* select.c
* - Implements the select() system call (and supporting code)
*/
-#define DEBUG 1
+#define DEBUG 0
#include <acess.h>
#include "vfs.h"
#include "vfs_int.h"
// int VFS_MarkFull(tVFS_Node *Node, BOOL IsBufferFull);
// int VFS_MarkAvaliable(tVFS_Node *Node, BOOL IsDataAvaliable);
// int VFS_MarkError(tVFS_Node *Node, BOOL IsErrorState);
- int VFS_int_Select_GetType(enum eVFS_SelectTypes Type, tVFS_Node *Node, tVFS_SelectList ***List, int **Flag, int *WantedFlag, int *MaxAllowed);
- int VFS_int_Select_Register(tVFS_SelectThread *Thread, int MaxHandle, fd_set *Handles, enum eVFS_SelectTypes Type, BOOL IsKernel);
- int VFS_int_Select_Deregister(tVFS_SelectThread *Thread, int MaxHandle, fd_set *Handles, enum eVFS_SelectTypes Type, BOOL IsKernel);
+ int VFS_int_Select_GetType(int Type, tVFS_Node *Node, tVFS_SelectList ***List, int **Flag, int *WantedFlag, int *MaxAllowed);
+ int VFS_int_Select_Register(tVFS_SelectThread *Thread, int MaxHandle, fd_set *Handles, int Type, BOOL IsKernel);
+ int VFS_int_Select_Deregister(tVFS_SelectThread *Thread, int MaxHandle, fd_set *Handles, int Type, BOOL IsKernel);
int VFS_int_Select_AddThread(tVFS_SelectList *List, tVFS_SelectThread *Thread, int MaxAllowed);
void VFS_int_Select_RemThread(tVFS_SelectList *List, tVFS_SelectThread *Thread);
void VFS_int_Select_SignalAll(tVFS_SelectList *List);
// === GLOBALS ===
// === FUNCTIONS ===
-int VFS_SelectNode(tVFS_Node *Node, enum eVFS_SelectTypes Type, tTime *Timeout)
+int VFS_SelectNode(tVFS_Node *Node, int TypeFlags, tTime *Timeout, const char *Name)
{
- tVFS_SelectThread thread_info;
- tVFS_SelectList **list;
- int *flag, wanted, maxAllowed;
-
- ENTER("pNode iType pTimeout", Node, Type, Timeout);
+ tVFS_SelectThread *thread_info;
+ int ret, type;
- Semaphore_Init(&thread_info.SleepHandle, 0, 0, "VFS_SelectNode()", "");
+ ENTER("pNode iTypeFlags pTimeout", Node, TypeFlags, Timeout);
- if( VFS_int_Select_GetType(Type, Node, &list, &flag, &wanted, &maxAllowed) ) {
- LEAVE('i', -1);
- return -1;
- }
+ thread_info = malloc(sizeof(tVFS_SelectThread));
+ if(!thread_info) LEAVE_RET('i', -1);
+
+ Semaphore_Init(&thread_info->SleepHandle, 0, 0, "VFS_SelectNode()", Name);
- VFS_int_Select_AddThread(*list, &thread_info, maxAllowed);
- if( *flag == wanted )
+ // Initialise
+ for( type = 0; type < 3; type ++ )
{
- VFS_int_Select_RemThread(*list, &thread_info);
- LEAVE('i', 1);
- return 1;
- }
+ tVFS_SelectList **list;
+ int *flag, wanted, maxAllowed;
+ if( !(TypeFlags & (1 << type)) ) continue;
+ if( VFS_int_Select_GetType(type, Node, &list, &flag, &wanted, &maxAllowed) ) {
+ free(thread_info);
+ LEAVE('i', -1);
+ return -1;
+ }
+
+ // Alloc if needed
+ if( !*list ) *list = calloc(1, sizeof(tVFS_SelectList));
+ VFS_int_Select_AddThread(*list, thread_info, maxAllowed);
+ if( *flag == wanted )
+ {
+ VFS_int_Select_RemThread(*list, thread_info);
+ free(thread_info);
+ LEAVE('i', 1);
