Commit 1f377e91 authored by Nick Mathewson's avatar Nick Mathewson 🤹
Browse files

Merge branch 'maint-0.3.4'

parents 11915967 163230e2

changes/bug27139

0 → 100644
+14 −0
Original line number Diff line number Diff line 
  o Minor bugfixes (32-bit OSX and iOS, timing):

    - Fix an integer overflow bug in our optimized 32-bit millisecond-

      difference algorithm for 32-bit Apple platforms. Previously, it

      would overflow when calculating the difference between two times

      more than 47 days apart.  Fixes part of bug 27139; bugfix on

      0.3.4.1-alpha.

    - Improve the precision of our 32-bit millisecond difference

      algorithm for 32-bit Apple platforms. Fixes part of bug 27139;

      bugfix on 0.3.4.1-alpha.

    - Relax the tolerance on the mainloop/update_time_jumps test

      when running on 32-bit Apple platforms. Fixes part of bug 27139;

      bugfix on 0.3.4.1-alpha.

src/lib/time/compat_time.c

+16 −6
Original line number Diff line number Diff line
@@ -237,6 +237,7 @@ monotime_reset_ratchets_for_testing(void) 
 */

static struct mach_timebase_info mach_time_info;

static struct mach_timebase_info mach_time_info_msec_cvt;

static int32_t mach_time_msec_cvt_threshold;

static int monotime_shift = 0;



static void
@@ -256,11 +257,15 @@ monotime_init_internal(void) 
  }

  {

    // For converting ticks to milliseconds in a 32-bit-friendly way, we

    // will first right-shift by 20, and then multiply by 20/19, since

    // (1<<20) * 19/20 is about 1e6.  We precompute a new numerate and

    // will first right-shift by 20, and then multiply by 2048/1953, since

    // (1<<20) * 1953/2048 is about 1e6.  We precompute a new numerator and

    // denominator here to avoid multiple multiplies.

    mach_time_info_msec_cvt.numer = mach_time_info.numer * 20;

    mach_time_info_msec_cvt.denom = mach_time_info.denom * 19;

    mach_time_info_msec_cvt.numer = mach_time_info.numer * 2048;

    mach_time_info_msec_cvt.denom = mach_time_info.denom * 1953;

    // For any value above this amount, we should divide before multiplying,

    // to avoid overflow.  For a value below this, we should multiply

    // before dividing, to improve accuracy.

    mach_time_msec_cvt_threshold = INT32_MAX / mach_time_info_msec_cvt.numer;

  }

}
@@ -323,9 +328,14 @@ monotime_coarse_diff_msec32_(const monotime_coarse_t *start, 
  /* We already require in di_ops.c that right-shift performs a sign-extend. */

  const int32_t diff_microticks = (int32_t)(diff_ticks >> 20);



  if (diff_microticks >= mach_time_msec_cvt_threshold) {

    return (diff_microticks / mach_time_info_msec_cvt.denom) *

      mach_time_info_msec_cvt.numer;

  } else {

    return (diff_microticks * mach_time_info_msec_cvt.numer) /

      mach_time_info_msec_cvt.denom;

  }

}



uint32_t

monotime_coarse_to_stamp(const monotime_coarse_t *t)

src/lib/time/compat_time.h

+1 −0
Original line number Diff line number Diff line
@@ -200,6 +200,7 @@ monotime_coarse_diff_msec32(const monotime_coarse_t *start, 
  // on a 64-bit platform, let's assume 64/64 division is cheap.

  return (int32_t) monotime_coarse_diff_msec(start, end);

#else

#define USING_32BIT_MSEC_HACK

  return monotime_coarse_diff_msec32_(start, end);

#endif

}

src/test/test_circuitmux.c

+9 −4
Original line number Diff line number Diff line
@@ -15,6 +15,8 @@ 


#include "core/or/destroy_cell_queue_st.h"



#include <math.h>



/* XXXX duplicated function from test_circuitlist.c */

static channel_t *

new_fake_channel(void)
@@ -105,16 +107,19 @@ test_cmux_compute_ticks(void *arg) 
  monotime_coarse_set_mock_time_nsec(now);

  tick = cell_ewma_get_current_tick_and_fraction(&rem);

  tt_uint_op(tick, OP_EQ, tick_zero);

  tt_double_op(rem, OP_GT, .149999999);

  tt_double_op(rem, OP_LT, .150000001);

#ifdef USING_32BIT_MSEC_HACK

  const double tolerance = .0005;

#else

  const double tolerance = .00000001;

#endif

  tt_double_op(fabs(rem - .15), OP_LT, tolerance);



  /* 25 second later and we should be in another tick. */

  now = START_NS + NS_PER_S * 25;

  monotime_coarse_set_mock_time_nsec(now);

  tick = cell_ewma_get_current_tick_and_fraction(&rem);

  tt_uint_op(tick, OP_EQ, tick_zero + 2);

  tt_double_op(rem, OP_GT, .499999999);

  tt_double_op(rem, OP_LT, .500000001);

  tt_double_op(fabs(rem - .5), OP_LT, tolerance);



 done:

  ;