Module: xenomai-forge
Branch: master
Commit: 014898add6a697e1a0d69f9e20b910ade74f1940
URL:
http://git.xenomai.org/?p=xenomai-forge.git;a=commit;h=014898add6a697e1a0d69f9e20b910ade74f1940
Author: Philippe Gerum <r...@xenomai.org>
Date: Sun Apr 14 18:59:29 2013 +0200
lib/cobalt: fix atfork handling
The TLS-based "current" key must be cleared upon fork in the child
context, so that assertion code checking the current mode does not
spuriously reuse the parent u_window.
In addition, the calling sequence of atfork handlers is fixed, so that
such handler installed by the deferred print support does not call
into assert_nrt() checks from a freshly forked child before the
"current" key is cleared.
---
lib/cobalt/assert_context.c | 5 +++--
lib/cobalt/current.c | 35 +++++++++++++++++++++--------------
lib/cobalt/init.c | 4 ++--
lib/cobalt/internal.h | 4 ++++
lib/cobalt/printf.c | 9 ++++++---
lib/cobalt/sem_heap.c | 1 +
6 files changed, 37 insertions(+), 21 deletions(-)
diff --git a/lib/cobalt/assert_context.c b/lib/cobalt/assert_context.c
index 9a864fc..6125355 100644
--- a/lib/cobalt/assert_context.c
+++ b/lib/cobalt/assert_context.c
@@ -23,6 +23,7 @@
#include <nucleus/thread.h>
#include <asm-generic/syscall.h>
#include <asm-generic/current.h>
+#include <unistd.h>
static void assert_nrt_inner(void)
{
@@ -32,8 +33,8 @@ static void assert_nrt_inner(void)
err = XENOMAI_SYSCALL1(sc_nucleus_current_info, &info);
if (err) {
- fprintf(stderr, "sc_nucleus_current_info failed: %s\n",
- strerror(-err));
+ fprintf(stderr, "sc_nucleus_current_info failed: %s, window=%p,
state=%lx, pid=%d\n",
+ strerror(-err), xeno_current_window,
xeno_current_window->state, getpid());
return;
}
diff --git a/lib/cobalt/current.c b/lib/cobalt/current.c
index 1822703..5b7ed19 100644
--- a/lib/cobalt/current.c
+++ b/lib/cobalt/current.c
@@ -12,9 +12,13 @@
extern unsigned long xeno_sem_heap[2];
+static void child_fork_handler(void);
+
#ifdef HAVE_TLS
+
__thread __attribute__ ((tls_model (CONFIG_XENO_TLS_MODEL)))
xnhandle_t xeno_current = XN_NO_HANDLE;
+
__thread __attribute__ ((tls_model (CONFIG_XENO_TLS_MODEL)))
struct xnthread_user_window *xeno_current_window;
@@ -23,8 +27,9 @@ static inline void __xeno_set_current(xnhandle_t current)
xeno_current = current;
}
-void xeno_init_current_keys(void)
+static void init_current_keys(void)
{
+ pthread_atfork(NULL, NULL, &child_fork_handler);
}
void xeno_set_current_window(unsigned long offset)
@@ -33,6 +38,7 @@ void xeno_set_current_window(unsigned long offset)
(xeno_sem_heap[0] + offset);
__cobalt_prefault(xeno_current_window);
}
+
#else /* !HAVE_TLS */
pthread_key_t xeno_current_window_key;
@@ -44,19 +50,13 @@ static inline void __xeno_set_current(xnhandle_t current)
pthread_setspecific(xeno_current_key, (void *)current);
}
-static void xeno_current_fork_handler(void)
-{
- if (xeno_get_current() != XN_NO_HANDLE)
- __xeno_set_current(XN_NO_HANDLE);
-}
-
static void init_current_keys(void)
{
int err = pthread_key_create(&xeno_current_key, NULL);
if (err)
goto error_exit;
- pthread_atfork(NULL, NULL, &xeno_current_fork_handler);
+ pthread_atfork(NULL, NULL, &child_fork_handler);
err = pthread_key_create(&xeno_current_window_key, NULL);
if (err) {
@@ -67,12 +67,6 @@ static void init_current_keys(void)
}
}
-void xeno_init_current_keys(void)
-{
