blob: 58e5bedf2f7634b3b97ea8110059f4bad7d2b513 [file] [log] [blame]
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "runtime.h"
#include "defs_GOOS_GOARCH.h"
#include "os_GOOS.h"
#include "signal_unix.h"
#include "stack.h"
#include "textflag.h"
enum
{
ESRCH = 3,
ENOTSUP = 91,
// From NetBSD's <sys/time.h>
CLOCK_REALTIME = 0,
CLOCK_VIRTUAL = 1,
CLOCK_PROF = 2,
CLOCK_MONOTONIC = 3
};
extern SigTab runtime·sigtab[];
static Sigset sigset_none;
static Sigset sigset_all = { ~(uint32)0, ~(uint32)0, ~(uint32)0, ~(uint32)0, };
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 *mp, G *gp, 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);
extern int32 runtime·lwp_self(void);
// From NetBSD's <sys/sysctl.h>
#define CTL_HW 6
#define HW_NCPU 3
static int32
getncpu(void)
{
uint32 mib[2];
uint32 out;
int32 ret;
uintptr nout;
// Fetch hw.ncpu via sysctl.
mib[0] = CTL_HW;
mib[1] = HW_NCPU;
nout = sizeof out;
out = 0;
ret = runtime·sysctl(mib, 2, (byte*)&out, &nout, nil, 0);
if(ret >= 0)
return out;
else
return 1;
}
#pragma textflag NOSPLIT
uintptr
runtime·semacreate(void)
{
return 1;
}
static void
semasleep(void)
{
int64 ns;
Timespec ts;
ns = (int64)(uint32)g->m->scalararg[0] | (int64)(uint32)g->m->scalararg[1]<<32;
g->m->scalararg[0] = 0;
g->m->scalararg[1] = 0;
// spin-mutex lock
while(runtime·xchg(&g->m->waitsemalock, 1))
runtime·osyield();
for(;;) {
// lock held
if(g->m->waitsemacount == 0) {
// sleep until semaphore != 0 or timeout.
// thrsleep unlocks m->waitsemalock.
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(&g->m->waitsemalock, 0);
runtime·lwp_park(nil, 0, &g->m->waitsemacount, nil);
} else {
ns = ns + runtime·nanotime();
// NOTE: tv_nsec is int64 on amd64, so this assumes a little-endian system.
ts.tv_nsec = 0;
ts.tv_sec = runtime·timediv(ns, 1000000000, (int32*)&ts.tv_nsec);
// TODO(jsing) - potential deadlock!
// See above for details.
runtime·atomicstore(&g->m->waitsemalock, 0);
runtime·lwp_park(&ts, 0, &g->m->waitsemacount, nil);
}
// reacquire lock
while(runtime·xchg(&g->m->waitsemalock, 1))
runtime·osyield();
}
// lock held (again)
if(g->m->waitsemacount != 0) {
// semaphore is available.
g->m->waitsemacount--;
// spin-mutex unlock
runtime·atomicstore(&g->m->waitsemalock, 0);
g->m->scalararg[0] = 0; // semaphore acquired
return;
}
// semaphore not available.
// if there is a timeout, stop now.
// otherwise keep trying.
if(ns >= 0)
break;
}
// lock held but giving up
// spin-mutex unlock
runtime·atomicstore(&g->m->waitsemalock, 0);
g->m->scalararg[0] = -1;
return;
}
#pragma textflag NOSPLIT
int32
runtime·semasleep(int64 ns)
{
int32 r;
void (*fn)(void);
g->m->scalararg[0] = (uint32)ns;
g->m->scalararg[1] = (uint32)(ns>>32);
fn = semasleep;
runtime·onM(&fn);
r = g->m->scalararg[0];
g->m->scalararg[0] = 0;
return r;
}
static void badsemawakeup(void);
#pragma textflag NOSPLIT
void
runtime·semawakeup(M *mp)
{
uint32 ret;
void (*fn)(void);
void *oldptr;
uintptr oldscalar;
// spin-mutex lock
while(runtime·xchg(&mp->waitsemalock, 1))
runtime·osyield();
mp->waitsemacount++;
// 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) {
// semawakeup can be called on signal stack.
