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author | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
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committer | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
commit | 5f8de423f190bbb79a62f804151bc24824fa32d8 (patch) | |
tree | 10027f336435511475e392454359edea8e25895d /js/src/vm/Probes.h | |
parent | 49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff) | |
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Add m-esr52 at 52.6.0
Diffstat (limited to 'js/src/vm/Probes.h')
-rw-r--r-- | js/src/vm/Probes.h | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/js/src/vm/Probes.h b/js/src/vm/Probes.h new file mode 100644 index 000000000..edcc9d33e --- /dev/null +++ b/js/src/vm/Probes.h @@ -0,0 +1,143 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- + * vim: set ts=8 sts=4 et sw=4 tw=99: + * 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 */ |