Add pcsound driver for OpenBSD.

Subversion-branch: /trunk/chocolate-doom
Subversion-revision: 965

1 files changed, 315 insertions, 0 deletions

diff --git a/pcsound/pcsound_bsd.c b/pcsound/pcsound_bsd.c
new file mode 100644
index 00000000..00367d1f
--- /dev/null
+++ b/pcsound/pcsound_bsd.c
@@ -0,0 +1,315 @@
+// Emacs style mode select   -*- C++ -*- 
+//-----------------------------------------------------------------------------
+//
+// Copyright(C) 2007 Simon Howard
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+// 02111-1307, USA.
+//
+// DESCRIPTION:
+//    PC speaker driver for [Open]BSD 
+//    (Should be NetBSD as well, but untested).
+//
+//-----------------------------------------------------------------------------
+
+#include "config.h"
+
+#ifdef HAVE_DEV_ISA_SPKRIO_H
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <signal.h>
+#include <dev/isa/spkrio.h>
+#include <sys/ioctl.h>
+#include <sys/signal.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include "SDL.h"
+#include "SDL_thread.h"
+
+#include "pcsound.h"
+#include "pcsound_internal.h"
+
+#define SPEAKER_DEVICE "/dev/speaker"
+
+//
+// This driver is far more complicated than it should be, because 
+// OpenBSD has sucky support for threads.  Because multithreading
+// is done in userspace, invoking the ioctl to make the speaker
+// beep will lock all threads until the beep has completed.  
+// 
+// Thus, to get the beeping to occur in real-time, we must invoke
+// the ioctl in a separate process.  To do this, a separate 
+// sound server is forked that listens on a socket for tones to
+// play.  When a tone is received, a reply is sent back to the
+// main process and the tone played.
+//
+// Meanwhile, back in the main process, there is a sound thread
+// that runs, invoking the pcsound callback function to get 
+// more tones.  This blocks on the sound server socket, waiting
+// for replies.  In this way, when the sound server finishes 
+// playing a tone, the next one is sent.
+//
+// This driver is a bit less accurate than the others, because
+// we can only specify sound durations in 1/100ths of a second,
+// as opposed to the normal millisecond durations.
+
+static pcsound_callback_func callback;
+static int sound_server_pid;
+static int sleep_adjust = 0;
+static int sound_thread_running;
+static SDL_Thread *sound_thread_handle;
+static int sound_server_pipe[2];
+
+// Play a sound, checking how long the system call takes to complete
+// and autoadjusting for drift.
+
+static void AdjustedBeep(int speaker_handle, int ms, int freq)
+{
+    unsigned int start_time;
+    unsigned int end_time;
+    unsigned int actual_time;
+    tone_t tone;
+
+    // Adjust based on previous error to keep the tempo right
+
+    if (sleep_adjust > ms)
+    {
+        sleep_adjust -= ms;
+        return;
+    }
+    else
+    {
+        ms -= sleep_adjust;
+    }
+
+    // Invoke the system call and time how long it takes
+
+    start_time = SDL_GetTicks();
+
+    tone.duration = ms / 10;        // in 100ths of a second
+    tone.frequency = freq;
+
+    // Always a positive duration
+
+    if (tone.duration < 1)
+    {
+        tone.duration = 1;
+    }
+
+    if (ioctl(speaker_handle, SPKRTONE, &tone) != 0)
+    {
+        perror("ioctl");
+        return;
+    }
+    
+    end_time = SDL_GetTicks();
+
+    if (end_time > start_time)
+    {
+        actual_time = end_time - start_time;
+    }
+    else
+    {
+        actual_time = ms;
+    }
+
+    if (actual_time < ms)
+    {
+        actual_time = ms;
+    }
+
+    // Save sleep_adjust for next time
