ref: 98ee23f4268dbb1395aa0b2cbfad9f53d1092b33
parent: 6e4f6ab9626d81e4106d3ccc974a76d832fdff13
author: Simon Howard <fraggle@gmail.com>
date: Sat May 30 19:24:11 EDT 2009
Add initial callback/timer API. Subversion-branch: /branches/opl-branch Subversion-revision: 1538
--- a/opl/Makefile.am
+++ b/opl/Makefile.am
@@ -10,5 +10,7 @@
opl.c opl.h \
opl_linux.c \
opl_sdl.c \
+ opl_queue.c opl_queue.h \
+ opl_timer.c opl_timer.h \
fmopl.c fmopl.h
--- /dev/null
+++ b/opl/examples/.gitignore
@@ -1,0 +1,5 @@
+Makefile.in
+Makefile
+.deps
+droplay
+
--- a/opl/examples/droplay.c
+++ b/opl/examples/droplay.c
@@ -116,44 +116,51 @@
OPL_Shutdown();
}
-void PlayFile(char *filename)
+struct timer_data
{- FILE *stream;
- char buf[8];
+ int running;
+ FILE *fstream;
+};
- stream = fopen(filename, "rb");
+void TimerCallback(void *data)
+{+ struct timer_data *timer_data = data;
+ int delay;
- if (fread(buf, 1, 8, stream) < 8)
+ if (!timer_data->running)
{- fprintf(stderr, "failed to read raw OPL header\n");
- exit(-1);
+ return;
}
- if (strncmp(buf, HEADER_STRING, 8) != 0)
- {- fprintf(stderr, "Raw OPL header not found\n");
- exit(-1);
- }
+ // Read data until we must make a delay.
- fseek(stream, 28, SEEK_SET);
-
- while (!feof(stream))
+ for (;;)
{int reg, val;
- reg = fgetc(stream);
- val = fgetc(stream);
+ // End of file?
- // Delay?
+ if (feof(timer_data->fstream))
+ {+ timer_data->running = 0;
+ return;
+ }
+ reg = fgetc(timer_data->fstream);
+ val = fgetc(timer_data->fstream);
+
+ // Register value of 0 or 1 indicates a delay.
+
if (reg == 0x00)
{- SDL_Delay(val);
+ delay = val;
+ break;
}
else if (reg == 0x01)
{- val |= (fgetc(stream) << 8);
- SDL_Delay(val);
+ val |= (fgetc(timer_data->fstream) << 8);
+ delay = val;
+ break;
}
else
{@@ -161,7 +168,50 @@
}
}
- fclose(stream);
+ // Schedule the next timer callback.
+
+ OPL_SetCallback(delay, TimerCallback, timer_data);
+}
+
+void PlayFile(char *filename)
+{+ struct timer_data timer_data;
+ int running;
+ char buf[8];
+
+ timer_data.fstream = fopen(filename, "rb");
+
+ if (fread(buf, 1, 8, timer_data.fstream) < 8)
+ {+ fprintf(stderr, "failed to read raw OPL header\n");
+ exit(-1);
+ }
+
+ if (strncmp(buf, HEADER_STRING, 8) != 0)
+ {+ fprintf(stderr, "Raw OPL header not found\n");
+ exit(-1);
+ }
+
+ fseek(timer_data.fstream, 28, SEEK_SET);
+ timer_data.running = 1;
+
+ // Start callback loop sequence.
+
+ OPL_SetCallback(0, TimerCallback, &timer_data);
+
+ // Sleep until the playback finishes.
