svn commit: r366429 - in head/sys: kern sys

[Konstantin Belousov]

Author: kib
Date: Sun Oct  4 16:33:42 2020
New Revision: 366429
URL: https://svnweb.freebsd.org/changeset/base/366429

Log:
  Add sig_intr(9).
  
  It gives the answer would the thread sleep according to current state
  of signals and suspensions.  Of course the answer is racy and allows
  for false-negatives (no sleep when signal is delivered after process
  lock is dropped).  Also the answer might change due to signal
  rescheduling among threads in multi-threaded process.
  
  Still it is the best approximation I can provide, to answering the
  question was the thread interrupted.
  
  Reviewed by:	markj
  Tested by:	pho, rmacklem
  Sponsored by:	The FreeBSD Foundation
  MFC after:	2 weeks
  Differential revision:	https://reviews.freebsd.org/D26628

Modified:
  head/sys/kern/kern_sig.c
  head/sys/sys/signalvar.h

Modified: head/sys/kern/kern_sig.c
==============================================================================
--- head/sys/kern/kern_sig.c	Sun Oct  4 16:30:05 2020	(r366428)
+++ head/sys/kern/kern_sig.c	Sun Oct  4 16:33:42 2020	(r366429)
@@ -3204,6 +3204,24 @@ sig_ast_needsigchk(struct thread *td)
 	return (ret);
 }
 
+int
+sig_intr(void)
+{
+	struct thread *td;
+	struct proc *p;
+	int ret;
+
+	td = curthread;
+	p = td->td_proc;
+
+	PROC_LOCK(p);
+	ret = sig_ast_checksusp(td);
+	if (ret == 0)
+		ret = sig_ast_needsigchk(td);
+	PROC_UNLOCK(p);
+	return (ret);
+}
+
 void
 proc_wkilled(struct proc *p)
 {

Modified: head/sys/sys/signalvar.h
==============================================================================
--- head/sys/sys/signalvar.h	Sun Oct  4 16:30:05 2020	(r366428)
+++ head/sys/sys/signalvar.h	Sun Oct  4 16:33:42 2020	(r366429)
@@ -408,6 +408,7 @@ int	sig_ffs(sigset_t *set);
 void	sigfastblock_clear(struct thread *td);
 void	sigfastblock_fetch(struct thread *td);
 void	sigfastblock_setpend(struct thread *td, bool resched);
+int	sig_intr(void);
 void	siginit(struct proc *p);
 void	signotify(struct thread *td);
 void	sigqueue_delete(struct sigqueue *queue, int sig);