For programs with the dependencies logic in pthread_once callback , using global locks may cause deadlock:
task A
pthread_once()
|
|-> nxrmutex_lock(&g_lock);
-> init_routine(); // callback to wait task B
task B
pthread_once()
|
->nxrmutex_lock(&g_lock); // Deadlock
->init_routine(); // hold resource to wake up task A
Signed-off-by: hujun5 <hujun5@xiaomi.com>
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_once.html
If an implementation detects that the value specified by the once_control
argument to pthread_once() does not refer to a pthread_once_t object
initialized by PTHREAD_ONCE_INIT, it is recommended that the function
should fail and report an [EINVAL] error.
Signed-off-by: zhangyuan21 <zhangyuan21@xiaomi.com>
OpenGroup specification was updated regarding the return value for
pthread_once, which after Issue 7 states that "the [EINVAL] error for an
uninitialized pthread_once_t object is removed; this condition results
in undefined behavior".
Squashed commit of the following:
libs/libxx: Fix some confusing in naming. If the directory is called libxx, then the library must be libxx.a (unless perhaps LIBCXX is selected).
libs/: Fix paths in moved library directories.
libs: Brute force move of libc, libnx, and libxx to libs. Cannot yet build it in that configuration.