+
+ do
+ {+ OPL_Lock();
+ running = timer_data.running;
+ OPL_Unlock();
+
+ SDL_Delay(100);
+ } while (running);
+
+ fclose(timer_data.fstream);
}
int main(int argc, char *argv[])
--- a/opl/opl.c
+++ b/opl/opl.c
@@ -105,3 +105,27 @@
}
}
+void OPL_SetCallback(unsigned int ms, opl_callback_t callback, void *data)
+{+ if (driver != NULL)
+ {+ driver->set_callback_func(ms, callback, data);
+ }
+}
+
+void OPL_Lock(void)
+{+ if (driver != NULL)
+ {+ driver->lock_func();
+ }
+}
+
+void OPL_Unlock(void)
+{+ if (driver != NULL)
+ {+ driver->unlock_func();
+ }
+}
+
--- a/opl/opl.h
+++ b/opl/opl.h
@@ -27,6 +27,8 @@
#ifndef OPL_OPL_H
#define OPL_OPL_H
+typedef void (*opl_callback_t)(void *data);
+
typedef enum
{OPL_REGISTER_PORT = 0,
@@ -71,6 +73,20 @@
// Read from one of the OPL I/O ports:
unsigned int OPL_ReadPort(opl_port_t port);
+
+// Set a timer callback. After the specified number of milliseconds
+// have elapsed, the callback will be invoked.
+
+void OPL_SetCallback(unsigned int ms, opl_callback_t callback, void *data);
+
+// Begin critical section, during which, OPL callbacks will not be
+// invoked.
+
+void OPL_Lock(void);
+
+// End critical section.
+
+void OPL_Unlock(void);
#endif
--- a/opl/opl_internal.h
+++ b/opl/opl_internal.h
@@ -33,6 +33,11 @@
typedef void (*opl_shutdown_func)(void);
typedef unsigned int (*opl_read_port_func)(opl_port_t port);
typedef void (*opl_write_port_func)(opl_port_t port, unsigned int value);
+typedef void (*opl_set_callback_func)(unsigned int ms,
+ opl_callback_t callback,
+ void *data);
+typedef void (*opl_lock_func)(void);
+typedef void (*opl_unlock_func)(void);
typedef struct
{@@ -42,6 +47,9 @@
opl_shutdown_func shutdown_func;
opl_read_port_func read_port_func;
opl_write_port_func write_port_func;
+ opl_set_callback_func set_callback_func;
+ opl_lock_func lock_func;
+ opl_unlock_func unlock_func;
} opl_driver_t;
#endif /* #ifndef OPL_INTERNAL_H */
--- a/opl/opl_linux.c
+++ b/opl/opl_linux.c
@@ -35,6 +35,7 @@
#include "opl.h"
#include "opl_internal.h"
+#include "opl_timer.h"
static unsigned int opl_port_base;
@@ -51,11 +52,23 @@
opl_port_base = port_base;
+ // Start callback thread
+
+ if (!OPL_Timer_StartThread())
+ {+ ioperm(port_base, 2, 0);
+ return 0;
+ }
+
return 1;
}
static void OPL_Linux_Shutdown(void)
{+ // Stop callback thread
+
+ OPL_Timer_StopThread();
+
// Release permissions
ioperm(opl_port_base, 2, 0);
@@ -77,7 +90,10 @@
OPL_Linux_Init,
OPL_Linux_Shutdown,
OPL_Linux_PortRead,
- OPL_Linux_PortWrite
+ OPL_Linux_PortWrite,
+ OPL_Timer_SetCallback,
+ OPL_Timer_Lock,
+ OPL_Timer_Unlock
};
#endif /* #ifdef HAVE_IOPERM */
--- /dev/null
+++ b/opl/opl_queue.c
@@ -1,0 +1,192 @@
+// Emacs style mode select -*- C++ -*-
+//-----------------------------------------------------------------------------
+//
+// Copyright(C) 2009 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:
+// Queue of waiting callbacks, stored in a binary min heap, so that we
+// can always get the first callback.
