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Improve lock hierarchy

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- NetBSD no longer needs a spin lock to create semaphores
- Windows fork() now locks process manager in correct order
This commit is contained in:
Justine Tunney 2024-07-24 15:55:57 -07:00
parent 7ba9a73840
commit d3a13e8d70
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GPG key ID: BE714B4575D6E328
14 changed files with 73 additions and 71 deletions
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10
libc/proc/fork.c
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@ -54,6 +54,8 @@ extern pthread_mutex_t _pthread_lock_obj;
static void _onfork_prepare(void) {
if (_weaken(_pthread_onfork_prepare))
_weaken(_pthread_onfork_prepare)();
if (IsWindows())
__proc_lock();
_pthread_lock();
__maps_lock();
__fds_lock();
@ -66,11 +68,15 @@ static void _onfork_parent(void) {
__fds_unlock();
__maps_unlock();
_pthread_unlock();
if (IsWindows())
__proc_unlock();
if (_weaken(_pthread_onfork_parent))
_weaken(_pthread_onfork_parent)();
}
static void _onfork_child(void) {
if (IsWindows())
__proc_wipe();
__fds_lock_obj = (pthread_mutex_t)PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
_rand64_lock_obj = (pthread_mutex_t)PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
_pthread_lock_obj = (pthread_mutex_t)PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
@ -87,8 +93,6 @@ int _fork(uint32_t dwCreationFlags) {
int ax, dx, tid, parent;
parent = __pid;
BLOCK_SIGNALS;
if (IsWindows())
__proc_lock();
if (__threaded)
_onfork_prepare();
started = timespec_real();
@ -149,8 +153,6 @@ int _fork(uint32_t dwCreationFlags) {
// this is the parent process
if (__threaded)
_onfork_parent();
if (IsWindows())
__proc_unlock();
STRACE("fork() → %d% m (took %ld us)", ax, micros);
}
ALLOW_SIGNALS;