os161 2.0.3

kern/include/kern/wait.h

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2003, 2008
+ *	The President and Fellows of Harvard College.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _KERN_WAIT_H_
+#define _KERN_WAIT_H_
+
+/*
+ * Definitions for wait().
+ */
+
+
+/* Flags for waitpid() and equivalent. */
+#define WNOHANG      1	/* Nonblocking. */
+#define WUNTRACED    2	/* Report stopping as well as exiting processes. */
+
+/* Special "pids" to wait for. */
+#define WAIT_ANY     (-1)	/* Any child process. */
+#define WAIT_MYPGRP  0		/* Any process in the same process group. */
+
+/*
+ * Result encoding.
+ *
+ * The lowest two bits say what happened; the rest encodes up to 30
+ * bits of exit code. Note that the traditional Unix encoding, which
+ * is different, wastes most of the bits and can only transmit 8 bits
+ * of exit code...
+ */
+#define _WWHAT(x)  ((x)&3)	/* lower two bits say what happened */
+#define _WVAL(x)   ((x)>>2)	/* the rest is the value */
+#define _MKWVAL(x) ((x)<<2)	/* encode a value */
+
+/* Four things can happen... */
+#define __WEXITED    0		/* Process exited by calling _exit(). */
+#define __WSIGNALED  1		/* Process received a fatal signal. */
+#define __WCORED     2		/* Process dumped core on a fatal signal. */
+#define __WSTOPPED   3		/* Process stopped (and didn't exit). */
+
+/* Test macros, used by applications. */
+#define WIFEXITED(x)   (_WWHAT(x)==__WEXITED)
+#define WIFSIGNALED(x) (_WWHAT(x)==__WSIGNALED || _WWHAT(x)==__WCORED)
+#define WIFSTOPPED(x)  (_WWHAT(x)==__WSTOPPED)
+#define WEXITSTATUS(x) (_WVAL(x))
+#define WTERMSIG(x)    (_WVAL(x))
+#define WSTOPSIG(x)    (_WVAL(x))
+#define WCOREDUMP(x)   (_WWHAT(x)==__WCORED)
+
+/* Encoding macros, used by the kernel to generate the wait result. */
+#define _MKWAIT_EXIT(x) (_MKWVAL(x)|__WEXITED)
+#define _MKWAIT_SIG(x)  (_MKWVAL(x)|__WSIGNALED)
+#define _MKWAIT_CORE(x) (_MKWVAL(x)|__WCORED)
+#define _MKWAIT_STOP(x) (_MKWVAL(x)|__WSTOPPED)
+
+#endif /* _KERN_WAIT_H_ */