mirror of
https://github.com/autc04/Retro68.git
synced 2024-06-06 21:29:40 +00:00
891 lines
22 KiB
C
891 lines
22 KiB
C
// 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 <errno.h>
|
||
#include <limits.h>
|
||
#include <signal.h>
|
||
#include <stdlib.h>
|
||
#include <pthread.h>
|
||
#include <unistd.h>
|
||
|
||
#include "config.h"
|
||
|
||
#ifdef HAVE_DL_ITERATE_PHDR
|
||
#include <link.h>
|
||
#endif
|
||
|
||
#include "runtime.h"
|
||
#include "arch.h"
|
||
#include "defs.h"
|
||
|
||
#ifdef USING_SPLIT_STACK
|
||
|
||
/* FIXME: These are not declared anywhere. */
|
||
|
||
extern void __splitstack_getcontext(void *context[10]);
|
||
|
||
extern void __splitstack_setcontext(void *context[10]);
|
||
|
||
extern void *__splitstack_makecontext(size_t, void *context[10], size_t *);
|
||
|
||
extern void * __splitstack_resetcontext(void *context[10], size_t *);
|
||
|
||
extern void __splitstack_releasecontext(void *context[10]);
|
||
|
||
extern void *__splitstack_find(void *, void *, size_t *, void **, void **,
|
||
void **);
|
||
|
||
extern void __splitstack_block_signals (int *, int *);
|
||
|
||
extern void __splitstack_block_signals_context (void *context[10], int *,
|
||
int *);
|
||
|
||
#endif
|
||
|
||
#ifndef PTHREAD_STACK_MIN
|
||
# define PTHREAD_STACK_MIN 8192
|
||
#endif
|
||
|
||
#if defined(USING_SPLIT_STACK) && defined(LINKER_SUPPORTS_SPLIT_STACK)
|
||
# define StackMin PTHREAD_STACK_MIN
|
||
#else
|
||
# define StackMin ((sizeof(char *) < 8) ? 2 * 1024 * 1024 : 4 * 1024 * 1024)
|
||
#endif
|
||
|
||
uintptr runtime_stacks_sys;
|
||
|
||
void gtraceback(G*)
|
||
__asm__(GOSYM_PREFIX "runtime.gtraceback");
|
||
|
||
static void gscanstack(G*);
|
||
|
||
#ifdef __rtems__
|
||
#define __thread
|
||
#endif
|
||
|
||
__thread G *g __asm__(GOSYM_PREFIX "runtime.g");
|
||
|
||
#ifndef SETCONTEXT_CLOBBERS_TLS
|
||
|
||
static inline void
|
||
initcontext(void)
|
||
{
|
||
}
|
||
|
||
static inline void
|
||
fixcontext(__go_context_t *c __attribute__ ((unused)))
|
||
{
|
||
}
|
||
|
||
#else
|
||
|
||
# if defined(__x86_64__) && defined(__sun__)
|
||
|
||
// x86_64 Solaris 10 and 11 have a bug: setcontext switches the %fs
|
||
// register to that of the thread which called getcontext. The effect
|
||
// is that the address of all __thread variables changes. This bug
|
||
// also affects pthread_self() and pthread_getspecific. We work
|
||
// around it by clobbering the context field directly to keep %fs the
|
||
// same.
|
||
|
||
static __thread greg_t fs;
|
||
|
||
static inline void
|
||
initcontext(void)
|
||
{
|
||
ucontext_t c;
|
||
|
||
getcontext(&c);
|
||
fs = c.uc_mcontext.gregs[REG_FSBASE];
|
||
}
|
||
|
||
static inline void
|
||
fixcontext(ucontext_t* c)
|
||
{
|
||
c->uc_mcontext.gregs[REG_FSBASE] = fs;
|
||
}
|
||
|
||
# elif defined(__NetBSD__)
|
||
|
||
// NetBSD has a bug: setcontext clobbers tlsbase, we need to save
|
||
// and restore it ourselves.
