Add original unix v6

2018-01-27 22:35:41 +09:00
commit 2c7099ee50
664 changed files with 106254 additions and 0 deletions
@@ -0,0 +1,156 @@
+#
+/*
+ */
+
+#include "../param.h"
+#include "../systm.h"
+#include "../user.h"
+#include "../proc.h"
+#include "../text.h"
+#include "../inode.h"
+
+/*
+ * Swap out process p.
+ * The ff flag causes its core to be freed--
+ * it may be off when called to create an image for a
+ * child process in newproc.
+ * Os is the old size of the data area of the process,
+ * and is supplied during core expansion swaps.
+ *
+ * panic: out of swap space
+ * panic: swap error -- IO error
+ */
+xswap(p, ff, os)
+int *p;
+{
+	register *rp, a;
+
+	rp = p;
+	if(os == 0)
+		os = rp->p_size;
+	a = malloc(swapmap, (rp->p_size+7)/8);
+	if(a == NULL)
+		panic("out of swap space");
+	xccdec(rp->p_textp);
+	rp->p_flag =| SLOCK;
+	if(swap(a, rp->p_addr, os, 0))
+		panic("swap error");
+	if(ff)
+		mfree(coremap, os, rp->p_addr);
+	rp->p_addr = a;
+	rp->p_flag =& ~(SLOAD|SLOCK);
+	rp->p_time = 0;
+	if(runout) {
+		runout = 0;
+		wakeup(&runout);
+	}
+}
+
+/*
+ * relinquish use of the shared text segment
+ * of a process.
+ */
+xfree()
+{
+	register *xp, *ip;
+
+	if((xp=u.u_procp->p_textp) != NULL) {
+		u.u_procp->p_textp = NULL;
+		xccdec(xp);
+		if(--xp->x_count == 0) {
+			ip = xp->x_iptr;
+			if((ip->i_mode&ISVTX) == 0) {
+				xp->x_iptr = NULL;
+				mfree(swapmap, (xp->x_size+7)/8, xp->x_daddr);
+				ip->i_flag =& ~ITEXT;
+				iput(ip);
+			}
+		}
+	}
+}
+
+/*
+ * Attach to a shared text segment.
+ * If there is no shared text, just return.
+ * If there is, hook up to it:
+ * if it is not currently being used, it has to be read
+ * in from the inode (ip) and established in the swap space.
+ * If it is being used, but is not currently in core,
+ * a swap has to be done to get it back.
+ * The full coroutine glory has to be invoked--
+ * see slp.c-- because if the calling process
+ * is misplaced in core the text image might not fit.
+ * Quite possibly the code after "out:" could check to
+ * see if the text does fit and simply swap it in.
+ *
+ * panic: out of swap space
+ */
+xalloc(ip)
+int *ip;
+{
+	register struct text *xp;
+	register *rp, ts;
+
+	if(u.u_arg[1] == 0)
+		return;
+	rp = NULL;
+	for(xp = &text[0]; xp < &text[NTEXT]; xp++)
+		if(xp->x_iptr == NULL) {
+			if(rp == NULL)
+				rp = xp;
+		} else
+			if(xp->x_iptr == ip) {
+				xp->x_count++;
+				u.u_procp->p_textp = xp;
+				goto out;
+			}
+	if((xp=rp) == NULL)
+		panic("out of text");
+	xp->x_count = 1;
+	xp->x_ccount = 0;
+	xp->x_iptr = ip;
+	ts = ((u.u_arg[1]+63)>>6) & 01777;
+	xp->x_size = ts;
+	if((xp->x_daddr = malloc(swapmap, (ts+7)/8)) == NULL)
+		panic("out of swap space");
+	expand(USIZE+ts);
+	estabur(0, ts, 0, 0);
+	u.u_count = u.u_arg[1];
+	u.u_offset[1] = 020;
+	u.u_base = 0;
+	readi(ip);
+	rp = u.u_procp;
+	rp->p_flag =| SLOCK;
+	swap(xp->x_daddr, rp->p_addr+USIZE, ts, 0);
+	rp->p_flag =& ~SLOCK;
+	rp->p_textp = xp;
+	rp = ip;
+	rp->i_flag =| ITEXT;
+	rp->i_count++;
+	expand(USIZE);
+
+out:
+	if(xp->x_ccount == 0) {
+		savu(u.u_rsav);
+		savu(u.u_ssav);
+		xswap(u.u_procp, 1, 0);
+		u.u_procp->p_flag =| SSWAP;
+		swtch();
+		/* no return */
+	}
+	xp->x_ccount++;
+}
+
+/*
+ * Decrement the in-core usage count of a shared text segment.
+ * When it drops to zero, free the core space.
+ */
+xccdec(xp)
+int *xp;
+{
+	register *rp;
+
+	if((rp=xp)!=NULL && rp->x_ccount!=0)
+		if(--rp->x_ccount == 0)
+			mfree(coremap, rp->x_size, rp->x_caddr);
+}