+//
+//-----------------------------------------------------------------------------
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "opl_queue.h"
+
+#define MAX_OPL_QUEUE 64
+
+typedef struct
+{+ opl_callback_t callback;
+ void *data;
+ unsigned int time;
+} opl_queue_entry_t;
+
+struct opl_callback_queue_s
+{+ opl_queue_entry_t entries[MAX_OPL_QUEUE];
+ unsigned int num_entries;
+};
+
+opl_callback_queue_t *OPL_Queue_Create(void)
+{+ opl_callback_queue_t *queue;
+
+ queue = malloc(sizeof(opl_callback_queue_t));
+ queue->num_entries = 0;
+
+ return queue;
+}
+
+void OPL_Queue_Destroy(opl_callback_queue_t *queue)
+{+ free(queue);
+}
+
+int OPL_Queue_IsEmpty(opl_callback_queue_t *queue)
+{+ return queue->num_entries == 0;
+}
+
+void OPL_Queue_Push(opl_callback_queue_t *queue,
+ opl_callback_t callback, void *data,
+ unsigned int time)
+{+ int entry_id;
+
+ if (queue->num_entries >= MAX_OPL_QUEUE)
+ {+ fprintf(stderr, "OPL_Queue_Push: Exceeded maximum callbacks\n");
+ return;
+ }
+
+ // Add to last queue entry.
+
+ entry_id = queue->num_entries;
+ ++queue->num_entries;
+
+ // Shift existing entries down in the heap.
+
+ while (entry_id > 0 && time < queue->entries[entry_id / 2].time)
+ {+ memcpy(&queue->entries[entry_id],
+ &queue->entries[entry_id / 2],
+ sizeof(opl_queue_entry_t));
+
+ entry_id /= 2;
+ }
+
+ // Insert new callback data.
+
+ queue->entries[entry_id].callback = callback;
+ queue->entries[entry_id].data = data;
+ queue->entries[entry_id].time = time;
+}
+
+int OPL_Queue_Pop(opl_callback_queue_t *queue,
+ opl_callback_t *callback, void **data)
+{+ opl_queue_entry_t *entry;
+ int child1, child2;
+ int i, next_i;
+
+ // Empty?
+
+ if (queue->num_entries <= 0)
+ {+ return 0;
+ }
+
+ // Store the result:
+
+ *callback = queue->entries[0].callback;
+ *data = queue->entries[0].data;
+
+ // Decrease the heap size, and keep pointer to the last entry in
+ // the heap, which must now be percolated down from the top.
+
+ --queue->num_entries;
+ entry = &queue->entries[queue->num_entries];
+
+ // Percolate down.
+
+ i = 0;
+
+ for (;;)
+ {+ child1 = i * 2 + 1;
+ child2 = i * 2 + 2;
+
+ if (child1 < queue->num_entries
+ && queue->entries[child1].time < entry->time)
+ {+ // Left child is less than entry.
+ // Use the minimum of left and right children.
+
+ if (child2 < queue->num_entries
+ && queue->entries[child2].time < queue->entries[child1].time)
+ {+ next_i = child2;
+ }
+ else
+ {+ next_i = child1;
+ }
+ }
+ else if (child2 < queue->num_entries
+ && queue->entries[child2].time < entry->time)
+ {+ // Right child is less than entry. Go down the right side.
+
+ next_i = child2;
+ }
+ else
+ {+ // Finished percolating.
+ break;
+ }
+
+ // Percolate the next value up and advance.
+
+ memcpy(&queue->entries[i],
+ &queue->entries[next_i],
+ sizeof(opl_queue_entry_t));
+ i = next_i;
+ }
+
+ // Store the old last-entry at its new position.
+
+ memcpy(&queue->entries[i], entry, sizeof(opl_queue_entry_t));
+
+ return 1;
+}
+
+unsigned int OPL_Queue_Peek(opl_callback_queue_t *queue)
+{+ if (queue->num_entries > 0)
+ {+ return queue->entries[0].time;
+ }
+ else
+ {+ return 0;
+ }
+}
+
--- /dev/null
+++ b/opl/opl_queue.h
@@ -1,0 +1,44 @@
+// Emacs style mode select -*- C++ -*-
+//-----------------------------------------------------------------------------
+//
+// Copyright(C) 2009 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:
+// OPL callback queue.