|
||
|
||
static __thread __greg_t tlsbase;
|
||
|
||
static inline void
|
||
initcontext(void)
|
||
{
|
||
ucontext_t c;
|
||
|
||
getcontext(&c);
|
||
tlsbase = c.uc_mcontext._mc_tlsbase;
|
||
}
|
||
|
||
static inline void
|
||
fixcontext(ucontext_t* c)
|
||
{
|
||
c->uc_mcontext._mc_tlsbase = tlsbase;
|
||
}
|
||
|
||
# elif defined(__sparc__)
|
||
|
||
static inline void
|
||
initcontext(void)
|
||
{
|
||
}
|
||
|
||
static inline void
|
||
fixcontext(ucontext_t *c)
|
||
{
|
||
/* ??? Using
|
||
register unsigned long thread __asm__("%g7");
|
||
c->uc_mcontext.gregs[REG_G7] = thread;
|
||
results in
|
||
error: variable ‘thread’ might be clobbered by \
|
||
‘longjmp’ or ‘vfork’ [-Werror=clobbered]
|
||
which ought to be false, as %g7 is a fixed register. */
|
||
|
||
if (sizeof (c->uc_mcontext.gregs[REG_G7]) == 8)
|
||
asm ("stx %%g7, %0" : "=m"(c->uc_mcontext.gregs[REG_G7]));
|
||
else
|
||
asm ("st %%g7, %0" : "=m"(c->uc_mcontext.gregs[REG_G7]));
|
||
}
|
||
|
||
# elif defined(_AIX)
|
||
|
||
static inline void
|
||
initcontext(void)
|
||
{
|
||
}
|
||
|
||
static inline void
|
||
fixcontext(ucontext_t* c)
|
||
{
|
||
// Thread pointer is in r13, per 64-bit ABI.
|
||
if (sizeof (c->uc_mcontext.jmp_context.gpr[13]) == 8)
|
||
asm ("std 13, %0" : "=m"(c->uc_mcontext.jmp_context.gpr[13]));
|
||
}
|
||
|
||
# else
|
||
|
||
# error unknown case for SETCONTEXT_CLOBBERS_TLS
|
||
|
||
# endif
|
||
|
||
#endif
|
||
|
||
// ucontext_arg returns a properly aligned ucontext_t value. On some
|
||
// systems a ucontext_t value must be aligned to a 16-byte boundary.
|
||
// The g structure that has fields of type ucontext_t is defined in
|
||
// Go, and Go has no simple way to align a field to such a boundary.
|
||
// So we make the field larger in runtime2.go and pick an appropriate
|
||
// offset within the field here.
|
||
static __go_context_t*
|
||
ucontext_arg(uintptr_t* go_ucontext)
|
||
{
|
||
uintptr_t p = (uintptr_t)go_ucontext;
|
||
size_t align = __alignof__(__go_context_t);
|
||
if(align > 16) {
|
||
// We only ensured space for up to a 16 byte alignment
|
||
// in libgo/go/runtime/runtime2.go.
|
||
runtime_throw("required alignment of __go_context_t too large");
|
||
}
|
||
p = (p + align - 1) &~ (uintptr_t)(align - 1);
|
||
return (__go_context_t*)p;
|
||
}
|
||
|
||
// We can not always refer to the TLS variables directly. The
|
||
// compiler will call tls_get_addr to get the address of the variable,
|
||
// and it may hold it in a register across a call to schedule. When
|
||
// we get back from the call we may be running in a different thread,
|
||
// in which case the register now points to the TLS variable for a
|
||
// different thread. We use non-inlinable functions to avoid this
|
||
// when necessary.
|
||
|
||
G* runtime_g(void) __attribute__ ((noinline, no_split_stack));
|
||
|
||
G*
|
||
runtime_g(void)
|
||
{
|
||
return g;
|
||
}
|
||
|
||
M* runtime_m(void) __attribute__ ((noinline, no_split_stack));
|
||
|
||
M*
|
||
runtime_m(void)
|
||
{
|
||
if(g == nil)
|
||
return nil;
|
||
return g->m;
|
||
}
|
||
|
||
// Set g.
