calog/libs/calogTime.c
2026-07-03 02:13:23 -05:00

91 lines
3.2 KiB
C

// calogTime.c -- calog time library (see calogTime.h). Three stateless natives over the
// POSIX clocks: a wall-clock read, a monotonic read, and a millisecond sleep. No shared
// state and no timers/threads -- each native is a pure function of its arguments (or a
// plain block of the calling context thread).
#define _POSIX_C_SOURCE 200809L
#include "calogTime.h"
#include <errno.h>
#include <time.h>
static int32_t timeMonotonicNative(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData);
static int32_t timeNowNative(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData);
static int32_t timeSleepNative(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData);
static double timeToSeconds(const struct timespec *ts);
int32_t calogTimeRegister(CalogT *calog) {
calogRegisterInline(calog, "timeNow", timeNowNative, NULL);
calogRegisterInline(calog, "timeMonotonic", timeMonotonicNative, NULL);
calogRegisterInline(calog, "timeSleep", timeSleepNative, NULL);
return calogOkE;
}
static int32_t timeMonotonicNative(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData) {
struct timespec ts;
(void)args;
(void)userData;
calogValueNil(result);
if (argCount != 0) {
return calogFail(result, calogErrArgE, "timeMonotonic expects ()");
}
if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0) {
return calogFail(result, calogErrUnsupportedE, "timeMonotonic: clock_gettime failed");
}
calogValueReal(result, timeToSeconds(&ts));
return calogOkE;
}
static int32_t timeNowNative(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData) {
struct timespec ts;
(void)args;
(void)userData;
calogValueNil(result);
if (argCount != 0) {
return calogFail(result, calogErrArgE, "timeNow expects ()");
}
if (clock_gettime(CLOCK_REALTIME, &ts) != 0) {
return calogFail(result, calogErrUnsupportedE, "timeNow: clock_gettime failed");
}
calogValueReal(result, timeToSeconds(&ts));
return calogOkE;
}
static int32_t timeSleepNative(CalogValueT *args, int32_t argCount, CalogValueT *result, void *userData) {
struct timespec request;
struct timespec remaining;
double ms;
int64_t nanos;
(void)userData;
calogValueNil(result);
if (argCount != 1 || (args[0].type != calogIntE && args[0].type != calogRealE)) {
return calogFail(result, calogErrArgE, "timeSleep expects (milliseconds)");
}
ms = (args[0].type == calogIntE) ? (double)args[0].as.i : args[0].as.r;
if (!(ms >= 0.0)) {
return calogFail(result, calogErrRangeE, "timeSleep: milliseconds must be non-negative");
}
nanos = (int64_t)(ms * 1000000.0);
request.tv_sec = (time_t)(nanos / 1000000000);
request.tv_nsec = (long)(nanos % 1000000000);
while (nanosleep(&request, &remaining) != 0) {
if (errno != EINTR) {
return calogFail(result, calogErrUnsupportedE, "timeSleep: nanosleep failed");
}
request = remaining;
}
return calogOkE;
}
static double timeToSeconds(const struct timespec *ts) {
return (double)ts->tv_sec + (double)ts->tv_nsec / 1000000000.0;
}