provide a proper curthread implementation

TODO.zfs

 
- - make the curthread macro do something useful, currently it can
-   only be used as a faux boolean for zio, and will cause harm otherwise
  - make delay() do something useful
  - sort out various timing functions in <sys/time.h>

bsd/porting/curthread.h

+#ifndef _BSD_PORTING_CURTHREAD_H
+#define _BSD_PORTING_CURTHREAD_H
+
+#include <bsd/porting/netport.h>
+
+__BEGIN_DECLS;
+
+extern struct thread *get_curthread(void);
+#define curthread	get_curthread()
+
+__END_DECLS;
+
+#endif /* _BSD_PORTING_CURTHREAD_H */

bsd/porting/kthread.cc

@@ -4,6 +4,7 @@
 #include <assert.h>
 #include "sched.hh"
 
+#include <bsd/porting/curthread.h>
 #include <bsd/porting/netport.h>
 #include <bsd/sys/sys/kthread.h>
 
@@ -28,3 +29,9 @@ kthread_exit(void)
 {
     sched::thread::exit();
 }
+
+struct thread *
+get_curthread(void)
+{
+    return reinterpret_cast<struct thread *>(sched::thread::current());
+}

bsd/sys/cddl/compat/opensolaris/sys/proc.h

@@ -29,6 +29,7 @@
 #ifndef _OPENSOLARIS_SYS_PROC_H_
 #define	_OPENSOLARIS_SYS_PROC_H_
 
+#include <bsd/porting/curthread.h>
 #include <sys/param.h>
 #include <stdint.h>
 #include <sys/lock.h>
@@ -59,9 +60,6 @@ typedef struct proc	proc_t;
 
 extern struct proc *zfsproc;
 
-// horrible hack for ZIO, will fail for code not abusing curthread as a boolean true
-#define curthread	((kthread_t *)1)
-
 static __inline kthread_t *
 thread_create(caddr_t stk, size_t stksize, void (*proc)(void *), void *arg,
     size_t len, proc_t *pp, int state, pri_t pri)