Marking a shm segment to remove it after using shmat function makes automatic removal of shm segment while num of attached apps decreses to zero. If app is killed it works too. But we could not mark segments which have assigned a key because this clears the key. These segments stay in memory after crash but as long as we do not want bigger segment size we could get to them. So I added check which removes this kind of segments in case while we could not get them and they are not used. After that we can create new segments with desired key and size.
In next part I optimized a bit sample mixing routines in c and x_86 asm. Hope this helps. Regards
-- Adam Tla/lka mailto:[EMAIL PROTECTED] ^v^ ^v^ ^v^ Computer Center, Technical University of Gdansk, Poland PGP public key: finger [EMAIL PROTECTED]
--- alsa-20040123/alsa-lib/src/pcm/pcm_dmix_old.c 2004-01-21 20:21:11.000000000
+0100
+++ alsa-20040123/alsa-lib/src/pcm/pcm_dmix.c 2004-01-23 13:13:53.000000000 +0100
@@ -59,14 +59,26 @@
static int shm_sum_create_or_connect(snd_pcm_direct_t *dmix)
{
static int shm_sum_discard(snd_pcm_direct_t *dmix);
+ struct shmid_ds buf;
+ int tmpid, err;
size_t size;
size = dmix->shmptr->s.channels *
dmix->shmptr->s.buffer_size *
sizeof(signed int);
+retryshm:
dmix->u.dmix.shmid_sum = shmget(dmix->ipc_key + 1, size, IPC_CREAT | 0666);
- if (dmix->u.dmix.shmid_sum < 0)
- return -errno;
+ err = -errno;
+ if (dmix->u.dmix.shmid_sum < 0){
+ if (errno == EINVAL)
+ if ((tmpid = shmget(dmix->ipc_key + 1, 0, 0666)) != -1)
+ if (!shmctl(tmpid, IPC_STAT, &buf))
+ if (!buf.shm_nattch)
+ /* no users so destroy the segment */
+ if (!shmctl(tmpid, IPC_RMID, NULL))
+ goto retryshm;
+ return err;
+ }
dmix->u.dmix.sum_buffer = shmat(dmix->u.dmix.shmid_sum, 0, 0);
if (dmix->u.dmix.sum_buffer == (void *) -1) {
shm_sum_discard(dmix);
@@ -214,7 +226,7 @@
{
register signed int sample, old_sample;
- while (size-- > 0) {
+ for (;;) {
sample = *src;
old_sample = *sum;
if (*dst == 0)
@@ -230,6 +242,8 @@
sample = old_sample;
*dst = sample;
} while (*sum != old_sample);
+ if (!--size)
+ return;
((char *)src) += src_step;
((char *)dst) += dst_step;
((char *)sum) += sum_step;
@@ -244,7 +258,7 @@
{
register signed int sample, old_sample;
- while (size-- > 0) {
+ for (;;) {
sample = *src / 256;
old_sample = *sum;
if (*dst == 0)
@@ -260,6 +274,8 @@
sample = old_sample * 256;
*dst = sample;
} while (*sum != old_sample);
+ if (!--size)
+ return;
((char *)src) += src_step;
((char *)dst) += dst_step;
((char *)sum) += sum_step;
@@ -366,9 +382,11 @@
dmix->slave_appl_ptr %= dmix->shmptr->s.boundary;
while (size > 0) {
transfer = appl_ptr + size > pcm->buffer_size ? pcm->buffer_size -
appl_ptr : size;
- transfer = slave_appl_ptr + transfer > dmix->shmptr->s.buffer_size ?
