Implement pcntl_waitid

ext/pcntl/config.m4

@@ -4,7 +4,7 @@ PHP_ARG_ENABLE([pcntl],
     [Enable pcntl support (CLI/CGI only)])])
 
 if test "$PHP_PCNTL" != "no"; then
-  for function in fork sigaction waitpid; do
+  for function in fork sigaction waitpid waitid; do
     AC_CHECK_FUNC([$function],,
       [AC_MSG_ERROR([ext/pcntl: required function $function() not found.])])
   done

ext/pcntl/pcntl.c

@@ -385,6 +385,57 @@ PHP_FUNCTION(pcntl_waitpid)
 }
 /* }}} */
 
+/* {{{ Waits on or returns the status of a forked child as defined by the waitid() system call */
+PHP_FUNCTION(pcntl_waitid)
+{
+	zend_long idtype = P_PID;
+	zend_long id = 0;
+	/* Optional by-ref array of ints */
+	zval *user_siginfo = NULL;
+	zend_long options = WEXITED;
+	int success;
+
+	ZEND_PARSE_PARAMETERS_START(2, 4)
+		Z_PARAM_LONG(idtype)
+		Z_PARAM_LONG(id)
+		Z_PARAM_OPTIONAL
+		Z_PARAM_ZVAL(user_siginfo)
+		Z_PARAM_LONG(options)
+	ZEND_PARSE_PARAMETERS_END();
+
+	// check idtype is one of P_PID, P_PIDFD, P_PGID, P_ALL
+	if (idtype != P_ALL && idtype != P_PID && idtype != P_PIDFD && idtype != P_PGID) {
+		php_error_docref(NULL, E_WARNING, "idtype must be one of P_PID, P_PIDFD, P_PGID, P_ALL");
+		RETURN_FALSE;
+	}
+
+	// check flags, minimum one of WEXITED, WSTOPPED, WCONTINUED,
+	// additionally WNOHANG or WNOWAIT can be set
+	if ((options & WEXITED) != WEXITED &&
+			(options & WSTOPPED) != WSTOPPED &&
+			(options & WCONTINUED) != WCONTINUED) {
+		php_error_docref(NULL, E_WARNING, "flags must include at least WEXITED, WSTOPPED or WCONTINUED");
+		RETURN_FALSE;
+	}
+
+	errno = 0;
+	siginfo_t siginfo;
+
+	success = waitid((idtype_t) idtype, (id_t) id, &siginfo, (int) options);
+
+	if (success == -1) {
+		PCNTL_G(last_error) = errno;
+		php_error_docref(NULL, E_WARNING, "%s", strerror(errno));
+		RETURN_FALSE;
+	}
+
+	// TODO verify that passing SIGCHLD does what we need
+	pcntl_siginfo_to_zval(SIGCHLD, &siginfo, user_siginfo);
+
+	RETURN_TRUE;
+}
+/* }}} */
+
 /* {{{ Waits on or returns the status of a forked child as defined by the waitpid() system call */
 PHP_FUNCTION(pcntl_wait)
 {

ext/pcntl/pcntl.stub.php

@@ -25,6 +25,49 @@
  */
 const WCONTINUED = UNKNOWN;
 #endif
+#ifdef WEXITED
+/**
+ * @var int
+ * @cvalue LONG_CONST(WEXITED)
+ */
+const WEXITED = UNKNOWN;
+#endif
+#ifdef WSTOPPED
+/**
+ * @var int
+ * @cvalue LONG_CONST(WSTOPPED)
+ */
+const WSTOPPED = UNKNOWN;
+#endif
+#ifdef WNOWAIT
+/**
+ * @var int
+ * @cvalue LONG_CONST(WNOWAIT)
+ */
+const WNOWAIT = UNKNOWN;
+#endif
+
+/* First argument to waitid */
+/**
+ * @var int
+ * @cvalue LONG_CONST(P_ALL)
+ */
+const P_ALL = UNKNOWN;
+/**
+ * @var int
+ * @cvalue LONG_CONST(P_PID)
+ */
+const P_PID = UNKNOWN;
+/**
+ * @var int
+ * @cvalue LONG_CONST(P_PGID)
+ */
+const P_PGID = UNKNOWN;
+/**
+ * @var int
+ * @cvalue LONG_CONST(P_PIDFD)
+ */
+const P_PIDFD = UNKNOWN;
 
 /* Signal Constants */
 
@@ -927,6 +970,9 @@ function pcntl_fork(): int {}
  */
 function pcntl_waitpid(int $process_id, &$status, int $flags = 0, &$resource_usage = []): int {}
 
+/** @param array $info */
+function pcntl_waitid(int $idtype, int $id, &$info = [], int $flags = 0): bool {}
+
 /**
  * @param int $status
  * @param array $resource_usage