src/pkg/runtime/os

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This source file includes following definitions.
unimplemented
runtime·semawakeup
runtime·semacreate
runtime·osinit
runtime·get_random_data
runtime·goenvs
runtime·newosproc
runtime·mpreinit
runtime·minit
runtime·unminit
macherror
mach_msg
machcall
runtime·mach_semcreate
runtime·mach_semdestroy
runtime·semasleep
runtime·mach_semrelease
runtime·sigpanic
runtime·osyield
runtime·memlimit
runtime·setsig
runtime·getsig
runtime·signalstack
runtime·unblocksignals
// 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_GOOS_GOARCH.h"
#include "os_GOOS.h"
#include "signal_unix.h"
#include "stack.h"
#include "../../cmd/ld/textflag.h"

extern SigTab runtime·sigtab[];

static Sigset sigset_none;
static Sigset sigset_all = ~(Sigset)0;

static void
unimplemented(int8 *name)
{
        runtime·prints(name);
        runtime·prints(" not implemented\n");
        *(int32*)1231 = 1231;
}

void
runtime·semawakeup(M *mp)
{
        runtime·mach_semrelease(mp->waitsema);
}

uintptr
runtime·semacreate(void)
{
        return runtime·mach_semcreate();
}

// BSD interface for threading.
void
runtime·osinit(void)
{
        // bsdthread_register delayed until end of goenvs so that we
        // can look at the environment first.

        // 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·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();

        // Register our thread-creation callback (see sys_darwin_{amd64,386}.s)
        // but only if we're not using cgo.  If we are using cgo we need
        // to let the C pthread library install its own thread-creation callback.
        if(!runtime·iscgo) {
                if(runtime·bsdthread_register() != 0) {
                        if(runtime·getenv("DYLD_INSERT_LIBRARIES"))
                                runtime·throw("runtime: bsdthread_register error (unset DYLD_INSERT_LIBRARIES)");
                        runtime·throw("runtime: bsdthread_register error");
                }
        }

}

void
runtime·newosproc(M *mp, void *stk)
{
        int32 errno;
        Sigset oset;

        mp->tls[0] = mp->id;    // so 386 asm can find it
        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);
        }

        runtime·sigprocmask(SIG_SETMASK, &sigset_all, &oset);
        errno = runtime·bsdthread_create(stk, mp, mp->g0, runtime·mstart);
        runtime·sigprocmask(SIG_SETMASK, &oset, nil);

        if(errno < 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).
// 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);   // OS X wants >=8K, Linux >=2K
}

// Called to initialize a new m (including the bootstrap m).
// Called on the new thread, can not allocate memory.
void
runtime·minit(void)
{
        // Initialize signal handling.
        runtime·signalstack((byte*)m->gsignal->stackguard - StackGuard, 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);
}

// Mach IPC, to get at semaphores
// Definitions are in /usr/include/mach on a Mac.

#pragma textflag NOSPLIT
static void
macherror(int32 r, int8 *fn)
{
        runtime·prints("mach error ");
        runtime·prints(fn);
        runtime·prints(": ");
        runtime·printint(r);
        runtime·prints("\n");
        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,
        KERN_OPERATION_TIMED_OUT = 49,
};

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_darwin_{amd64,386}.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);

#pragma textflag NOSPLIT
int32
runtime·semasleep(int64 ns)
{
        int32 r, secs, nsecs;

        if(ns >= 0) {
                secs = runtime·timediv(ns, 1000000000, &nsecs);
                r = runtime·mach_semaphore_timedwait(m->waitsema, secs, nsecs);
                if(r == KERN_ABORTED || r == KERN_OPERATION_TIMED_OUT)
                        return -1;
                if(r != 0)
                        macherror(r, "semaphore_wait");
                return 0;
        }
        while((r = runtime·mach_semaphore_wait(m->waitsema)) != 0) {
                if(r == KERN_ABORTED)   // interrupted
                        continue;
                macherror(r, "semaphore_wait");
        }
        return 0;
}

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)
{
        if(!runtime·canpanic(g))
                runtime·throw("unexpected signal during runtime execution");

        switch(g->sig) {
        case SIGBUS:
                if(g->sigcode0 == BUS_ADRERR && g->sigcode1 < 0x1000 || g->paniconfault) {
                        if(g->sigpc == 0)
                                runtime·panicstring("call of nil func value");
                        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 || g->paniconfault) {
                        if(g->sigpc == 0)
                                runtime·panicstring("call of nil func value");
                        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);
}

#pragma textflag NOSPLIT
void
runtime·osyield(void)
{
        runtime·usleep(1);
}

uintptr
runtime·memlimit(void)
{
        // NOTE(rsc): Could use getrlimit here,
        // like on FreeBSD or Linux, but Darwin doesn't enforce
        // ulimit -v, so it's unclear why we'd try to stay within
        // the limit.
        return 0;
}

void
runtime·setsig(int32 i, GoSighandler *fn, bool restart)
{
        Sigaction sa;
                
        runtime·memclr((byte*)&sa, sizeof sa);
        sa.sa_flags = SA_SIGINFO|SA_ONSTACK;
        if(restart)
                sa.sa_flags |= SA_RESTART;
        sa.sa_mask = ~(uintptr)0;
        sa.sa_tramp = (void*)runtime·sigtramp; // runtime·sigtramp's job is to call into real handler
        *(uintptr*)sa.__sigaction_u = (uintptr)fn;
        runtime·sigaction(i, &sa, nil);
}

GoSighandler*
runtime·getsig(int32 i)
{
        Sigaction sa;

        runtime·memclr((byte*)&sa, sizeof sa);
        runtime·sigaction(i, nil, &sa);
        return *(void**)sa.__sigaction_u;
}

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);
}
/* [<][>][^][v][top][bottom][index][help] */
root/src/pkg/runtime/os_darwin.c

DEFINITIONS
