1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/vm/Probes.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,170 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef vm_Probes_h
1.11 +#define vm_Probes_h
1.12 +
1.13 +#ifdef INCLUDE_MOZILLA_DTRACE
1.14 +#include "javascript-trace.h"
1.15 +#endif
1.16 +
1.17 +#include "vm/Stack.h"
1.18 +
1.19 +namespace js {
1.20 +
1.21 +namespace probes {
1.22 +
1.23 +/*
1.24 + * Static probes
1.25 + *
1.26 + * The probe points defined in this file are scattered around the SpiderMonkey
1.27 + * source tree. The presence of probes::SomeEvent() means that someEvent is
1.28 + * about to happen or has happened. To the extent possible, probes should be
1.29 + * inserted in all paths associated with a given event, regardless of the
1.30 + * active runmode (interpreter/traceJIT/methodJIT/ionJIT).
1.31 + *
1.32 + * When a probe fires, it is handled by any probe handling backends that have
1.33 + * been compiled in. By default, most probes do nothing or at least do nothing
1.34 + * expensive, so the presence of the probe should have negligible effect on
1.35 + * running time. (Probes in slow paths may do something by default, as long as
1.36 + * there is no noticeable slowdown.)
1.37 + *
1.38 + * For some probes, the mere existence of the probe is too expensive even if it
1.39 + * does nothing when called. For example, just having consistent information
1.40 + * available for a function call entry/exit probe causes the JITs to
1.41 + * de-optimize function calls. In those cases, the JITs may query at compile
1.42 + * time whether a probe is desired, and omit the probe invocation if not. If a
1.43 + * probe is runtime-disabled at compilation time, it is not guaranteed to fire
1.44 + * within a compiled function if it is later enabled.
1.45 + *
1.46 + * Not all backends handle all of the probes listed here.
1.47 + */
1.48 +
1.49 +/*
1.50 + * Internal use only: remember whether "profiling", whatever that means, is
1.51 + * currently active. Used for state management.
1.52 + */
1.53 +extern bool ProfilingActive;
1.54 +
1.55 +extern const char nullName[];
1.56 +extern const char anonymousName[];
1.57 +
1.58 +/*
1.59 + * Test whether we are tracking JS function call enter/exit. The JITs use this
1.60 + * to decide whether they can optimize in a way that would prevent probes from
1.61 + * firing.
1.62 + */
1.63 +bool CallTrackingActive(JSContext *);
1.64 +
1.65 +/*
1.66 + * Test whether anything is looking for JIT native code registration events.
1.67 + * This information will not be collected otherwise.
1.68 + */
1.69 +bool WantNativeAddressInfo(JSContext *);
1.70 +
1.71 +/* Entering a JS function */
1.72 +bool EnterScript(JSContext *, JSScript *, JSFunction *, InterpreterFrame *);
1.73 +
1.74 +/* About to leave a JS function */
1.75 +void ExitScript(JSContext *, JSScript *, JSFunction *, bool popSPSFrame);
1.76 +
1.77 +/* Executing a script */
1.78 +bool StartExecution(JSScript *script);
1.79 +
1.80 +/* Script has completed execution */
1.81 +bool StopExecution(JSScript *script);
1.82 +
1.83 +/*
1.84 + * Object has been created. |obj| must exist (its class and size are read)
1.85 + */
1.86 +bool CreateObject(ExclusiveContext *cx, JSObject *obj);
1.87 +
1.88 +/*
1.89 + * Object is about to be finalized. |obj| must still exist (its class is
1.90 + * read)
1.91 + */
1.92 +bool FinalizeObject(JSObject *obj);
1.93 +
1.94 +/* JIT code observation */
1.95 +
1.96 +enum JITReportGranularity {
1.97 + JITREPORT_GRANULARITY_NONE = 0,
1.98 + JITREPORT_GRANULARITY_FUNCTION = 1,
1.99 + JITREPORT_GRANULARITY_LINE = 2,
1.100 + JITREPORT_GRANULARITY_OP = 3
1.101 +};
1.102 +
1.103 +/*
1.104 + * Finest granularity of JIT information desired by all watchers.
1.105 + */
1.106 +JITReportGranularity
1.107 +JITGranularityRequested(JSContext *cx);
1.108 +
1.109 +/*
1.110 + * A whole region of code has been deallocated, containing any number of ICs.
1.111 + * (ICs are unregistered in a batch, so individual ICs are not registered.)
1.112 + */
1.113 +void
1.114 +DiscardExecutableRegion(void *start, size_t size);
1.115 +
1.116 +/*
1.117 + * Internal: DTrace-specific functions to be called during probes::EnterScript
1.118 + * and probes::ExitScript. These will not be inlined, but the argument
1.119 + * marshalling required for these probe points is expensive enough that it
1.120 + * shouldn't really matter.
1.121 + */
1.122 +void DTraceEnterJSFun(JSContext *cx, JSFunction *fun, JSScript *script);
1.123 +void DTraceExitJSFun(JSContext *cx, JSFunction *fun, JSScript *script);
1.124 +
1.125 +} /* namespace Probes */
1.126 +
1.127 +#ifdef INCLUDE_MOZILLA_DTRACE
1.128 +static const char *ObjectClassname(JSObject *obj) {
1.129 + if (!obj)
1.130 + return "(null object)";
1.131 + const Class *clasp = obj->getClass();
1.132 + if (!clasp)
1.133 + return "(null)";
1.134 + const char *class_name = clasp->name;
1.135 + if (!class_name)
1.136 + return "(null class name)";
1.137 + return class_name;
1.138 +}
1.139 +#endif
1.140 +
1.141 +inline bool
1.142 +probes::CreateObject(ExclusiveContext *cx, JSObject *obj)
1.143 +{
1.144 + bool ok = true;
1.145 +
1.146 +#ifdef INCLUDE_MOZILLA_DTRACE
1.147 + if (JAVASCRIPT_OBJECT_CREATE_ENABLED())
1.148 + JAVASCRIPT_OBJECT_CREATE(ObjectClassname(obj), (uintptr_t)obj);
1.149 +#endif
1.150 +
1.151 + return ok;
1.152 +}
1.153 +
1.154 +inline bool
1.155 +probes::FinalizeObject(JSObject *obj)
1.156 +{
1.157 + bool ok = true;
1.158 +
1.159 +#ifdef INCLUDE_MOZILLA_DTRACE
1.160 + if (JAVASCRIPT_OBJECT_FINALIZE_ENABLED()) {
1.161 + const Class *clasp = obj->getClass();
1.162 +
1.163 + /* the first arg is nullptr - reserved for future use (filename?) */
1.164 + JAVASCRIPT_OBJECT_FINALIZE(nullptr, (char *)clasp->name, (uintptr_t)obj);
1.165 + }
1.166 +#endif
1.167 +
1.168 + return ok;
1.169 +}
1.170 +
1.171 +} /* namespace js */
1.172 +
1.173 +#endif /* vm_Probes_h */
