syscall.Wait4

c/os/os.go

@@ -263,21 +263,50 @@ func Execve(path *c.Char, argv **c.Char, envp **c.Char) c.Int
 //go:linkname Execvp C.execvp
 func Execvp(file *c.Char, argv **c.Char) c.Int
 
+// -----------------------------------------------------------------------------
+
+type PidT c.Int
+
 //go:linkname Fork C.fork
-func Fork() c.Int
+func Fork() PidT
+
+//go:linkname Getpid C.getpid
+func Getpid() PidT
+
+//go:linkname Getppid C.getppid
+func Getppid() PidT
 
 //go:linkname Kill C.kill
-func Kill(pid c.Int, sig c.Int) c.Int
+func Kill(pid PidT, sig c.Int) c.Int
+
+// If wait() returns due to a stopped or terminated child process, the process ID
+// of the child is returned to the calling process.  Otherwise, a value of -1 is
+// returned and errno is set to indicate the error.
+//
+//go:linkname Wait C.wait
+func Wait(statLoc *c.Int) PidT
+
+// If wait3(), wait4(), or waitpid() returns due to a stopped or terminated child
+// process, the process ID of the child is returned to the calling process.  If
+// there are no children not previously awaited, -1 is returned with errno set to
+// [ECHILD].  Otherwise, if WNOHANG is specified and there are no stopped or exited
+// children, 0 is returned.  If an error is detected or a caught signal aborts the
+// call, a value of -1 is returned and errno is set to indicate the error.
+//
+//go:linkname Wait3 C.wait3
+func Wait3(statLoc *c.Int, options c.Int, rusage *syscall.Rusage) PidT
+
+//go:linkname Wait4 C.wait4
+func Wait4(pid PidT, statLoc *c.Int, options c.Int, rusage *syscall.Rusage) PidT
+
+//go:linkname Waitpid C.waitpid
+func Waitpid(pid PidT, statLoc *c.Int, options c.Int) PidT
+
+// -----------------------------------------------------------------------------
 
 //go:linkname Exit C.exit
 func Exit(c.Int)
 
-//go:linkname Getpid C.getpid
-func Getpid() c.Int
-
-//go:linkname Getppid C.getppid
-func Getppid() c.Int
-
 //go:linkname Getuid C.getuid
 func Getuid() UidT
 

internal/lib/syscall/exec_libc2.go

@@ -6,6 +6,13 @@
 
 package syscall
 
+import (
+	"runtime"
+	"unsafe"
+
+	"github.com/goplus/llgo/c"
+)
+
 type SysProcAttr struct {
 	Chroot     string      // Chroot.
 	Credential *Credential // Credential.
@@ -48,8 +55,7 @@ func runtime_AfterForkInChild()
 // functions that do not grow the stack.
 //
 //go:norace
-func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr *ProcAttr, sys *SysProcAttr, pipe int) (pid int, err1 Errno) {
+func forkAndExecInChild(argv0 *c.Char, argv, envv **c.Char, chroot, dir *c.Char, attr *ProcAttr, sys *SysProcAttr, pipe int) (pid int, err1 Errno) {
-	/* TODO(xsw):
 	// Declare all variables at top in case any
 	// declarations require heap allocation (e.g., err1).
 	var (
@@ -57,7 +63,7 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr
 		nextfd          int
 		i               int
 		err             error
-			pgrp            _C_int
+		pgrp            c.Int
 		cred            *Credential
 		ngroups, groups uintptr
 	)
@@ -279,12 +285,10 @@ func forkAndExecInChild(argv0 *byte, argv, envv []*byte, chroot, dir *byte, attr
 		uintptr(unsafe.Pointer(&argv[0])),
 		uintptr(unsafe.Pointer(&envv[0])))
 
-	childerror:
+childerror:
 	// send error code on pipe
 	rawSyscall(abi.FuncPCABI0(libc_write_trampoline), uintptr(pipe), uintptr(unsafe.Pointer(&err1)), unsafe.Sizeof(err1))
 	for {
 		rawSyscall(abi.FuncPCABI0(libc_exit_trampoline), 253, 0, 0)
 	}
-	*/
-	panic("todo: syscall.forkAndExecInChild")
 }

internal/lib/syscall/exec_unix.go

@@ -12,11 +12,11 @@ import (
 	"errors"
 	"runtime"
 	"sync"
-	"syscall"
 	"unsafe"
 
