gcc_freebsd_arm.c

Documentation: runtime/cgo

     1  // Copyright 2012 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 <sys/types.h>
     6  #include <machine/sysarch.h>
     7  #include <sys/signalvar.h>
     8  #include <pthread.h>
     9  #include <signal.h>
    10  #include <string.h>
    11  #include "libcgo.h"
    12  #include "libcgo_unix.h"
    13  
    14  #ifdef ARM_TP_ADDRESS
    15  // ARM_TP_ADDRESS is (ARM_VECTORS_HIGH + 0x1000) or 0xffff1000
    16  // and is known to runtime.read_tls_fallback. Verify it with
    17  // cpp.
    18  #if ARM_TP_ADDRESS != 0xffff1000
    19  #error Wrong ARM_TP_ADDRESS!
    20  #endif
    21  #endif
    22  
    23  static void *threadentry(void*);
    24  
    25  static void (*setg_gcc)(void*);
    26  
    27  void
    28  x_cgo_init(G *g, void (*setg)(void*))
    29  {
    30  	pthread_attr_t attr;
    31  	size_t size;
    32  
    33  	setg_gcc = setg;
    34  	pthread_attr_init(&attr);
    35  	pthread_attr_getstacksize(&attr, &size);
    36  	g->stacklo = (uintptr)&attr - size + 4096;
    37  	pthread_attr_destroy(&attr);
    38  }
    39  
    40  
    41  void
    42  _cgo_sys_thread_start(ThreadStart *ts)
    43  {
    44  	pthread_attr_t attr;
    45  	sigset_t ign, oset;
    46  	pthread_t p;
    47  	size_t size;
    48  	int err;
    49  
    50  	SIGFILLSET(ign);
    51  	pthread_sigmask(SIG_SETMASK, &ign, &oset);
    52  
    53  	// Not sure why the memset is necessary here,
    54  	// but without it, we get a bogus stack size
    55  	// out of pthread_attr_getstacksize. C'est la Linux.
    56  	memset(&attr, 0, sizeof attr);
    57  	pthread_attr_init(&attr);
    58  	size = 0;
    59  	pthread_attr_getstacksize(&attr, &size);
    60  	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
    61  	ts->g->stackhi = size;
    62  	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);
    63  
    64  	pthread_sigmask(SIG_SETMASK, &oset, nil);
    65  
    66  	if (err != 0) {
    67  		fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err));
    68  		abort();
    69  	}
    70  }
    71  
    72  extern void crosscall_arm1(void (*fn)(void), void (*setg_gcc)(void*), void *g);
    73  static void*
    74  threadentry(void *v)
    75  {
    76  	ThreadStart ts;
    77  
    78  	ts = *(ThreadStart*)v;
    79  	free(v);
    80  
    81  	crosscall_arm1(ts.fn, setg_gcc, (void*)ts.g);
    82  	return nil;
    83  }
    84
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