diff options
Diffstat (limited to 'lib/libpthread/thread/thr_create.c')
| -rw-r--r-- | lib/libpthread/thread/thr_create.c | 58 |
1 files changed, 57 insertions, 1 deletions
diff --git a/lib/libpthread/thread/thr_create.c b/lib/libpthread/thread/thr_create.c index f5e0b63..1b12c7b 100644 --- a/lib/libpthread/thread/thr_create.c +++ b/lib/libpthread/thread/thr_create.c @@ -29,7 +29,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id$ + * $Id: uthread_create.c,v 1.13 1999/06/20 08:28:14 jb Exp $ */ #include <errno.h> #include <stdlib.h> @@ -37,6 +37,10 @@ #include <fcntl.h> #include <unistd.h> #include <sys/time.h> +#ifdef _PTHREAD_GSTACK +#include <sys/types.h> +#include <sys/mman.h> +#endif #ifdef _THREAD_SAFE #include <machine/reg.h> #include <pthread.h> @@ -77,12 +81,64 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr, /* Check if a stack was specified in the thread attributes: */ if ((stack = pattr->stackaddr_attr) != NULL) { } +#ifdef _PTHREAD_GSTACK + /* Allocate memory for a default-size stack: */ + else if (pattr->stacksize_attr == PTHREAD_STACK_DEFAULT) { + struct stack * spare_stack; + + /* Allocate or re-use a default-size stack. */ + + /* Use the garbage collector mutex for synchronization + * of the spare stack list. + * + * XXX This may not be ideal. */ + if (pthread_mutex_lock(&_gc_mutex) != 0) + PANIC("Cannot lock gc mutex"); + + if (NULL != (spare_stack = SLIST_FIRST(&_stackq))) { + /* Use the spare stack. */ + SLIST_REMOVE_HEAD(&_stackq, qe); + stack = sizeof(struct stack) + (void *) spare_stack - PTHREAD_STACK_DEFAULT; + } else { + /* Allocate a new stack. */ + stack = _next_stack + PTHREAD_STACK_GUARD; + /* Even if stack allocation fails, we don't want to try to use this location again, so unconditionally + * decrement _next_stack. Under normal operating conditions, the most likely reason for an mmap() + * error is a stack overflow of the adjacent thread stack. */ + _next_stack -= (PTHREAD_STACK_DEFAULT + PTHREAD_STACK_GUARD); + + /* Red zone: */ + if (MAP_FAILED == mmap(_next_stack, PTHREAD_STACK_GUARD, 0, MAP_ANON, -1, 0)) { + ret = EAGAIN; + free(new_thread); + } + /* Stack: */ + else if (MAP_FAILED == mmap(stack, PTHREAD_STACK_DEFAULT, PROT_READ | PROT_WRITE, MAP_STACK, -1, 0)) { + ret = EAGAIN; + munmap(_next_stack, PTHREAD_STACK_GUARD); + free(new_thread); + } + } + + /* Unlock the garbage collector mutex. */ + if (pthread_mutex_unlock(&_gc_mutex) != 0) + PANIC("Cannot unlock gc mutex"); + } + /* The user wants a stack of a particular size. Lets hope they really know what they want, and simply malloc the + * stack. */ + else if ((stack = (void *) malloc(pattr->stacksize_attr)) == NULL) { + /* Insufficient memory to create a thread: */ + ret = EAGAIN; + free(new_thread); + } +#else /* Allocate memory for the stack: */ else if ((stack = (void *) malloc(pattr->stacksize_attr)) == NULL) { /* Insufficient memory to create a thread: */ ret = EAGAIN; free(new_thread); } +#endif /* Check for errors: */ if (ret != 0) { } else { |
