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

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

     1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-

     2  * vim: set ts=8 sts=4 et sw=4 tw=99:

     3  * This Source Code Form is subject to the terms of the Mozilla Public

     4  * License, v. 2.0. If a copy of the MPL was not distributed with this

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #include "vm/SPSProfiler.h"

     9 #include "mozilla/DebugOnly.h"

    11 #include "jsnum.h"

    12 #include "jsprf.h"

    13 #include "jsscript.h"

    15 #include "jit/BaselineJIT.h"

    16 #include "vm/StringBuffer.h"

    18 using namespace js;

    20 using mozilla::DebugOnly;

    22 SPSProfiler::SPSProfiler(JSRuntime *rt)

    23   : rt(rt),

    24     stack_(nullptr),

    25     size_(nullptr),

    26     max_(0),

    27     slowAssertions(false),

    28     enabled_(false),

    29     lock_(nullptr),

    30     eventMarker_(nullptr)

    31 {

    32     JS_ASSERT(rt != nullptr);

    33 }

    35 bool

    36 SPSProfiler::init()

    37 {

    38 #ifdef JS_THREADSAFE

    39     lock_ = PR_NewLock();

    40     if (lock_ == nullptr)

    41         return false;

    42 #endif

    43     return true;

    44 }

    46 SPSProfiler::~SPSProfiler()

    47 {

    48     if (strings.initialized()) {

    49         for (ProfileStringMap::Enum e(strings); !e.empty(); e.popFront())

    50             js_free(const_cast<char *>(e.front().value()));

    51     }

    52 #ifdef JS_THREADSAFE

    53     if (lock_)

    54         PR_DestroyLock(lock_);

    55 #endif

    56 }

    58 void

    59 SPSProfiler::setProfilingStack(ProfileEntry *stack, uint32_t *size, uint32_t max)

    60 {

    61     AutoSPSLock lock(lock_);

    62     JS_ASSERT_IF(size_ && *size_ != 0, !enabled());

    63     if (!strings.initialized())

    64         strings.init();

    65     stack_ = stack;

    66     size_  = size;

    67     max_   = max;

    68 }

    70 void

    71 SPSProfiler::setEventMarker(void (*fn)(const char *))

    72 {

    73     eventMarker_ = fn;

    74 }

    76 void

    77 SPSProfiler::enable(bool enabled)

    78 {

    79     JS_ASSERT(installed());

    81     if (enabled_ == enabled)

    82         return;

    84     /*

    85      * Ensure all future generated code will be instrumented, or that all

    86      * currently instrumented code is discarded

    87      */

    88     ReleaseAllJITCode(rt->defaultFreeOp());

    90     enabled_ = enabled;

    92 #ifdef JS_ION

    93     /* Toggle SPS-related jumps on baseline jitcode.

    94      * The call to |ReleaseAllJITCode| above will release most baseline jitcode, but not

    95      * jitcode for scripts with active frames on the stack.  These scripts need to have

    96      * their profiler state toggled so they behave properly.

    97      */

    98     jit::ToggleBaselineSPS(rt, enabled);

    99 #endif

   100 }

   102 /* Lookup the string for the function/script, creating one if necessary */

   103 const char*

   104 SPSProfiler::profileString(JSScript *script, JSFunction *maybeFun)

   105 {

   106     AutoSPSLock lock(lock_);

   107     JS_ASSERT(strings.initialized());

   108     ProfileStringMap::AddPtr s = strings.lookupForAdd(script);

   109     if (s)

   110         return s->value();

   111     const char *str = allocProfileString(script, maybeFun);

   112     if (str == nullptr)

   113         return nullptr;

   114     if (!strings.add(s, script, str)) {

   115         js_free(const_cast<char *>(str));

   116         return nullptr;

   117     }

   118     return str;

   119 }

   121 void

   122 SPSProfiler::onScriptFinalized(JSScript *script)

   123 {

   124     /*

   125      * This function is called whenever a script is destroyed, regardless of

   126      * whether profiling has been turned on, so don't invoke a function on an

   127      * invalid hash set. Also, even if profiling was enabled but then turned

   128      * off, we still want to remove the string, so no check of enabled() is

   129      * done.

