ext/pcntl: Added rusage parameter to pcntl_waitid

This functionality is not part of the POSIX interface.

- On FreeBSD, the wait6 system call provides it
- On Linux, the raw waitid system call provides it (glibc does not)

close phpGH-15921

Author: vrza

NEWS

@@ -134,6 +134,9 @@ PHP                                                                        NEWS
 - Output:
   . Fixed calculation of aligned buffer size. (cmb)
 
+- PCNTL:
+  . Extend pcntl_waitid with rusage parameter. (vrza)
+
 - PCRE:
   . Upgraded to pre2lib from 10.44 to 10.45. (nielsdos)
   . Remove PCRE2_EXTRA_ALLOW_LOOKAROUND_BSK from pcre compile options.

UPGRADING

@@ -289,6 +289,8 @@ PHP 8.5 UPGRADE NOTES
 
 - PCNTL:
   . pcntl_exec() now has a formal return type of false.
+  . pcntl_waitid() takes an additional resource_usage argument to
+    gather various platform specific metrics about the child process.
 
 - PDO_PGSQL:
   . PDO::pgsqlCopyFromArray also supports inputs as Iterable.

ext/pcntl/config.m4

@@ -25,6 +25,8 @@ if test "$PHP_PCNTL" != "no"; then
     wait3
     wait4
     waitid
+    wait6
+    syscall
   ]))
 
   AC_CHECK_FUNCS([WIFCONTINUED],,
@@ -43,6 +45,9 @@ if test "$PHP_PCNTL" != "no"; then
     ]),,,
     [#include <sys/wait.h>])
 
+  AC_CHECK_DECLS([SYS_waitid],,,
+    [#include <sys/syscall.h>])
+
   dnl if unsupported, -1 means automatically ENOSYS in this context
   AC_CACHE_CHECK([if sched_getcpu is supported], [php_cv_func_sched_getcpu],
   [AC_RUN_IFELSE([AC_LANG_SOURCE([

ext/pcntl/pcntl.c

@@ -125,7 +125,15 @@ typedef psetid_t cpu_set_t;
 #include <pthread/qos.h>
 #endif
 
-#ifdef HAVE_PIDFD_OPEN
+#if defined(__linux__) && defined(HAVE_DECL_SYS_WAITID) && HAVE_DECL_SYS_WAITID == 1 && defined(HAVE_SYSCALL)
+#define HAVE_LINUX_RAW_SYSCALL_WAITID 1
+#endif
+
+#if defined(HAVE_LINUX_RAW_SYSCALL_WAITID)
+#include <unistd.h>
+#endif
+
+#if defined(HAVE_PIDFD_OPEN) || defined(HAVE_LINUX_RAW_SYSCALL_WAITID)
 #include <sys/syscall.h>
 #endif
 
@@ -401,19 +409,49 @@ PHP_FUNCTION(pcntl_waitid)
 	bool id_is_null = 1;
 	zval *user_siginfo = NULL;
 	zend_long options = WEXITED;
+	zval *z_rusage = NULL;
 
-	ZEND_PARSE_PARAMETERS_START(0, 4)
+	siginfo_t siginfo;
+	int status;
+
+	ZEND_PARSE_PARAMETERS_START(0, 5)
 		Z_PARAM_OPTIONAL
 		Z_PARAM_LONG(idtype)
 		Z_PARAM_LONG_OR_NULL(id, id_is_null)
 		Z_PARAM_ZVAL(user_siginfo)
 		Z_PARAM_LONG(options)
+		Z_PARAM_ZVAL(z_rusage)
 	ZEND_PARSE_PARAMETERS_END();
 
 	errno = 0;
-	siginfo_t siginfo;
+	memset(&siginfo, 0, sizeof(siginfo_t));
 
-	int status = waitid((idtype_t) idtype, (id_t) id, &siginfo, (int) options);
+#if defined(HAVE_WAIT6) || defined(HAVE_LINUX_RAW_SYSCALL_WAITID)
+	if (z_rusage) {
+		z_rusage = zend_try_array_init(z_rusage);
+		if (!z_rusage) {
+			RETURN_THROWS();
+		}
+		struct rusage rusage;
+# if defined(HAVE_WAIT6) /* FreeBSD */
+		struct __wrusage wrusage;
+		memset(&wrusage, 0, sizeof(struct __wrusage));
+		pid_t pid = wait6((idtype_t) idtype, (id_t) id, &status, (int) options, &wrusage, &siginfo);
+		status = pid > 0 ? 0 : pid;
+		memcpy(&rusage, &wrusage.wru_self, sizeof(struct rusage));
+# else /* Linux */
+		memset(&rusage, 0, sizeof(struct rusage));
+		status = syscall(SYS_waitid, (idtype_t) idtype, (id_t) id, &siginfo, (int) options, &rusage);
+# endif
+		if (status == 0) {
+			PHP_RUSAGE_TO_ARRAY(rusage, z_rusage);
+		}
+	} else { /* POSIX */
+		status = waitid((idtype_t) idtype, (id_t) id, &siginfo, (int) options);
+	}
+#else /* POSIX */
+	status = waitid((idtype_t) idtype, (id_t) id, &siginfo, (int) options);
+#endif
 