 	"github.com/goplus/llgo/c"
 	"github.com/goplus/llgo/c/os"
+	"github.com/goplus/llgo/c/syscall"
 )
 
 // ForkLock is used to synchronize creation of new file descriptors
@@ -175,7 +175,7 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error)
 	Close(p[1])
 	for {
 		n, err = readlen(p[0], (*byte)(unsafe.Pointer(&err1)), int(unsafe.Sizeof(err1)))
-		if err != EINTR {
+		if err != Errno(syscall.EINTR) {
 			break
 		}
 	}
@@ -185,13 +185,13 @@ func forkExec(argv0 string, argv []string, attr *ProcAttr) (pid int, err error)
 			err = Errno(err1)
 		}
 		if err == nil {
-			err = EPIPE
+			err = Errno(syscall.EPIPE)
 		}
 
 		// Child failed; wait for it to exit, to make sure
 		// the zombies don't accumulate.
 		_, err1 := Wait4(pid, &wstatus, 0, nil)
-		for err1 == EINTR {
+		for err1 == Errno(syscall.EINTR) {
 			_, err1 = Wait4(pid, &wstatus, 0, nil)
 		}
 		return 0, err
@@ -230,5 +230,5 @@ func Exec(argv0 string, argv []string, envv []string) (err error) {
 	if ret == 0 {
 		return nil
 	}
-	return syscall.Errno(ret)
+	return Errno(ret)
 }

internal/lib/syscall/syscall.go

@@ -78,13 +78,21 @@ func Getpid() (pid int) {
 }
 
 func Kill(pid int, signum Signal) (err error) {
-	ret := os.Kill(c.Int(pid), c.Int(signum))
+	ret := os.Kill(os.PidT(pid), c.Int(signum))
 	if ret == 0 {
 		return nil
 	}
 	return Errno(ret)
 }
 
+func wait4(pid int, wstatus *c.Int, options int, rusage *syscall.Rusage) (wpid int, err error) {
+	ret := os.Wait4(os.PidT(pid), wstatus, c.Int(options), rusage)
+	if ret >= 0 {
+		return int(ret), nil
+	}
+	return 0, Errno(os.Errno)
+}
+
 func Open(path string, mode int, perm uint32) (fd int, err error) {
 	ret := os.Open(c.AllocaCStr(path), c.Int(mode), os.ModeT(perm))
 	if ret >= 0 {
@@ -109,6 +117,14 @@ func Read(fd int, p []byte) (n int, err error) {
 	return 0, Errno(os.Errno)
 }
 
+func readlen(fd int, buf *byte, nbuf int) (n int, err error) {
+	ret := os.Read(c.Int(fd), unsafe.Pointer(buf), uintptr(nbuf))
+	if ret >= 0 {
+		return ret, nil // TODO(xsw): confirm err == nil (not io.EOF) when ret == 0
+	}
+	return 0, Errno(os.Errno)
+}
+
 func Close(fd int) (err error) {
 	ret := os.Close(c.Int(fd))
 	if ret == 0 {

internal/lib/syscall/syscall_bsd.go

@@ -13,6 +13,7 @@
 package syscall
 
 import (
+	"github.com/goplus/llgo/c"
 	"github.com/goplus/llgo/c/syscall"
 )
 
@@ -127,9 +128,8 @@ func (w WaitStatus) StopSignal() Signal {
 
 func (w WaitStatus) TrapCause() int { return -1 }
 
-/* TODO(xsw):
+func Wait4(pid int, wstatus *WaitStatus, options int, rusage *syscall.Rusage) (wpid int, err error) {
-func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int, err error) {
+	var status c.Int
-	var status _C_int
 	wpid, err = wait4(pid, &status, options, rusage)
 	if wstatus != nil {
 		*wstatus = WaitStatus(status)
@@ -137,6 +137,7 @@ func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int,
 	return
 }
 
+/* TODO(xsw):
 func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, _Socklen, error) {
 	if sa.Port < 0 || sa.Port > 0xFFFF {
 		return nil, 0, EINVAL