unix: add Eventfd function on Linux

Add support for the eventfd2 syscall on Linux.

Use the eventfd2 syscall instead of eventfd, as the latter does not
provide a flags argument and glibc also maps its eventfd() function to
the eventfd2 syscall, see the Notes section in
http://man7.org/linux/man-pages/man2/eventfd.2.html

Also add the corresponding flags values EFD_CLOEXEC, EFD_NONBLOCK and
EFD_SEMAPHORE.

Change-Id: Ia8c99e68d5966ab5c7ebe7e45423943fd7d8214e
Reviewed-on: https://go-review.googlesource.com/45093
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

unix/mkerrors.sh

@@ -143,6 +143,7 @@ struct ltchars {
 
 #include <bits/sockaddr.h>
 #include <sys/epoll.h>
+#include <sys/eventfd.h>
 #include <sys/inotify.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
@@ -375,7 +376,7 @@ ccflags="$@"
 		$2 ~ /^SYSCTL_VERS/ ||
 		$2 ~ /^(MS|MNT)_/ ||
 		$2 ~ /^TUN(SET|GET|ATTACH|DETACH)/ ||
-		$2 ~ /^(O|F|FD|NAME|S|PTRACE|PT)_/ ||
+		$2 ~ /^(O|F|E?FD|NAME|S|PTRACE|PT)_/ ||
 		$2 ~ /^LINUX_REBOOT_CMD_/ ||
 		$2 ~ /^LINUX_REBOOT_MAGIC[12]$/ ||
 		$2 !~ "NLA_TYPE_MASK" &&

unix/syscall_linux.go

@@ -1171,6 +1171,7 @@ func Mount(source string, target string, fstype string, flags uintptr, data stri
 //sysnb	EpollCreate(size int) (fd int, err error)
 //sysnb	EpollCreate1(flag int) (fd int, err error)
 //sysnb	EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error)
+//sys	Eventfd(initval uint, flags int) (fd int, err error) = SYS_EVENTFD2
 //sys	Exit(code int) = SYS_EXIT_GROUP
 //sys	Faccessat(dirfd int, path string, mode uint32, flags int) (err error)
 //sys	Fallocate(fd int, mode uint32, off int64, len int64) (err error)
@@ -1316,7 +1317,6 @@ func Vmsplice(fd int, iovs []Iovec, flags int) (int, error) {
 // EpollCtlOld
 // EpollPwait
 // EpollWaitOld
-// Eventfd
 // Execve
 // Fgetxattr
 // Flistxattr

unix/zerrors_linux_386.go

@@ -325,6 +325,9 @@ const (
 	ECHOKE                               = 0x800
 	ECHONL                               = 0x40
 	ECHOPRT                              = 0x400
+	EFD_CLOEXEC                          = 0x80000
+	EFD_NONBLOCK                         = 0x800
+	EFD_SEMAPHORE                        = 0x1
 	ENCODING_DEFAULT                     = 0x0
 	ENCODING_FM_MARK                     = 0x3
 	ENCODING_FM_SPACE                    = 0x4

unix/zerrors_linux_amd64.go

@@ -325,6 +325,9 @@ const (
 	ECHOKE                               = 0x800
 	ECHONL                               = 0x40
 	ECHOPRT                              = 0x400
+	EFD_CLOEXEC                          = 0x80000
+	EFD_NONBLOCK                         = 0x800
+	EFD_SEMAPHORE                        = 0x1
 	ENCODING_DEFAULT                     = 0x0
 	ENCODING_FM_MARK                     = 0x3
 	ENCODING_FM_SPACE                    = 0x4

unix/zerrors_linux_arm.go

@@ -325,6 +325,9 @@ const (
 	ECHOKE                               = 0x800
 	ECHONL                               = 0x40
 	ECHOPRT                              = 0x400
+	EFD_CLOEXEC                          = 0x80000
+	EFD_NONBLOCK                         = 0x800
+	EFD_SEMAPHORE                        = 0x1
 	ENCODING_DEFAULT                     = 0x0
 	ENCODING_FM_MARK                     = 0x3
 	ENCODING_FM_SPACE                    = 0x4

