Dispatch async signals during time_sleep_until()

NEWS

@@ -123,6 +123,8 @@ PHP                                                                        NEWS
     sockets. (David Carlier)
 
 - Standard:
+  . Dispatch asynchronous signal handlers while time_sleep_until() waits.
+    (Nicolas Grekas)
   . Fixed bug #60110 (fclose(), file_put_contents(), copy() do not return false
     properly). (Jakub Zelenka, Ilija Tovilo)
   . Fixed three Windows-only proc_open() defects: an uninitialized

UPGRADING

@@ -37,6 +37,11 @@ PHP 8.7 UPGRADE NOTES
     application terminate one attribute and append further ones.
 
 - Standard:
+  . With pcntl_async_signals(true), time_sleep_until() now runs signal
+    handlers before the sleep ends. Previously, handlers waited until the
+    deadline. If a handler returns normally, the sleep resumes until the
+    original deadline. A handler can now interrupt the sleep by throwing an
+    exception or calling exit.
   . The number of filters that can be chained in a php://filter URL is limited
     to 16 by default. Set the stream context option max_filter_count to change
     this.

ext/standard/basic_functions.c

@@ -31,6 +31,7 @@
 #include "ext/standard/info.h"
 #include "ext/session/php_session.h"
 #include "zend_exceptions.h"
+#include "zend_hrtime.h"
 #include "zend_ini.h"
 #include "zend_operators.h"
 #include "ext/standard/php_dns.h"
@@ -1206,8 +1207,9 @@ PHP_FUNCTION(time_sleep_until)
 {
 	double target_secs;
 	struct timeval tm;
-	struct timespec php_req, php_rem;
+	struct timespec php_req;
 	uint64_t current_ns, target_ns, diff_ns;
+	zend_hrtime_t start;
 	const uint64_t ns_per_sec = 1000000000;
 	const double top_target_sec = (double)(UINT64_MAX / ns_per_sec);
 
@@ -1218,6 +1220,7 @@ PHP_FUNCTION(time_sleep_until)
 	if (gettimeofday((struct timeval *) &tm, NULL) != 0) {
 		RETURN_FALSE;
 	}
+	start = zend_hrtime();
 
 	if (UNEXPECTED(!(target_secs >= 0 && target_secs <= top_target_sec))) {
 		zend_argument_value_error(1, "must be between 0 and %" PRIu64, (uint64_t)top_target_sec);
@@ -1235,13 +1238,23 @@ PHP_FUNCTION(time_sleep_until)
 	php_req.tv_sec = (time_t) (diff_ns / ns_per_sec);
 	php_req.tv_nsec = (long) (diff_ns % ns_per_sec);
 
-	while (nanosleep(&php_req, &php_rem)) {
-		if (errno == EINTR) {
-			php_req.tv_sec = php_rem.tv_sec;
-			php_req.tv_nsec = php_rem.tv_nsec;
-		} else {
+	while (nanosleep(&php_req, NULL)) {
+		if (errno != EINTR) {
 			RETURN_FALSE;
 		}
+		if (UNEXPECTED(atomic_load(&EG(vm_interrupt)))) {
+			zend_fcall_interrupt(execute_data);
+			if (UNEXPECTED(EG(exception))) {
+				RETURN_THROWS();
+			}
+		}
+		zend_hrtime_t elapsed = zend_hrtime() - start;
+		if (elapsed >= diff_ns) {
+			break;
+		}
+		uint64_t remaining_ns = diff_ns - elapsed;
+		php_req.tv_sec = (time_t) (remaining_ns / ns_per_sec);
+		php_req.tv_nsec = (long) (remaining_ns % ns_per_sec);
 	}
 
 	RETURN_TRUE;

ext/standard/tests/misc/time_sleep_until_async_signals.phpt

@@ -0,0 +1,30 @@
+--TEST--
+time_sleep_until() dispatches async signals and keeps the original deadline
+--EXTENSIONS--
+pcntl
+--SKIPIF--
+<?php
+if (!function_exists('time_sleep_until')) die('skip time_sleep_until() not available');
+if (getenv('SKIP_SLOW_TESTS')) die('skip slow test');
+?>
+--FILE--
+<?php
+pcntl_async_signals(true);
+$deadline = microtime(true) + 2;
+$calledBeforeDeadline = false;
+pcntl_signal(SIGALRM, static function () use ($deadline, &$calledBeforeDeadline): void {
+    $calledBeforeDeadline = microtime(true) < $deadline;
+    time_sleep_until($deadline + 0.1);
+});
+
+pcntl_alarm(1);
+var_dump(time_sleep_until($deadline));
+var_dump($calledBeforeDeadline);
+var_dump(microtime(true) >= $deadline);
+var_dump(microtime(true) < $deadline + 0.8);
+?>
+--EXPECT--
+bool(true)
+bool(true)
+bool(true)
+bool(true)

ext/standard/tests/misc/time_sleep_until_async_signals_exception.phpt

@@ -0,0 +1,29 @@
+--TEST--
+An async signal handler can throw during time_sleep_until()
+--EXTENSIONS--
+pcntl
+--SKIPIF--
+<?php
+if (!function_exists('time_sleep_until')) die('skip time_sleep_until() not available');
+if (getenv('SKIP_SLOW_TESTS')) die('skip slow test');
+?>
+--FILE--
+<?php
+pcntl_async_signals(true);
+$deadline = microtime(true) + 2;
+pcntl_signal(SIGALRM, static function () use ($deadline): void {
+    var_dump(microtime(true) < $deadline);
+    throw new Exception('Interrupted');
+});
+
+pcntl_alarm(1);
+try {
+    time_sleep_until($deadline);
+    echo "Sleep completed\n";
+} catch (Exception $e) {
+    echo $e->getMessage(), "\n";
+}
+?>
+--EXPECT--
+bool(true)
+Interrupted

ext/standard/tests/misc/time_sleep_until_async_signals_exit.phpt

@@ -0,0 +1,24 @@
+--TEST--
+An async signal handler can exit during time_sleep_until()
+--EXTENSIONS--
+pcntl
+--SKIPIF--
+<?php
+if (!function_exists('time_sleep_until')) die('skip time_sleep_until() not available');
+if (getenv('SKIP_SLOW_TESTS')) die('skip slow test');
+?>
+--FILE--
+<?php
+pcntl_async_signals(true);
+$deadline = microtime(true) + 2;
+pcntl_signal(SIGALRM, static function () use ($deadline): void {
+    var_dump(microtime(true) < $deadline);
+    exit;
+});
+
+pcntl_alarm(1);
+time_sleep_until($deadline);
+echo "Sleep completed\n";
+?>
+--EXPECT--
+bool(true)

ext/standard/tests/misc/time_sleep_until_manual_signals.phpt

@@ -0,0 +1,27 @@
+--TEST--
+time_sleep_until() leaves manually dispatched signals pending
+--EXTENSIONS--
+pcntl
+--SKIPIF--
+<?php
+if (!function_exists('time_sleep_until')) die('skip time_sleep_until() not available');
+if (getenv('SKIP_SLOW_TESTS')) die('skip slow test');
+?>
+--FILE--
+<?php
+pcntl_async_signals(false);
+$called = false;
+pcntl_signal(SIGALRM, static function () use (&$called): void {
+    $called = true;
+});
+
+pcntl_alarm(1);
+var_dump(time_sleep_until(microtime(true) + 2));
+var_dump($called);
+pcntl_signal_dispatch();
+var_dump($called);
+?>
+--EXPECT--
+bool(true)
+bool(false)
+bool(true)