tools/CodeProfiling.cpp

   1 /*
   2  * Copyright (C) 2012 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "CodeProfiling.h"
  28
  29 #include "CodeProfile.h"
  30 #include <wtf/MetaAllocator.h>
  31
  32 #if HAVE(SIGNAL_H)
  33 #include <signal.h>
  34 #endif
  35
  36 #if OS(LINUX) || OS(DARWIN)
  37 #include <sys/time.h>
  38 #endif
  39
  40 namespace JSC {
  41
  42 volatile CodeProfile* CodeProfiling::s_profileStack = 0;
  43 CodeProfiling::Mode CodeProfiling::s_mode = CodeProfiling::Disabled;
  44 WTF::MetaAllocatorTracker* CodeProfiling::s_tracker = 0;
  45
  46 #if COMPILER(CLANG)
  47 #pragma clang diagnostic push
  48 #pragma clang diagnostic ignored "-Wmissing-noreturn"
  49 #endif
  50
  51 #if (OS(DARWIN) && !PLATFORM(EFL) && !PLATFORM(GTK) && CPU(X86_64)) || (OS(LINUX) && CPU(X86))
  52 // Helper function to start & stop the timer.
  53 // Presently we're using the wall-clock timer, since this seems to give the best results.
  54 static void setProfileTimer(unsigned usec)
  55 {
  56     itimerval timer;
  57     timer.it_value.tv_sec = 0;
  58     timer.it_value.tv_usec = usec;
  59     timer.it_interval.tv_sec = 0;
  60     timer.it_interval.tv_usec = usec;
  61     setitimer(ITIMER_REAL, &timer, 0);
  62 }
  63 #endif
  64
  65 #if COMPILER(CLANG)
  66 #pragma clang diagnostic pop
  67 #endif
  68
  69 #if OS(DARWIN) && !PLATFORM(EFL) && !PLATFORM(GTK) && CPU(X86_64)
  70 static void profilingTimer(int, siginfo_t*, void* uap)
  71 {
  72     mcontext_t context = static_cast<ucontext_t*>(uap)->uc_mcontext;
  73     CodeProfiling::sample(reinterpret_cast<void*>(context->__ss.__rip),
  74                           reinterpret_cast<void**>(context->__ss.__rbp));
  75 }
  76 #elif OS(LINUX) && CPU(X86)
  77 static void profilingTimer(int, siginfo_t*, void* uap)
  78 {
  79     mcontext_t context = static_cast<ucontext_t*>(uap)->uc_mcontext;
  80     CodeProfiling::sample(reinterpret_cast<void*>(context.gregs[REG_EIP]),
  81                           reinterpret_cast<void**>(context.gregs[REG_EBP]));
  82 }
  83 #endif
  84
  85 // Callback triggered when the timer is fired.
  86 void CodeProfiling::sample(void* pc, void** framePointer)
  87 {
  88     CodeProfile* profileStack = const_cast<CodeProfile*>(s_profileStack);
  89     if (profileStack)
  90         profileStack->sample(pc, framePointer);
  91 }
  92
  93 void CodeProfiling::notifyAllocator(WTF::MetaAllocator* allocator)
  94 {
  95     // Check for JSC_CODE_PROFILING.
  96     const char* codeProfilingMode = getenv("JSC_CODE_PROFILING");
  97     if (!codeProfilingMode)
  98         return;
  99
 100     // Check for a valid mode, currently "1", "2", or "3".
 101     if (!codeProfilingMode[0] || codeProfilingMode[1])
 102         return;
 103     switch (*codeProfilingMode) {
 104     case '1':
 105         s_mode = Enabled;
 106         break;
 107     case '2':
 108         s_mode = Verbose;
 109         break;
 110     case '3':
 111         s_mode = VeryVerbose;
 112         break;
 113     default:
 114         return;
 115     }
 116
 117     ASSERT(enabled());
 118     ASSERT(!s_tracker);
 119     s_tracker = new WTF::MetaAllocatorTracker();
 120     allocator->trackAllocations(s_tracker);
 121 }
 122
 123 void* CodeProfiling::getOwnerUIDForPC(void* address)
 124 {
 125     if (!s_tracker)
 126         return 0;
 127     WTF::MetaAllocatorHandle* handle = s_tracker->find(address);
 128     if (!handle)
 129         return 0;
 130     return handle->ownerUID();
 131 }
 132
 133 void CodeProfiling::begin(const SourceCode& source)
 134 {
 135     // Push a new CodeProfile onto the stack for each script encountered.
 136     CodeProfile* profileStack = const_cast<CodeProfile*>(s_profileStack);
 137     bool alreadyProfiling = profileStack;
 138     s_profileStack = profileStack = new CodeProfile(source, profileStack);
 139
 140     // Is the profiler already running - if so, the timer will already be set up.
 141     if (alreadyProfiling)
 142         return;
 143
 144 #if (OS(DARWIN) && !PLATFORM(EFL) && !PLATFORM(GTK) && CPU(X86_64)) || (OS(LINUX) && CPU(X86))
 145     // Regsiter a signal handler & itimer.
 146     struct sigaction action;
 147     action.sa_sigaction = reinterpret_cast<void (*)(int, siginfo_t *, void *)>(profilingTimer);
 148     sigfillset(&action.sa_mask);
 149     action.sa_flags = SA_SIGINFO;
 150     sigaction(SIGALRM, &action, 0);
 151     setProfileTimer(100);
 152 #endif
 153 }
 154
 155 void CodeProfiling::end()
 156 {
 157     // Pop the current profiler off the stack.
 158     CodeProfile* current = const_cast<CodeProfile*>(s_profileStack);
 159     ASSERT(current);
 160     s_profileStack = current->parent();
 161
 162     // Is this the outermost script being profiled? - if not, just return.
 163     // We perform all output of profiles recursively from the outermost script,
 164     // to minimize profiling overhead from skewing results.
 165     if (s_profileStack)
 166         return;
 167
 168 #if (OS(DARWIN) && !PLATFORM(EFL) && !PLATFORM(GTK) && CPU(X86_64)) || (OS(LINUX) && CPU(X86))
 169     // Stop profiling
 170     setProfileTimer(0);
 171 #endif
 172
 173     current->report();
 174     delete current;
 175 }
 176
 177 }