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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef vm_Probes_h
#define vm_Probes_h
#ifdef INCLUDE_MOZILLA_DTRACE
#include "javascript-trace.h"
#endif
#include "vm/Stack.h"
namespace js {
namespace probes {
/*
* Static probes
*
* The probe points defined in this file are scattered around the SpiderMonkey
* source tree. The presence of probes::SomeEvent() means that someEvent is
* about to happen or has happened. To the extent possible, probes should be
* inserted in all paths associated with a given event, regardless of the
* active runmode (interpreter/traceJIT/methodJIT/ionJIT).
*
* When a probe fires, it is handled by any probe handling backends that have
* been compiled in. By default, most probes do nothing or at least do nothing
* expensive, so the presence of the probe should have negligible effect on
* running time. (Probes in slow paths may do something by default, as long as
* there is no noticeable slowdown.)
*
* For some probes, the mere existence of the probe is too expensive even if it
* does nothing when called. For example, just having consistent information
* available for a function call entry/exit probe causes the JITs to
* de-optimize function calls. In those cases, the JITs may query at compile
* time whether a probe is desired, and omit the probe invocation if not. If a
* probe is runtime-disabled at compilation time, it is not guaranteed to fire
* within a compiled function if it is later enabled.
*
* Not all backends handle all of the probes listed here.
*/
/*
* Internal use only: remember whether "profiling", whatever that means, is
* currently active. Used for state management.
*/
extern bool ProfilingActive;
extern const char nullName[];
extern const char anonymousName[];
/*
* Test whether we are tracking JS function call enter/exit. The JITs use this
* to decide whether they can optimize in a way that would prevent probes from
* firing.
*/
bool CallTrackingActive(JSContext*);
/* Entering a JS function */
bool EnterScript(JSContext*, JSScript*, JSFunction*, InterpreterFrame*);
/* About to leave a JS function */
void ExitScript(JSContext*, JSScript*, JSFunction*, bool popSPSFrame);
/* Executing a script */
bool StartExecution(JSScript* script);
/* Script has completed execution */
bool StopExecution(JSScript* script);
/*
* Object has been created. |obj| must exist (its class and size are read)
*/
bool CreateObject(ExclusiveContext* cx, JSObject* obj);
/*
* Object is about to be finalized. |obj| must still exist (its class is
* read)
*/
bool FinalizeObject(JSObject* obj);
/*
* Internal: DTrace-specific functions to be called during probes::EnterScript
* and probes::ExitScript. These will not be inlined, but the argument
* marshalling required for these probe points is expensive enough that it
* shouldn't really matter.
*/
void DTraceEnterJSFun(JSContext* cx, JSFunction* fun, JSScript* script);
void DTraceExitJSFun(JSContext* cx, JSFunction* fun, JSScript* script);
} // namespace probes
#ifdef INCLUDE_MOZILLA_DTRACE
static const char* ObjectClassname(JSObject* obj) {
if (!obj)
return "(null object)";
const Class* clasp = obj->getClass();
if (!clasp)
return "(null)";
const char* class_name = clasp->name;
if (!class_name)
return "(null class name)";
return class_name;
}
#endif
inline bool
probes::CreateObject(ExclusiveContext* cx, JSObject* obj)
{
bool ok = true;
#ifdef INCLUDE_MOZILLA_DTRACE
if (JAVASCRIPT_OBJECT_CREATE_ENABLED())
JAVASCRIPT_OBJECT_CREATE(ObjectClassname(obj), (uintptr_t)obj);
#endif
return ok;
}
inline bool
probes::FinalizeObject(JSObject* obj)
{
bool ok = true;
#ifdef INCLUDE_MOZILLA_DTRACE
if (JAVASCRIPT_OBJECT_FINALIZE_ENABLED()) {
const Class* clasp = obj->getClass();
/* the first arg is nullptr - reserved for future use (filename?) */
JAVASCRIPT_OBJECT_FINALIZE(nullptr, (char*)clasp->name, (uintptr_t)obj);
}
#endif
return ok;
}
} /* namespace js */
#endif /* vm_Probes_h */
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