+//
+//-----------------------------------------------------------------------------
+
+#ifndef OPL_QUEUE_H
+#define OPL_QUEUE_H
+
+#include "opl.h"
+
+typedef struct opl_callback_queue_s opl_callback_queue_t;
+
+opl_callback_queue_t *OPL_Queue_Create(void);
+int OPL_Queue_IsEmpty(opl_callback_queue_t *queue);
+void OPL_Queue_Destroy(opl_callback_queue_t *queue);
+void OPL_Queue_Push(opl_callback_queue_t *queue,
+ opl_callback_t callback, void *data,
+ unsigned int time);
+int OPL_Queue_Pop(opl_callback_queue_t *queue,
+ opl_callback_t *callback, void **data);
+unsigned int OPL_Queue_Peek(opl_callback_queue_t *queue);
+
+#endif /* #ifndef OPL_QUEUE_H */
+
--- a/opl/opl_sdl.c
+++ b/opl/opl_sdl.c
@@ -37,9 +37,12 @@
#include "opl.h"
#include "opl_internal.h"
+#include "opl_queue.h"
+
// TODO:
#define opl_sample_rate 22050
+static opl_callback_queue_t *callback_queue;
static FM_OPL *opl_emulator = NULL;
static int sdl_was_initialised = 0;
static int mixing_freq, mixing_channels;
@@ -65,6 +68,7 @@
{Mix_CloseAudio();
SDL_QuitSubSystem(SDL_INIT_AUDIO);
+ OPL_Queue_Destroy(callback_queue);
sdl_was_initialised = 0;
}
@@ -82,6 +86,8 @@
if (!SDLIsInitialised())
{+ callback_queue = OPL_Queue_Create();
+
if (SDL_Init(SDL_INIT_AUDIO) < 0)
{fprintf(stderr, "Unable to set up sound.\n");
@@ -161,6 +167,20 @@
}
}
+static void OPL_SDL_SetCallback(unsigned int ms,
+ opl_callback_t callback,
+ void *data)
+{+}
+
+static void OPL_SDL_Lock(void)
+{+}
+
+static void OPL_SDL_Unlock(void)
+{+}
+
opl_driver_t opl_sdl_driver =
{"SDL",
@@ -167,6 +187,9 @@
OPL_SDL_Init,
OPL_SDL_Shutdown,
OPL_SDL_PortRead,
- OPL_SDL_PortWrite
+ OPL_SDL_PortWrite,
+ OPL_SDL_SetCallback,
+ OPL_SDL_Lock,
+ OPL_SDL_Unlock
};
--- /dev/null
+++ b/opl/opl_timer.c
@@ -1,0 +1,197 @@
+// Emacs style mode select -*- C++ -*-
+//-----------------------------------------------------------------------------
+//
+// Copyright(C) 2009 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:
+// OPL timer thread.
+// Once started using OPL_Timer_StartThread, the thread sleeps,
+// waking up to invoke callbacks set using OPL_Timer_SetCallback.
+//
+//-----------------------------------------------------------------------------
+
+#include "SDL.h"
+
+#include "opl_timer.h"
+#include "opl_queue.h"
+
+typedef enum
+{+ THREAD_STATE_STOPPED,
+ THREAD_STATE_RUNNING,
+ THREAD_STATE_STOPPING,
+} thread_state_t;
+
+static SDL_Thread *timer_thread = NULL;
+static thread_state_t timer_thread_state;
+static int current_time;
+
+// Queue of callbacks waiting to be invoked.
+// The callback queue mutex is held while the callback queue structure
+// or current_time is being accessed.
+
+static opl_callback_queue_t *callback_queue;
+static SDL_mutex *callback_queue_mutex;
+
+// The timer mutex is held while timer callback functions are being
+// invoked, so that the calling code can prevent clashes.
+
+static SDL_mutex *timer_mutex;
+
+// Returns true if there is a callback at the head of the queue ready
+// to be invoked. Otherwise, next_time is set to the time when the
+// timer thread must wake up again to check.
+
+static int CallbackWaiting(unsigned int *next_time)
+{+ // If there are no queued callbacks, sleep for 50ms at a time
+ // until a callback is added.
+
+ if (OPL_Queue_IsEmpty(callback_queue))
+ {+ *next_time = current_time + 50;
+ return 0;
+ }
+
+ // Read the time of the first callback in the queue.
+ // If the time for the callback has not yet arrived,
+ // we must sleep until the callback time.
