blob: b35dae02fe2fd7560e3363aa5e4c615f41f8e33a [file] [log] [blame]
// Copyright 2009 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.h"
#include "os.h"
#include "stack.h"
extern SigTab runtime·sigtab[];
static void
unimplemented(int8 *name)
{
runtime·prints(name);
runtime·prints(" not implemented\n");
*(int32*)1231 = 1231;
}
// Thread-safe allocation of a semaphore.
// Psema points at a kernel semaphore key.
// It starts out zero, meaning no semaphore.
// Fill it in, being careful of others calling initsema
// simultaneously.
static void
initsema(uint32 *psema)
{
uint32 sema;
if(*psema != 0) // already have one
return;
sema = runtime·mach_semcreate();
if(!runtime·cas(psema, 0, sema)){
// Someone else filled it in. Use theirs.
runtime·mach_semdestroy(sema);
return;
}
}
// Blocking locks.
// Implement Locks, using semaphores.
// l->key is the number of threads who want the lock.
// In a race, one thread increments l->key from 0 to 1
// and the others increment it from >0 to >1. The thread
// who does the 0->1 increment gets the lock, and the
// others wait on the semaphore. When the 0->1 thread
// releases the lock by decrementing l->key, l->key will
// be >0, so it will increment the semaphore to wake up
// one of the others. This is the same algorithm used
// in Plan 9's user-level locks.
void
runtime·lock(Lock *l)
{
if(m->locks < 0)
runtime·throw("lock count");
m->locks++;
if(runtime·xadd(&l->key, 1) > 1) { // someone else has it; wait
// Allocate semaphore if needed.
if(l->sema == 0)
initsema(&l->sema);
runtime·mach_semacquire(l->sema);
}
}
void
runtime·unlock(Lock *l)
{
m->locks--;
if(m->locks < 0)
runtime·throw("lock count");
if(runtime·xadd(&l->key, -1) > 0) { // someone else is waiting
// Allocate semaphore if needed.
if(l->sema == 0)
initsema(&l->sema);
runtime·mach_semrelease(l->sema);
}
}
static void
destroylock(Lock *l)
{
if(l->sema != 0) {
runtime·mach_semdestroy(l->sema);
l->sema = 0;
}
}
// User-level semaphore implementation:
// try to do the operations in user space on u,
// but when it's time to block, fall back on the kernel semaphore k.
// This is the same algorithm used in Plan 9.
void
runtime·usemacquire(Usema *s)
{
if((int32)runtime·xadd(&s->u, -1) < 0) {
if(s->k == 0)
initsema(&s->k);
runtime·mach_semacquire(s->k);
}
}
void
runtime·usemrelease(Usema *s)
{
if((int32)runtime·xadd(&s->u, 1) <= 0) {
if(s->k == 0)
initsema(&s->k);
runtime·mach_semrelease(s->k);
}
}
// Event notifications.
void
runtime·noteclear(Note *n)
{
n->wakeup = 0;
}
void
runtime·notesleep(Note *n)
{
while(!n->wakeup)
runtime·usemacquire(&n->sema);
}
void
runtime·notewakeup(Note *n)
{
n->wakeup = 1;
runtime·usemrelease(&n->sema);
}
// BSD interface for threading.
void
runtime·osinit(void)
{
// Register our thread-creation callback (see {amd64,386}/sys.s)
// but only if we're not using cgo. If we are using cgo we need
// to let the C pthread libary install its own thread-creation callback.
if(!runtime·iscgo)
runtime·bsdthread_register();
runtime·destroylock = destroylock;
// Use sysctl to fetch hw.ncpu.
uint32 mib[2];
uint32 out;
int32 ret;
uintptr nout;
mib[0] = 6;
mib[1] = 3;
nout = sizeof out;
out = 0;
ret = runtime·sysctl(mib, 2, (byte*)&out, &nout, nil, 0);
if(ret >= 0)
runtime·ncpu = out;
}
void
runtime·goenvs(void)
{
runtime·goenvs_unix();
}
void
runtime·newosproc(M *m, G *g, void *stk, void (*fn)(void))
{
int32 errno;
m->tls[0] = m->id; // so 386 asm can find it
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);
}
if((errno = runtime·bsdthread_create(stk, m, g, fn)) < 0) {
runtime·printf("runtime: failed to create new OS thread (have %d already; errno=%d)\n", runtime·mcount(), -errno);
runtime·throw("runtime.newosproc");
}
}
// Called to initialize a new m (including the bootstrap m).
