Reworked semaphores to be symetric

[tpg/acess2.git] / Kernel / drv / fifo.c

diff --git a/Kernel/drv/fifo.c b/Kernel/drv/fifo.c
index cbbd107..0057053 100644 (file)
--- a/Kernel/drv/fifo.c
+++ b/Kernel/drv/fifo.c
@@ -4,6 +4,7 @@
 #include <acess.h>
 #include <modules.h>
 #include <fs_devfs.h>
+#include <semaphore.h>
 
 // === CONSTANTS ===
 #define DEFAULT_RING_SIZE      2048
@@ -19,6 +20,7 @@ typedef struct sPipe {
         int    WritePos;
         int    BufSize;
        char    *Buffer;
+       tSemaphore      Semaphore;
 } tPipe;
 
 // === PROTOTYPES ===
@@ -219,20 +221,18 @@ Uint64 FIFO_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
        {
                // Wait for buffer to fill
                if(pipe->Flags & PF_BLOCKING) {
-                       while(pipe->ReadPos == pipe->WritePos) {
-                               Threads_Yield();
-                               //MAGIC_BREAK();
-                       }
+                       len = Semaphore_Wait( &pipe->Semaphore, remaining );
                }
                else
+               {
                        if(pipe->ReadPos == pipe->WritePos)
                                return 0;
-               
-               // Read buffer
-               if(pipe->WritePos - pipe->ReadPos < remaining)
-                       len = pipe->WritePos - pipe->ReadPos;
-               else
-                       len = remaining;
+                       // Read buffer
+                       if(pipe->WritePos - pipe->ReadPos < remaining)
+                               len = pipe->WritePos - pipe->ReadPos;
+                       else
+                               len = remaining;
+               }
                
                // Check if read overflows buffer
                if(len > pipe->BufSize - pipe->ReadPos)
@@ -275,18 +275,19 @@ Uint64 FIFO_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
        while(remaining)
        {
                // Wait for buffer to empty
-               if(pipe->Flags & PF_BLOCKING)
-                       while(pipe->ReadPos == (pipe->WritePos+1)%pipe->BufSize)
-                               Threads_Yield();
+               if(pipe->Flags & PF_BLOCKING) {
+                       len = Semaphore_Signal( &pipe->Semaphore, remaining );
+               }
                else
+               {
                        if(pipe->ReadPos == (pipe->WritePos+1)%pipe->BufSize)
                                return 0;
-               
-               // Write buffer
-               if(pipe->ReadPos - pipe->WritePos < remaining)
-                       len = pipe->ReadPos - pipe->WritePos;
-               else
-                       len = remaining;
+                       // Write buffer
+                       if(pipe->ReadPos - pipe->WritePos < remaining)
+                               len = pipe->ReadPos - pipe->WritePos;
+                       else
+                               len = remaining;
+               }
                
                // Check if write overflows buffer
                if(len > pipe->BufSize - pipe->WritePos)
@@ -321,24 +322,25 @@ Uint64 FIFO_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
 tPipe *FIFO_Int_NewPipe(int Size, char *Name)
 {
        tPipe   *ret;
-        int    allocsize = sizeof(tPipe) + sizeof(tVFS_ACL) + Size;
+        int    namelen = strlen(Name) + 1;
+        int    allocsize = sizeof(tPipe) + sizeof(tVFS_ACL) + Size + namelen;
        
        ret = malloc(allocsize);
        if(!ret)        return NULL;
        
        // Clear Return
        memset(ret, 0, allocsize);
-       
-       ret->Name = Name;
        ret->Flags = PF_BLOCKING;
        
        // Allocate Buffer
        ret->BufSize = Size;
        ret->Buffer = (void*)( (Uint)ret + sizeof(tPipe) + sizeof(tVFS_ACL) );
-       if(!ret->Buffer) {
-               free(ret);
-               return NULL;
-       }
+       
+       // Set name (and FIFO name)
+       ret->Name = ret->Buffer + Size;
+       strcpy(ret->Name, Name);
+       // - Start empty, max of `Size`
+       Semaphore_Init( &ret->Semaphore, 0, Size, "FIFO", ret->Name );
        
        // Set Node
        ret->Node.Size = 0;