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go/src/runtime/cgo/gcc_android_386.c
Hyang-Ah Hana Kim 05c4c6e2f4 cmd,runtime: TLS setup for android/386
Same ugly hack as https://go-review.googlesource.com/15991.

Update golang/go#9327.

Change-Id: I58284e83268a15de95eabc833c3e01bf1e3faa2e
Reviewed-on: https://go-review.googlesource.com/16678
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2015-11-11 21:59:24 +00:00

88 lines
2.0 KiB
C

// 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.
#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 (0x23581321U)
static void
inittls(void)
{
uint32 x;
pthread_key_t tofree[128], k;
int i, ntofree;
/*
* Same logic, code as gcc_android_amd64.c:/inittls.
* Note that this is a temporary hack that should be fixed soon.
*
* TODO: fix this.
*
* The linker and runtime hard-code this constant offset
* from %gs where we expect to find g. Disgusting.
*
* Known to src/cmd/link/internal/ld/sym.go:/0xf8
* and to src/runtime/sys_linux_386.s:/0xf8 or /GOOS_android.
* TODO(hyangah): check 0xb0 works with API23+
*
* 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("movl %%gs:0xf8, %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_386(ts.fn);
return nil;
}
void (*x_cgo_inittls)(void) = inittls;
void* (*x_cgo_threadentry)(void*) = threadentry;