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// Copyright 2015 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.
// +build cgo
#include <string.h> /* for strerror */
#include <pthread.h>
#include <signal.h>
#include "libcgo.h"
static void* threadentry(void*);
static pthread_key_t k1;
#define magic1 (0x23581321345589ULL)
static void
inittls(void)
{
uint64 x;
pthread_key_t tofree[128], k;
int i, ntofree;
/*
* Same logic, code as gcc_darwin_386.c:/inittls.
* Note that this is a temporary hack that should be fixed soon.
* Android-L and M bionic's pthread implementation differ
* significantly, and can change any time.
* https://android-review.googlesource.com/#/c/134202
*
* We chose %fs:0x1d0 which seems to work in testing with Android
* emulators (API22, API23) but it may break any time.
*
* TODO: fix this.
*
* The linker and runtime hard-code this constant offset
* from %fs where we expect to find g. Disgusting.
*
* Known to src/cmd/link/internal/ld/sym.go:/0x1d0
* and to src/runtime/sys_linux_amd64.s:/0x1d0 or /GOOS_android.
*
* As disgusting as on the darwin/386, darwin/amd64.
*/
ntofree = 0;
for(;;) {
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 %%fs:0x1d0, %0" : "=r"(x));
pthread_setspecific(k, 0);
if(x == magic1) {
k1 = k;
break;
}
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;
}
// TODO: output to stderr is not useful for apps.
// Can we fall back to Android's log library?
/*
* We got the key we wanted. Free the others.
*/
for(i=0; i<ntofree; i++) {
pthread_key_delete(tofree[i]);
}
}
static void*
threadentry(void *v)
{
ThreadStart ts;
ts = *(ThreadStart*)v;
free(v);
pthread_setspecific(k1, (void*)ts.g);
crosscall_amd64(ts.fn);
return nil;
}
void (*x_cgo_inittls)(void) = inittls;
void* (*x_cgo_threadentry)(void*) = threadentry;
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