- static pthread_once_t xeno_init_current_keys_once = PTHREAD_ONCE_INIT;
- pthread_once(&xeno_init_current_keys_once, init_current_keys);
-}
-
void xeno_set_current_window(unsigned long offset)
{
struct xnthread_user_window *window;
@@ -81,8 +75,15 @@ void xeno_set_current_window(unsigned long offset)
pthread_setspecific(xeno_current_window_key, window);
__cobalt_prefault(window);
}
+
#endif /* !HAVE_TLS */
+static void child_fork_handler(void)
+{
+ if (xeno_get_current() != XN_NO_HANDLE)
+ __xeno_set_current(XN_NO_HANDLE);
+}
+
xnhandle_t xeno_slow_get_current(void)
{
xnhandle_t current;
@@ -106,3 +107,9 @@ void xeno_set_current(void)
}
__xeno_set_current(current);
}
+
+void xeno_init_current_keys(void)
+{
+ static pthread_once_t xeno_init_current_keys_once = PTHREAD_ONCE_INIT;
+ pthread_once(&xeno_init_current_keys_once, init_current_keys);
+}
diff --git a/lib/cobalt/init.c b/lib/cobalt/init.c
index 6743a06..d3e8e9f 100644
--- a/lib/cobalt/init.c
+++ b/lib/cobalt/init.c
@@ -154,8 +154,6 @@ void __init_cobalt_interface(void)
struct sigaction sa;
const char *p;
- rt_print_auto_init(1);
-
muxid = bind_interface();
if (muxid < 0) {
report_error("interface unavailable");
@@ -223,4 +221,6 @@ no_shadow:
(int) sizeof(struct __shadow_mutex));
exit(EXIT_FAILURE);
}
+
+ cobalt_print_init();
}
diff --git a/lib/cobalt/internal.h b/lib/cobalt/internal.h
index 6324622..a939a2b 100644
--- a/lib/cobalt/internal.h
+++ b/lib/cobalt/internal.h
@@ -71,4 +71,8 @@ int cobalt_event_inquire(cobalt_event_t *event,
int cobalt_event_destroy(cobalt_event_t *event);
+void cobalt_print_init(void);
+
+void cobalt_print_exit(void);
+
#endif /* XENO_COBALT_INTERNAL_H */
diff --git a/lib/cobalt/printf.c b/lib/cobalt/printf.c
index f9f2ecb..c4e524f 100644
--- a/lib/cobalt/printf.c
+++ b/lib/cobalt/printf.c
@@ -32,6 +32,7 @@
#include <asm/xenomai/atomic.h> /* For atomic_cmpxchg */
#include <asm-generic/stack.h>
#include <asm-generic/current.h>
+#include "internal.h"
#define RT_PRINT_BUFFER_ENV "RT_PRINT_BUFFER"
#define RT_PRINT_DEFAULT_BUFFER 16*1024
@@ -666,7 +667,7 @@ static void forked_child_init(void)
spawn_printer_thread();
}
-static __attribute__ ((constructor)) void __rt_print_init(void)
+void cobalt_print_init(void)
{
const char *value_str;
unsigned long long period;
@@ -740,7 +741,7 @@ static __attribute__ ((constructor)) void
__rt_print_init(void)
xnarch_atomic_set(&pool_bitmap[i], ~0UL);
if (buffers_count % BITS_PER_LONG)
xnarch_atomic_set(&pool_bitmap[i],
- (1UL << (buffers_count %
BITS_PER_LONG)) - 1);
+ (1UL << (buffers_count %
BITS_PER_LONG)) - 1);
for (i = 0; i < buffers_count; i++) {
struct print_buffer *buffer =
@@ -761,9 +762,11 @@ static __attribute__ ((constructor)) void
__rt_print_init(void)
spawn_printer_thread();
pthread_atfork(NULL, NULL, forked_child_init);
+
+ rt_print_auto_init(1);
}
-static __attribute__ ((destructor)) void __rt_print_exit(void)
+void cobalt_print_exit(void)
{
if (buffers) {
/* Flush the buffers. Do not call print_buffers here
diff --git a/lib/cobalt/sem_heap.c b/lib/cobalt/sem_heap.c
index 5916732..3315387 100644
--- a/lib/cobalt/sem_heap.c
+++ b/lib/cobalt/sem_heap.c
@@ -14,6 +14,7 @@
#include <asm/xenomai/syscall.h>
#include <asm-generic/sem_heap.h>
#include <asm-generic/current.h>
+#include "internal.h"
#define PRIVATE 0
#define SHARED 1
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