The Tor Browser: js/src/vm/SPSProfiler.cpp@6474c204b198 (annotated)

js/src/vm/SPSProfiler.cpp@6474c204b198 (annotated)

js/src/vm/SPSProfiler.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- 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/. */
 #include "vm/SPSProfiler.h"
 #include "mozilla/DebugOnly.h"
 #include "jsnum.h"
 #include "jsprf.h"
 #include "jsscript.h"
 #include "jit/BaselineJIT.h"
 #include "vm/StringBuffer.h"
 using namespace js;
 using mozilla::DebugOnly;
 SPSProfiler::SPSProfiler(JSRuntime *rt)
   : rt(rt),
     stack_(nullptr),
     size_(nullptr),
     max_(0),
     slowAssertions(false),
     enabled_(false),
     lock_(nullptr),
     eventMarker_(nullptr)
 {
     JS_ASSERT(rt != nullptr);
 }
 bool
 SPSProfiler::init()
 {
 #ifdef JS_THREADSAFE
     lock_ = PR_NewLock();
     if (lock_ == nullptr)
         return false;
 #endif
     return true;
 }
 SPSProfiler::~SPSProfiler()
 {
     if (strings.initialized()) {
         for (ProfileStringMap::Enum e(strings); !e.empty(); e.popFront())
             js_free(const_cast<char *>(e.front().value()));
     }
 #ifdef JS_THREADSAFE
     if (lock_)
         PR_DestroyLock(lock_);
 #endif
 }
 void
 SPSProfiler::setProfilingStack(ProfileEntry *stack, uint32_t *size, uint32_t max)
 {
     AutoSPSLock lock(lock_);
     JS_ASSERT_IF(size_ && *size_ != 0, !enabled());
     if (!strings.initialized())
         strings.init();
     stack_ = stack;
     size_  = size;
     max_   = max;
 }
 void
 SPSProfiler::setEventMarker(void (*fn)(const char *))
 {
     eventMarker_ = fn;
 }
 void
 SPSProfiler::enable(bool enabled)
 {
     JS_ASSERT(installed());
     if (enabled_ == enabled)
         return;
     /*
      * Ensure all future generated code will be instrumented, or that all
      * currently instrumented code is discarded
      */
     ReleaseAllJITCode(rt->defaultFreeOp());
     enabled_ = enabled;
 #ifdef JS_ION
     /* Toggle SPS-related jumps on baseline jitcode.
      * The call to |ReleaseAllJITCode| above will release most baseline jitcode, but not
      * jitcode for scripts with active frames on the stack.  These scripts need to have
      * their profiler state toggled so they behave properly.
      */
     jit::ToggleBaselineSPS(rt, enabled);
 #endif
 }
 /* Lookup the string for the function/script, creating one if necessary */
 const char*
 SPSProfiler::profileString(JSScript *script, JSFunction *maybeFun)
 {
     AutoSPSLock lock(lock_);
     JS_ASSERT(strings.initialized());
     ProfileStringMap::AddPtr s = strings.lookupForAdd(script);
     if (s)
         return s->value();
     const char *str = allocProfileString(script, maybeFun);
     if (str == nullptr)
         return nullptr;
     if (!strings.add(s, script, str)) {
         js_free(const_cast<char *>(str));
         return nullptr;
     }
     return str;
 }
 void
 SPSProfiler::onScriptFinalized(JSScript *script)
 {
     /*
      * This function is called whenever a script is destroyed, regardless of
      * whether profiling has been turned on, so don't invoke a function on an
      * invalid hash set. Also, even if profiling was enabled but then turned
      * off, we still want to remove the string, so no check of enabled() is
      * done.
      */
     AutoSPSLock lock(lock_);
     if (!strings.initialized())
         return;
     if (ProfileStringMap::Ptr entry = strings.lookup(script)) {
