Add m-esr52 at 52.6.0

1 files changed, 382 insertions, 0 deletions

diff --git a/js/src/vm/Time.cpp b/js/src/vm/Time.cpp
new file mode 100644
index 000000000..69e2cc41d
--- /dev/null
+++ b/js/src/vm/Time.cpp
@@ -0,0 +1,382 @@
+/* -*- 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/. */
+
+/* PR time code. */
+
+#include "vm/Time.h"
+
+#include "mozilla/DebugOnly.h"
+#include "mozilla/MathAlgorithms.h"
+
+#ifdef SOLARIS
+#define _REENTRANT 1
+#endif
+#include <string.h>
+#include <time.h>
+
+#include "jstypes.h"
+#include "jsutil.h"
+
+#ifdef XP_WIN
+#include <windef.h>
+#include <winbase.h>
+#include <crtdbg.h>   /* for _CrtSetReportMode */
+#include <mmsystem.h> /* for timeBegin/EndPeriod */
+#include <stdlib.h>   /* for _set_invalid_parameter_handler */
+
+#include "prinit.h"
+
+#endif
+
+#ifdef XP_UNIX
+
+#ifdef _SVID_GETTOD   /* Defined only on Solaris, see Solaris <sys/types.h> */
+extern int gettimeofday(struct timeval* tv);
+#endif
+
+#include <sys/time.h>
+
+#endif /* XP_UNIX */
+
+using mozilla::DebugOnly;
+
+#if defined(XP_UNIX)
+int64_t
+PRMJ_Now()
+{
+    struct timeval tv;
+
+#ifdef _SVID_GETTOD   /* Defined only on Solaris, see Solaris <sys/types.h> */
+    gettimeofday(&tv);
+#else
+    gettimeofday(&tv, 0);
+#endif /* _SVID_GETTOD */
+
+    return int64_t(tv.tv_sec) * PRMJ_USEC_PER_SEC + int64_t(tv.tv_usec);
+}
+
+#else
+
+// Returns the number of microseconds since the Unix epoch.
+static double
+FileTimeToUnixMicroseconds(const FILETIME& ft)
+{
+    // Get the time in 100ns intervals.
+    int64_t t = (int64_t(ft.dwHighDateTime) << 32) | int64_t(ft.dwLowDateTime);
+
+    // The Windows epoch is around 1600. The Unix epoch is around 1970.
+    // Subtract the difference.
+    static const int64_t TimeToEpochIn100ns = 0x19DB1DED53E8000;
+    t -= TimeToEpochIn100ns;
+
+    // Divide by 10 to convert to microseconds.
+    return double(t) * 0.1;
+}
+
+struct CalibrationData {
+    double freq;         /* The performance counter frequency */
+    double offset;       /* The low res 'epoch' */
+    double timer_offset; /* The high res 'epoch' */
+
+    bool calibrated;
+
+    CRITICAL_SECTION data_lock;
+};
+
+static CalibrationData calibration = { 0 };
+
+static void
+NowCalibrate()
+{
+    MOZ_ASSERT(calibration.freq > 0);
+
+    // By wrapping a timeBegin/EndPeriod pair of calls around this loop,
+    // the loop seems to take much less time (1 ms vs 15ms) on Vista.
+    timeBeginPeriod(1);
+    FILETIME ft, ftStart;
+    GetSystemTimeAsFileTime(&ftStart);
+    do {
+        GetSystemTimeAsFileTime(&ft);
+    } while (memcmp(&ftStart, &ft, sizeof(ft)) == 0);
+    timeEndPeriod(1);
+
+    LARGE_INTEGER now;
+    QueryPerformanceCounter(&now);
+
+    calibration.offset = FileTimeToUnixMicroseconds(ft);
+    calibration.timer_offset = double(now.QuadPart);
+    calibration.calibrated = true;
+}
+
+static const unsigned DataLockSpinCount = 4096;
+
+static void (WINAPI* pGetSystemTimePreciseAsFileTime)(LPFILETIME) = nullptr;
+
+void
+PRMJ_NowInit()
+{
+    memset(&calibration, 0, sizeof(calibration));
+
+    // According to the documentation, QueryPerformanceFrequency will never
+    // return false or return a non-zero frequency on systems that run
+    // Windows XP or later. Also, the frequency is fixed so we only have to
+    // query it once.
+    LARGE_INTEGER liFreq;
+    DebugOnly<BOOL> res = QueryPerformanceFrequency(&liFreq);
+    MOZ_ASSERT(res);
+    calibration.freq = double(liFreq.QuadPart);
+    MOZ_ASSERT(calibration.freq > 0.0);
+
+    InitializeCriticalSectionAndSpinCount(&calibration.data_lock, DataLockSpinCount);
+
+    // Windows 8 has a new API function we can use.
