feat(rust): port program timing helpers

Move the implementation of programs/timefn.c into rust/src/timefn.rs. The
file provides the monotonic nanosecond clock (UTIL_getTime, span helpers,
UTIL_waitForNextTick, UTIL_support_MT_measurements) used by the CLI and by
several C test tools. timefn.c remains as a declaration-only shim so the
original source lists and header configuration keep working, and it pins the
ABI with static asserts: UTIL_time_t is returned by value and must stay a
plain 64-bit counter, which the Rust #[repr(C)] mirror also asserts.

Platform selection mirrors the C preprocessor structure: Windows uses
QueryPerformanceCounter, Apple targets use mach_absolute_time, and other
POSIX systems use libc clock_gettime(CLOCK_MONOTONIC). Only the unix path is
exercised by this environment; the Windows and Apple paths are written from
the C source and compile-checked logically but are untested here. The C90
clock() fallback is unreachable on Rust-supported targets, so multi-threaded
measurement support is always reported.

The symbols live in the program-only zstd-cli-rs package, keeping them out
of library builds. Linking that archive into C test binaries surfaced a
structural problem: rustc's local ThinLTO promotes internal symbols across
codegen units, so extracting the timefn object could drag in the zstd_cli
parser object, whose FIO_* externs test binaries cannot satisfy. The parser
is therefore gated behind a new additive `cli` cargo feature (default on).
Program archives build with cli,compression,decompression as before, while
tests/Makefile links a helpers-only archive (rust/target/cli-helpers) built
with --no-default-features, which contains no fileio references at all.

tests/Makefile gains build rules for the helpers archive and adds it as a
prerequisite of every binary that compiles the timefn shim: fullbench(32),
fullbench-lib, fullbench-dll, fuzzer(32), zstreamtest(32/asan/tsan/ubsan),
paramgrill, decodecorpus, and poolTests. Prerequisite order places the
archive after all C objects in `$^` link lines; the known-broken -dll
recipes filter to %.c, so they name the archive explicitly. Original C test
sources are untouched; only link inputs changed.

zstd-cli-rs now depends on libc (already used by the core crate) for
clock_gettime and the Mach timebase bindings.

Test Plan:
- cd rust && cargo fmt --check && cargo clippy --all-targets -- -D warnings
  && cargo test --all-targets && cargo build --release
- cd rust/cli && cargo fmt --check && cargo clippy --all-targets -- -D
  warnings && cargo test --all-targets; repeat tests with
  --no-default-features plus features compression / decompression / (none)
- make -C programs zstd; roundtrip echo hello | zstd | zstd -d
- make -C tests fullbench fuzzer zstreamtest paramgrill decodecorpus
  poolTests; ./tests/fullbench -i0; ./tests/fuzzer -i1 --no-big-tests;
  ./tests/poolTests; make -C tests test-rust-lib-smoke
- verified with nm that the helpers archive member defining UTIL_getTime has
  no FIO_*/ZSTD_* undefined references