         const char *tofree = entry->value();
         strings.remove(entry);
         js_free(const_cast<char *>(tofree));
     }
 }
 void
 SPSProfiler::markEvent(const char *event)
 {
     JS_ASSERT(enabled());
     if (eventMarker_) {
         JS::AutoAssertNoGC nogc;
         eventMarker_(event);
     }
 }
 bool
 SPSProfiler::enter(JSScript *script, JSFunction *maybeFun)
 {
     const char *str = profileString(script, maybeFun);
     if (str == nullptr)
         return false;
 #ifdef DEBUG
     // In debug builds, assert the JS pseudo frames already on the stack
     // have a non-null pc. Only look at the top frames to avoid quadratic
     // behavior.
     if (*size_ > 0 && *size_ - 1 < max_) {
         size_t start = (*size_ > 4) ? *size_ - 4 : 0;
         for (size_t i = start; i < *size_ - 1; i++)
             MOZ_ASSERT_IF(stack_[i].js(), stack_[i].pc() != nullptr);
     }
 #endif
     push(str, nullptr, script, script->code());
     return true;
 }
 void
 SPSProfiler::exit(JSScript *script, JSFunction *maybeFun)
 {
     pop();
 #ifdef DEBUG
     /* Sanity check to make sure push/pop balanced */
     if (*size_ < max_) {
         const char *str = profileString(script, maybeFun);
         /* Can't fail lookup because we should already be in the set */
         JS_ASSERT(str != nullptr);
         // Bug 822041
         if (!stack_[*size_].js()) {
             fprintf(stderr, "--- ABOUT TO FAIL ASSERTION ---\n");
             fprintf(stderr, " stack=%p size=%d/%d\n", (void*) stack_, *size_, max_);
             for (int32_t i = *size_; i >= 0; i--) {
                 if (stack_[i].js())
                     fprintf(stderr, "  [%d] JS %s\n", i, stack_[i].label());
                 else
                     fprintf(stderr, "  [%d] C line %d %s\n", i, stack_[i].line(), stack_[i].label());
             }
         }
         JS_ASSERT(stack_[*size_].js());
         JS_ASSERT(stack_[*size_].script() == script);
         JS_ASSERT(strcmp((const char*) stack_[*size_].label(), str) == 0);
         stack_[*size_].setLabel(nullptr);
         stack_[*size_].setPC(nullptr);
     }
 #endif
 }
 void
 SPSProfiler::enterNative(const char *string, void *sp)
 {
     /* these operations cannot be re-ordered, so volatile-ize operations */
     volatile ProfileEntry *stack = stack_;
     volatile uint32_t *size = size_;
     uint32_t current = *size;
     JS_ASSERT(enabled());
     if (current < max_) {
         stack[current].setLabel(string);
         stack[current].setStackAddress(sp);
         stack[current].setScript(nullptr);
         stack[current].setLine(0);
     }
     *size = current + 1;
 }
 void
 SPSProfiler::push(const char *string, void *sp, JSScript *script, jsbytecode *pc)
 {
     /* these operations cannot be re-ordered, so volatile-ize operations */
     volatile ProfileEntry *stack = stack_;
     volatile uint32_t *size = size_;
     uint32_t current = *size;
     JS_ASSERT(installed());
     if (current < max_) {
         stack[current].setLabel(string);
         stack[current].setStackAddress(sp);
         stack[current].setScript(script);
         stack[current].setPC(pc);
     }
     *size = current + 1;
 }
 void
 SPSProfiler::pop()
 {
     JS_ASSERT(installed());
     (*size_)--;
     JS_ASSERT(*(int*)size_ >= 0);
 }
 /*
  * Serializes the script/function pair into a "descriptive string" which is
  * allowed to fail. This function cannot trigger a GC because it could finalize