+ return 1;
+ }
+ }
+
+ // - Fast return for polling
+ if( Timeout && *Timeout == 0 ) return 0;
+
+ // Wait for things
if( !Timeout || *Timeout > 0 )
{
+ LOG("Semaphore_Wait()");
// TODO: Actual timeout
- Semaphore_Wait(&thread_info.SleepHandle, 0);
+ Semaphore_Wait(&thread_info->SleepHandle, 1);
}
- VFS_int_Select_RemThread(*list, &thread_info);
+ // Get return value
+ ret = 0;
+ for( type = 0; type < 3; type ++ )
+ {
+ tVFS_SelectList **list;
+ int *flag, wanted, maxAllowed;
+ if( !(TypeFlags & (1 << type)) ) continue;
+ VFS_int_Select_GetType(type, Node, &list, &flag, &wanted, &maxAllowed);
+ LOG("VFS_int_Select_RemThread()");
+ VFS_int_Select_RemThread(*list, thread_info);
+ ret = ret || *flag == wanted;
+ }
- LEAVE('i', *flag == wanted);
- return *flag == wanted;
+ free(thread_info);
+
+ LEAVE('i', ret);
+ return ret;
}
int VFS_Select(int MaxHandle, fd_set *ReadHandles, fd_set *WriteHandles, fd_set *ErrHandles, tTime *Timeout, BOOL IsKernel)
{
- tVFS_SelectThread thread_info;
+ tVFS_SelectThread *thread_info;
int ret;
- Semaphore_Init(&thread_info.SleepHandle, 0, 0, "VFS_Select()", "");
+ thread_info = malloc(sizeof(tVFS_SelectThread));
+ if(!thread_info) return -1;
- // Notes: The idea is to make sure we onlt enter wait (on the semaphore)
+ ENTER("iMaxHandle pReadHandles pWriteHandles pErrHandles pTimeout bIsKernel",
+ MaxHandle, ReadHandles, WriteHandles, ErrHandles, Timeout, IsKernel);
+
+ Semaphore_Init(&thread_info->SleepHandle, 0, 0, "VFS_Select()", "");
+
+ // Notes: The idea is to make sure we only 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
// 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);
- ret += VFS_int_Select_Register(&thread_info, MaxHandle, ErrHandles, 2, IsKernel);
+ ret = VFS_int_Select_Register(thread_info, MaxHandle, ReadHandles, 0, IsKernel);
+ ret += VFS_int_Select_Register(thread_info, MaxHandle, WriteHandles, 1, IsKernel);
+ ret += VFS_int_Select_Register(thread_info, MaxHandle, ErrHandles, 2, IsKernel);
+
+ LOG("Register ret = %i", ret);
// If there were events waiting, de-register and return
if( ret )
{
- ret = VFS_int_Select_Deregister(&thread_info, MaxHandle, ReadHandles, 0, IsKernel);
- ret += VFS_int_Select_Deregister(&thread_info, MaxHandle, WriteHandles, 1, IsKernel);
- ret += VFS_int_Select_Deregister(&thread_info, MaxHandle, ErrHandles, 2, IsKernel);
+ ret = VFS_int_Select_Deregister(thread_info, MaxHandle, ReadHandles, 0, IsKernel);
+ ret += VFS_int_Select_Deregister(thread_info, MaxHandle, WriteHandles, 1, IsKernel);
+ ret += VFS_int_Select_Deregister(thread_info, MaxHandle, ErrHandles, 2, IsKernel);
+ free(thread_info);
+ LEAVE('i', ret);
return ret;
}
// Wait (only if there is no timeout, or it is greater than zero
if( !Timeout || *Timeout > 0 )
{
- ret = Semaphore_Wait(&thread_info.SleepHandle, 0);
+ ret = Semaphore_Wait(&thread_info->SleepHandle, 1);
+ // TODO: Do something with ret?
