Module Name: src
Committed By: isaki
Date: Sat Jan 11 04:53:10 UTC 2020
Modified Files:
src/sys/dev/audio: audio.c audiovar.h
Log Message:
Simplify async_mixer handling.
- It makes FIOASYNC code in mixer_ioctl() symmetric.
- For readability, mixer_async_{add,remove}() should take pid argument
though pid is always curproc.
To generate a diff of this commit:
cvs rdiff -u -r1.40 -r1.41 src/sys/dev/audio/audio.c
cvs rdiff -u -r1.6 -r1.7 src/sys/dev/audio/audiovar.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/audio/audio.c
diff -u src/sys/dev/audio/audio.c:1.40 src/sys/dev/audio/audio.c:1.41
--- src/sys/dev/audio/audio.c:1.40 Sat Jan 11 04:06:13 2020
+++ src/sys/dev/audio/audio.c Sat Jan 11 04:53:10 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: audio.c,v 1.40 2020/01/11 04:06:13 isaki Exp $ */
+/* $NetBSD: audio.c,v 1.41 2020/01/11 04:53:10 isaki Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -142,7 +142,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.40 2020/01/11 04:06:13 isaki Exp $");
+__KERNEL_RCSID(0, "$NetBSD: audio.c,v 1.41 2020/01/11 04:53:10 isaki Exp $");
#ifdef _KERNEL_OPT
#include "audio.h"
@@ -463,6 +463,9 @@ audio_track_bufstat(audio_track_t *track
int audio_idle_timeout = 30;
#endif
+/* Number of elements of async mixer's pid */
+#define AM_CAPACITY (4)
+
struct portname {
const char *name;
int mask;
@@ -604,7 +607,8 @@ static void mixer_init(struct audio_soft
static int mixer_open(dev_t, struct audio_softc *, int, int, struct lwp *);
static int mixer_close(struct audio_softc *, audio_file_t *);
static int mixer_ioctl(struct audio_softc *, u_long, void *, int, struct lwp *);
-static void mixer_remove(struct audio_softc *);
+static void mixer_async_add(struct audio_softc *, pid_t);
+static void mixer_async_remove(struct audio_softc *, pid_t);
static void mixer_signal(struct audio_softc *);
static int au_portof(struct audio_softc *, char *, int);
@@ -878,6 +882,9 @@ audioattach(device_t parent, device_t se
sc->sc_blk_ms = AUDIO_BLK_MS;
SLIST_INIT(&sc->sc_files);
cv_init(&sc->sc_exlockcv, "audiolk");
+ sc->sc_am_capacity = 0;
+ sc->sc_am_used = 0;
+ sc->sc_am = NULL;
mutex_enter(sc->sc_lock);
sc->sc_props = hw_if->get_props(sc->hw_hdl);
@@ -1283,6 +1290,8 @@ audiodetach(device_t self, int flags)
kmem_free(sc->sc_rmixer, sizeof(*sc->sc_rmixer));
}
mutex_exit(sc->sc_lock);
+ if (sc->sc_am)
+ kern_free(sc->sc_am);
seldestroy(&sc->sc_wsel);
seldestroy(&sc->sc_rsel);
@@ -7604,23 +7613,60 @@ mixer_open(dev_t dev, struct audio_softc
}
/*
+ * Add a process to those to be signalled on mixer activity.
+ * If the process has already been added, do nothing.
+ * Must be called with sc_lock held.
+ */
+static void
+mixer_async_add(struct audio_softc *sc, pid_t pid)
+{
+ int i;
+
+ KASSERT(mutex_owned(sc->sc_lock));
+
+ /* If already exists, returns without doing anything. */
+ for (i = 0; i < sc->sc_am_used; i++) {
+ if (sc->sc_am[i] == pid)
+ return;
+ }
+
+ /* Extend array if necessary. */
+ if (sc->sc_am_used >= sc->sc_am_capacity) {
+ sc->sc_am_capacity += AM_CAPACITY;
+ sc->sc_am = kern_realloc(sc->sc_am,
+ sc->sc_am_capacity * sizeof(pid_t), M_WAITOK);
+ TRACE(2, "realloc am_capacity=%d", sc->sc_am_capacity);
+ }
+
+ TRACE(2, "am[%d]=%d", sc->sc_am_used, (int)pid);
+ sc->sc_am[sc->sc_am_used++] = pid;
+}
+
+/*
* Remove a process from those to be signalled on mixer activity.
+ * If the process has not been added, do nothing.
* Must be called with sc_lock held.
