Kernel - Some rational comments to select

[tpg/acess2.git] / Kernel / vfs / select.c

diff --git a/Kernel/vfs/select.c b/Kernel/vfs/select.c
index 46d6f39..3cb0af2 100644 (file)
--- a/Kernel/vfs/select.c
+++ b/Kernel/vfs/select.c
@@ -58,6 +58,15 @@ int VFS_Select(int MaxHandle, fd_set *ReadHandles, fd_set *WriteHandles, fd_set
        tVFS_SelectThread       thread_info;
         int    ret;
        
+       Semaphore_Init(&thread_info.SleepHandle, 0, 0, "VFS_Select()", "");
+       
+       // Notes: The idea is to make sure we onlt enter wait (on the semaphore)
+       // if we are going to be woken up (either by an event at a later time,
+       // or by an event that happened while or before we were registering).
+       // Hence, register must happen _before_ we check the state flag
+       // (See VFS_int_Select_Register), that way either we pick up the flag,
+       // or the semaphore is incremeneted (or both, but never none)
+       
        // Register with nodes
        ret  = VFS_int_Select_Register(&thread_info, MaxHandle, ReadHandles, 0, IsKernel);
        ret += VFS_int_Select_Register(&thread_info, MaxHandle, WriteHandles, 1, IsKernel);