dmix->shmptr->s.buffer_size - slave_appl_ptr : transfer;
- size -= transfer;
+ if ((transfer = slave_appl_ptr + transfer >
dmix->shmptr->s.buffer_size ? dmix->shmptr->s.buffer_size - slave_appl_ptr : transfer))
mix_areas(dmix, src_areas, dst_areas, appl_ptr, slave_appl_ptr,
transfer);
+ if (transfer >= size)
+ return;
+ size -= transfer;
slave_appl_ptr += transfer;
slave_appl_ptr %= dmix->shmptr->s.buffer_size;
appl_ptr += transfer;
--- alsa-20040123/alsa-lib/src/pcm/pcm_mmap_old.c 2004-01-23 13:06:01.000000000
+0100
+++ alsa-20040123/alsa-lib/src/pcm/pcm_mmap.c 2004-01-23 13:09:49.000000000 +0100
@@ -368,6 +368,11 @@
SYSERR("shmat failed");
return -errno;
}
+ /* automatically remove segment if not used */
+ if (shmctl(id, IPC_RMID, NULL) < 0){
+ SYSERR("shmctl mark remove failed");
+ return -errno;
+ }
i->u.shm.area = snd_shm_area_create(id, ptr);
if (i->u.shm.area == NULL) {
SYSERR("snd_shm_area_create failed");
--- alsa-20040123/alsa-lib/src/pcm/pcm_direct_old.c 2004-01-21 20:21:11.000000000
+0100
+++ alsa-20040123/alsa-lib/src/pcm/pcm_direct.c 2004-01-23 12:40:46.000000000 +0100
@@ -101,11 +101,21 @@
{
static int snd_pcm_direct_shm_discard(snd_pcm_direct_t *dmix);
struct shmid_ds buf;
- int ret = 0;
+ int tmpid, err;
+retryget:
dmix->shmid = shmget(dmix->ipc_key, sizeof(snd_pcm_direct_share_t), IPC_CREAT
| 0666);
- if (dmix->shmid < 0)
- return -errno;
+ err = -errno;
+ if (dmix->shmid < 0){
+ if (errno == EINVAL)
+ if ((tmpid = shmget(dmix->ipc_key, 0, 0666)) != -1)
+ if (!shmctl(tmpid, IPC_STAT, &buf))
+ if (!buf.shm_nattch)
+ /* no users so destroy the segment */
+ if (!shmctl(tmpid, IPC_RMID, NULL))
+ goto retryget;
+ return err;
+ }
dmix->shmptr = shmat(dmix->shmid, 0, 0);
if (dmix->shmptr == (void *) -1) {
snd_pcm_direct_shm_discard(dmix);
@@ -118,9 +128,9 @@
}
if (buf.shm_nattch == 1) { /* we're the first user, clear the segment */
memset(dmix->shmptr, 0, sizeof(snd_pcm_direct_share_t));
- ret = 1;
+ return 1;
}
- return ret;
+ return 0;
}
int snd_pcm_direct_shm_discard(snd_pcm_direct_t *dmix)
--- alsa-20040123/alsa-lib/src/pcm/pcm_dmix_i386_old.h 2004-01-23 13:01:39.000000000
+0100
+++ alsa-20040123/alsa-lib/src/pcm/pcm_dmix_i386.h 2004-01-15 11:06:36.000000000
+0100
@@ -51,16 +51,17 @@
"\tmovl %1, %%edi\n"
"\tmovl %2, %%esi\n"
"\tmovl %3, %%ebx\n"
+ "\tjmp 2f\n"
+
/*
- * while (size-- > 0) {
+ * for (;;)
*/
- "\tcmpl $0, %0\n"
- "jz 6f\n"
-
"\t.p2align 4,,15\n"
-
"1:"
+ "\tadd %4, %%edi\n"
+ "\tadd %5, %%esi\n"
+ "\tadd %6, %%ebx\n"
/*
* sample = *src;
@@ -69,14 +70,17 @@
* sample -= sum_sample;
* xadd(*sum, sample);
*/
- "\tmovw $0, %%ax\n"
- "\tmovw $1, %%cx\n"
+
+ "2:"
+ "\txor %%ax, %%ax\n"
+ "\tmovw %%ax, %%cx\n"
+ "\tincw %%cx\n"
"\tmovl (%%ebx), %%edx\n"
"\t" LOCK_PREFIX "cmpxchgw %%cx, (%%edi)\n"
"\tmovswl (%%esi), %%ecx\n"
- "\tjnz 2f\n"
+ "\tjnz 3f\n"
"\tsubl %%edx, %%ecx\n"
- "2:"
+ "3:"
"\t" LOCK_PREFIX "addl %%ecx, (%%ebx)\n"
/*
@@ -87,25 +91,22 @@
* } while (v != *sum);
*/
- "3:"
+ "4:"
"\tmovl (%%ebx), %%ecx\n"
"\tcmpl $0x7fff,%%ecx\n"
- "\tjg 4f\n"
+ "\tjg 5f\n"
"\tcmpl $-0x8000,%%ecx\n"
- "\tjl 5f\n"
+ "\tjl 6f\n"
"\tmovw %%cx, (%%edi)\n"
"\tcmpl %%ecx, (%%ebx)\n"
- "\tjnz 3b\n"