*/
static void
-mixer_remove(struct audio_softc *sc)
+mixer_async_remove(struct audio_softc *sc, pid_t pid)
{
- struct mixer_asyncs **pm, *m;
- pid_t pid;
+ int i;
KASSERT(mutex_owned(sc->sc_lock));
- pid = curproc->p_pid;
- for (pm = &sc->sc_async_mixer; *pm; pm = &(*pm)->next) {
- if ((*pm)->pid == pid) {
- m = *pm;
- *pm = m->next;
- kmem_free(m, sizeof(*m));
+ for (i = 0; i < sc->sc_am_used; i++) {
+ if (sc->sc_am[i] == pid) {
+ sc->sc_am[i] = sc->sc_am[--sc->sc_am_used];
+ TRACE(2, "am[%d](%d) removed, used=%d",
+ i, (int)pid, sc->sc_am_used);
+
+ /* Empty array if no longer necessary. */
+ if (sc->sc_am_used == 0) {
+ kern_free(sc->sc_am);
+ sc->sc_am = NULL;
+ sc->sc_am_capacity = 0;
+ TRACE(2, "released");
+ }
return;
}
}
@@ -7633,12 +7679,15 @@ mixer_remove(struct audio_softc *sc)
static void
mixer_signal(struct audio_softc *sc)
{
- struct mixer_asyncs *m;
proc_t *p;
+ int i;
+
+ KASSERT(mutex_owned(sc->sc_lock));
- for (m = sc->sc_async_mixer; m; m = m->next) {
+ for (i = 0; i < sc->sc_am_used; i++) {
mutex_enter(proc_lock);
- if ((p = proc_find(m->pid)) != NULL)
+ p = proc_find(sc->sc_am[i]);
+ if (p)
psignal(p, SIGIO);
mutex_exit(proc_lock);
}
@@ -7653,7 +7702,7 @@ mixer_close(struct audio_softc *sc, audi
mutex_enter(sc->sc_lock);
TRACE(1, "");
- mixer_remove(sc);
+ mixer_async_remove(sc, curproc->p_pid);
mutex_exit(sc->sc_lock);
kmem_free(file, sizeof(*file));
@@ -7664,7 +7713,6 @@ int
mixer_ioctl(struct audio_softc *sc, u_long cmd, void *addr, int flag,
struct lwp *l)
{
- struct mixer_asyncs *ma;
mixer_devinfo_t *mi;
mixer_ctrl_t *mc;
int error;
@@ -7684,17 +7732,11 @@ mixer_ioctl(struct audio_softc *sc, u_lo
switch (cmd) {
case FIOASYNC:
+ mutex_enter(sc->sc_lock);
if (*(int *)addr) {
- ma = kmem_alloc(sizeof(struct mixer_asyncs), KM_SLEEP);
+ mixer_async_add(sc, curproc->p_pid);
} else {
- ma = NULL;
- }
- mutex_enter(sc->sc_lock);
- mixer_remove(sc); /* remove old entry */
- if (ma != NULL) {
- ma->next = sc->sc_async_mixer;
- ma->pid = curproc->p_pid;
- sc->sc_async_mixer = ma;
+ mixer_async_remove(sc, curproc->p_pid);
}
mutex_exit(sc->sc_lock);
error = 0;
Index: src/sys/dev/audio/audiovar.h
diff -u src/sys/dev/audio/audiovar.h:1.6 src/sys/dev/audio/audiovar.h:1.7
--- src/sys/dev/audio/audiovar.h:1.6 Sat Jan 11 04:06:13 2020
+++ src/sys/dev/audio/audiovar.h Sat Jan 11 04:53:10 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: audiovar.h,v 1.6 2020/01/11 04:06:13 isaki Exp $ */
+/* $NetBSD: audiovar.h,v 1.7 2020/01/11 04:53:10 isaki Exp $ */
/*-
* Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -194,13 +194,15 @@ struct audio_softc {
struct selinfo sc_rsel;
/*
- * processes who want mixer SIGIO.
+ * Processes who want mixer SIGIO.
+ * sc_am is an array of pids, or NULL if empty.
+ * sc_am_capacity is the number of allocated elements.
+ * sc_am_used is the number of elements actually used.
* Must be protected by sc_lock.
*/
- struct mixer_asyncs {
- struct mixer_asyncs *next;
- pid_t pid;
- } *sc_async_mixer;
+ pid_t *sc_am;
+ int sc_am_capacity;
+ int sc_am_used;
/*
* Thread lock and interrupt lock obtained by get_locks().