Refs: rust/README.md
This commit is contained in:
2026-07-11 09:45:26 +02:00
parent 959e485201
commit a814af32f8
9 changed files with 277 additions and 166 deletions
+8 -155
View File
@@ -8,161 +8,14 @@
* You may select, at your option, one of the above-listed licenses.
*/
/* === Dependencies === */
/* The implementation lives in rust/src/timefn.rs, built into the Rust CLI
* static archive. This translation unit stays in the original source lists so
* build configuration keeps working while the implementation is in Rust. */
#include "timefn.h"
#include "platform.h" /* set _POSIX_C_SOURCE */
#include <time.h> /* CLOCK_MONOTONIC, TIME_UTC */
/*-****************************************
* Time functions
******************************************/
#if defined(_WIN32) /* Windows */
#include <windows.h> /* LARGE_INTEGER */
#include <stdlib.h> /* abort */
#include <stdio.h> /* perror */
UTIL_time_t UTIL_getTime(void)
{
static LARGE_INTEGER ticksPerSecond;
static int init = 0;
if (!init) {
if (!QueryPerformanceFrequency(&ticksPerSecond)) {
perror("timefn::QueryPerformanceFrequency");
abort();
}
init = 1;
}
{ UTIL_time_t r;
LARGE_INTEGER x;
QueryPerformanceCounter(&x);
r.t = (PTime)(x.QuadPart * 1000000000ULL / ticksPerSecond.QuadPart);
return r;
}
}
#elif defined(__APPLE__) && defined(__MACH__)
#include <mach/mach_time.h> /* mach_timebase_info_data_t, mach_timebase_info, mach_absolute_time */
UTIL_time_t UTIL_getTime(void)
{
static mach_timebase_info_data_t rate;
static int init = 0;
if (!init) {
mach_timebase_info(&rate);
init = 1;
}
{ UTIL_time_t r;
r.t = mach_absolute_time() * (PTime)rate.numer / (PTime)rate.denom;
return r;
}
}
/* POSIX.1-2001 (optional) */
#elif defined(CLOCK_MONOTONIC)
#include <stdlib.h> /* abort */
#include <stdio.h> /* perror */
UTIL_time_t UTIL_getTime(void)
{
/* time must be initialized, othersize it may fail msan test.
* No good reason, likely a limitation of timespec_get() for some target */
struct timespec time = { 0, 0 };
if (clock_gettime(CLOCK_MONOTONIC, &time) != 0) {
perror("timefn::clock_gettime(CLOCK_MONOTONIC)");
abort();
}
{ UTIL_time_t r;
r.t = (PTime)time.tv_sec * 1000000000ULL + (PTime)time.tv_nsec;
return r;
}
}
/* C11 requires support of timespec_get().
* However, FreeBSD 11 claims C11 compliance while lacking timespec_get().
* Double confirm timespec_get() support by checking the definition of TIME_UTC.
* However, some versions of Android manage to simultaneously define TIME_UTC
* and lack timespec_get() support... */
#elif (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) /* C11 */) \
&& defined(TIME_UTC) && !defined(__ANDROID__)
#include <stdlib.h> /* abort */
#include <stdio.h> /* perror */
UTIL_time_t UTIL_getTime(void)
{
/* time must be initialized, othersize it may fail msan test.
* No good reason, likely a limitation of timespec_get() for some target */
struct timespec time = { 0, 0 };
if (timespec_get(&time, TIME_UTC) != TIME_UTC) {
perror("timefn::timespec_get(TIME_UTC)");
abort();
}
{ UTIL_time_t r;
r.t = (PTime)time.tv_sec * 1000000000ULL + (PTime)time.tv_nsec;
return r;
}
}
#else /* relies on standard C90 (note : clock_t produces wrong measurements for multi-threaded workloads) */
UTIL_time_t UTIL_getTime(void)
{
UTIL_time_t r;
r.t = (PTime)clock() * 1000000000ULL / CLOCKS_PER_SEC;
return r;
}
#define TIME_MT_MEASUREMENTS_NOT_SUPPORTED
#endif
/* ==== Common functions, valid for all time API ==== */
PTime UTIL_getSpanTimeNano(UTIL_time_t clockStart, UTIL_time_t clockEnd)
{
return clockEnd.t - clockStart.t;
}
PTime UTIL_getSpanTimeMicro(UTIL_time_t begin, UTIL_time_t end)
{
return UTIL_getSpanTimeNano(begin, end) / 1000ULL;
}
PTime UTIL_clockSpanMicro(UTIL_time_t clockStart )
{
UTIL_time_t const clockEnd = UTIL_getTime();
return UTIL_getSpanTimeMicro(clockStart, clockEnd);
}
PTime UTIL_clockSpanNano(UTIL_time_t clockStart )
{
UTIL_time_t const clockEnd = UTIL_getTime();
return UTIL_getSpanTimeNano(clockStart, clockEnd);
}
void UTIL_waitForNextTick(void)
{
UTIL_time_t const clockStart = UTIL_getTime();
UTIL_time_t clockEnd;
do {
clockEnd = UTIL_getTime();
} while (UTIL_getSpanTimeNano(clockStart, clockEnd) == 0);
}
int UTIL_support_MT_measurements(void)
{
# if defined(TIME_MT_MEASUREMENTS_NOT_SUPPORTED)
return 0;
# else
return 1;
# endif
}
/* The Rust port mirrors this exact ABI: UTIL_time_t is returned by value and
* must remain a plain 64-bit nanosecond counter. */
typedef char UTIL_staticAssert_ptimeIs64Bit[(sizeof(PTime) == 8) ? 1 : -1];
typedef char UTIL_staticAssert_timeIsPlainCounter[
(sizeof(UTIL_time_t) == sizeof(PTime)) ? 1 : -1];