// Save old ptrarg/scalararg so we can restore them.
oldptr = g->m->ptrarg[0];
oldscalar = g->m->scalararg[0];
g->m->ptrarg[0] = mp;
g->m->scalararg[0] = ret;
fn = badsemawakeup;
if(g == g->m->gsignal)
fn();
else
runtime·onM(&fn);
g->m->ptrarg[0] = oldptr;
g->m->scalararg[0] = oldscalar;
}
// spin-mutex unlock
runtime·atomicstore(&mp->waitsemalock, 0);
}
static void
badsemawakeup(void)
{
M *mp;
int32 ret;
mp = g->m->ptrarg[0];
g->m->ptrarg[0] = nil;
ret = g->m->scalararg[0];
g->m->scalararg[0] = 0;
runtime·printf("thrwakeup addr=%p sem=%d ret=%d\n", &mp->waitsemacount, mp->waitsemacount, ret);
}
void
runtime·newosproc(M *mp, void *stk)
{
UcontextT uc;
int32 ret;
if(0) {
runtime·printf(
"newosproc stk=%p m=%p g=%p id=%d/%d ostk=%p\n",
stk, mp, mp->g0, mp->id, (int32)mp->tls[0], &mp);
}
mp->tls[0] = mp->id; // so 386 asm can find it
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, mp, mp->g0, runtime·mstart);
ret = runtime·lwp_create(&uc, 0, &mp->procid);
if(ret < 0) {
runtime·printf("runtime: failed to create new OS thread (have %d already; errno=%d)\n", runtime·mcount() - 1, -ret);
runtime·throw("runtime.newosproc");
}
}
void
runtime·osinit(void)
{
runtime·ncpu = getncpu();
}
#pragma textflag NOSPLIT
void
runtime·get_random_data(byte **rnd, int32 *rnd_len)
{
#pragma dataflag NOPTR
static byte urandom_data[HashRandomBytes];
int32 fd;
fd = runtime·open("/dev/urandom", 0 /* O_RDONLY */, 0);
if(runtime·read(fd, urandom_data, HashRandomBytes) == HashRandomBytes) {
*rnd = urandom_data;
*rnd_len = HashRandomBytes;
} else {
*rnd = nil;
*rnd_len = 0;
}
runtime·close(fd);
}
void
runtime·goenvs(void)
{
runtime·goenvs_unix();
}
// Called to initialize a new m (including the bootstrap m).
// Called on the parent thread (main thread in case of bootstrap), can allocate memory.
void
runtime·mpreinit(M *mp)
{
mp->gsignal = runtime·malg(32*1024);
mp->gsignal->m = mp;
}
// Called to initialize a new m (including the bootstrap m).
// Called on the new thread, can not allocate memory.
void
runtime·minit(void)
{
g->m->procid = runtime·lwp_self();
// Initialize signal handling
runtime·signalstack((byte*)g->m->gsignal->stack.lo, 32*1024);
runtime·sigprocmask(SIG_SETMASK, &sigset_none, nil);
}
// Called from dropm to undo the effect of an minit.
void
runtime·unminit(void)
{
runtime·signalstack(nil, 0);
}
uintptr
runtime·memlimit(void)
{
return 0;
}
extern void runtime·sigtramp(void);
typedef struct sigaction {
union {
void (*_sa_handler)(int32);
void (*_sa_sigaction)(int32, Siginfo*, void *);
} _sa_u; /* signal handler */
uint32 sa_mask[4]; /* signal mask to apply */
int32 sa_flags; /* see signal options below */
} SigactionT;
void
runtime·setsig(int32 i, GoSighandler *fn, bool restart)
{
SigactionT sa;
runtime·memclr((byte*)&sa, sizeof sa);
sa.sa_flags = SA_SIGINFO|SA_ONSTACK;
if(restart)
sa.sa_flags |= SA_RESTART;
sa.sa_mask[0] = ~0U;
sa.sa_mask[1] = ~0U;
sa.sa_mask[2] = ~0U;
sa.sa_mask[3] = ~0U;
if (fn == runtime·sighandler)
fn = (void*)runtime·sigtramp;
sa._sa_u._sa_sigaction = (void*)fn;
runtime·sigaction(i, &sa, nil);
}
GoSighandler*
runtime·getsig(int32 i)
{
SigactionT sa;
runtime·memclr((byte*)&sa, sizeof sa);
runtime·sigaction(i, nil, &sa);
if((void*)sa._sa_u._sa_sigaction == runtime·sigtramp)
return runtime·sighandler;
return (void*)sa._sa_u._sa_sigaction;
}
void
runtime·signalstack(byte *p, int32 n)
{
StackT st;
st.ss_sp = (void*)p;
st.ss_size = n;
st.ss_flags = 0;
if(p == nil)
st.ss_flags = SS_DISABLE;
runtime·sigaltstack(&st, nil);
}
void
runtime·unblocksignals(void)
{
runtime·sigprocmask(SIG_SETMASK, &sigset_none, nil);
}
#pragma textflag NOSPLIT
int8*
runtime·signame(int32 sig)
{
return runtime·sigtab[sig].name;
}