diff options
Diffstat (limited to 'src/glut/dos/callback.c')
| -rw-r--r-- | src/glut/dos/callback.c | 33 |
1 files changed, 19 insertions, 14 deletions
diff --git a/src/glut/dos/callback.c b/src/glut/dos/callback.c index 174cbdda99..773dfb2758 100644 --- a/src/glut/dos/callback.c +++ b/src/glut/dos/callback.c @@ -19,7 +19,7 @@ */ /* - * DOS/DJGPP glut driver v1.4 for Mesa + * DOS/DJGPP glut driver v1.5 for Mesa * * Copyright (C) 2002 - Borca Daniel * Email : dborca@yahoo.com @@ -38,8 +38,6 @@ typedef struct { int fid; /* func-id as returned from PCHW */ } GLUTSShotCB; -static GLboolean g_sscb_semaphore; - GLUTidleCB g_idle_func = NULL; @@ -47,11 +45,12 @@ GLUTidleCB g_idle_func = NULL; static void g_single_shot_callback (void *opaque) { GLUTSShotCB *cb = (GLUTSShotCB *)opaque; - while (g_sscb_semaphore) { - } if (!--cb->ttl) { cb->func(cb->value); pc_remove_int(cb->fid); + /* We won't be needing this slot anymore, so free it. This operation + * must be the last thing, and must be atomic, to mutex `glutTimerFunc' + */ cb->func = NULL; } } ENDOFUNC(g_single_shot_callback) @@ -139,7 +138,6 @@ void APIENTRY glutTimerFunc (unsigned int millis, GLUTtimerCB func, int value) if (virgin) { virgin = GL_FALSE; LOCKDATA(g_sscb); - LOCKDATA(g_sscb_semaphore); LOCKFUNC(g_single_shot_callback); /* we should lock the callee also... */ } @@ -153,20 +151,27 @@ void APIENTRY glutTimerFunc (unsigned int millis, GLUTtimerCB func, int value) freq = 1000 / millis; ttl = 1; } - g_sscb_semaphore++; for (i = 0; i < MAX_SSHOT_CB; i++) { if (g_sscb[i].func == NULL) { - int fid = pc_install_int((PFUNC)func, &g_sscb[i], freq); - if (fid >= 0) { - g_sscb[i].func = func; - g_sscb[i].value = value; - g_sscb[i].ttl = ttl; - g_sscb[i].fid = fid; + /* We will be needing this slot, so alloc it. This operation + * must be the first thing, and must be atomic, to mutex callbacks! + */ + g_sscb[i].func = func; + g_sscb[i].value = value; + g_sscb[i].ttl = ttl; + /* There is a very small gap here: `pc_install_int' enables + * interrupts just before returning FID value (which will be + * used inside callback). The critical gap is 1 millisecond + * - which I'm sure we won't overrun... + */ + g_sscb[i].fid = pc_install_int((PFUNC)func, &g_sscb[i], freq); + if (g_sscb[i].fid < 0) { + /* Interrupt could not be set! Release the slot back */ + g_sscb[i].func = NULL; } break; } } - g_sscb_semaphore--; } } |