Import X server from vnc-3.3.7.

[rdpsrv] / Xserver / programs / Xserver / os / iopreader.c

diff --git a/Xserver/programs/Xserver/os/iopreader.c b/Xserver/programs/Xserver/os/iopreader.c
new file mode 100644 (file)
index 0000000..092c7a7
--- /dev/null
+++ b/Xserver/programs/Xserver/os/iopreader.c
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+/* $XConsortium: iopreader.c,v 1.2 94/04/12 17:24:33 dpw Exp $ */
+
+/* Copyright (c) 1987 by the Regents of the University of California
+ * Copyright (c) 1994 by the Vrije Universiteit, Amsterdam.
+ *
+ * Permission to use, copy, modify, and distribute this
+ * software and its documentation for any purpose and without
+ * fee is hereby granted, provided that the above copyright
+ * notice appear in all copies.  The University of California
+ * and the Vrije Universiteit make no representations about
+ * the suitability of this software for any purpose.
+ * It is provided "as is" without express or implied warranty.
+ */
+
+#ifdef AMOEBA
+/*
+ * iopreader.c
+ *
+ */
+#define port am_port_t
+#include <amoeba.h>
+#include <ampolicy.h>
+#include <cmdreg.h>
+#include <stdcom.h>
+#include <stderr.h>
+#include <server/iop/iop.h>
+#undef port
+
+#include "osdep.h"
+
+#define DEVREADER_STACK        8000
+#define        MAXEVENTQUEUE   32
+
+capability iopcap;
+
+static mutex lock;
+static semaphore empty, filled;
+
+static IOPEvent event_queue[MAXEVENTQUEUE];
+static int event_qin, event_qout;
+
+void IOPCleanUp();
+static void IOPServerReader();
+
+/*
+ * Initialize the IOP server
+ */
+void
+InitializeIOPServerReader()
+{
+    capability         hostcap;
+    errstat            err;
+
+    /*
+     * Initialize event queue
+     */
+    event_qin = event_qout = 0;
+    sema_init(&empty, MAXEVENTQUEUE);
+    sema_init(&filled, 0);
+    mu_init(&lock);
+
+    /* 
+     * Get IOP capability, and enable the server
+     */
+    if (XServerHostName == NULL)
+       FatalError("No hostname, no screen\n");
+    
+    if ((err = host_lookup(XServerHostName, &hostcap)) != STD_OK ||
+        (err = dir_lookup(&hostcap, DEF_IOPSVRNAME, &iopcap)) != STD_OK)
+    {
+       FatalError("Cannot find IOP server for %s: %s\n",
+                   XServerHostName, err_why(err));
+    }
+
+    /*
+     * Enable IOP server
+     */
+    if ((err = iop_enable(&iopcap)) != STD_OK)
+       FatalError("iop_enable failed (%s)\n", err_why(err));
+
+    /*
+     * Start IOP reader thread
+     */
+    atexit(IOPCleanUp);
+    if (thread_newthread(IOPServerReader, DEVREADER_STACK, 0, 0) <= 0)
+       FatalError("Cannot start IOP reader thread\n");
+}
+
+/*
+ * IOP clean up, actuall disable the IOP server. Its the IOP's own choice
+ * what do do (perhaps restore the screen?).
+ */
+void
+IOPCleanUp()
+{
+    errstat err;
+
+    if ((err = iop_disable(&iopcap)) != STD_OK)
+       ErrorF("iop_disable failed (%s)\n", err_why(err));
+}
+
+/*
+ * This threads polls the IOP server for events. Once an event (or a
+ * number of events) are read, they are queued up using a traditional
+ * producer/consumer approach.
+ */
+static void
+IOPServerReader()
+{
+    IOPEvent           queue[MAXEVENTQUEUE-1];
+    int                        nevents, i;
+    errstat            err;
+
+    WaitForInitialization();
+
+#ifdef XDEBUG
+    if (amDebug) ErrorF("IOPServerReader() running ...\n");
+#endif
+
+    for (;;) {
+       do {
+           nevents = MAXEVENTQUEUE - 1;
+           err = iop_getevents(&iopcap, queue, &nevents);
+           if (err != STD_OK) {
+               if (err != RPC_FAILURE) {
+                   ErrorF("iop_getevents failed (%s)\n", err_why(err));
+               }
+               nevents = 0;
+           }
+       } while (nevents <= 0);
+
+       /* store event(s) in the global event queue */
+       sema_mdown(&empty, nevents);
+       mu_lock(&lock);
+       for (i = 0; i < nevents; i++) {
+           event_queue[event_qin] = queue[i];
+           event_qin = (event_qin + 1) % MAXEVENTQUEUE;
+       }
+       mu_unlock(&lock);
+       sema_mup(&filled, nevents);
+       WakeUpMainThread();
+    }
+}
+
+/*
+ * Return the number of IOP events waiting
+ */
+int
+AmoebaEventsAvailable()
+{
+    return sema_level(&filled);
+}
+
+/*
+ * Get the IOP events from the queue. ``size'' is the maximum the
+ * requestor cares to handle, the actual size read is returned as
+ * result.
+ */
+int
+AmoebaGetEvents(queue, size)
+    IOPEvent   *queue;
+    int                size;
+{
+    int                nevents, i;
+
+    if (sema_level(&filled) <= 0) return 0;
+    if ((nevents = sema_level(&filled)) > size)
+       nevents = size;
+    sema_mdown(&filled, nevents);
+    mu_lock(&lock);
+    for (i = 0; i < nevents; i++) {
+       queue[i] = event_queue[event_qout];
+       event_qout = (event_qout + 1) % MAXEVENTQUEUE;
+    }
+    mu_unlock(&lock);
+    sema_mup(&empty, nevents);
+    return nevents;
+}
+#endif /* AMOEBA */