void
runtime·minit(void)
{
// Initialize signal handling.
m->gsignal = runtime·malg(32*1024); // OS X wants >=8K, Linux >=2K
runtime·signalstack(m->gsignal->stackguard - StackGuard, 32*1024);
}
// Mach IPC, to get at semaphores
// Definitions are in /usr/include/mach on a Mac.
static void
macherror(int32 r, int8 *fn)
{
runtime·printf("mach error %s: %d\n", fn, r);
runtime·throw("mach error");
}
enum
{
DebugMach = 0
};
static MachNDR zerondr;
#define MACH_MSGH_BITS(a, b) ((a) | ((b)<<8))
static int32
mach_msg(MachHeader *h,
int32 op,
uint32 send_size,
uint32 rcv_size,
uint32 rcv_name,
uint32 timeout,
uint32 notify)
{
// TODO: Loop on interrupt.
return runtime·mach_msg_trap(h, op, send_size, rcv_size, rcv_name, timeout, notify);
}
// Mach RPC (MIG)
enum
{
MinMachMsg = 48,
Reply = 100,
};
#pragma pack on
typedef struct CodeMsg CodeMsg;
struct CodeMsg
{
MachHeader h;
MachNDR NDR;
int32 code;
};
#pragma pack off
static int32
machcall(MachHeader *h, int32 maxsize, int32 rxsize)
{
uint32 *p;
int32 i, ret, id;
uint32 port;
CodeMsg *c;
if((port = m->machport) == 0){
port = runtime·mach_reply_port();
m->machport = port;
}
h->msgh_bits |= MACH_MSGH_BITS(MACH_MSG_TYPE_COPY_SEND, MACH_MSG_TYPE_MAKE_SEND_ONCE);
h->msgh_local_port = port;
h->msgh_reserved = 0;
id = h->msgh_id;
if(DebugMach){
p = (uint32*)h;
runtime·prints("send:\t");
for(i=0; i<h->msgh_size/sizeof(p[0]); i++){
runtime·prints(" ");
runtime·printpointer((void*)p[i]);
if(i%8 == 7)
runtime·prints("\n\t");
}
if(i%8)
runtime·prints("\n");
}
ret = mach_msg(h, MACH_SEND_MSG|MACH_RCV_MSG,
h->msgh_size, maxsize, port, 0, 0);
if(ret != 0){
if(DebugMach){
runtime·prints("mach_msg error ");
runtime·printint(ret);
runtime·prints("\n");
}
return ret;
}
if(DebugMach){
p = (uint32*)h;
runtime·prints("recv:\t");
for(i=0; i<h->msgh_size/sizeof(p[0]); i++){
runtime·prints(" ");
runtime·printpointer((void*)p[i]);
if(i%8 == 7)
runtime·prints("\n\t");
}
if(i%8)
runtime·prints("\n");
}
if(h->msgh_id != id+Reply){
if(DebugMach){
runtime·prints("mach_msg reply id mismatch ");
runtime·printint(h->msgh_id);
runtime·prints(" != ");
runtime·printint(id+Reply);
runtime·prints("\n");
}
return -303; // MIG_REPLY_MISMATCH
}
// Look for a response giving the return value.
// Any call can send this back with an error,
// and some calls only have return values so they
// send it back on success too. I don't quite see how
// you know it's one of these and not the full response
// format, so just look if the message is right.
c = (CodeMsg*)h;
if(h->msgh_size == sizeof(CodeMsg)
&& !(h->msgh_bits & MACH_MSGH_BITS_COMPLEX)){
if(DebugMach){
runtime·prints("mig result ");
runtime·printint(c->code);
runtime·prints("\n");
}
return c->code;
}
if(h->msgh_size != rxsize){
if(DebugMach){
runtime·prints("mach_msg reply size mismatch ");
runtime·printint(h->msgh_size);
runtime·prints(" != ");
runtime·printint(rxsize);
runtime·prints("\n");
}
return -307; // MIG_ARRAY_TOO_LARGE
}
return 0;
}
// Semaphores!
enum
{
Tmach_semcreate = 3418,
Rmach_semcreate = Tmach_semcreate + Reply,
Tmach_semdestroy = 3419,
Rmach_semdestroy = Tmach_semdestroy + Reply,
// Mach calls that get interrupted by Unix signals
// return this error code. We retry them.
