simplify pthread_attr_t stack/guard size representation

previously, the pthread_attr_t object was always initialized all-zero,
and stack/guard size were represented as differences versus their
defaults. this required lots of confusing offset arithmetic everywhere
they were used. instead, have pthread_attr_init fill in the default
values, and work with absolute sizes everywhere.

diff --git a/src/thread/pthread_attr_get.c b/src/thread/pthread_attr_get.c
index 3d296bf..4aa5afd 100644 (file)
--- a/src/thread/pthread_attr_get.c
+++ b/src/thread/pthread_attr_get.c
@@ -7,7 +7,7 @@ int pthread_attr_getdetachstate(const pthread_attr_t *a, int *state)
 }
 int pthread_attr_getguardsize(const pthread_attr_t *restrict a, size_t *restrict size)
 {
-       *size = a->_a_guardsize + DEFAULT_GUARD_SIZE;
+       *size = a->_a_guardsize;
        return 0;
 }
 
@@ -39,14 +39,14 @@ int pthread_attr_getstack(const pthread_attr_t *restrict a, void **restrict addr
 {
        if (!a->_a_stackaddr)
                return EINVAL;
-       *size = a->_a_stacksize + DEFAULT_STACK_SIZE;
+       *size = a->_a_stacksize;
        *addr = (void *)(a->_a_stackaddr - *size);
        return 0;
 }
 
 int pthread_attr_getstacksize(const pthread_attr_t *restrict a, size_t *restrict size)
 {
-       *size = a->_a_stacksize + DEFAULT_STACK_SIZE;
+       *size = a->_a_stacksize;
        return 0;
 }
 

diff --git a/src/thread/pthread_attr_init.c b/src/thread/pthread_attr_init.c
index 969e0a3..8f6e337 100644 (file)
--- a/src/thread/pthread_attr_init.c
+++ b/src/thread/pthread_attr_init.c
@@ -3,5 +3,7 @@
 int pthread_attr_init(pthread_attr_t *a)
 {
        *a = (pthread_attr_t){0};
+       a->_a_stacksize = DEFAULT_STACK_SIZE;
+       a->_a_guardsize = DEFAULT_GUARD_SIZE;
        return 0;
 }

diff --git a/src/thread/pthread_attr_setguardsize.c b/src/thread/pthread_attr_setguardsize.c
index 9f21d24..1c5c60a 100644 (file)
--- a/src/thread/pthread_attr_setguardsize.c
+++ b/src/thread/pthread_attr_setguardsize.c
@@ -3,6 +3,6 @@
 int pthread_attr_setguardsize(pthread_attr_t *a, size_t size)
 {
        if (size > SIZE_MAX/8) return EINVAL;
-       a->_a_guardsize = size - DEFAULT_GUARD_SIZE;
+       a->_a_guardsize = size;
        return 0;
 }

diff --git a/src/thread/pthread_attr_setstack.c b/src/thread/pthread_attr_setstack.c
index 61707a3..1eddcbd 100644 (file)
--- a/src/thread/pthread_attr_setstack.c
+++ b/src/thread/pthread_attr_setstack.c
@@ -4,6 +4,6 @@ int pthread_attr_setstack(pthread_attr_t *a, void *addr, size_t size)
 {
        if (size-PTHREAD_STACK_MIN > SIZE_MAX/4) return EINVAL;
        a->_a_stackaddr = (size_t)addr + size;
-       a->_a_stacksize = size - DEFAULT_STACK_SIZE;
+       a->_a_stacksize = size;
        return 0;
 }

diff --git a/src/thread/pthread_attr_setstacksize.c b/src/thread/pthread_attr_setstacksize.c
index 09d3fda..9c6a880 100644 (file)
--- a/src/thread/pthread_attr_setstacksize.c
+++ b/src/thread/pthread_attr_setstacksize.c
@@ -4,6 +4,6 @@ int pthread_attr_setstacksize(pthread_attr_t *a, size_t size)
 {
        if (size-PTHREAD_STACK_MIN > SIZE_MAX/4) return EINVAL;
        a->_a_stackaddr = 0;
-       a->_a_stacksize = size - DEFAULT_STACK_SIZE;
+       a->_a_stacksize = size;
        return 0;
 }

diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index 9f6b98e..db9e575 100644 (file)
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -208,7 +208,7 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
 
        if (attr._a_stackaddr) {
                size_t need = libc.tls_size + __pthread_tsd_size;
-               size = attr._a_stacksize + DEFAULT_STACK_SIZE;
+               size = attr._a_stacksize;
                stack = (void *)(attr._a_stackaddr & -16);
                stack_limit = (void *)(attr._a_stackaddr - size);
                /* Use application-provided stack for TLS only when
@@ -223,8 +223,8 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
                        guard = 0;
                }
        } else {
-               guard = ROUND(DEFAULT_GUARD_SIZE + attr._a_guardsize);
-               size = guard + ROUND(DEFAULT_STACK_SIZE + attr._a_stacksize
+               guard = ROUND(attr._a_guardsize);
+               size = guard + ROUND(attr._a_stacksize
                        + libc.tls_size +  __pthread_tsd_size);
        }
 

diff --git a/src/thread/pthread_getattr_np.c b/src/thread/pthread_getattr_np.c
index 10ea512..ae26a5a 100644 (file)
--- a/src/thread/pthread_getattr_np.c
+++ b/src/thread/pthread_getattr_np.c
@@ -9,7 +9,7 @@ int pthread_getattr_np(pthread_t t, pthread_attr_t *a)
        a->_a_detach = !!t->detached;
        if (t->stack) {
                a->_a_stackaddr = (uintptr_t)t->stack;
-               a->_a_stacksize = t->stack_size - DEFAULT_STACK_SIZE;
+               a->_a_stacksize = t->stack_size;
        } else {
                char *p = (void *)libc.auxv;
                size_t l = PAGE_SIZE;
@@ -17,7 +17,7 @@ int pthread_getattr_np(pthread_t t, pthread_attr_t *a)
                a->_a_stackaddr = (uintptr_t)p;
                while (mremap(p-l-PAGE_SIZE, PAGE_SIZE, 2*PAGE_SIZE, 0)==MAP_FAILED && errno==ENOMEM)
                        l += PAGE_SIZE;
-               a->_a_stacksize = l - DEFAULT_STACK_SIZE;
+               a->_a_stacksize = l;
        }
        return 0;
 }