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// 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 <string.h> /* for strerror */
#include <pthread.h>
#include <signal.h>
#include "libcgo.h"
static void* threadentry(void*);
static pthread_key_t k1, k2;
#define magic1 (0x23581321345589ULL)
static void
inittls(void)
{
uint64 x, y;
pthread_key_t tofree[128], k;
int i, ntofree;
int havek1, havek2;
/*
* Same logic, code as darwin_386.c:/inittls, except that words
* are 8 bytes long now, and the thread-local storage starts
* at 0x60 on Leopard / Snow Leopard. So the offsets are
* 0x60+8*0x108 = 0x8a0 and 0x60+8*0x109 = 0x8a8.
*
* The linker and runtime hard-code these constant offsets
* from %gs where we expect to find m and g.
* Known to ../../../cmd/6l/obj.c:/8a0
* and to ../sys_darwin_amd64.s:/8a0
*
* As disgusting as on the 386; same justification.
*/
havek1 = 0;
havek2 = 0;
ntofree = 0;
while(!havek1 || !havek2) {
if(pthread_key_create(&k, nil) < 0) {
fprintf(stderr, "runtime/cgo: pthread_key_create failed\n");
abort();
}
pthread_setspecific(k, (void*)magic1);
asm volatile("movq %%gs:0x8a0, %0" : "=r"(x));
asm volatile("movq %%gs:0x8a8, %0" : "=r"(y));
if(x == magic1) {
havek1 = 1;
k1 = k;
} else if(y == magic1) {
havek2 = 1;
k2 = k;
} else {
if(ntofree >= nelem(tofree)) {
fprintf(stderr, "runtime/cgo: could not obtain pthread_keys\n");
fprintf(stderr, "\ttried");
for(i=0; i<ntofree; i++)
fprintf(stderr, " %#x", (unsigned)tofree[i]);
fprintf(stderr, "\n");
abort();
}
tofree[ntofree++] = k;
}
pthread_setspecific(k, 0);
}
/*
* We got the keys we wanted. Free the others.
*/
for(i=0; i<ntofree; i++)
pthread_key_delete(tofree[i]);
}
void
x_cgo_init(G *g)
{
pthread_attr_t attr;
size_t size;
pthread_attr_init(&attr);
pthread_attr_getstacksize(&attr, &size);
g->stackguard = (uintptr)&attr - size + 4096;
pthread_attr_destroy(&attr);
inittls();
}
void
_cgo_sys_thread_start(ThreadStart *ts)
{
pthread_attr_t attr;
sigset_t ign, oset;
pthread_t p;
size_t size;
int err;
sigfillset(&ign);
pthread_sigmask(SIG_SETMASK, &ign, &oset);
pthread_attr_init(&attr);
pthread_attr_getstacksize(&attr, &size);
ts->g->stackguard = size;
err = pthread_create(&p, &attr, threadentry, ts);
pthread_sigmask(SIG_SETMASK, &oset, nil);
if (err != 0) {
fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err));
abort();
}
}
static void*
threadentry(void *v)
{
ThreadStart ts;
ts = *(ThreadStart*)v;
free(v);
ts.g->stackbase = (uintptr)&ts;
/*
* _cgo_sys_thread_start set stackguard to stack size;
* change to actual guard pointer.
*/
ts.g->stackguard = (uintptr)&ts - ts.g->stackguard + 4096;
pthread_setspecific(k1, (void*)ts.g);
pthread_setspecific(k2, (void*)ts.m);
crosscall_amd64(ts.fn);
return nil;
}
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