+    if (HMODULE h = GetModuleHandle("kernel32.dll")) {
+        pGetSystemTimePreciseAsFileTime =
+            (void (WINAPI*)(LPFILETIME))GetProcAddress(h, "GetSystemTimePreciseAsFileTime");
+    }
+}
+
+void
+PRMJ_NowShutdown()
+{
+    DeleteCriticalSection(&calibration.data_lock);
+}
+
+#define MUTEX_LOCK(m) EnterCriticalSection(m)
+#define MUTEX_UNLOCK(m) LeaveCriticalSection(m)
+#define MUTEX_SETSPINCOUNT(m, c) SetCriticalSectionSpinCount((m),(c))
+
+// Please see bug 363258 for why the win32 timing code is so complex.
+int64_t
+PRMJ_Now()
+{
+    if (pGetSystemTimePreciseAsFileTime) {
+        // Windows 8 has a new API function that does all the work.
+        FILETIME ft;
+        pGetSystemTimePreciseAsFileTime(&ft);
+        return int64_t(FileTimeToUnixMicroseconds(ft));
+    }
+
+    bool calibrated = false;
+    bool needsCalibration = !calibration.calibrated;
+    double cachedOffset = 0.0;
+    while (true) {
+        if (needsCalibration) {
+            MUTEX_LOCK(&calibration.data_lock);
+
+            // Recalibrate only if no one else did before us.
+            if (calibration.offset == cachedOffset) {
+                // Since calibration can take a while, make any other
+                // threads immediately wait.
+                MUTEX_SETSPINCOUNT(&calibration.data_lock, 0);
+
+                NowCalibrate();
+
+                calibrated = true;
+
+                // Restore spin count.
+                MUTEX_SETSPINCOUNT(&calibration.data_lock, DataLockSpinCount);
+            }
+
+            MUTEX_UNLOCK(&calibration.data_lock);
+        }
+
+        // Calculate a low resolution time.
+        FILETIME ft;
+        GetSystemTimeAsFileTime(&ft);
+        double lowresTime = FileTimeToUnixMicroseconds(ft);
+
+        // Grab high resolution time.
+        LARGE_INTEGER now;
+        QueryPerformanceCounter(&now);
+        double highresTimerValue = double(now.QuadPart);
+
+        MUTEX_LOCK(&calibration.data_lock);
+        double highresTime = calibration.offset +
+            PRMJ_USEC_PER_SEC * (highresTimerValue - calibration.timer_offset) / calibration.freq;
+        cachedOffset = calibration.offset;
+        MUTEX_UNLOCK(&calibration.data_lock);
+
+        // Assume the NT kernel ticks every 15.6 ms. Unfortunately there's no
+        // good way to determine this (NtQueryTimerResolution is an undocumented
+        // API), but 15.6 ms seems to be the max possible value. Hardcoding 15.6
+        // means we'll recalibrate if the highres and lowres timers diverge by
+        // more than 30 ms.
+        static const double KernelTickInMicroseconds = 15625.25;
+
+        // Check for clock skew.
+        double diff = lowresTime - highresTime;
+
+        // For some reason that I have not determined, the skew can be
+        // up to twice a kernel tick. This does not seem to happen by
+        // itself, but I have only seen it triggered by another program
+        // doing some kind of file I/O. The symptoms are a negative diff
+        // followed by an equally large positive diff.
+        if (mozilla::Abs(diff) <= 2 * KernelTickInMicroseconds) {
+            // No detectable clock skew.
+            return int64_t(highresTime);
+        }
+
+        if (calibrated) {
+            // If we already calibrated once this instance, and the
+            // clock is still skewed, then either the processor(s) are
+            // wildly changing clockspeed or the system is so busy that
+            // we get switched out for long periods of time. In either
+            // case, it would be infeasible to make use of high
+            // resolution results for anything, so let's resort to old
+            // behavior for this call. It's possible that in the
+            // future, the user will want the high resolution timer, so
+            // we don't disable it entirely.
+            return int64_t(lowresTime);
+        }
+
+        // It is possible that when we recalibrate, we will return a
+        // value less than what we have returned before; this is
+        // unavoidable. We cannot tell the different between a
+        // faulty QueryPerformanceCounter implementation and user
+        // changes to the operating system time. Since we must
+        // respect user changes to the operating system time, we
+        // cannot maintain the invariant that Date.now() never
+        // decreases; the old implementation has this behavior as
+        // well.
