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workq_kernreturn: Extract initial flags and fix x86_64 assembly arguments
We need to initialize the flags in case we terminate as soon as we're created (because `_pthread_wqthread` requires valid flags).
This also fixes the x86_64 assembly to ensure that the 6th argument is actually passed (for some reason, the old code was causing the 6th argument to be a copy of the 5th). We don't need to specifically use `rbx`, so just use `r` and let the compiler decide what to use.
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-17
+31
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src/kernel/emulation/linux/bsdthread/workq_kernreturn.c
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src/kernel/emulation/linux/bsdthread/workq_kernreturn.c
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// This is horrible, but it may work
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static struct wq_kevent_data* wq_event_pending = NULL;
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static int extract_wq_flags(int priority) {
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int flags = 0;
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int qos = _pthread_priority_thread_qos(priority);
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// Apple has created a mess of QoS in libdispatch and sometimes libdispatch doesn't set QoS properly when building with configurations Apple (apparently) hasn't tested
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//
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// we only do this is a hack/workaround until we improve our workqueue/kqueue support to use libdispatch's new SPIs
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if (qos == 0) {
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qos = 4; // default libdispatch QoS
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}
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flags = WQ_FLAG_THREAD_NEWSPI | qos | WQ_FLAG_THREAD_PRIO_QOS;
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if (priority & _PTHREAD_PRIORITY_OVERCOMMIT_FLAG) {
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flags |= WQ_FLAG_THREAD_OVERCOMMIT;
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}
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return flags;
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};
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long sys_workq_kernreturn(int options, void* item, int affinity, int prio)
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{
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#ifndef VARIANT_DYLD
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// Semaphore locked state (wait for wakeup)
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me.sem = 0;
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// extract initial flags
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// (in case we only get created and used once and then terminate; `_pthread_wqthread` requires a valid `flags` argument)
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dthread = _pthread_getspecific_direct(_PTHREAD_TSD_SLOT_PTHREAD_SELF);
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prio = _pthread_getspecific_direct(_PTHREAD_TSD_SLOT_PTHREAD_QOS_CLASS);
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// doesn't extract `WQ_FLAG_THREAD_KEVENT` if we had it set, but that shouldn't matter
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// like i said before, the only case where we actually need these flags to be set here is when the thread is going to die immediately after creation
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me.flags = extract_wq_flags(prio);
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// Enqueue for future WQOPS_QUEUE_REQTHREADS
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TAILQ_INSERT_HEAD(&workq_parked_head, &me, entries);
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···
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// arguments are in rdi, rsi, rdx, rcx, r8, r9
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__asm__ __volatile__ (
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// "int3\n"
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"movq %%rbx, %%r8\n" // 5th argument
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"movl %3, %%r8d\n" // 5th argument
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"movl %5, %%r9d\n" // 6th argument
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"movq %0, %%rsp\n"
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"subq $32, %%rsp\n"
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"jmpq *%2\n"
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:: "D" (dthread), "S" (thread_self), "a" (wqueue_entry_point),
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"b" (me.flags | WQ_FLAG_THREAD_REUSE), "c" ((!terminating && me.event) ? me.event->events : NULL),
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"r" (me.flags | WQ_FLAG_THREAD_REUSE), "c" ((!terminating && me.event) ? me.event->events : NULL),
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"r" (terminating ? WORKQ_EXIT_THREAD_NKEVENT : (me.event ? me.event->nevents : 0)), "d" (dthread->stackbottom)
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);
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#elif defined(__i386__)
···
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{
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// affinity contains thread count
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int i, flags, qos = _pthread_priority_thread_qos(prio);
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// Apple has created a mess of QoS in libdispatch and sometimes libdispatch doesn't set QoS properly
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// when building with configurations Apple (apparently) hasn't tested
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//
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// we only do this is a hack/workaround until we improve our workqueue/kqueue support to use libdispatch's new SPIs
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if (qos == 0) {
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qos = 4; // default libdispatch QoS
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}
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flags = WQ_FLAG_THREAD_NEWSPI | qos | WQ_FLAG_THREAD_PRIO_QOS;
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if (prio & _PTHREAD_PRIORITY_OVERCOMMIT_FLAG) {
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flags |= WQ_FLAG_THREAD_OVERCOMMIT;
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}
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int i, flags = extract_wq_flags(prio);
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if (wq_event != NULL)
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flags |= WQ_FLAG_THREAD_KEVENT;