diff options
Diffstat (limited to 'src/xz/mytime.c')
| -rw-r--r-- | src/xz/mytime.c | 105 |
1 files changed, 98 insertions, 7 deletions
diff --git a/src/xz/mytime.c b/src/xz/mytime.c index 7e8a074961f4..7d9a27d58b56 100644 --- a/src/xz/mytime.c +++ b/src/xz/mytime.c @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: 0BSD + /////////////////////////////////////////////////////////////////////////////// // /// \file mytime.c @@ -5,14 +7,14 @@ // // Author: Lasse Collin // -// This file has been put into the public domain. -// You can do whatever you want with this file. -// /////////////////////////////////////////////////////////////////////////////// #include "private.h" -#if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC) +#if defined(MYTHREAD_VISTA) || defined(_MSC_VER) + // Nothing +#elif defined(HAVE_CLOCK_GETTIME) \ + && (!defined(__MINGW32__) || defined(MYTHREAD_POSIX)) # include <time.h> #else # include <sys/time.h> @@ -20,7 +22,22 @@ uint64_t opt_flush_timeout = 0; +// start_time holds the time when the (de)compression was started. +// It's from mytime_now() and thus only useful for calculating relative +// time differences (elapsed time). start_time is initialized by calling +// mytime_set_start_time() and modified by mytime_sigtstp_handler(). +// +// When mytime_sigtstp_handler() is used, start_time is made volatile. +// I'm not sure if that is really required since access to it is guarded +// by signals_block()/signals_unblock() since accessing an uint64_t isn't +// atomic on all systems. But since the variable isn't accessed very +// frequently making it volatile doesn't hurt. +#ifdef USE_SIGTSTP_HANDLER +static volatile uint64_t start_time; +#else static uint64_t start_time; +#endif + static uint64_t next_flush; @@ -30,16 +47,41 @@ static uint64_t next_flush; static uint64_t mytime_now(void) { -#if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_CLOCK_MONOTONIC) +#if defined(MYTHREAD_VISTA) || defined(_MSC_VER) + // Since there is no SIGALRM on Windows, this function gets + // called frequently when the progress indicator is in use. + // Progress indicator doesn't need high-resolution time. + // GetTickCount64() has very low overhead but needs at least WinVista. + // + // MinGW-w64 provides the POSIX functions clock_gettime() and + // gettimeofday() in a manner that allow xz to run on older + // than WinVista. If the threading method needs WinVista anyway, + // there's no reason to avoid a WinVista API here either. + return GetTickCount64(); + +#elif defined(HAVE_CLOCK_GETTIME) \ + && (!defined(__MINGW32__) || defined(MYTHREAD_POSIX)) + // MinGW-w64: clock_gettime() is defined in winpthreads but we need + // nothing else from winpthreads (unless, for some odd reason, POSIX + // threading has been selected). By avoiding clock_gettime(), we + // avoid the dependency on libwinpthread-1.dll or the need to link + // against the static version. The downside is that the fallback + // method, gettimeofday(), doesn't provide monotonic time. + struct timespec tv; + +# ifdef HAVE_CLOCK_MONOTONIC // If CLOCK_MONOTONIC was available at compile time but for some // reason isn't at runtime, fallback to CLOCK_REALTIME which // according to POSIX is mandatory for all implementations. static clockid_t clk_id = CLOCK_MONOTONIC; - struct timespec tv; while (clock_gettime(clk_id, &tv)) clk_id = CLOCK_REALTIME; +# else + clock_gettime(CLOCK_REALTIME, &tv); +# endif return (uint64_t)tv.tv_sec * 1000 + (uint64_t)(tv.tv_nsec / 1000000); + #else struct timeval tv; gettimeofday(&tv, NULL); @@ -48,10 +90,49 @@ mytime_now(void) } +#ifdef USE_SIGTSTP_HANDLER +extern void +mytime_sigtstp_handler(int sig lzma_attribute((__unused__))) +{ + // Measure how long the process stays in the stopped state and add + // that amount to start_time. This way the the progress indicator + // won't count the stopped time as elapsed time and the estimated + // remaining time won't be confused by the time spent in the + // stopped state. + // + // FIXME? Is raising SIGSTOP the correct thing to do? POSIX.1-2017 + // says that orphan processes shouldn't stop on SIGTSTP. So perhaps + // the most correct thing to do could be to revert to the default + // handler for SIGTSTP, unblock SIGTSTP, and then raise(SIGTSTP). + // It's quite a bit more complicated than just raising SIGSTOP though. + // + // The difference between raising SIGTSTP vs. SIGSTOP can be seen on + // the shell command line too by running "echo $?" after stopping + // a process but perhaps that doesn't matter. + const uint64_t t = mytime_now(); + raise(SIGSTOP); + start_time += mytime_now() - t; + return; +} +#endif + + extern void mytime_set_start_time(void) { +#ifdef USE_SIGTSTP_HANDLER + // Block the signals when accessing start_time so that we cannot + // end up with a garbage value. start_time is volatile but access + // to it isn't atomic at least on 32-bit systems. + signals_block(); +#endif + start_time = mytime_now(); + +#ifdef USE_SIGTSTP_HANDLER + signals_unblock(); +#endif + return; } @@ -59,7 +140,17 @@ mytime_set_start_time(void) extern uint64_t mytime_get_elapsed(void) { - return mytime_now() - start_time; +#ifdef USE_SIGTSTP_HANDLER + signals_block(); +#endif + + const uint64_t t = mytime_now() - start_time; + +#ifdef USE_SIGTSTP_HANDLER + signals_unblock(); +#endif + + return t; } |