+        needsCalibration = true;
+    }
+}
+#endif
+
+#ifdef XP_WIN
+static void
+PRMJ_InvalidParameterHandler(const wchar_t* expression,
+                             const wchar_t* function,
+                             const wchar_t* file,
+                             unsigned int   line,
+                             uintptr_t      pReserved)
+{
+    /* empty */
+}
+#endif
+
+/* Format a time value into a buffer. Same semantics as strftime() */
+size_t
+PRMJ_FormatTime(char* buf, int buflen, const char* fmt, PRMJTime* prtm)
+{
+    size_t result = 0;
+#if defined(XP_UNIX) || defined(XP_WIN)
+    struct tm a;
+    int fake_tm_year = 0;
+#ifdef XP_WIN
+    _invalid_parameter_handler oldHandler;
+    int oldReportMode;
+#endif
+
+    memset(&a, 0, sizeof(struct tm));
+
+    a.tm_sec = prtm->tm_sec;
+    a.tm_min = prtm->tm_min;
+    a.tm_hour = prtm->tm_hour;
+    a.tm_mday = prtm->tm_mday;
+    a.tm_mon = prtm->tm_mon;
+    a.tm_wday = prtm->tm_wday;
+
+    /*
+     * On systems where |struct tm| has members tm_gmtoff and tm_zone, we
+     * must fill in those values, or else strftime will return wrong results
+     * (e.g., bug 511726, bug 554338).
+     */
+#if defined(HAVE_LOCALTIME_R) && defined(HAVE_TM_ZONE_TM_GMTOFF)
+    {
+        /*
+         * Fill out |td| to the time represented by |prtm|, leaving the
+         * timezone fields zeroed out. localtime_r will then fill in the
+         * timezone fields for that local time according to the system's
+         * timezone parameters.
+         */
+        struct tm td;
+        memset(&td, 0, sizeof(td));
+        td.tm_sec = prtm->tm_sec;
+        td.tm_min = prtm->tm_min;
+        td.tm_hour = prtm->tm_hour;
+        td.tm_mday = prtm->tm_mday;
+        td.tm_mon = prtm->tm_mon;
+        td.tm_wday = prtm->tm_wday;
+        td.tm_year = prtm->tm_year - 1900;
+        td.tm_yday = prtm->tm_yday;
+        td.tm_isdst = prtm->tm_isdst;
+        time_t t = mktime(&td);
+        localtime_r(&t, &td);
+
+        a.tm_gmtoff = td.tm_gmtoff;
+        a.tm_zone = td.tm_zone;
+    }
+#endif
+
+    /*
+     * Years before 1900 and after 9999 cause strftime() to abort on Windows.
+     * To avoid that we replace it with FAKE_YEAR_BASE + year % 100 and then
+     * replace matching substrings in the strftime() result with the real year.
+     * Note that FAKE_YEAR_BASE should be a multiple of 100 to make 2-digit
+     * year formats (%y) work correctly (since we won't find the fake year
+     * in that case).
+     * e.g. new Date(1873, 0).toLocaleFormat('%Y %y') => "1873 73"
+     * See bug 327869.
+     */
+#define FAKE_YEAR_BASE 9900
+    if (prtm->tm_year < 1900 || prtm->tm_year > 9999) {
+        fake_tm_year = FAKE_YEAR_BASE + prtm->tm_year % 100;
+        a.tm_year = fake_tm_year - 1900;
+    }
+    else {
+        a.tm_year = prtm->tm_year - 1900;
+    }
+    a.tm_yday = prtm->tm_yday;
+    a.tm_isdst = prtm->tm_isdst;
+
+    /*
+     * Even with the above, SunOS 4 seems to detonate if tm_zone and tm_gmtoff
+     * are null.  This doesn't quite work, though - the timezone is off by
+     * tzoff + dst.  (And mktime seems to return -1 for the exact dst
+     * changeover time.)
+     */
+
+#ifdef XP_WIN
+    oldHandler = _set_invalid_parameter_handler(PRMJ_InvalidParameterHandler);
+    oldReportMode = _CrtSetReportMode(_CRT_ASSERT, 0);
+#endif
+
+    result = strftime(buf, buflen, fmt, &a);
+
+#ifdef XP_WIN
+    _set_invalid_parameter_handler(oldHandler);
+    _CrtSetReportMode(_CRT_ASSERT, oldReportMode);
+#endif
+
+    if (fake_tm_year && result) {
+        char real_year[16];
+        char fake_year[16];
+        size_t real_year_len;
+        size_t fake_year_len;
+        char* p;
+
+        sprintf(real_year, "%d", prtm->tm_year);
+        real_year_len = strlen(real_year);
+        sprintf(fake_year, "%d", fake_tm_year);
+        fake_year_len = strlen(fake_year);
+
+        /* Replace the fake year in the result with the real year. */
+        for (p = buf; (p = strstr(p, fake_year)); p += real_year_len) {
+            size_t new_result = result + real_year_len - fake_year_len;
+            if ((int)new_result >= buflen) {
+                return 0;
+            }
+            memmove(p + real_year_len, p + fake_year_len, strlen(p + fake_year_len));
+            memcpy(p, real_year, real_year_len);
+            result = new_result;
+            *(buf + result) = '\0';
+        }
+    }
+#endif
+    return result;
+}