+//#define THREADED_CD_IO
+
+/* threaded reader */
+#ifdef THREADED_CD_IO
+#include <pthread.h>
+#define tioprintf printf
+
+static pthread_t thr_thread = 0;
+static pthread_cond_t thr_cond = PTHREAD_COND_INITIALIZER;
+static pthread_mutex_t thr_mutex = PTHREAD_MUTEX_INITIALIZER;
+static unsigned char *thr_buffer[2][2048 + 304] __attribute__((aligned(4)));
+static int thr_lba_need;
+static int thr_lba_have[2];
+
+static void thr_read_lba(int slot, int lba)
+{
+ int is_bin = Pico_mcd->TOC.Tracks[0].ftype == TYPE_BIN;
+ int where_seek = is_bin ? (lba * 2352 + 16) : (lba << 11);
+
+ pm_seek(Pico_mcd->TOC.Tracks[0].F, where_seek, SEEK_SET);
+ pm_read(thr_buffer[slot], 2048, Pico_mcd->TOC.Tracks[0].F);
+ thr_lba_have[slot] = lba;
+}
+
+static void *buffering_thread(void *arg)
+{
+ int free_slot, lba;
+
+ elprintf(EL_STATUS, "CD I/O thread started.");
+
+ pthread_mutex_lock(&thr_mutex);
+
+ while (1)
+ {
+ if (thr_lba_need < 0) goto wait;
+
+ free_slot = -1;
+ if (thr_lba_have[0] == -1) free_slot = 0;
+ if (thr_lba_have[1] == -1) free_slot = 1;
+ if (free_slot == -1) goto wait;
+
+ lba = thr_lba_need;
+ if (lba != thr_lba_have[free_slot^1]) {
+ thr_read_lba(free_slot, lba);
+ tioprintf("t done %i %i\n", lba, free_slot);
+ continue;
+ }
+ lba++;
+ if (lba != thr_lba_have[free_slot^1]) {
+ thr_read_lba(free_slot, lba);
+ tioprintf("t done %i %i\n", lba, free_slot);
+ continue;
+ }
+
+wait:
+ pthread_cond_wait(&thr_cond, &thr_mutex);
+ tioprintf("t wake\n");
+ }
+
+ pthread_mutex_unlock(&thr_mutex);
+
+ return NULL;
+}
+
+static void threaded_read(void *dest, int lba)
+{
+ int i, have = -1;
+ tioprintf("\n");
+
+ if (lba == thr_lba_have[0]) have = 0;
+ if (lba == thr_lba_have[1]) have = 1;
+ if (have != -1)
+ {
+ tioprintf("r hit %i %i\n", lba, have);
+ memcpy32(dest, (int *)thr_buffer[have], 2048/4);
+ if (lba != prev_lba) {
+ thr_lba_have[have] = -1; // make free slot
+ thr_lba_need = lba + 1; // guess a sequential read..
+ pthread_cond_signal(&thr_cond);
+ sched_yield();
+ prev_lba = lba;
+ }
+ return;
+ }
+
+ tioprintf("r miss %i\n", lba);
+ thr_lba_need = lba;
+ pthread_mutex_lock(&thr_mutex);
+ pthread_mutex_unlock(&thr_mutex);
+ if (lba == thr_lba_have[0]) have = 0;
+ if (lba == thr_lba_have[1]) have = 1;
+ if (have == -1)
+ {
+ // try again..
+ thr_lba_have[0] = thr_lba_have[1] = -1;
+ for (i = 0; have == -1 && i < 10; i++)
+ {
+ tioprintf("r hard %i\n", lba);
+ pthread_cond_signal(&thr_cond);
+ sched_yield();
+ pthread_mutex_lock(&thr_mutex);
+ pthread_mutex_unlock(&thr_mutex);
+ if (lba == thr_lba_have[0]) have = 0;
+ if (lba == thr_lba_have[1]) have = 1;
+ }
+ }
+
+ // we MUST have the data at this point..
+ if (have == -1) { tioprintf("BUG!\n"); exit(1); }
+ tioprintf("r reco %i %i\n", lba, have);
+ memcpy32(dest, (int *)thr_buffer[have], 2048/4);
+ thr_lba_have[have] = -1;
+ pthread_cond_signal(&thr_cond);
+
+ prev_lba = lba;
+ return;
+}
+#endif
+