unix/zerrors_linux_arm64.go

@@ -325,6 +325,9 @@ const (
 	ECHOKE                               = 0x800
 	ECHONL                               = 0x40
 	ECHOPRT                              = 0x400
+	EFD_CLOEXEC                          = 0x80000
+	EFD_NONBLOCK                         = 0x800
+	EFD_SEMAPHORE                        = 0x1
 	ENCODING_DEFAULT                     = 0x0
 	ENCODING_FM_MARK                     = 0x3
 	ENCODING_FM_SPACE                    = 0x4

unix/zerrors_linux_mips.go

@@ -325,6 +325,9 @@ const (
 	ECHOKE                               = 0x800
 	ECHONL                               = 0x40
 	ECHOPRT                              = 0x400
+	EFD_CLOEXEC                          = 0x80000
+	EFD_NONBLOCK                         = 0x80
+	EFD_SEMAPHORE                        = 0x1
 	ENCODING_DEFAULT                     = 0x0
 	ENCODING_FM_MARK                     = 0x3
 	ENCODING_FM_SPACE                    = 0x4

unix/zerrors_linux_mips64.go

@@ -325,6 +325,9 @@ const (
 	ECHOKE                               = 0x800
 	ECHONL                               = 0x40
 	ECHOPRT                              = 0x400
+	EFD_CLOEXEC                          = 0x80000
+	EFD_NONBLOCK                         = 0x80
+	EFD_SEMAPHORE                        = 0x1
 	ENCODING_DEFAULT                     = 0x0
 	ENCODING_FM_MARK                     = 0x3
 	ENCODING_FM_SPACE                    = 0x4

unix/zerrors_linux_mips64le.go

@@ -325,6 +325,9 @@ const (
 	ECHOKE                               = 0x800
 	ECHONL                               = 0x40
 	ECHOPRT                              = 0x400
+	EFD_CLOEXEC                          = 0x80000
+	EFD_NONBLOCK                         = 0x80
+	EFD_SEMAPHORE                        = 0x1
 	ENCODING_DEFAULT                     = 0x0
 	ENCODING_FM_MARK                     = 0x3
 	ENCODING_FM_SPACE                    = 0x4

unix/zerrors_linux_mipsle.go

@@ -325,6 +325,9 @@ const (
 	ECHOKE                               = 0x800
 	ECHONL                               = 0x40
 	ECHOPRT                              = 0x400
+	EFD_CLOEXEC                          = 0x80000
+	EFD_NONBLOCK                         = 0x80
+	EFD_SEMAPHORE                        = 0x1
 	ENCODING_DEFAULT                     = 0x0
 	ENCODING_FM_MARK                     = 0x3
 	ENCODING_FM_SPACE                    = 0x4

unix/zerrors_linux_ppc64.go

@@ -325,6 +325,9 @@ const (
 	ECHOKE                               = 0x1
 	ECHONL                               = 0x10
 	ECHOPRT                              = 0x20
+	EFD_CLOEXEC                          = 0x80000
+	EFD_NONBLOCK                         = 0x800
+	EFD_SEMAPHORE                        = 0x1
 	ENCODING_DEFAULT                     = 0x0
 	ENCODING_FM_MARK                     = 0x3
 	ENCODING_FM_SPACE                    = 0x4

unix/zerrors_linux_ppc64le.go

@@ -325,6 +325,9 @@ const (
 	ECHOKE                               = 0x1
 	ECHONL                               = 0x10
 	ECHOPRT                              = 0x20
+	EFD_CLOEXEC                          = 0x80000
+	EFD_NONBLOCK                         = 0x800
+	EFD_SEMAPHORE                        = 0x1
 	ENCODING_DEFAULT                     = 0x0
 	ENCODING_FM_MARK                     = 0x3
 	ENCODING_FM_SPACE                    = 0x4

