Kernel+ProcessManager: Let processes have an icon and show it in the table.

Processes can now have an icon assigned, which is essentially a 16x16 RGBA32
bitmap exposed as a shared buffer ID.

You set the icon ID by calling set_process_icon(int) and the icon ID will be
exposed through /proc/all.

To make this work, I added a mechanism for making shared buffers globally
accessible. For safety reasons, each app seals the icon buffer before making
it global.

Right now the first call to GWindow::set_icon() is what determines the
process icon. We'll probably change this in the future. :^)

Libraries/LibC/unistd.cpp

@@ -442,6 +442,18 @@ int share_buffer_with(int shared_buffer_id, pid_t peer_pid)
     __RETURN_WITH_ERRNO(rc, rc, -1);
 }
 
+int share_buffer_globally(int shared_buffer_id)
+{
+    int rc = syscall(SC_share_buffer_globally, shared_buffer_id);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
+
+int set_process_icon(int icon_id)
+{
+    int rc = syscall(SC_set_process_icon, icon_id);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
+
 void* get_shared_buffer(int shared_buffer_id)
 {
     int rc = syscall(SC_get_shared_buffer, shared_buffer_id);

Libraries/LibC/unistd.h

@@ -24,10 +24,12 @@ int create_thread(int (*)(void*), void*);
 void exit_thread(int);
 int create_shared_buffer(int, void** buffer);
 int share_buffer_with(int, pid_t peer_pid);
+int share_buffer_globally(int);
 void* get_shared_buffer(int shared_buffer_id);
 int release_shared_buffer(int shared_buffer_id);
 int seal_shared_buffer(int shared_buffer_id);
 int get_shared_buffer_size(int shared_buffer_id);
+int set_process_icon(int icon_id);
 int read_tsc(unsigned* lsw, unsigned* msw);
 inline int getpagesize() { return 4096; }
 pid_t fork();

Libraries/LibCore/CProcessStatisticsReader.cpp

@@ -43,6 +43,7 @@ HashMap<pid_t, CProcessStatistics> CProcessStatisticsReader::get_all()
         process.ticks = process_object.get("ticks").to_u32();
         process.priority = process_object.get("priority").to_string();
         process.syscall_count = process_object.get("syscall_count").to_u32();
+        process.icon_id = process_object.get("icon_id").to_int();
 
         // and synthetic data last
         process.username = username_from_uid(process.uid);

Libraries/LibCore/CProcessStatisticsReader.h

@@ -24,6 +24,7 @@ struct CProcessStatistics {
     unsigned ticks;
     String priority;
     unsigned syscall_count;
+    int icon_id;
 
     // synthetic
     String username;

Libraries/LibGUI/GWindow.cpp

@@ -635,6 +635,16 @@ void GWindow::set_icon(const GraphicsBitmap* icon)
         painter.blit({ 0, 0 }, *icon, icon->rect());
     }
 
+    int rc = seal_shared_buffer(m_icon->shared_buffer_id());
+    ASSERT(rc == 0);
+
+    rc = share_buffer_globally(m_icon->shared_buffer_id());
+    ASSERT(rc == 0);
+
+    static bool has_set_process_icon;
+    if (!has_set_process_icon)
+        set_process_icon(m_icon->shared_buffer_id());
+
     WSAPI_ClientMessage message;
     message.type = WSAPI_ClientMessage::Type::SetWindowIconBitmap;
     message.window_id = m_window_id;