows specifying a custom thread id
   * and timestamp. This is useful for when tracing data cannot be registered
   * in real time. For example, this could be used by storing timestamps
   * internally and then registering the events retroactively.
   */
  [version=0.2]
  void AddTraceEventWithThreadIdAndTimestamp(
      [in] int8_t phase,
      [in] mem_t category_enabled,
      [in] cstr_t name,
      [in] uint64_t id,
      [in] int32_t thread_id,
      [in] PP_TraceEventTime timestamp,
      [in] uint32_t num_args,
      [in, size_as=num_args] str_t[] arg_names,
      [in, size_as=num_args] uint8_t[] arg_types,
      [in, size_as=num_args] uint64_t[] arg_values,
      [in] uint8_t flags);

  /**
   * Get the current clock value. Since this uses the same function as the trace
   * events use internally, it can be used to create events with explicit time
   * stamps.
   */
  [version=0.2]
  PP_TraceEventTime Now();

  /**
   * Sets the thread name of the calling thread in the tracing system so it will
   * show up properly in chrome://tracing.
   */
  void SetThreadName([in] cstr_t thread_name);
};