--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/thread/os2/SDL_syssem.c	Wed Nov 23 07:29:56 2005 +0000
@@ -0,0 +1,199 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Library General Public License for more details.
+
+    You should have received a copy of the GNU Library General Public
+    License along with this library; if not, write to the Free
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+    Sam Lantinga
+    slouken@libsdl.org
+*/
+
+#ifdef SAVE_RCSID
+static char rcsid =
+ "@(#) $Id$";
+#endif
+
+/* Semaphore functions using the OS/2 API */
+
+#include <stdio.h>
+#include <stdlib.h>
+#define INCL_DOS
+#define INCL_DOSERRORS
+#define INCL_DOSSEMAPHORES
+#include <os2.h>
+
+#include "SDL_error.h"
+#include "SDL_thread.h"
+#include "SDL_timer.h"
+
+
+struct SDL_semaphore {
+        HMTX id;
+        HEV  changed;
+        Uint32 value;
+};
+
+
+/* Create a semaphore */
+DECLSPEC SDL_sem * SDLCALL SDL_CreateSemaphore(Uint32 initial_value)
+{
+        SDL_sem *sem;
+        ULONG ulrc;
+
+        /* Allocate sem memory */
+        sem = (SDL_sem *)malloc(sizeof(*sem));
+        if ( sem ) {
+                /* Create the mutex semaphore */
+                ulrc = DosCreateMutexSem(NULL,&(sem->id),0,TRUE);
+                if ( ulrc ) {
+                        SDL_SetError("Couldn't create semaphore");
+                        free(sem);
+                        sem = NULL;
+                } else
+                {
+                    DosCreateEventSem(NULL, &(sem->changed), 0, FALSE);
+                    sem->value = initial_value;
+                    DosReleaseMutexSem(sem->id);
+                }
+        } else {
+                SDL_OutOfMemory();
+        }
+        return(sem);
+}
+
+/* Free the semaphore */
+DECLSPEC void SDLCALL SDL_DestroySemaphore(SDL_sem *sem)
+{
+        if ( sem ) {
+                if ( sem->id ) {
+                        DosCloseEventSem(sem->changed);
+                        DosCloseMutexSem(sem->id);
+                        sem->id = 0;
+                }
+                free(sem);
+        }
+}
+
+DECLSPEC int SDLCALL SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
+{
+        ULONG ulrc;
+
+        if ( ! sem ) {
+                SDL_SetError("Passed a NULL sem");
+                return -1;
+        }
+
+        if ( timeout == SDL_MUTEX_MAXWAIT ) {
+           while (1) {
+              ulrc = DosRequestMutexSem(sem->id, SEM_INDEFINITE_WAIT);
+              if (ulrc) {
+                 /* if error waiting mutex */
+                 SDL_SetError("DosRequestMutexSem() failed");
+                 return -1;
+              } else if (sem->value) {
+                        sem->value--;
+                        DosReleaseMutexSem(sem->id);
+                        return 0;
+                     } else {
+                        ULONG ulPostCount;
+                        DosResetEventSem(sem->changed, &ulPostCount);
+                        DosReleaseMutexSem(sem->id);
+                        /* continue waiting until somebody posts the semaphore */
+                        DosWaitEventSem(sem->changed, SEM_INDEFINITE_WAIT);
+                     }
+           }
+        } else
+        if ( timeout == 0 )
+        {
+            ulrc = DosRequestMutexSem(sem->id, SEM_INDEFINITE_WAIT);
+            if (ulrc==NO_ERROR)
+            {
+                if (sem->value)
+                {
+                    sem->value--;
+                    DosReleaseMutexSem(sem->id);
+                    return 0;
+                } else
+                {
+                    DosReleaseMutexSem(sem->id);
+                    return SDL_MUTEX_TIMEDOUT;
+                }
+            } else
+            {
+                SDL_SetError("DosRequestMutexSem() failed");
+                return -1;
+            }
+        } else {
+            ulrc = DosRequestMutexSem(sem->id, SEM_INDEFINITE_WAIT);
+            if (ulrc) {
+               /* if error waiting mutex */
+               SDL_SetError("DosRequestMutexSem() failed");
+               return -1;
+            } else
+              if (sem->value) {
+                sem->value--;
+                DosReleaseMutexSem(sem->id);
+                return 0;
+              } else {
+                ULONG ulPostCount;
+                DosResetEventSem(sem->changed, &ulPostCount);
+                DosReleaseMutexSem(sem->id);
+                /* continue waiting until somebody posts the semaphore */
+                ulrc = DosWaitEventSem(sem->changed, timeout);
+                if (ulrc==NO_ERROR)
+                  return 0;
+                else
+                  return SDL_MUTEX_TIMEDOUT;
+              }
+        }
+        /* never reached */
+        return -1;
+}
+
+DECLSPEC int SDLCALL SDL_SemTryWait(SDL_sem *sem)
+{
+        return SDL_SemWaitTimeout(sem, 0);
+}
+
+DECLSPEC int SDLCALL SDL_SemWait(SDL_sem *sem)
+{
+        return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT);
+}
+
+/* Returns the current count of the semaphore */
+DECLSPEC Uint32 SDLCALL SDL_SemValue(SDL_sem *sem)
+{
+        if ( ! sem ) {
+                SDL_SetError("Passed a NULL sem");
+                return 0;
+        }
+        return sem->value;
+}
+
+DECLSPEC int SDLCALL SDL_SemPost(SDL_sem *sem)
+{
+        if ( ! sem ) {
+                SDL_SetError("Passed a NULL sem");
+                return -1;
+        }
+        if ( DosRequestMutexSem(sem->id,SEM_INDEFINITE_WAIT) ) {
+                SDL_SetError("DosRequestMutexSem() failed");
+                return -1;
+        }
+        sem->value++;
+        DosPostEventSem(sem->changed);
+        DosReleaseMutexSem(sem->id);
+        return 0;
+}