+
+ *next_time = OPL_Queue_Peek(callback_queue);
+
+ return *next_time <= current_time;
+}
+
+static unsigned int GetNextTime(void)
+{+ opl_callback_t callback;
+ void *callback_data;
+ unsigned int next_time;
+ int have_callback;
+
+ // Keep running through callbacks until there are none ready to
+ // run. When we run out of callbacks, next_time will be set.
+
+ do
+ {+ SDL_LockMutex(callback_queue_mutex);
+
+ // Check if the callback at the head of the list is ready to
+ // be invoked. If so, pop from the head of the queue.
+
+ have_callback = CallbackWaiting(&next_time);
+
+ if (have_callback)
+ {+ OPL_Queue_Pop(callback_queue, &callback, &callback_data);
+ }
+
+ SDL_UnlockMutex(callback_queue_mutex);
+
+ // Now invoke the callback, if we have one.
+ // The timer mutex is held while the callback is invoked.
+
+ if (have_callback)
+ {+ SDL_LockMutex(timer_mutex);
+ callback(callback_data);
+ SDL_UnlockMutex(timer_mutex);
+ }
+ } while (have_callback);
+
+ return next_time;
+}
+
+static int ThreadFunction(void *unused)
+{+ unsigned int next_time;
+ unsigned int now;
+
+ // Keep running until OPL_Timer_StopThread is called.
+
+ while (timer_thread_state == THREAD_STATE_RUNNING)
+ {+ // Get the next time that we must sleep until, and
+ // wait until that time.
+
+ next_time = GetNextTime();
+ now = SDL_GetTicks();
+
+ if (next_time > now)
+ {+ SDL_Delay(next_time - now);
+ }
+
+ // Update the current time.
+
+ SDL_LockMutex(callback_queue_mutex);
+ current_time = next_time;
+ SDL_UnlockMutex(callback_queue_mutex);
+ }
+
+ timer_thread_state = THREAD_STATE_STOPPED;
+
+ return 0;
+}
+
+int OPL_Timer_StartThread(void)
+{+ timer_thread_state = THREAD_STATE_RUNNING;
+ timer_thread = SDL_CreateThread(ThreadFunction, NULL);
+ timer_mutex = SDL_CreateMutex();
+
+ callback_queue = OPL_Queue_Create();
+ callback_queue_mutex = SDL_CreateMutex();
+ current_time = SDL_GetTicks();
+
+ if (timer_thread == NULL)
+ {+ timer_thread_state = THREAD_STATE_STOPPED;
+ return 0;
+ }
+
+ return 1;
+}
+
+void OPL_Timer_StopThread(void)
+{+ timer_thread_state = THREAD_STATE_STOPPING;
+
+ while (timer_thread_state != THREAD_STATE_STOPPED)
+ {+ SDL_Delay(1);
+ }
+}
+
+void OPL_Timer_SetCallback(unsigned int ms, opl_callback_t callback, void *data)
+{+ SDL_LockMutex(callback_queue_mutex);
+ OPL_Queue_Push(callback_queue, callback, data, current_time + ms);
+ SDL_UnlockMutex(callback_queue_mutex);
+}
+
+void OPL_Timer_Lock(void)
+{+ SDL_LockMutex(timer_mutex);
+}
+
+void OPL_Timer_Unlock(void)
+{+ SDL_UnlockMutex(timer_mutex);
+}
+
--- /dev/null
+++ b/opl/opl_timer.h
@@ -1,0 +1,40 @@
+// Emacs style mode select -*- C++ -*-
+//-----------------------------------------------------------------------------
+//
+// Copyright(C) 2009 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:
+// OPL timer thread.
+//
+//-----------------------------------------------------------------------------
+
+#ifndef OPL_TIMER_H
+#define OPL_TIMER_H
+
+#include "opl.h"
+
+int OPL_Timer_StartThread(void);
+void OPL_Timer_StopThread(void);
+void OPL_Timer_SetCallback(unsigned int ms,
+ opl_callback_t callback,
+ void *data);
+void OPL_Timer_Lock(void);
+void OPL_Timer_Unlock(void);
+
+#endif /* #ifndef OPL_TIMER_H */
+