我正在修改一些现有的声音代码，并注意到在完成将配置数据写入硬件后，该代码不会调用snd_pcm_hw_params_free()。由于遗留原因，该应用程序会针对播放的每种声音打开和关闭声音硬件。这一定会导致内存泄漏，因为snd_pcm_hw_params_t *从未被释放。因此，我在`snd_pcm_hw_params_free()中添加了一个调用，现在得到以下错误:
[root@n00200C709F3D namb2]# ./freetest
*** glibc detected *** ./freetest: free(): invalid pointer: 0xbfe39000 ***
======= Backtrace: =========
/lib/libc.so.6[0xb75dc595]
/lib/libc.so.6(cfree+0x59)[0xb75dc9d9]
/emsnamb/namb2/lib/libasound.so.2(snd_pcm_hw_params_free+0x1d)[0xb7707bad]
./freetest[0x804876b]
/lib/libc.so.6(__libc_start_main+0xdc)[0xb7588e9c]
./freetest(memset+0x31)[0x80485b1]
======= Memory map: ========
08048000-08049000 r-xp 00000000 00:0e 5413865 /var/tmp/namb2/freetest
08049000-0804a000 rwxp 00000000 00:0e 5413865 /var/tmp/namb2/freetest
0804a000-08094000 rwxp 00000000 00:00 0 [heap]
b74f1000-b74fc000 r-xp 00000000 fe:00 48544 /lib/libgcc_s-4.1.2-20080825.so.1
b74fc000-b74fd000 rwxp 0000a000 fe:00 48544 /lib/libgcc_s-4.1.2-20080825.so.1
b7506000-b7516000 rwxs 00000000 00:04 149192707 /SYSV0056a4d6 (deleted)
b7516000-b7526000 rwxs 00000000 00:0d 1789 /dev/snd/pcmC0D0p
b7526000-b7527000 rwxp 00000000 00:00 0
b7527000-b752e000 r-xp 00000000 fe:00 48586 /lib/librt-2.5.so
b752e000-b752f000 r-xp 00006000 fe:00 48586 /lib/librt-2.5.so
b752f000-b7530000 rwxp 00007000 fe:00 48586 /lib/librt-2.5.so
b7530000-b7531000 rwxp 00000000 00:00 0
b7531000-b7544000 r-xp 00000000 fe:00 48582 /lib/libpthread-2.5.so
b7544000-b7545000 r-xp 00013000 fe:00 48582 /lib/libpthread-2.5.so
b7545000-b7546000 rwxp 00014000 fe:00 48582 /lib/libpthread-2.5.so
b7546000-b7548000 rwxp 00000000 00:00 0
b7548000-b754a000 r-xp 00000000 fe:00 48536 /lib/libdl-2.5.so
b754a000-b754b000 r-xp 00001000 fe:00 48536 /lib/libdl-2.5.so
b754b000-b754c000 rwxp 00002000 fe:00 48536 /lib/libdl-2.5.so
b754c000-b7571000 r-xp 00000000 fe:00 48557 /lib/libm-2.5.so
b7571000-b7572000 r-xp 00024000 fe:00 48557 /lib/libm-2.5.so
b7572000-b7573000 rwxp 00025000 fe:00 48557 /lib/libm-2.5.so
b7573000-b76b2000 r-xp 00000000 fe:00 48509 /lib/libc-2.5.so
b76b2000-b76b4000 r-xp 0013f000 fe:00 48509 /lib/libc-2.5.so
b76b4000-b76b5000 rwxp 00141000 fe:00 48509 /lib/libc-2.5.so
b76b5000-b76b8000 rwxp 00000000 00:00 0
b76be000-b76bf000 rwxs 81000000 00:0d 1789 /dev/snd/pcmC0D0p
b76bf000-b76c0000 r-xs 80000000 00:0d 1789 /dev/snd/pcmC0D0p
b76c0000-b76c1000 rwxs 00000000 00:04 149159938 /SYSV0056a4d5 (deleted)
b76c1000-b779b000 r-xp 00000000 fe:00 48500 /lib/libasound.so.2.0.0
b779b000-b77a0000 rwxp 000d9000 fe:00 48500 /lib/libasound.so.2.0.0
b77a0000-b77a1000 rwxp 00000000 00:00 0
b77a1000-b77a2000 r-xp 00000000 00:00 0 [vdso]
b77a2000-b77bc000 r-xp 00000000 fe:00 48490 /lib/ld-2.5.so
b77bc000-b77bd000 r-xp 00019000 fe:00 48490 /lib/ld-2.5.so
b77bd000-b77be000 rwxp 0001a000 fe:00 48490 /lib/ld-2.5.so
bfe1a000-bfe3b000 rwxp 00000000 00:00 0 [stack]
Aborted
下面的测试程序显示了此问题。这是否表明我的
libasound安装被某种程度破坏了？#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <alsa/asoundlib.h>
int main(int argc, char *argv[])
{
snd_pcm_t *handle;
snd_pcm_hw_params_t *params;
int rc;
if((rc = snd_pcm_open(&handle, "default", SND_PCM_STREAM_PLAYBACK, 0)) < 0)
{
printf("Playback open error: %s\n", snd_strerror(rc));
exit(EXIT_FAILURE);
}
/* Allocate a hardware parameters object. */
snd_pcm_hw_params_alloca(¶ms);
/* Fill it in with default values. */
if (snd_pcm_hw_params_any(handle, params) < 0)
{
fprintf(stderr, "Can not configure this PCM device.\n");
snd_pcm_close(handle);
return(-1);
}
/* Write the parameters to the driver */
if ( (rc = snd_pcm_hw_params(handle, params)) < 0 )
{
fprintf(stderr, "unable to set hw parameters: %s\n", snd_strerror(rc));
snd_pcm_close(handle);
return -1;
}
snd_pcm_hw_params_free(params);
snd_pcm_close(handle);
return 0;
}
最佳答案
snd_pcm_hw_params_alloca()文档说:
标准的alloca()函数从堆栈分配内存；该函数退出时，该内存将自动释放。
您只能将snd_pcm_hw_params_free()用于分配了snd_pcm_hw_params_malloc()的对象。
关于c - ALSA : snd_pcm_hw_params_free() causing memory error，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/40350971/