runtime: make go work on netbsd/amd64
R=golang-dev, rsc, devon.odell
CC=golang-dev
https://golang.org/cl/6222044
diff --git a/src/pkg/runtime/thread_netbsd.c b/src/pkg/runtime/thread_netbsd.c
index 1b2df85..72557c7 100644
--- a/src/pkg/runtime/thread_netbsd.c
+++ b/src/pkg/runtime/thread_netbsd.c
@@ -11,7 +11,7 @@
ESRCH = 3,
ENOTSUP = 91,
- // From NetBSD's sys/time.h
+ // From NetBSD's <sys/time.h>
CLOCK_REALTIME = 0,
CLOCK_VIRTUAL = 1,
CLOCK_PROF = 2,
@@ -20,9 +20,14 @@
extern SigTab runtime·sigtab[];
-extern int64 runtime·rfork_thread(int32 flags, void *stack, M *m, G *g, void (*fn)(void));
-extern int32 runtime·thrsleep(void *ident, int32 clock_id, void *tsp, void *lock);
-extern int32 runtime·thrwakeup(void *ident, int32 n);
+static Sigset sigset_all = { ~(uint32)0, ~(uint32)0, ~(uint32)0, ~(uint32)0, };
+static Sigset sigset_none;
+
+extern void runtime·getcontext(UcontextT *context);
+extern int32 runtime·lwp_create(UcontextT *context, uintptr flags, void *lwpid);
+extern void runtime·lwp_mcontext_init(void *mc, void *stack, M *m, G *g, void (*fn)(void));
+extern int32 runtime·lwp_park(Timespec *abstime, int32 unpark, void *hint, void *unparkhint);
+extern int32 runtime·lwp_unpark(int32 lwp, void *hint);
// From NetBSD's <sys/sysctl.h>
#define CTL_HW 6
@@ -68,13 +73,30 @@
if(m->waitsemacount == 0) {
// sleep until semaphore != 0 or timeout.
// thrsleep unlocks m->waitsemalock.
- if(ns < 0)
- runtime·thrsleep(&m->waitsemacount, 0, nil, &m->waitsemalock);
- else {
+ if(ns < 0) {
+ // TODO(jsing) - potential deadlock!
+ //
+ // There is a potential deadlock here since we
+ // have to release the waitsemalock mutex
+ // before we call lwp_park() to suspend the
+ // thread. This allows another thread to
+ // release the lock and call lwp_unpark()
+ // before the thread is actually suspended.
+ // If this occurs the current thread will end
+ // up sleeping indefinitely. Unfortunately
+ // the NetBSD kernel does not appear to provide
+ // a mechanism for unlocking the userspace
+ // mutex once the thread is actually parked.
+ runtime·atomicstore(&m->waitsemalock, 0);
+ runtime·lwp_park(nil, 0, &m->waitsemacount, nil);
+ } else {
ns += runtime·nanotime();
ts.tv_sec = ns/1000000000LL;
ts.tv_nsec = ns%1000000000LL;
- runtime·thrsleep(&m->waitsemacount, CLOCK_REALTIME, &ts, &m->waitsemalock);
+ // TODO(jsing) - potential deadlock!
+ // See above for details.
+ runtime·atomicstore(&m->waitsemalock, 0);
+ runtime·lwp_park(&ts, 0, &m->waitsemacount, nil);
}
// reacquire lock
while(runtime·xchg(&m->waitsemalock, 1))
@@ -112,28 +134,26 @@
while(runtime·xchg(&mp->waitsemalock, 1))
runtime·osyield();
mp->waitsemacount++;
- ret = runtime·thrwakeup(&mp->waitsemacount, 1);
+ // TODO(jsing) - potential deadlock, see semasleep() for details.
+ // Confirm that LWP is parked before unparking...
+ ret = runtime·lwp_unpark(mp->procid, &mp->waitsemacount);
if(ret != 0 && ret != ESRCH)
runtime·printf("thrwakeup addr=%p sem=%d ret=%d\n", &mp->waitsemacount, mp->waitsemacount, ret);
// spin-mutex unlock
runtime·atomicstore(&mp->waitsemalock, 0);
}
-// From NetBSD's sys/param.h
-#define RFPROC (1<<4) /* change child (else changes curproc) */
-#define RFMEM (1<<5) /* share `address space' */
-#define RFNOWAIT (1<<6) /* parent need not wait() on child */
-#define RFTHREAD (1<<13) /* create a thread, not a process */
+// From NetBSD's <sys/ucontext.h>
+#define _UC_SIGMASK 0x01
+#define _UC_CPU 0x04
void
runtime·newosproc(M *m, G *g, void *stk, void (*fn)(void))
{
- int32 flags;
+ UcontextT uc;
int32 ret;
- flags = RFPROC | RFTHREAD | RFMEM | RFNOWAIT;
-
- if (0) {
+ if(0) {
runtime·printf(
"newosproc stk=%p m=%p g=%p fn=%p id=%d/%d ostk=%p\n",
stk, m, g, fn, m->id, m->tls[0], &m);
@@ -141,10 +161,18 @@
m->tls[0] = m->id; // so 386 asm can find it
- if((ret = runtime·rfork_thread(flags, stk, m, g, fn)) < 0) {
+ runtime·getcontext(&uc);
+
+ uc.uc_flags = _UC_SIGMASK | _UC_CPU;
+ uc.uc_link = nil;
+ uc.uc_sigmask = sigset_all;
+
+ runtime·lwp_mcontext_init(&uc.uc_mcontext, stk, m, g, fn);
+
+ ret = runtime·lwp_create(&uc, 0, &m->procid);
+
+ if(ret < 0) {
runtime·printf("runtime: failed to create new OS thread (have %d already; errno=%d)\n", runtime·mcount() - 1, -ret);
- if (ret == -ENOTSUP)
- runtime·printf("runtime: is kern.rthreads disabled?\n");
runtime·throw("runtime.newosproc");
}
}
@@ -153,6 +181,9 @@
runtime·osinit(void)
{
runtime·ncpu = getncpu();
+
+ // Main thread is always LWP 1.
+ m->procid = 1;
}
void
@@ -168,6 +199,7 @@
// Initialize signal handling
m->gsignal = runtime·malg(32*1024);
runtime·signalstack(m->gsignal->stackguard - StackGuard, 32*1024);
+ runtime·sigprocmask(SIG_SETMASK, &sigset_none, nil);
}
void
