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* allow the sbrk backend to be requested via UMEM_OPTIONS=backend=sbrk, but note that this appears to be broken on non-solaris platforms.

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* make a safer/better check for number of cpus on linux
 * use pthread_once to register the forkhandler, as it is possible to call it twice in some scenarios without this protection
This commit is contained in:
Wez Furlong 2010-04-30 21:27:09 +00:00
parent b2ee64fc04
commit f82ad44b62
2 changed files with 36 additions and 25 deletions
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55
init_lib.c
View file

@ -56,28 +56,31 @@ vmem_heap_init(void)
{
#ifdef _WIN32
vmem_backend = VMEM_BACKEND_MMAP;
(void) vmem_sbrk_arena(NULL, NULL);
#else
#if 0
# if defined(sun)
void *handle = dlopen("libmapmalloc.so.1", RTLD_NOLOAD);
if (handle != NULL) {
#endif
log_message("sbrk backend disabled\n");
vmem_backend = VMEM_BACKEND_MMAP;
#if 0
}
#endif
#endif
# else
if (vmem_backend == 0) {
/* prefer mmap, as sbrk() seems to have problems wither working
* with other allocators or has some Solaris specific assumptions. */
vmem_backend = VMEM_BACKEND_MMAP;
}
# endif
if ((vmem_backend & VMEM_BACKEND_MMAP) != 0) {
vmem_backend = VMEM_BACKEND_MMAP;
(void) vmem_mmap_arena(NULL, NULL);
} else {
#ifndef _WIN32
vmem_backend = VMEM_BACKEND_SBRK;
(void) vmem_sbrk_arena(NULL, NULL);
#endif
}
#endif
}
/*ARGSUSED*/
@ -104,28 +107,32 @@ umem_get_max_ncpus(void)
* in /proc/stat. To avoid recursion in the malloc replacement
* version of libumem, read /proc/stat into a static buffer.
*/
static char proc_stat[8192];
int fd;
int ncpus = 1;
static int ncpus = 0;
fd = open("/proc/stat", O_RDONLY);
if (fd >= 0) {
const ssize_t n = read(fd, proc_stat, sizeof(proc_stat) - 1);
if (n >= 0) {
const char *cur;
const char *next;
if (ncpus == 0) {
char proc_stat[8192];
int fd;
proc_stat[n] = '\0';
cur = proc_stat;
while (*cur && (next = strstr(cur + 3, "cpu"))) {
cur = next;
ncpus = 1;
fd = open("/proc/stat", O_RDONLY);
if (fd >= 0) {
const ssize_t n = read(fd, proc_stat, sizeof(proc_stat) - 1);
if (n >= 0) {
const char *cur;
const char *next;
proc_stat[n] = '\0';
cur = proc_stat;
while (*cur && (next = strstr(cur + 3, "cpu"))) {
cur = next;
}
if (*cur)
ncpus = atoi(cur + 3) + 1;
}
if (*cur)
ncpus = atoi(cur + 3) + 1;
close(fd);
}
close(fd);
}
return ncpus;

6
umem.c
View file

@ -621,6 +621,9 @@ static umem_cache_t *umem_alloc_table[UMEM_MAXBUF >> UMEM_ALIGN_SHIFT] = {
caddr_t umem_min_stack;
caddr_t umem_max_stack;
#ifndef UMEM_STANDALONE
static pthread_once_t umem_forkhandler_once = PTHREAD_ONCE_INIT;
#endif
/*
* we use the _ versions, since we don't want to be cancelled.
@ -2907,7 +2910,8 @@ umem_startup(caddr_t start, size_t len, size_t pagesize, caddr_t minstack,
int idx;
/* Standalone doesn't fork */
#else
umem_forkhandler_init(); /* register the fork handler */
/* register the fork handler */
(void) pthread_once(&umem_forkhandler_once, umem_forkhandler_init);
#endif
#ifdef __lint