From cf4f3eafc6016ccdb57773215dcdd5ebac95c07d Mon Sep 17 00:00:00 2001
From: rsc <devnull@localhost>
Date: Mon, 8 Nov 2004 16:03:42 +0000
Subject: extra files

---
 src/libthread/proctab.ch | 97 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 src/libthread/proctab.ch

(limited to 'src/libthread/proctab.ch')

diff --git a/src/libthread/proctab.ch b/src/libthread/proctab.ch
new file mode 100644
index 00000000..d51543f9
--- /dev/null
+++ b/src/libthread/proctab.ch
@@ -0,0 +1,97 @@
+/*
+ * Proc structure hash table indexed by proctabid() (usually getpid()).
+ * No lock is necessary for lookups (important when called from signal
+ * handlers).
+ * 
+ * To be included from other files (e.g., Linux-clone.c).
+ */
+
+#define T ((void*)-1)
+
+enum
+{
+	PTABHASH = 1031,
+};
+
+static Lock ptablock;
+static Proc *proctab[PTABHASH];
+static Proc *theproc;
+static int multi;
+
+void
+_threadmultiproc(void)
+{
+	if(multi == 0){
+		multi = 1;
+		_threadsetproc(theproc);
+	}
+}
+
+void
+_threadsetproc(Proc *p)
+{
+	int i, h;
+	Proc **t;
+
+	if(!multi){
+		theproc = p;
+		return;
+	}
+	lock(&ptablock);
+	p->procid = procid();
+	h = p->procid%PTABHASH;
+	for(i=0; i<PTABHASH; i++){
+		t = &proctab[(h+i)%PTABHASH];
+		if(*t==nil || *t==T){
+			*t = p;
+			break;
+		}
+	}
+	unlock(&ptablock);
+	if(i == PTABHASH)
+		sysfatal("too many procs - proctab is full");
+}
+
+static Proc**
+_threadfindproc(int id)
+{
+	int i, h;
+	Proc **t;
+
+	if(!multi)
+		return &theproc;
+
+	h = id%PTABHASH;
+	for(i=0; i<PTABHASH; i++){
+		t = &proctab[(h+i)%PTABHASH];
+		if(*t != nil && *t != T && (*t)->procid == id){
+			unlock(&ptablock);
+			return t;
+		}
+	}
+	return nil;
+}
+
+Proc*
+_threadgetproc(void)
+{
+	Proc **t;
+
+	t = _threadfindproc(procid());
+	if(t == nil)
+		return nil;
+	return *t;
+}
+
+Proc*
+_threaddelproc(void)
+{
+	Proc **t, *p;
+
+	t = _threadfindproc(procid());
+	if(t == nil)
+		return nil;
+	p = *t;
+	*t = T;
+	return p;
+}
-- 
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