diff options
| -rw-r--r-- | CHANGES | 2 | ||||
| -rw-r--r-- | shmem/unix/shm.c | 55 |
2 files changed, 23 insertions, 34 deletions
@@ -2,7 +2,7 @@ Changes for APR 2.0.0 *) Fix POSIX shared memory (shm_open) use for named shared memory. - PR 55928. [Jozef Hatala <jh-asf skrt org>] + PR 55928. [Jozef Hatala <jh-asf skrt org>, Jim Jagielski] *) Windows platform: Remove support for Windows 9x. diff --git a/shmem/unix/shm.c b/shmem/unix/shm.c index 90dc3061a..3fb20123d 100644 --- a/shmem/unix/shm.c +++ b/shmem/unix/shm.c @@ -33,48 +33,37 @@ #ifndef NAME_MAX #define NAME_MAX 255 #endif -static const char *make_shm_open_safe_name(const char *filename, - apr_pool_t *pool) -{ - const char *in; - char *result; - char *out; - apr_size_t len = 0; - if (filename == NULL) - return NULL; +/* See proc_mutex.c and sem_open for the reason for all this! */ +static unsigned int rshash (const char *p) { + /* hash function from Robert Sedgwicks 'Algorithms in C' book */ + unsigned int b = 378551; + unsigned int a = 63689; + unsigned int retval = 0; - len = strlen(filename); - if (filename[0] != '/') { - ++len; + for( ; *p; p++) { + retval = retval * a + (*p); + a *= b; } - if (len > NAME_MAX) { - len = NAME_MAX; - } - /* Allocate the required string */ - result = apr_palloc(pool, len+1); - in = filename; - if (*in == '/') { - ++in; - } + return retval; +} - out = result; - *out++ = '/'; +static const char *make_shm_open_safe_name(const char *filename, + apr_pool_t *pool) +{ + apr_ssize_t flen; + unsigned int h1, h2; - for ( ; --len; ++in, ++out) { - if (*in == '/') { - /* '/' becomes '|' */ - *out = '|'; - } else { - /* Everything else remains unchanged */ - *out = *in; - } + if (filename == NULL) { + return NULL; } - *out = '\0'; + flen = strlen(filename); + h1 = (apr_hashfunc_default(filename, &flen) & 0xffffffff); + h2 = (rshash(filename) & 0xffffffff); + return apr_psprintf(pool, "/ShM.%xH%x", h1, h2); - return result; } #endif |