From: Alan Cox <alan@linux.intel.com>
Date: Sat, 13 Feb 2016 20:34:15 +0000 (+0000)
Subject: waitpid: add more job control bits
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=99a85682a5040679a1cfcb7b06e27916ca0dca54;p=FUZIX.git

waitpid: add more job control bits

Our SIGSTOP handling still isn't quite right for the case we get a stop while
already sleeping.
---

diff --git a/Kernel/include/kernel.h b/Kernel/include/kernel.h
index 1b938187..22fa1ea8 100644
--- a/Kernel/include/kernel.h
+++ b/Kernel/include/kernel.h
@@ -382,6 +382,7 @@ typedef struct p_tab {
 /**HP**/
     uint16_t	p_pgrp;		/* Process group */
     uint8_t	p_nice;
+    uint8_t	p_event;	/* Events */
     usize_t	p_top;		/* Copy of u_top */
 #ifdef CONFIG_PROFIL
     uint8_t	p_profscale;
@@ -471,8 +472,9 @@ struct s_argblk {
 
 
 /* waitpid options */
-#define WNOHANG		1	/* don't support others yet */
-
+#define WNOHANG		1
+#define WUNTRACED	2
+#define _WSTOPPED	0xFF
 
 /* Open() parameters. */
 
diff --git a/Kernel/process.c b/Kernel/process.c
index 0846ceb2..11ae84ca 100644
--- a/Kernel/process.c
+++ b/Kernel/process.c
@@ -500,21 +500,23 @@ void ssig(ptptr proc, uint16_t sig)
 	irq = di();
 
 	if (proc->p_status != P_EMPTY) {	/* Presumably was killed just now */
-	        /* SIGSTOP can't be ignored and puts the process into P_STOPPED */
-	        /* FIXME: Level 2 will need a lot more handling here, both SIGTSTP
-	           handling and the wait() handling for stopping */
+	        /* SIGSTOP can't be ignored and puts the process into P_STOPPED.
+	           We need to sort out handling of SIGSTOP when waiting - we should
+	           really interrupt the syscall and stop */
 	        if (sig == SIGSTOP || sig == SIGTTIN || sig == SIGTTOU) {
 	                if (proc->p_status == P_RUNNING ||
                             proc->p_status == P_READY)
                                     nready--;
                         proc->p_status = P_STOPPED;
+                        proc->p_event = sig;
                 /* SIGCONT likewise has an unblockable effect */
 		} else if (sig == SIGCONT && proc->p_status == P_STOPPED) {
 		        proc->p_status = P_READY;
+		        proc->p_event = 0;
 		        nready++;
 		}
 		/* Routine signal behaviour */
-		else if (!(proc->p_ignored & sigm)) {
+		if (!(proc->p_ignored & sigm)) {
 			/* Don't wake for held signals */
 			if (!(proc->p_held & sigm)) {
 				switch (proc->p_status) {
diff --git a/Kernel/syscall_proc.c b/Kernel/syscall_proc.c
index ff900ee7..2d88b56a 100644
--- a/Kernel/syscall_proc.c
+++ b/Kernel/syscall_proc.c
@@ -302,14 +302,12 @@ arg_t _waitpid(void)
 			return -1;
 		}
 		for (p = ptab; p < ptab_end; ++p) {
-			if (p->p_status == P_ZOMBIE
-			    && p->p_pptr == udata.u_ptab) {
-				if (pid == -1 || p->p_pid == pid
-				    || p->p_pgrp == -pid) {
+			if (p->p_pptr == udata.u_ptab &&
+				(pid == -1 || p->p_pid == pid ||
+					p->p_pgrp == -pid)) {
+				if (p->p_status == P_ZOMBIE) {
 					if (statloc)
-						uputw(p->p_exitval,
-						      statloc);
-
+						uputw(p->p_exitval, statloc);
 					retval = p->p_pid;
 					p->p_status = P_EMPTY;
 
@@ -319,6 +317,11 @@ arg_t _waitpid(void)
 					udata.u_cstime += ((clock_t *)&p->p_priority)[1];
 					return retval;
 				}
+				if (p->p_event && (options & WUNTRACED)) {
+					retval = (uint16_t)p->p_event << 8 | _WSTOPPED;
+					p->p_event = 0;
+					return retval;
+				}
 			}
 		}
 		/* Nothing yet, so wait */