unix/zerrors_linux_s390x.go

@@ -325,6 +325,9 @@ const (
 	ECHOKE                               = 0x800
 	ECHONL                               = 0x40
 	ECHOPRT                              = 0x400
+	EFD_CLOEXEC                          = 0x80000
+	EFD_NONBLOCK                         = 0x800
+	EFD_SEMAPHORE                        = 0x1
 	ENCODING_DEFAULT                     = 0x0
 	ENCODING_FM_MARK                     = 0x3
 	ENCODING_FM_SPACE                    = 0x4

unix/zsyscall_linux_386.go

@@ -511,6 +511,17 @@ func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Eventfd(initval uint, flags int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_EVENTFD2, uintptr(initval), uintptr(flags), 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Exit(code int) {
 	Syscall(SYS_EXIT_GROUP, uintptr(code), 0, 0)
 	return

unix/zsyscall_linux_amd64.go

@@ -511,6 +511,17 @@ func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Eventfd(initval uint, flags int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_EVENTFD2, uintptr(initval), uintptr(flags), 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Exit(code int) {
 	Syscall(SYS_EXIT_GROUP, uintptr(code), 0, 0)
 	return

unix/zsyscall_linux_arm.go

@@ -511,6 +511,17 @@ func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Eventfd(initval uint, flags int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_EVENTFD2, uintptr(initval), uintptr(flags), 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Exit(code int) {
 	Syscall(SYS_EXIT_GROUP, uintptr(code), 0, 0)
 	return

unix/zsyscall_linux_arm64.go

@@ -511,6 +511,17 @@ func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Eventfd(initval uint, flags int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_EVENTFD2, uintptr(initval), uintptr(flags), 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Exit(code int) {
 	Syscall(SYS_EXIT_GROUP, uintptr(code), 0, 0)
 	return

unix/zsyscall_linux_mips.go

@@ -511,6 +511,17 @@ func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Eventfd(initval uint, flags int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_EVENTFD2, uintptr(initval), uintptr(flags), 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Exit(code int) {
 	Syscall(SYS_EXIT_GROUP, uintptr(code), 0, 0)
 	return

unix/zsyscall_linux_mips64.go

@@ -511,6 +511,17 @@ func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Eventfd(initval uint, flags int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_EVENTFD2, uintptr(initval), uintptr(flags), 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Exit(code int) {
 	Syscall(SYS_EXIT_GROUP, uintptr(code), 0, 0)
 	return

unix/zsyscall_linux_mips64le.go

@@ -511,6 +511,17 @@ func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Eventfd(initval uint, flags int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_EVENTFD2, uintptr(initval), uintptr(flags), 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Exit(code int) {
 	Syscall(SYS_EXIT_GROUP, uintptr(code), 0, 0)
 	return

unix/zsyscall_linux_mipsle.go

@@ -511,6 +511,17 @@ func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Eventfd(initval uint, flags int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_EVENTFD2, uintptr(initval), uintptr(flags), 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Exit(code int) {
 	Syscall(SYS_EXIT_GROUP, uintptr(code), 0, 0)
 	return

unix/zsyscall_linux_ppc64.go

@@ -511,6 +511,17 @@ func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Eventfd(initval uint, flags int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_EVENTFD2, uintptr(initval), uintptr(flags), 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Exit(code int) {
 	Syscall(SYS_EXIT_GROUP, uintptr(code), 0, 0)
 	return

unix/zsyscall_linux_ppc64le.go

@@ -511,6 +511,17 @@ func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Eventfd(initval uint, flags int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_EVENTFD2, uintptr(initval), uintptr(flags), 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Exit(code int) {
 	Syscall(SYS_EXIT_GROUP, uintptr(code), 0, 0)
 	return

unix/zsyscall_linux_s390x.go

@@ -511,6 +511,17 @@ func EpollCtl(epfd int, op int, fd int, event *EpollEvent) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Eventfd(initval uint, flags int) (fd int, err error) {
+	r0, _, e1 := Syscall(SYS_EVENTFD2, uintptr(initval), uintptr(flags), 0)
+	fd = int(r0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Exit(code int) {
 	Syscall(SYS_EXIT_GROUP, uintptr(code), 0, 0)
 	return