# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1626128771 -7200
# Node ID ac4025f8f4e03e5a49556f3a0fe36eed270c2508
# Parent  929003b4e133c8353335f2be79b3a0c308d3f8ab
Tidied up the notification management, introducing C++ library data structures.

diff -r 929003b4e133 -r ac4025f8f4e0 libfsserver/include/fsserver/notification.h
--- a/libfsserver/include/fsserver/notification.h	Mon Jul 12 23:18:16 2021 +0200
+++ b/libfsserver/include/fsserver/notification.h	Tue Jul 13 00:26:11 2021 +0200
@@ -22,11 +22,29 @@
 #pragma once
 
 #include <set>
+#include <vector>
 
 #include <systypes/base.h>
 
 
 
+/* Collection data types. */
+
+typedef std::set<l4_cap_idx_t> NotifierSet;
+
+/* Notification endpoint details. */
+
+class NotificationEndpoint
+{
+public:
+    NotifierSet notifiers;
+    notify_flags_t flags, deferred;
+};
+
+typedef std::vector<NotificationEndpoint> NotificationEndpointList;
+
+
+
 /* Notification support, allowing pipe or file users to receive events due to
    activity on those objects. */
 
@@ -35,20 +53,16 @@
 protected:
     /* Endpoint count. */
 
-    unsigned int _max_endpoints;
+    unsigned int _min_endpoints;
 
-    /* Notification endpoints and flags, set up at initialisation for the
-       appropriate number of endpoints. */
+    /* Notification endpoint details. */
 
-    std::set<l4_cap_idx_t> *_notifiers;
-    notify_flags_t *_flags, *_deferred;
+    NotificationEndpointList _endpoints;
 
     virtual void release_notifiers();
 
 public:
-    explicit NotificationSupport(unsigned int endpoints);
-
-    virtual ~NotificationSupport();
+    explicit NotificationSupport(unsigned int endpoints=0);
 
     virtual void notify(unsigned int endpoint, notify_flags_t flags);
 
diff -r 929003b4e133 -r ac4025f8f4e0 libfsserver/include/fsserver/pipe_paging.h
--- a/libfsserver/include/fsserver/pipe_paging.h	Mon Jul 12 23:18:16 2021 +0200
+++ b/libfsserver/include/fsserver/pipe_paging.h	Tue Jul 13 00:26:11 2021 +0200
@@ -55,7 +55,7 @@
 
     /* Endpoint status. */
 
-    unsigned int _endpoints = 2;
+    unsigned int _active_endpoints = 2;
 
     /* Common functionality. */
 
diff -r 929003b4e133 -r ac4025f8f4e0 libfsserver/lib/generic/notification.cc
--- a/libfsserver/lib/generic/notification.cc	Mon Jul 12 23:18:16 2021 +0200
+++ b/libfsserver/lib/generic/notification.cc	Tue Jul 13 00:26:11 2021 +0200
@@ -29,39 +29,29 @@
 /* Initialise endpoints and flags for notifications. */
 
 NotificationSupport::NotificationSupport(unsigned int endpoints)
-: _max_endpoints(endpoints)
+: _min_endpoints(endpoints)
 {
-    _notifiers = new std::set<l4_cap_idx_t>[endpoints];
-    _flags = new notify_flags_t[endpoints];
-    _deferred = new notify_flags_t[endpoints];
-
-    for (unsigned int endpoint = 0; endpoint < _max_endpoints; endpoint++)
-    {
-        _flags[endpoint] = 0;
-        _deferred[endpoint] = 0;
-    }
-}
-
-NotificationSupport::~NotificationSupport()
-{
-    delete _notifiers;
-    delete _flags;
-    delete _deferred;
+    _endpoints.resize(_min_endpoints);
 }
 
 /* Subscribe to an endpoint's notifications using a notification endpoint. */
 
 void NotificationSupport::subscribe(unsigned int endpoint, l4_cap_idx_t notifier, notify_flags_t flags)
 {
-    _notifiers[endpoint].insert(notifier);
-    _flags[endpoint] = flags;
+    if (endpoint >= _endpoints.size())
+        _endpoints.resize(endpoint + 1);
+
+    NotificationEndpoint &ep = _endpoints[endpoint];
+
+    ep.notifiers.insert(notifier);
+    ep.flags = flags;
 
