make linking of thread-start with explicit scheduling conditional

the wrapper start function that performs scheduling operations is
unreachable if pthread_attr_setinheritsched is never called, so move
it there rather than the pthread_create source file, saving some code
size for static-linked programs.

diff --git a/src/internal/pthread_impl.h b/src/internal/pthread_impl.h
index 69352ef24c22948863406c18ec11d06ffee3cbf2..c2deffb9542b2445b93f7c7be8c8bfffae785084 100644 (file)
--- a/src/internal/pthread_impl.h
+++ b/src/internal/pthread_impl.h
@@ -56,6 +56,14 @@ struct pthread {
        void **dtv_copy;
 };
 
+struct start_sched_args {
+       void *start_arg;
+       void *(*start_fn)(void *);
+       sigset_t mask;
+       pthread_attr_t *attr;
+       volatile int futex;
+};
+
 enum {
        DT_EXITED = 0,
        DT_EXITING,

diff --git a/src/thread/pthread_attr_setinheritsched.c b/src/thread/pthread_attr_setinheritsched.c
index c91d8f83cc749acb79b5d9259f97432f54805175..e540e846f8849e5fc42a7d0360038c30d3514bf6 100644 (file)
--- a/src/thread/pthread_attr_setinheritsched.c
+++ b/src/thread/pthread_attr_setinheritsched.c
@@ -1,4 +1,25 @@
 #include "pthread_impl.h"
+#include "syscall.h"
+
+__attribute__((__visibility__("hidden")))
+void *__start_sched(void *p)
+{
+       struct start_sched_args *ssa = p;
+       void *start_arg = ssa->start_arg;
+       void *(*start_fn)(void *) = ssa->start_fn;
+       pthread_t self = __pthread_self();
+
+       int ret = -__syscall(SYS_sched_setscheduler, self->tid,
+               ssa->attr->_a_policy, &ssa->attr->_a_prio);
+       if (!ret) __restore_sigs(&ssa->mask);
+       a_store(&ssa->futex, ret);
+       __wake(&ssa->futex, 1, 1);
+       if (ret) {
+               self->detach_state = DT_DYNAMIC;
+               return 0;
+       }
+       return start_fn(start_arg);
+}
 
 int pthread_attr_setinheritsched(pthread_attr_t *a, int inherit)
 {

diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index 5f07ab49ed2ea98fc04f4a9aefebf98425191427..2c066cffffe5c222457f456b34da0de36815d5b1 100644 (file)
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -19,6 +19,12 @@ weak_alias(dummy_0, __pthread_tsd_run_dtors);
 weak_alias(dummy_0, __do_orphaned_stdio_locks);
 weak_alias(dummy_0, __dl_thread_cleanup);
 
+static void *dummy_1(void *p)
+{
+       return 0;
+}
+weak_alias(dummy_1, __start_sched);
+
 _Noreturn void __pthread_exit(void *result)
 {
        pthread_t self = __pthread_self();
@@ -132,33 +138,6 @@ void __do_cleanup_pop(struct __ptcb *cb)
        __pthread_self()->cancelbuf = cb->__next;
 }
 
-struct start_sched_args {
-       void *start_arg;
-       void *(*start_fn)(void *);
-       sigset_t mask;
-       pthread_attr_t *attr;
-       volatile int futex;
-};
-
-static void *start_sched(void *p)
-{
-       struct start_sched_args *ssa = p;
-       void *start_arg = ssa->start_arg;
-       void *(*start_fn)(void *) = ssa->start_fn;
-       pthread_t self = __pthread_self();
-
-       int ret = -__syscall(SYS_sched_setscheduler, self->tid,
-               ssa->attr->_a_policy, &ssa->attr->_a_prio);
-       if (!ret) __restore_sigs(&ssa->mask);
-       a_store(&ssa->futex, ret);
-       __wake(&ssa->futex, 1, 1);
-       if (ret) {
-               self->detach_state = DT_DYNAMIC;
-               return 0;
-       }
-       return start_fn(start_arg);
-}
-
 static int start(void *p)
 {
        pthread_t self = p;
@@ -302,7 +281,7 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
                ssa.start_fn = new->start;
                ssa.start_arg = new->start_arg;
                ssa.attr = &attr;
-               new->start = start_sched;
+               new->start = __start_sched;
                new->start_arg = &ssa;
                __block_app_sigs(&ssa.mask);
        }