JavaScriptCore/runtime/TimeoutChecker.cpp
changeset 0 4f2f89ce4247
child 2 303757a437d3
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/runtime/TimeoutChecker.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,155 @@
+/*
+ * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 2.  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "TimeoutChecker.h"
+
+#include "CallFrame.h"
+#include "JSGlobalObject.h"
+
+#if OS(DARWIN)
+#include <mach/mach.h>
+#elif OS(WINDOWS)
+#include <windows.h>
+#else
+#include "CurrentTime.h"
+#endif
+
+#if PLATFORM(BREWMP)
+#include <AEEStdLib.h>
+#endif
+
+using namespace std;
+
+namespace JSC {
+
+// Number of ticks before the first timeout check is done.
+static const int ticksUntilFirstCheck = 1024;
+
+// Number of milliseconds between each timeout check.
+static const int intervalBetweenChecks = 1000;
+
+// Returns the time the current thread has spent executing, in milliseconds.
+static inline unsigned getCPUTime()
+{
+#if OS(DARWIN)
+    mach_msg_type_number_t infoCount = THREAD_BASIC_INFO_COUNT;
+    thread_basic_info_data_t info;
+
+    // Get thread information
+    mach_port_t threadPort = mach_thread_self();
+    thread_info(threadPort, THREAD_BASIC_INFO, reinterpret_cast<thread_info_t>(&info), &infoCount);
+    mach_port_deallocate(mach_task_self(), threadPort);
+    
+    unsigned time = info.user_time.seconds * 1000 + info.user_time.microseconds / 1000;
+    time += info.system_time.seconds * 1000 + info.system_time.microseconds / 1000;
+    
+    return time;
+#elif OS(WINDOWS)
+    union {
+        FILETIME fileTime;
+        unsigned long long fileTimeAsLong;
+    } userTime, kernelTime;
+    
+    // GetThreadTimes won't accept NULL arguments so we pass these even though
+    // they're not used.
+    FILETIME creationTime, exitTime;
+    
+    GetThreadTimes(GetCurrentThread(), &creationTime, &exitTime, &kernelTime.fileTime, &userTime.fileTime);
+    
+    return userTime.fileTimeAsLong / 10000 + kernelTime.fileTimeAsLong / 10000;
+#elif OS(SYMBIAN)
+    RThread current;
+    TTimeIntervalMicroSeconds cpuTime;
+
+    TInt err = current.GetCpuTime(cpuTime);
+    ASSERT_WITH_MESSAGE(err == KErrNone, "GetCpuTime failed with %d", err);
+    return cpuTime.Int64() / 1000;
+#elif PLATFORM(BREWMP)
+    // This function returns a continuously and linearly increasing millisecond
+    // timer from the time the device was powered on.
+    // There is only one thread in BREW, so this is enough.
+    return GETUPTIMEMS();
+#else
+    // FIXME: We should return the time the current thread has spent executing.
+    return currentTime() * 1000;
+#endif
+}
+
+TimeoutChecker::TimeoutChecker()
+    : m_timeoutInterval(0)
+    , m_startCount(0)
+{
+    reset();
+}
+
+void TimeoutChecker::reset()
+{
+    m_ticksUntilNextCheck = ticksUntilFirstCheck;
+    m_timeAtLastCheck = 0;
+    m_timeExecuting = 0;
+}
+
+bool TimeoutChecker::didTimeOut(ExecState* exec)
+{
+    unsigned currentTime = getCPUTime();
+    
+    if (!m_timeAtLastCheck) {
+        // Suspicious amount of looping in a script -- start timing it
+        m_timeAtLastCheck = currentTime;
+        return false;
+    }
+    
+    unsigned timeDiff = currentTime - m_timeAtLastCheck;
+    
+    if (timeDiff == 0)
+        timeDiff = 1;
+    
+    m_timeExecuting += timeDiff;
+    m_timeAtLastCheck = currentTime;
+    
+    // Adjust the tick threshold so we get the next checkTimeout call in the
+    // interval specified in intervalBetweenChecks.
+    m_ticksUntilNextCheck = static_cast<unsigned>((static_cast<float>(intervalBetweenChecks) / timeDiff) * m_ticksUntilNextCheck);
+    // If the new threshold is 0 reset it to the default threshold. This can happen if the timeDiff is higher than the
+    // preferred script check time interval.
+    if (m_ticksUntilNextCheck == 0)
+        m_ticksUntilNextCheck = ticksUntilFirstCheck;
+    
+    if (m_timeoutInterval && m_timeExecuting > m_timeoutInterval) {
+        if (exec->dynamicGlobalObject()->shouldInterruptScript())
+            return true;
+        
+        reset();
+    }
+    
+    return false;
+}
+
+} // namespace JSC