diff --git a/src/libipc/platform/posix/mutex.h b/src/libipc/platform/posix/mutex.h index 8a4ac5f..a19ace8 100644 --- a/src/libipc/platform/posix/mutex.h +++ b/src/libipc/platform/posix/mutex.h @@ -150,21 +150,19 @@ public: void close() noexcept { if ((ref_ != nullptr) && (shm_ != nullptr) && (mutex_ != nullptr)) { - // Try to unlock the mutex before destroying it. - // This is important for robust mutexes on FreeBSD, which maintain - // a per-thread robust list. If we destroy a mutex while it's in - // the robust list (even if not locked), FreeBSD may encounter - // dangling pointers later, leading to segfaults. - // We ignore any errors from unlock() since: - // 1. If we don't hold the lock, EPERM is expected and harmless - // 2. If the mutex is already unlocked, this is a no-op - // 3. If there's an error, we still want to proceed with cleanup - ::pthread_mutex_unlock(mutex_); - if (shm_->name() != nullptr) { release_mutex(shm_->name(), [this] { auto self_ref = ref_->fetch_sub(1, std::memory_order_relaxed); if ((shm_->ref() <= 1) && (self_ref <= 1)) { + // Before destroying the mutex, try to unlock it. + // This is important for robust mutexes on FreeBSD, which maintain + // a per-thread robust list. If we destroy a mutex while it's locked + // or still in the robust list, FreeBSD may encounter dangling pointers + // later, leading to segfaults. + // Only unlock here (when we're the last reference) to avoid + // interfering with other threads that might be using the mutex. + ::pthread_mutex_unlock(mutex_); + int eno; if ((eno = ::pthread_mutex_destroy(mutex_)) != 0) { ipc::error("fail pthread_mutex_destroy[%d]\n", eno); @@ -182,11 +180,11 @@ public: void clear() noexcept { if ((shm_ != nullptr) && (mutex_ != nullptr)) { - // Try to unlock before destroying, same reasoning as in close() - ::pthread_mutex_unlock(mutex_); - if (shm_->name() != nullptr) { release_mutex(shm_->name(), [this] { + // Unlock before destroying, same reasoning as in close() + ::pthread_mutex_unlock(mutex_); + int eno; if ((eno = ::pthread_mutex_destroy(mutex_)) != 0) { ipc::error("fail pthread_mutex_destroy[%d]\n", eno);