+ "\tjnz 4b\n"
/*
* while (size-- > 0)
*/
- "\tadd %4, %%edi\n"
- "\tadd %5, %%esi\n"
- "\tadd %6, %%ebx\n"
"\tdecl %0\n"
- "\tjnz 1b\n"
- "\tjmp 6f\n"
+ "\tjz 7f\n"
+ "\tjmp 1b\n"
/*
* sample > 0x7fff
@@ -113,16 +114,13 @@
"\t.p2align 4,,15\n"
- "4:"
+ "5:"
"\tmovw $0x7fff, (%%edi)\n"
"\tcmpl %%ecx,(%%ebx)\n"
- "\tjnz 3b\n"
- "\tadd %4, %%edi\n"
- "\tadd %5, %%esi\n"
- "\tadd %6, %%ebx\n"
+ "\tjnz 4b\n"
"\tdecl %0\n"
"\tjnz 1b\n"
- "\tjmp 6f\n"
+ "\tjmp 7f\n"
/*
* sample < -0x8000
@@ -130,18 +128,15 @@
"\t.p2align 4,,15\n"
- "5:"
+ "6:"
"\tmovw $-0x8000, (%%edi)\n"
"\tcmpl %%ecx, (%%ebx)\n"
- "\tjnz 3b\n"
- "\tadd %4, %%edi\n"
- "\tadd %5, %%esi\n"
- "\tadd %6, %%ebx\n"
+ "\tjnz 4b\n"
"\tdecl %0\n"
"\tjnz 1b\n"
// "\tjmp 6f\n"
- "6:"
+ "7:"
: /* no output regs */
: "m" (size), "m" (dst), "m" (src), "m" (sum), "m" (dst_step), "m"
(src_step), "m" (sum_step)
@@ -174,17 +169,15 @@
"\tmovl %1, %%edi\n"
"\tmovl %2, %%esi\n"
"\tmovl %3, %%ebx\n"
-
- /*
- * while (size-- > 0) {
- */
- "\tcmpl $0, %0\n"
- "jz 6f\n"
+ "\tjmp 2f\n"
"\t.p2align 4,,15\n"
-
"1:"
+ "\tadd %4, %%edi\n"
+ "\tadd %5, %%esi\n"
+ "\tadd %6, %%ebx\n"
+ "2:"
/*
* sample = *src;
* sum_sample = *sum;
@@ -192,14 +185,15 @@
* sample -= sum_sample;
* xadd(*sum, sample);
*/
- "\tmovw $0, %%ax\n"
- "\tmovw $1, %%cx\n"
+ "\txor %%ax, %%ax\n"
+ "\tmovw %%ax, %%cx\n"
+ "\tincw %%cx\n"
"\tmovl (%%ebx), %%edx\n"
"\t" LOCK_PREFIX "cmpxchgw %%cx, (%%edi)\n"
"\tmovswl (%%esi), %%ecx\n"
- "\tjnz 2f\n"
+ "\tjnz 3f\n"
"\tsubl %%edx, %%ecx\n"
- "2:"
+ "3:"
"\t" LOCK_PREFIX "addl %%ecx, (%%ebx)\n"
/*
@@ -210,27 +204,20 @@
* } while (v != *sum);
*/
- "3:"
+ "4:"
"\tmovl (%%ebx), %%ecx\n"
"\tmovd %%ecx, %%mm0\n"
"\tpackssdw %%mm1, %%mm0\n"
"\tmovd %%mm0, %%eax\n"
"\tmovw %%ax, (%%edi)\n"
"\tcmpl %%ecx, (%%ebx)\n"
- "\tjnz 3b\n"
+ "\tjnz 4b\n"
/*
* while (size-- > 0)
*/
- "\tadd %4, %%edi\n"
- "\tadd %5, %%esi\n"
- "\tadd %6, %%ebx\n"
"\tdecl %0\n"
"\tjnz 1b\n"
- "\tjmp 6f\n"
-
- "6:"
-
"\temms\n"
: /* no output regs */
@@ -265,12 +252,6 @@
"\tmovl %2, %%esi\n"
"\tmovl %3, %%ebx\n"
- /*
- * while (size-- > 0) {
- */
- "\tcmpl $0, %0\n"
- "jz 6f\n"
-
"\t.p2align 4,,15\n"
"1:"
@@ -334,12 +315,12 @@
/*
* while (size-- > 0)
*/
+ "\tdecl %0\n"
+ "\tjz 6f\n"
"\tadd %4, %%edi\n"
"\tadd %5, %%esi\n"
"\tadd %6, %%ebx\n"
- "\tdecl %0\n"
- "\tjnz 1b\n"
- // "\tjmp 6f\n"
+ "\tjmp 1b\n"
"6:"
: /* no output regs */
--- alsa-20040123/alsa-lib/src/shmarea_old.c 2004-01-23 12:18:09.000000000 +0100
+++ alsa-20040123/alsa-lib/src/shmarea.c 2004-01-23 12:23:54.000000000 +0100
@@ -56,17 +56,6 @@
return area;
}
-static void _x_destroy(struct snd_shm_area *area)
-{
- struct shmid_ds buf;
-
- shmdt(area->ptr);
- if (shmctl(area->shmid, IPC_STAT, &buf) >= 0) {
- if (buf.shm_nattch == 0)
- shmctl(area->shmid, IPC_RMID, NULL);
- }
-}
-
int snd_shm_area_destroy(struct snd_shm_area *area)
{
if (area == NULL)
@@ -74,7 +63,7 @@
if (--area->share)
return 0;
list_del(&area->list);
- _x_destroy(area);
+ shmdt(area->ptr);
free(area);
return 0;
}
@@ -88,6 +77,6 @@
list_for_each(pos, &shm_areas) {
area = list_entry(pos, struct snd_shm_area, list);
- _x_destroy(area);
+ shmdt(area->ptr);
}
}