   130      */

   131     AutoSPSLock lock(lock_);

   132     if (!strings.initialized())

   133         return;

   134     if (ProfileStringMap::Ptr entry = strings.lookup(script)) {

   135         const char *tofree = entry->value();

   136         strings.remove(entry);

   137         js_free(const_cast<char *>(tofree));

   138     }

   139 }

   141 void

   142 SPSProfiler::markEvent(const char *event)

   143 {

   144     JS_ASSERT(enabled());

   145     if (eventMarker_) {

   146         JS::AutoAssertNoGC nogc;

   147         eventMarker_(event);

   148     }

   149 }

   151 bool

   152 SPSProfiler::enter(JSScript *script, JSFunction *maybeFun)

   153 {

   154     const char *str = profileString(script, maybeFun);

   155     if (str == nullptr)

   156         return false;

   158 #ifdef DEBUG

   159     // In debug builds, assert the JS pseudo frames already on the stack

   160     // have a non-null pc. Only look at the top frames to avoid quadratic

   161     // behavior.

   162     if (*size_ > 0 && *size_ - 1 < max_) {

   163         size_t start = (*size_ > 4) ? *size_ - 4 : 0;

   164         for (size_t i = start; i < *size_ - 1; i++)

   165             MOZ_ASSERT_IF(stack_[i].js(), stack_[i].pc() != nullptr);

   166     }

   167 #endif

   169     push(str, nullptr, script, script->code());

   170     return true;

   171 }

   173 void

   174 SPSProfiler::exit(JSScript *script, JSFunction *maybeFun)

   175 {

   176     pop();

   178 #ifdef DEBUG

   179     /* Sanity check to make sure push/pop balanced */

   180     if (*size_ < max_) {

   181         const char *str = profileString(script, maybeFun);

   182         /* Can't fail lookup because we should already be in the set */

   183         JS_ASSERT(str != nullptr);

   185         // Bug 822041

   186         if (!stack_[*size_].js()) {

   187             fprintf(stderr, "--- ABOUT TO FAIL ASSERTION ---\n");

   188             fprintf(stderr, " stack=%p size=%d/%d\n", (void*) stack_, *size_, max_);

   189             for (int32_t i = *size_; i >= 0; i--) {

   190                 if (stack_[i].js())

   191                     fprintf(stderr, "  [%d] JS %s\n", i, stack_[i].label());

   192                 else

   193                     fprintf(stderr, "  [%d] C line %d %s\n", i, stack_[i].line(), stack_[i].label());

   194             }

   195         }

   197         JS_ASSERT(stack_[*size_].js());

   198         JS_ASSERT(stack_[*size_].script() == script);

   199         JS_ASSERT(strcmp((const char*) stack_[*size_].label(), str) == 0);

   200         stack_[*size_].setLabel(nullptr);

   201         stack_[*size_].setPC(nullptr);

   202     }

   203 #endif

   204 }

   206 void

   207 SPSProfiler::enterNative(const char *string, void *sp)

   208 {

   209     /* these operations cannot be re-ordered, so volatile-ize operations */

   210     volatile ProfileEntry *stack = stack_;

   211     volatile uint32_t *size = size_;

   212     uint32_t current = *size;

   214     JS_ASSERT(enabled());

   215     if (current < max_) {

   216         stack[current].setLabel(string);

   217         stack[current].setStackAddress(sp);

   218         stack[current].setScript(nullptr);

   219         stack[current].setLine(0);

   220     }

   221     *size = current + 1;

   222 }

   224 void

   225 SPSProfiler::push(const char *string, void *sp, JSScript *script, jsbytecode *pc)

   226 {

   227     /* these operations cannot be re-ordered, so volatile-ize operations */

   228     volatile ProfileEntry *stack = stack_;

   229     volatile uint32_t *size = size_;

   230     uint32_t current = *size;

   232     JS_ASSERT(installed());

   233     if (current < max_) {

   234         stack[current].setLabel(string);

   235         stack[current].setStackAddress(sp);

   236         stack[current].setScript(script);

   237         stack[current].setPC(pc);

   238     }

   239     *size = current + 1;

   240 }

   242 void

   243 SPSProfiler::pop()

   244 {

   245     JS_ASSERT(installed());

   246     (*size_)--;

   247     JS_ASSERT(*(int*)size_ >= 0);

   248 }

   250 /*

   251  * Serializes the script/function pair into a "descriptive string" which is

   252  * allowed to fail. This function cannot trigger a GC because it could finalize

   253  * some scripts, resize the hash table of profile strings, and invalidate the

   254  * AddPtr held while invoking allocProfileString.