}
// Fill output (modify *Handles)
// - Also, de-register
- ret = VFS_int_Select_Deregister(&thread_info, MaxHandle, ReadHandles, 0, IsKernel);
- ret += VFS_int_Select_Deregister(&thread_info, MaxHandle, WriteHandles, 1, IsKernel);
- ret += VFS_int_Select_Deregister(&thread_info, MaxHandle, ErrHandles, 2, IsKernel);
+ ret = VFS_int_Select_Deregister(thread_info, MaxHandle, ReadHandles, 0, IsKernel);
+ ret += VFS_int_Select_Deregister(thread_info, MaxHandle, WriteHandles, 1, IsKernel);
+ ret += VFS_int_Select_Deregister(thread_info, MaxHandle, ErrHandles, 2, IsKernel);
+ free(thread_info);
+ LEAVE('i', ret);
return ret;
}
// Mark a node as having data ready for reading
int VFS_MarkAvaliable(tVFS_Node *Node, BOOL IsDataAvaliable)
{
+ ENTER("pNode bIsDataAvaliable", Node, IsDataAvaliable);
Node->DataAvaliable = !!IsDataAvaliable;
if( Node->DataAvaliable )
VFS_int_Select_SignalAll(Node->ReadThreads);
+ LEAVE('i', 0);
return 0;
}
// Mark a node as having a full buffer
int VFS_MarkFull(tVFS_Node *Node, BOOL IsBufferFull)
{
+ ENTER("pNode bIsDataAvaliable", Node, IsBufferFull);
Node->BufferFull = !!IsBufferFull;
if( !Node->BufferFull )
VFS_int_Select_SignalAll(Node->WriteThreads);
+ LEAVE('i', 0);
return 0;
}
// Mark a node as errored
int VFS_MarkError(tVFS_Node *Node, BOOL IsErrorState)
{
+ ENTER("pNode bIsDataAvaliable", Node, IsErrorState);
Node->ErrorOccurred = !!IsErrorState;
if( Node->ErrorOccurred )
VFS_int_Select_SignalAll(Node->ErrorThreads);
+ LEAVE('i', 0);
return 0;
}
// --- Internal ---
-int VFS_int_Select_GetType(enum eVFS_SelectTypes Type, tVFS_Node *Node, tVFS_SelectList ***List, int **Flag, int *WantedFlag, int *MaxAllowed)
+int VFS_int_Select_GetType(int Type, tVFS_Node *Node, tVFS_SelectList ***List, int **Flag, int *WantedFlag, int *MaxAllowed)
{
// Get the type of the listen
switch(Type)
/**
* \return Number of files with an action
*/
-int VFS_int_Select_Register(tVFS_SelectThread *Thread, int MaxHandle, fd_set *Handles, enum eVFS_SelectTypes Type, BOOL IsKernel)
+int VFS_int_Select_Register(tVFS_SelectThread *Thread, int MaxHandle, fd_set *Handles, int Type, BOOL IsKernel)
{
int i, numFlagged = 0;
tVFS_SelectList **list;
if( !Handles ) return 0;
+ ENTER("pThread iMaxHandle pHandles iType iIsKernel", Thread, MaxHandle, Handles, Type, IsKernel);
+
for( i = 0; i < MaxHandle; i ++ )
{
tVFS_Handle *handle;
// Is the descriptor set
if( !FD_ISSET(i, Handles) ) continue;
+ LOG("FD #%i", i);
handle = VFS_GetHandle( i | (IsKernel?VFS_KERNEL_FLAG:0) );
// Is the handle valid?
