CD-ROM: Optimize Windows IOCTL disc change checking.

src/cdrom/cdrom.c

@@ -46,6 +46,7 @@
 cdrom_t cdrom[CDROM_NUM] = { 0 };
 
 int cdrom_interface_current;
+int cdrom_assigned_letters = 0;
 
 #ifdef ENABLE_CDROM_LOG
 int cdrom_do_log = ENABLE_CDROM_LOG;
@@ -2795,6 +2796,8 @@ cdrom_global_init(void)
 void
 cdrom_hard_reset(void)
 {
+    cdrom_assigned_letters = 0;
+
     for (uint8_t i = 0; i < CDROM_NUM; i++) {
         cdrom_t *dev = &cdrom[i];
 
@@ -2825,6 +2828,7 @@ cdrom_hard_reset(void)
             }
 
             dev->cd_status = CD_STATUS_EMPTY;
+            dev->host_letter = 0xff;
 
             if (strlen(dev->image_path) > 0) {
 #ifdef _WIN32

src/include/86box/cdrom.h

@@ -335,6 +335,8 @@ typedef struct cdrom {
     uint8_t            subch_buffer[96];
 
     int                cdrom_sector_size;
+    /* Only used on Windows hosts for disc change notifications. */
+    uint8_t            host_letter;
 
     /* Needs some extra breathing space in case of overflows. */
     uint8_t            raw_buffer[4096];
@@ -437,6 +439,8 @@ extern int             cdrom_is_empty(const uint8_t id);
 extern void            cdrom_eject(const uint8_t id);
 extern void            cdrom_reload(const uint8_t id);
 
+extern int             cdrom_assigned_letters;
+
 #ifdef __cplusplus
 }
 #endif

src/qt/qt_winrawinputfilter.cpp

@@ -157,28 +157,17 @@ WindowsRawInputFilter::~WindowsRawInputFilter()
 static void
 notify_drives(ULONG unitmask, int empty)
 {
-    char p[1024] = { 0 };
+    if (unitmask & cdrom_assigned_letters)  for (int i = 0; i < CDROM_NUM; i++) {
+        cdrom_t *dev = &(cdrom[i]);
 
-    for (int i = 0; i < 26; ++i) {
-        if (unitmask & (1 << i)) {
-            cdrom_t *dev = NULL;
-
-            sprintf(p, "ioctl://\\\\.\\%c:", 'A' + i);
-
-            for (int i = 0; i < CDROM_NUM; i++)
-                if (!stricmp(cdrom[i].image_path, p)) {
-                    dev = &(cdrom[i]);
+        if ((dev->host_letter != 0xff) &&
+            (unitmask & (1 << dev->host_letter))) {
             if (empty)
                 cdrom_set_empty(dev);
             else
                 cdrom_update_status(dev);
-                    // pclog("CD-ROM %i      : Drive notified of media %s\n",
-                          // dev->id, empty ? "removal" : "change");
         }
     }
-
-        unitmask = unitmask >> 1;
-    }
 }
 
 static void

src/qt/win_cdrom_ioctl.c

@@ -748,6 +748,11 @@ ioctl_close(void *local)
 
     log_close(ioctl->log);
     ioctl->log = NULL;
+
+    cdrom_assigned_letters &= ~(1 << ioctl->dev->host_letter);
+    ioctl->dev->host_letter = 0xff;
+
+    free(ioctl);
 }
 
 static void
@@ -802,6 +807,9 @@ ioctl_open(cdrom_t *dev, const char *drv)
 
         dev->ops                = &ioctl_ops;
 
+        dev->host_letter        = (drv[12] & 0xdf) - 0x41;
+        cdrom_assigned_letters |= (1 << dev->host_letter);
+
         ioctl_load(ioctl);
     }