  * some scripts, resize the hash table of profile strings, and invalidate the
  * AddPtr held while invoking allocProfileString.
  */
 const char *
 SPSProfiler::allocProfileString(JSScript *script, JSFunction *maybeFun)
 {
     // Note: this profiler string is regexp-matched by
     // browser/devtools/profiler/cleopatra/js/parserWorker.js.
     // Determine if the function (if any) has an explicit or guessed name.
     bool hasAtom = maybeFun && maybeFun->displayAtom();
     // Get the function name, if any, and its length.
     const jschar *atom = nullptr;
     size_t lenAtom = 0;
     if (hasAtom) {
         atom = maybeFun->displayAtom()->charsZ();
         lenAtom = maybeFun->displayAtom()->length();
     }
     // Get the script filename, if any, and its length.
     const char *filename = script->filename();
     if (filename == nullptr)
         filename = "<unknown>";
     size_t lenFilename = strlen(filename);
     // Get the line number and its length as a string.
     uint64_t lineno = script->lineno();
     size_t lenLineno = 1;
     for (uint64_t i = lineno; i /= 10; lenLineno++);
     // Determine the required buffer size.
     size_t len = lenFilename + lenLineno + 1; // +1 for the ":" separating them.
     if (hasAtom)
         len += lenAtom + 3; // +3 for the " (" and ")" it adds.
     // Allocate the buffer.
     char *cstr = js_pod_malloc<char>(len + 1);
     if (cstr == nullptr)
         return nullptr;
     // Construct the descriptive string.
     DebugOnly<size_t> ret;
     if (hasAtom)
         ret = JS_snprintf(cstr, len + 1, "%hs (%s:%llu)", atom, filename, lineno);
     else
         ret = JS_snprintf(cstr, len + 1, "%s:%llu", filename, lineno);
     MOZ_ASSERT(ret == len, "Computed length should match actual length!");
     return cstr;
 }
 SPSEntryMarker::SPSEntryMarker(JSRuntime *rt
                                MOZ_GUARD_OBJECT_NOTIFIER_PARAM_IN_IMPL)
     : profiler(&rt->spsProfiler)
 {
     MOZ_GUARD_OBJECT_NOTIFIER_INIT;
     if (!profiler->installed()) {
         profiler = nullptr;
         return;
     }
     size_before = *profiler->size_;
     profiler->pushNoCopy("js::RunScript", this, nullptr, nullptr);
 }
 SPSEntryMarker::~SPSEntryMarker()
 {
     if (profiler != nullptr) {
         profiler->pop();
         JS_ASSERT(size_before == *profiler->size_);
     }
 }
 JS_FRIEND_API(jsbytecode*)
 ProfileEntry::pc() const volatile
 {
     return idx == NullPCIndex ? nullptr : script()->offsetToPC(idx);
 }
 JS_FRIEND_API(void)
 ProfileEntry::setPC(jsbytecode *pc) volatile
 {
     idx = pc == nullptr ? NullPCIndex : script()->pcToOffset(pc);
 }
 JS_FRIEND_API(void)
 js::SetRuntimeProfilingStack(JSRuntime *rt, ProfileEntry *stack, uint32_t *size, uint32_t max)
 {
     rt->spsProfiler.setProfilingStack(stack, size, max);
 }
 JS_FRIEND_API(void)
 js::EnableRuntimeProfilingStack(JSRuntime *rt, bool enabled)
 {
     rt->spsProfiler.enable(enabled);
 }
 JS_FRIEND_API(void)
 js::RegisterRuntimeProfilingEventMarker(JSRuntime *rt, void (*fn)(const char *))
 {
     JS_ASSERT(rt->spsProfiler.enabled());
     rt->spsProfiler.setEventMarker(fn);
 }
 JS_FRIEND_API(jsbytecode*)
 js::ProfilingGetPC(JSRuntime *rt, JSScript *script, void *ip)
 {
     return rt->spsProfiler.ipToPC(script, size_t(ip));
 }

The Tor Browser / annotate

js/src/vm/SPSProfiler.cpp@6474c204b198 (annotated)

js/src/vm/SPSProfiler.cpp