 	if (status == -1) {
 		PCNTL_G(last_error) = errno;

ext/pcntl/pcntl.stub.php

@@ -1006,8 +1006,11 @@ function pcntl_fork(): int {}
     function pcntl_waitpid(int $process_id, &$status, int $flags = 0, &$resource_usage = []): int {}
 
 #if defined (HAVE_WAITID) && defined (HAVE_POSIX_IDTYPES) && defined (HAVE_DECL_WEXITED) && HAVE_DECL_WEXITED == 1
-    /** @param array $info */
-    function pcntl_waitid(int $idtype = P_ALL, ?int $id = null, &$info = [], int $flags = WEXITED): bool {}
+    /**
+    * @param array $info
+    * @param array $resource_usage
+    */
+    function pcntl_waitid(int $idtype = P_ALL, ?int $id = null, &$info = [], int $flags = WEXITED, &$resource_usage = []): bool {}
 #endif
 
     /**

ext/pcntl/pcntl_arginfo.h

@@ -26,10 +26,12 @@ if ($pid == -1) {
 } else {
     pcntl_signal(SIGUSR1, function ($_signo, $_siginfo) { exit(42); });
     posix_kill(posix_getpid(), SIGSTOP);
-    pcntl_signal_dispatch();
-    sleep(42);
-    pcntl_signal_dispatch();
-    exit(6);
+    $nanoseconds = 100;
+    while (true) {
+        pcntl_signal_dispatch();
+        time_nanosleep(0, $nanoseconds);
+        $nanoseconds *= 2;
+    }
 }
 ?>
 --EXPECTF--

ext/pcntl/tests/pcntl_waitid.phpt

@@ -0,0 +1,72 @@
+--TEST--
+pcntl_waitid() and rusage
+--EXTENSIONS--
+pcntl
+posix
+--SKIPIF--
+<?php
+if (!function_exists('pcntl_waitid')) die('skip pcntl_waitid unavailable');
+if (!str_contains(PHP_OS, 'Linux') && !str_contains(PHP_OS, 'FreeBSD')) {
+    die('skip pcntl_waitid can return rusage only on FreeBSD and Linux');
+}
+?>
+--FILE--
+<?php
+$pid = pcntl_fork();
+if ($pid == -1) {
+    die('failed');
+} else if ($pid) {
+    var_dump(pcntl_waitid(P_PID, $pid, $siginfo, WSTOPPED, $rusage));
+    var_dump($rusage['ru_utime.tv_sec']);
+    var_dump($rusage['ru_utime.tv_usec']);
+
+    $rusage = array(1,2,3);
+    posix_kill($pid, SIGCONT);
+    var_dump(pcntl_waitid(P_PID, $pid, $siginfo, WCONTINUED, $rusage));
+    var_dump($rusage['ru_utime.tv_sec']);
+    var_dump($rusage['ru_utime.tv_usec']);
+
+    posix_kill($pid, SIGUSR1);
+    var_dump(pcntl_waitid(P_PID, $pid, $siginfo, WEXITED, $rusage));
+    var_dump($rusage['ru_maxrss']);
+    var_dump($siginfo['status']);
+
+    $rusage = 'string';
+    var_dump(pcntl_waitid(P_PID, $pid, $siginfo, WEXITED | WNOHANG, $rusage));
+    var_dump(gettype($rusage));
+    var_dump(count($rusage));
+
+    $rusage = new stdClass;
+    var_dump(pcntl_waitid(P_PID, $pid, $siginfo, WEXITED | WNOHANG, $rusage));
+    var_dump(gettype($rusage));
+    var_dump(count($rusage));
+
+    fwrite(STDOUT, 'END' . PHP_EOL);
+} else {
+    pcntl_signal(SIGUSR1, function ($_signo, $_siginfo) { exit(42); });
+    posix_kill(posix_getpid(), SIGSTOP);
+    $nanoseconds = 100;
+    while (true) {
+        pcntl_signal_dispatch();
+        time_nanosleep(0, $nanoseconds);
+        $nanoseconds *= 2;
+    }
+}
+?>
+--EXPECTF--
+bool(true)
+int(%d)
+int(%d)
+bool(true)
+int(%d)
+int(%d)
+bool(true)
+int(%d)
+int(42)
+bool(false)
+string(5) "array"
+int(0)
+bool(false)
+string(5) "array"
+int(0)
+END