github.com/freddyisaac/sicortex-golang@v0.0.0-20231019035217-e03519e66f60/src/runtime/cgo/gcc_android_386.c (about)

     1  // Copyright 2015 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  #include <string.h> /* for strerror */
     6  #include <pthread.h>
     7  #include <signal.h>
     8  #include "libcgo.h"
     9  
    10  static void* threadentry(void*);
    11  static pthread_key_t k1;
    12  
    13  #define magic1 (0x23581321U)
    14  
    15  static void
    16  inittls(void)
    17  {
    18  	uint32 x;
    19  	pthread_key_t tofree[128], k;
    20  	int i, ntofree;
    21  
    22  	/*
    23  	 * Same logic, code as gcc_android_amd64.c:/inittls.
    24  	 * Note that this is a temporary hack that should be fixed soon.
    25  	 *
    26  	 * TODO: fix this.
    27  	 *
    28  	 * The linker and runtime hard-code this constant offset
    29  	 * from %gs where we expect to find g. Disgusting.
    30  	 *
    31  	 * Known to src/cmd/link/internal/ld/sym.go:/0xf8
    32  	 * and to src/runtime/sys_linux_386.s:/0xf8 or /GOOS_android.
    33  	 * TODO(hyangah): check 0xb0 works with API23+
    34  	 *
    35  	 * As disgusting as on the darwin/386, darwin/amd64.
    36  	 */
    37  	ntofree = 0;
    38  	for(;;) {
    39  		if(pthread_key_create(&k, nil) < 0) {
    40  			fprintf(stderr, "runtime/cgo: pthread_key_create failed\n");
    41  			abort();
    42  		}
    43  		pthread_setspecific(k, (void*)magic1);
    44  		asm volatile("movl %%gs:0xf8, %0" : "=r"(x));
    45  		pthread_setspecific(k, 0);
    46  		if (x == magic1) {
    47  			k1 = k;
    48  			break;
    49  		}
    50  		if(ntofree >= nelem(tofree)) {
    51  			fprintf(stderr, "runtime/cgo: could not obtain pthread_keys\n");
    52  			fprintf(stderr, "\ttried");
    53  			for(i=0; i<ntofree; i++)
    54  				fprintf(stderr, " %#x", (unsigned)tofree[i]);
    55  			fprintf(stderr, "\n");
    56  			abort();
    57  		}
    58  		tofree[ntofree++] = k;
    59  	}
    60  	// TODO: output to stderr is not useful for apps.
    61  	// Can we fall back to Android's log library?
    62  
    63  	/*
    64  	 * We got the key we wanted.  Free the others.
    65  	 */
    66  	for(i=0; i<ntofree; i++) {
    67  		pthread_key_delete(tofree[i]);
    68  	}
    69  }
    70  
    71  
    72  static void*
    73  threadentry(void *v)
    74  {
    75  	ThreadStart ts;
    76  
    77  	ts = *(ThreadStart*)v;
    78  	free(v);
    79  
    80  	pthread_setspecific(k1, (void*)ts.g);
    81  
    82  	crosscall_386(ts.fn);
    83  	return nil;
    84  }
    85  
    86  void (*x_cgo_inittls)(void) = inittls;
    87  void* (*x_cgo_threadentry)(void*) = threadentry;