}
// Get the type of the listen
- if( VFS_int_Select_GetType(Type, handle->Node, &list, &flag, &wantedFlagValue, &maxAllowed) )
+ if( VFS_int_Select_GetType(Type, handle->Node, &list, &flag, &wantedFlagValue, &maxAllowed) ) {
+ LEAVE('i', 0);
return 0;
+ }
// Alloc if needed
if( !*list ) {
numFlagged ++;
}
+ LEAVE('i', numFlagged);
+
return numFlagged;
}
/**
* \return Number of files with an action
*/
-int VFS_int_Select_Deregister(tVFS_SelectThread *Thread, int MaxHandle, fd_set *Handles, enum eVFS_SelectTypes Type, BOOL IsKernel)
+int VFS_int_Select_Deregister(tVFS_SelectThread *Thread, int MaxHandle, fd_set *Handles, int Type, BOOL IsKernel)
{
int i, numFlagged = 0;
tVFS_SelectList **list;
if( !Handles ) return 0;
+ ENTER("pThread iMaxHandle pHandles iType iIsKernel", Thread, MaxHandle, Handles, Type, IsKernel);
+
for( i = 0; i < MaxHandle; i ++ )
{
tVFS_Handle *handle;
// Is the descriptor set
if( !FD_ISSET(i, Handles) ) continue;
+ LOG("FD #%i", i);
handle = VFS_GetHandle( i | (IsKernel?VFS_KERNEL_FLAG:0) );
// Is the handle valid?
// Get the type of the listen
// Get the type of the listen
- if( VFS_int_Select_GetType(Type, handle->Node, &list, &flag, &wantedFlagValue, NULL) )
+ if( VFS_int_Select_GetType(Type, handle->Node, &list, &flag, &wantedFlagValue, NULL) ) {
+ LEAVE('i', 0);
return 0;
+ }
// Remove
VFS_int_Select_RemThread(*list, Thread );
}
}
+ LEAVE('i', numFlagged);
+
return numFlagged;
}
int i, count = 0;
tVFS_SelectListEnt *block, *prev;
+ ENTER("pList pThread iMaxAllowed", List, Thread, MaxAllowed);
+
// Lock to avoid concurrency issues
Mutex_Acquire(&List->Lock);
{
block->Threads[i] = Thread;
Mutex_Release(&List->Lock);
+ LEAVE('i', 0);
return 0;
}
count ++;
if( MaxAllowed && count >= MaxAllowed ) {
+ LEAVE('i', 1);
return 1;
}
}
block = block->Next;
} while(block);
+ LOG("New block");
+
// Create new block
block = malloc( sizeof(tVFS_SelectListEnt) );
if( !block ) {
// Release
Mutex_Release(&List->Lock);
+ LEAVE('i', 0);
return 0;
}
int i;
tVFS_SelectListEnt *block, *prev;
+ ENTER("pList pThread", List, Thread);
+
// Lock to avoid concurrency issues
Mutex_Acquire(&List->Lock);
break;
// If empty, free it
if( i == NUM_THREADS_PER_ALLOC ) {
+ LOG("Deleting block");
prev->Next = block->Next;
free(block);
}
}
Mutex_Release(&List->Lock);
+ LEAVE('-');
return ;
}
}
// Not on list, is this an error?
Mutex_Release(&List->Lock);
+
+ LOG("Not on list");
+ LEAVE('-');
}
/**
void VFS_int_Select_SignalAll(tVFS_SelectList *List)
{
int i;
- tVFS_SelectListEnt *block, *prev;
+ tVFS_SelectListEnt *block;
+
+ if( !List ) return ;
+
+ ENTER("pList", List);
// Lock to avoid concurrency issues
Mutex_Acquire(&List->Lock);
{
if( block->Threads[i] )
{
+ LOG("block(%p)->Threads[%i] = %p", block, i, block->Threads[i]);
Semaphore_Signal( &block->Threads[i]->SleepHandle, 1 );
}
}
- prev = block;
block = block->Next;
} while(block);
Mutex_Release(&List->Lock);
+
+ LEAVE('-');
}