KERN_ABORTED = 14,
};
typedef struct Tmach_semcreateMsg Tmach_semcreateMsg;
typedef struct Rmach_semcreateMsg Rmach_semcreateMsg;
typedef struct Tmach_semdestroyMsg Tmach_semdestroyMsg;
// Rmach_semdestroyMsg = CodeMsg
#pragma pack on
struct Tmach_semcreateMsg
{
MachHeader h;
MachNDR ndr;
int32 policy;
int32 value;
};
struct Rmach_semcreateMsg
{
MachHeader h;
MachBody body;
MachPort semaphore;
};
struct Tmach_semdestroyMsg
{
MachHeader h;
MachBody body;
MachPort semaphore;
};
#pragma pack off
uint32
runtime·mach_semcreate(void)
{
union {
Tmach_semcreateMsg tx;
Rmach_semcreateMsg rx;
uint8 pad[MinMachMsg];
} m;
int32 r;
m.tx.h.msgh_bits = 0;
m.tx.h.msgh_size = sizeof(m.tx);
m.tx.h.msgh_remote_port = runtime·mach_task_self();
m.tx.h.msgh_id = Tmach_semcreate;
m.tx.ndr = zerondr;
m.tx.policy = 0; // 0 = SYNC_POLICY_FIFO
m.tx.value = 0;
while((r = machcall(&m.tx.h, sizeof m, sizeof(m.rx))) != 0){
if(r == KERN_ABORTED) // interrupted
continue;
macherror(r, "semaphore_create");
}
if(m.rx.body.msgh_descriptor_count != 1)
unimplemented("mach_semcreate desc count");
return m.rx.semaphore.name;
}
void
runtime·mach_semdestroy(uint32 sem)
{
union {
Tmach_semdestroyMsg tx;
uint8 pad[MinMachMsg];
} m;
int32 r;
m.tx.h.msgh_bits = MACH_MSGH_BITS_COMPLEX;
m.tx.h.msgh_size = sizeof(m.tx);
m.tx.h.msgh_remote_port = runtime·mach_task_self();
m.tx.h.msgh_id = Tmach_semdestroy;
m.tx.body.msgh_descriptor_count = 1;
m.tx.semaphore.name = sem;
m.tx.semaphore.disposition = MACH_MSG_TYPE_MOVE_SEND;
m.tx.semaphore.type = 0;
while((r = machcall(&m.tx.h, sizeof m, 0)) != 0){
if(r == KERN_ABORTED) // interrupted
continue;
macherror(r, "semaphore_destroy");
}
}
// The other calls have simple system call traps in sys.s
int32 runtime·mach_semaphore_wait(uint32 sema);
int32 runtime·mach_semaphore_timedwait(uint32 sema, uint32 sec, uint32 nsec);
int32 runtime·mach_semaphore_signal(uint32 sema);
int32 runtime·mach_semaphore_signal_all(uint32 sema);
void
runtime·mach_semacquire(uint32 sem)
{
int32 r;
while((r = runtime·mach_semaphore_wait(sem)) != 0) {
if(r == KERN_ABORTED) // interrupted
continue;
macherror(r, "semaphore_wait");
}
}
void
runtime·mach_semrelease(uint32 sem)
{
int32 r;
while((r = runtime·mach_semaphore_signal(sem)) != 0) {
if(r == KERN_ABORTED) // interrupted
continue;
macherror(r, "semaphore_signal");
}
}
void
runtime·sigpanic(void)
{
switch(g->sig) {
case SIGBUS:
if(g->sigcode0 == BUS_ADRERR && g->sigcode1 < 0x1000)
runtime·panicstring("invalid memory address or nil pointer dereference");
runtime·printf("unexpected fault address %p\n", g->sigcode1);
runtime·throw("fault");
case SIGSEGV:
if((g->sigcode0 == 0 || g->sigcode0 == SEGV_MAPERR || g->sigcode0 == SEGV_ACCERR) && g->sigcode1 < 0x1000)
runtime·panicstring("invalid memory address or nil pointer dereference");
runtime·printf("unexpected fault address %p\n", g->sigcode1);
runtime·throw("fault");
case SIGFPE:
switch(g->sigcode0) {
case FPE_INTDIV:
runtime·panicstring("integer divide by zero");
case FPE_INTOVF:
runtime·panicstring("integer overflow");
}
runtime·panicstring("floating point error");
}
runtime·panicstring(runtime·sigtab[g->sig].name);
}
// TODO(rsc): place holder to fix build.
void
runtime·osyield(void)
{
}