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author | arpi_esp <arpi_esp@b3059339-0415-0410-9bf9-f77b7e298cf2> | 2001-02-24 20:28:24 +0000 |
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committer | arpi_esp <arpi_esp@b3059339-0415-0410-9bf9-f77b7e298cf2> | 2001-02-24 20:28:24 +0000 |
commit | d34041569e71fc9bd772354e94dc9d16061072a5 (patch) | |
tree | 8f481cae1c70f32d1756fbe5f39000577b73042d /linux/shmem.c | |
parent | e95a95ece09bac96bdfd37322f96c6f57ef79ebc (diff) | |
download | mpv-d34041569e71fc9bd772354e94dc9d16061072a5.tar.bz2 mpv-d34041569e71fc9bd772354e94dc9d16061072a5.tar.xz |
Initial revision
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@2 b3059339-0415-0410-9bf9-f77b7e298cf2
Diffstat (limited to 'linux/shmem.c')
-rw-r--r-- | linux/shmem.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/linux/shmem.c b/linux/shmem.c new file mode 100644 index 0000000000..7563175fb0 --- /dev/null +++ b/linux/shmem.c @@ -0,0 +1,83 @@ +/* + * shmem.c - Shared memory allocation + * + * based on mpg123's xfermem.c by + * Oliver Fromme <oliver.fromme@heim3.tu-clausthal.de> + * Sun Apr 6 02:26:26 MET DST 1997 + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> +#include <sys/types.h> +#include <sys/time.h> +#include <sys/uio.h> +#include <sys/mman.h> +#include <sys/socket.h> +#include <fcntl.h> + +#ifdef AIX +#include <sys/select.h> +#endif + +#include <sys/ipc.h> +#include <sys/shm.h> + +extern int errno; + +#if defined(MAP_ANONYMOUS) && !defined(MAP_ANON) +#define MAP_ANON MAP_ANONYMOUS +#endif + +static int shmem_type=0; + +void* shmem_alloc(int size){ +void* p; +int devzero; +while(1){ + switch(shmem_type){ + case 0: // ========= MAP_ANON|MAP_SHARED ========== + p=mmap(0,size,PROT_READ|PROT_WRITE,MAP_ANON|MAP_SHARED,-1,0); + if(p==MAP_FAILED) break; // failed + printf("shmem: %d bytes allocated using mmap anon (%X)\n",size,p); + return p; + case 1: // ========= MAP_SHARED + /dev/zero ========== + if ((devzero = open("/dev/zero", O_RDWR, 0)) == -1) break; + p=mmap(0,size,PROT_READ|PROT_WRITE,MAP_SHARED,devzero,0); + if(p==MAP_FAILED) break; // failed + printf("shmem: %d bytes allocated using mmap /dev/zero (%X)\n",size,p); + return p; + case 2: { // ========= shmget() ========== + struct shmid_ds shmemds; + int shmemid; + if ((shmemid = shmget(IPC_PRIVATE, size, IPC_CREAT | 0600)) == -1) break; + if ((int)(p = shmat(shmemid, 0, 0)) == -1){ + perror ("shmat()"); + shmctl (shmemid, IPC_RMID, &shmemds); + break; + } + if (shmctl(shmemid, IPC_RMID, &shmemds) == -1) { + perror ("shmctl()"); + if (shmdt(p) == -1) perror ("shmdt()"); + break; + } + printf("shmem: %d bytes allocated using shmget() & shmat() (%X)\n",size,p); + return p; + } + default: + printf("FATAL: Cannot alloate %d bytes shared memory :(\n",size); + return NULL; + } + ++shmem_type; +} +} + +void shmem_free(void* p){ + switch(shmem_type){ + case 2: + if (shmdt(p) == -1) perror ("shmdt()"); + break; + } +} |