+
+    sleep_adjust = actual_time - ms;
+}
+
+static void SoundServer(void)
+{
+    int speaker_handle;
+    tone_t tone;
+    int result;
+
+    // Try to open the speaker device
+
+    speaker_handle = open(SPEAKER_DEVICE, O_WRONLY);
+
+    if (speaker_handle == -1)
+    {
+        // Don't have permissions for the console device?
+
+	fprintf(stderr, "PCSound_BSD_Init: Failed to open '%s': %s\n",
+			SPEAKER_DEVICE, strerror(errno));
+        return;
+    }
+
+    // Run in a loop, invoking the callback
+
+    for (;;)
+    {
+        result = read(sound_server_pipe[1], &tone, sizeof(tone_t));
+
+        if (result < 0)
+        {
+            perror("read");
+            return;
+        }
+
+        // Send back a response, so the main process knows to send another
+
+        write(sound_server_pipe[1], &tone, sizeof(tone_t));
+
+        // Beep! (blocks until complete)
+
+        AdjustedBeep(speaker_handle, tone.duration, tone.frequency);
+    }
+
+    // Finished, close the handle
+
+    close(speaker_handle);
+}
+
+// Start up the sound server.  Returns non-zero if successful.
+
+static int StartSoundServer(void)
+{
+    int result;
+
+    // Create a pipe for communications
+
+    if (socketpair(AF_UNIX, SOCK_STREAM, 0, sound_server_pipe) < 0)
+    {
+        perror("socketpair");
+        return 0;
+    }
+
+    // Start a separate process to generate PC speaker output
+    // We can't use the SDL threading functions because OpenBSD's
+    // threading sucks :-(
+    
+    result = fork();
+
+    if (result < 0)
+    {
+        fprintf(stderr, "Failed to fork sound server!\n");
+        return 0;
+    }
+    else if (result == 0)
+    {
+        // This is the child (sound server)
+
+        SoundServer();
+
+        exit(0);
+    }
+    else
+    {
+        // This is the parent
+
+        sound_server_pid = result;
+    }
+
+    return 1;
+}
+
+static void StopSoundServer(void)
+{
+    int status;
+
+    kill(sound_server_pid, SIGINT);
+    waitpid(sound_server_pid, &status, 0);
+}
+
+static int SoundThread(void *unused)
+{
+    tone_t tone;
+    int duration;
+    int frequency;
+
+    while (sound_thread_running)
+    {
+        // Get the next frequency to play
+
+        callback(&duration, &frequency);
+
+//printf("dur: %i, freq: %i\n", duration, frequency);
+
+        // Build up a tone structure and send to the sound server
+
+        tone.frequency = frequency;
+        tone.duration = duration;
+
+        if (write(sound_server_pipe[0], &tone, sizeof(tone_t)) < 0) 
+        {
+            perror("write");
+            break;
+        }
+
+        // Wait until the sound server responds before sending another
+
+        if (read(sound_server_pipe[0], &tone, sizeof(tone_t)) < 0)
+        {
+            perror("read");
+            break;
+        }
+    }
+
+    return 0;
+}
+
+static int PCSound_BSD_Init(pcsound_callback_func callback_func)
+{
+    callback = callback_func;
+
+    if (!StartSoundServer())
+    {
+        fprintf(stderr, "PCSound_BSD_Init: Failed to start sound server.\n");
+        return 0;
+    }
+
+    sound_thread_running = 1;
+    sound_thread_handle = SDL_CreateThread(SoundThread, NULL);
+
+    return 1;
+}
+
+static void PCSound_BSD_Shutdown(void)
+{
+    // Stop the sound thread
+
+    sound_thread_running = 0;
+
+    SDL_WaitThread(sound_thread_handle, NULL);
+
+    // Stop the sound server
+
+    StopSoundServer();
+}
+
+pcsound_driver_t pcsound_bsd_driver =
+{
+    "BSD",
+    PCSound_BSD_Init,
+    PCSound_BSD_Shutdown,
+};
+
+#endif /* #ifdef HAVE_DEV_ISA_SPKRIO_H */
+