   255  */

   256 const char *

   257 SPSProfiler::allocProfileString(JSScript *script, JSFunction *maybeFun)

   258 {

   259     // Note: this profiler string is regexp-matched by

   260     // browser/devtools/profiler/cleopatra/js/parserWorker.js.

   262     // Determine if the function (if any) has an explicit or guessed name.

   263     bool hasAtom = maybeFun && maybeFun->displayAtom();

   265     // Get the function name, if any, and its length.

   266     const jschar *atom = nullptr;

   267     size_t lenAtom = 0;

   268     if (hasAtom) {

   269         atom = maybeFun->displayAtom()->charsZ();

   270         lenAtom = maybeFun->displayAtom()->length();

   271     }

   273     // Get the script filename, if any, and its length.

   274     const char *filename = script->filename();

   275     if (filename == nullptr)

   276         filename = "<unknown>";

   277     size_t lenFilename = strlen(filename);

   279     // Get the line number and its length as a string.

   280     uint64_t lineno = script->lineno();

   281     size_t lenLineno = 1;

   282     for (uint64_t i = lineno; i /= 10; lenLineno++);

   284     // Determine the required buffer size.

   285     size_t len = lenFilename + lenLineno + 1; // +1 for the ":" separating them.

   286     if (hasAtom)

   287         len += lenAtom + 3; // +3 for the " (" and ")" it adds.

   289     // Allocate the buffer.

   290     char *cstr = js_pod_malloc<char>(len + 1);

   291     if (cstr == nullptr)

   292         return nullptr;

   294     // Construct the descriptive string.

   295     DebugOnly<size_t> ret;

   296     if (hasAtom)

   297         ret = JS_snprintf(cstr, len + 1, "%hs (%s:%llu)", atom, filename, lineno);

   298     else

   299         ret = JS_snprintf(cstr, len + 1, "%s:%llu", filename, lineno);

   301     MOZ_ASSERT(ret == len, "Computed length should match actual length!");

   303     return cstr;

   304 }

   306 SPSEntryMarker::SPSEntryMarker(JSRuntime *rt

   307                                MOZ_GUARD_OBJECT_NOTIFIER_PARAM_IN_IMPL)

   308     : profiler(&rt->spsProfiler)

   309 {

   310     MOZ_GUARD_OBJECT_NOTIFIER_INIT;

   311     if (!profiler->installed()) {

   312         profiler = nullptr;

   313         return;

   314     }

   315     size_before = *profiler->size_;

   316     profiler->pushNoCopy("js::RunScript", this, nullptr, nullptr);

   317 }

   319 SPSEntryMarker::~SPSEntryMarker()

   320 {

   321     if (profiler != nullptr) {

   322         profiler->pop();

   323         JS_ASSERT(size_before == *profiler->size_);

   324     }

   325 }

   327 JS_FRIEND_API(jsbytecode*)

   328 ProfileEntry::pc() const volatile

   329 {

   330     return idx == NullPCIndex ? nullptr : script()->offsetToPC(idx);

   331 }

   333 JS_FRIEND_API(void)

   334 ProfileEntry::setPC(jsbytecode *pc) volatile

   335 {

   336     idx = pc == nullptr ? NullPCIndex : script()->pcToOffset(pc);

   337 }

   339 JS_FRIEND_API(void)

   340 js::SetRuntimeProfilingStack(JSRuntime *rt, ProfileEntry *stack, uint32_t *size, uint32_t max)

   341 {

   342     rt->spsProfiler.setProfilingStack(stack, size, max);

   343 }

   345 JS_FRIEND_API(void)

   346 js::EnableRuntimeProfilingStack(JSRuntime *rt, bool enabled)

   347 {

   348     rt->spsProfiler.enable(enabled);

   349 }

   351 JS_FRIEND_API(void)

   352 js::RegisterRuntimeProfilingEventMarker(JSRuntime *rt, void (*fn)(const char *))

   353 {

   354     JS_ASSERT(rt->spsProfiler.enabled());

   355     rt->spsProfiler.setEventMarker(fn);

   356 }

   358 JS_FRIEND_API(jsbytecode*)

   359 js::ProfilingGetPC(JSRuntime *rt, JSScript *script, void *ip)

   360 {

   361     return rt->spsProfiler.ipToPC(script, size_t(ip));

   362 }

The Tor Browser / file revision

js/src/vm/SPSProfiler.cpp@6474c204b198

js/src/vm/SPSProfiler.cpp