     /* Send deferred conditions held from before subscription occurred. */
 
-    if (_deferred[endpoint])
+    if (ep.deferred)
     {
-        notify(endpoint, _deferred[endpoint]);
-        _deferred[endpoint] = 0;
+        notify(endpoint, ep.deferred);
+        ep.deferred = 0;
     }
 }
 
@@ -69,14 +59,22 @@
 
 void NotificationSupport::unsubscribe(unsigned int endpoint, l4_cap_idx_t notifier)
 {
-    std::set<l4_cap_idx_t>::iterator it = _notifiers[endpoint].find(notifier);
+    if (endpoint >= _endpoints.size())
+        return;
 
-    if (it != _notifiers[endpoint].end())
+    NotificationEndpoint &ep = _endpoints[endpoint];
+    NotifierSet::iterator it = ep.notifiers.find(notifier);
+
+    if (it != ep.notifiers.end())
     {
-        _notifiers[endpoint].erase(it);
-        _flags[endpoint] = 0;
-        _deferred[endpoint] = 0;
+        ep.notifiers.erase(it);
         ipc_cap_free_um(notifier);
+
+        if (ep.notifiers.empty())
+        {
+            ep.flags = 0;
+            ep.deferred = 0;
+        }
     }
 }
 
@@ -84,32 +82,37 @@
 
 void NotificationSupport::notify(unsigned int endpoint, notify_flags_t flags)
 {
+    if (endpoint >= _endpoints.size())
+        return;
+
+    NotificationEndpoint &ep = _endpoints[endpoint];
+
     /* Notify the endpoint or hold any notification for potential future
        subscription. */
 
-    if (!_notifiers[endpoint].empty())
+    if (!ep.notifiers.empty())
     {
-        if (flags & _flags[endpoint])
+        if (flags & ep.flags)
         {
-            std::set<l4_cap_idx_t>::iterator it;
+            NotifierSet::iterator it;
 
-            for (it = _notifiers[endpoint].begin(); it != _notifiers[endpoint].end(); it++)
+            for (it = ep.notifiers.begin(); it != ep.notifiers.end(); it++)
             {
                 client_Notifier notifier(*it);
 
-                notifier.notify(flags & _flags[endpoint]);
+                notifier.notify(flags & ep.flags);
             }
         }
     }
     else
-        _deferred[endpoint] = flags;
+        ep.deferred = flags;
 }
 
 /* Notify the other endpoints. */
 
 void NotificationSupport::notify_others(unsigned int endpoint, notify_flags_t flags)
 {
-    for (unsigned int i = 0; i < _max_endpoints; i++)
+    for (unsigned int i = 0; i < _endpoints.size(); i++)
         if (i != endpoint)
             notify(i, flags);
 }
@@ -118,14 +121,17 @@
 
 void NotificationSupport::release_notifiers()
 {
-    for (unsigned int endpoint = 0; endpoint < _max_endpoints; endpoint++)
+    for (unsigned int endpoint = 0; endpoint < _endpoints.size(); endpoint++)
     {
-        std::set<l4_cap_idx_t>::iterator it;
+        NotificationEndpoint &ep = _endpoints[endpoint];
+        NotifierSet::iterator it;
 
-        for (it = _notifiers[endpoint].begin(); it != _notifiers[endpoint].end(); it++)
+        for (it = ep.notifiers.begin(); it != ep.notifiers.end(); it++)
             ipc_cap_free_um(*it);
 
-        _notifiers[endpoint].clear();
+        ep.notifiers.clear();
+        ep.flags = 0;
+        ep.deferred = 0;
     }
 }
 
diff -r 929003b4e133 -r ac4025f8f4e0 libfsserver/lib/pipes/pipe_paging.cc
--- a/libfsserver/lib/pipes/pipe_paging.cc	Mon Jul 12 23:18:16 2021 +0200
+++ b/libfsserver/lib/pipes/pipe_paging.cc	Tue Jul 13 00:26:11 2021 +0200
@@ -47,7 +47,7 @@
 
 int PipePaging::closed()
 {
-    return _endpoints < 2;
+    return _active_endpoints < 2;
 }
 
 void PipePaging::discard_region(unsigned int i)
@@ -66,14 +66,14 @@
 
 void PipePaging::detach()
 {
-    if (!_endpoints)
+    if (!_active_endpoints)
         return;
     else
-        _endpoints--;
+        _active_endpoints--;
 
     /* Return if the other endpoint is attached. */
 
-    if (_endpoints)
+    if (_active_endpoints)
         return;
 
     /* Discard all regions from the pipe. */