|
||
|
||
void runtime_setg(G*) __attribute__ ((no_split_stack));
|
||
|
||
void
|
||
runtime_setg(G* gp)
|
||
{
|
||
g = gp;
|
||
}
|
||
|
||
void runtime_newosproc(M *)
|
||
__asm__(GOSYM_PREFIX "runtime.newosproc");
|
||
|
||
// Start a new thread.
|
||
void
|
||
runtime_newosproc(M *mp)
|
||
{
|
||
pthread_attr_t attr;
|
||
sigset_t clear, old;
|
||
pthread_t tid;
|
||
int tries;
|
||
int ret;
|
||
|
||
if(pthread_attr_init(&attr) != 0)
|
||
runtime_throw("pthread_attr_init");
|
||
if(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) != 0)
|
||
runtime_throw("pthread_attr_setdetachstate");
|
||
|
||
// Block signals during pthread_create so that the new thread
|
||
// starts with signals disabled. It will enable them in minit.
|
||
sigfillset(&clear);
|
||
|
||
#ifdef SIGTRAP
|
||
// Blocking SIGTRAP reportedly breaks gdb on Alpha GNU/Linux.
|
||
sigdelset(&clear, SIGTRAP);
|
||
#endif
|
||
|
||
sigemptyset(&old);
|
||
pthread_sigmask(SIG_BLOCK, &clear, &old);
|
||
|
||
for (tries = 0; tries < 20; tries++) {
|
||
ret = pthread_create(&tid, &attr, runtime_mstart, mp);
|
||
if (ret != EAGAIN) {
|
||
break;
|
||
}
|
||
runtime_usleep((tries + 1) * 1000); // Milliseconds.
|
||
}
|
||
|
||
pthread_sigmask(SIG_SETMASK, &old, nil);
|
||
|
||
if (ret != 0) {
|
||
runtime_printf("pthread_create failed: %d\n", ret);
|
||
runtime_throw("pthread_create");
|
||
}
|
||
|
||
if(pthread_attr_destroy(&attr) != 0)
|
||
runtime_throw("pthread_attr_destroy");
|
||
}
|
||
|
||
// Switch context to a different goroutine. This is like longjmp.
|
||
void runtime_gogo(G*) __attribute__ ((noinline));
|
||
void
|
||
runtime_gogo(G* newg)
|
||
{
|
||
#ifdef USING_SPLIT_STACK
|
||
__splitstack_setcontext((void*)(&newg->stackcontext[0]));
|
||
#endif
|
||
g = newg;
|
||
newg->fromgogo = true;
|
||
fixcontext(ucontext_arg(&newg->context[0]));
|
||
__go_setcontext(ucontext_arg(&newg->context[0]));
|
||
runtime_throw("gogo setcontext returned");
|
||
}
|
||
|
||
// Save context and call fn passing g as a parameter. This is like
|
||
// setjmp. Because getcontext always returns 0, unlike setjmp, we use
|
||
// g->fromgogo as a code. It will be true if we got here via
|
||
// setcontext. g == nil the first time this is called in a new m.
|
||
void runtime_mcall(FuncVal *) __attribute__ ((noinline));
|
||
void
|
||
runtime_mcall(FuncVal *fv)
|
||
{
|
||
M *mp;
|
||
G *gp;
|
||
#ifndef USING_SPLIT_STACK
|
||
void *afterregs;
|
||
#endif
|
||
|
||
// Ensure that all registers are on the stack for the garbage
|
||
// collector.
|
||
__builtin_unwind_init();
|
||
flush_registers_to_secondary_stack();
|
||
|
||
gp = g;
|
||
mp = gp->m;
|
||
if(gp == mp->g0)
|
||
runtime_throw("runtime: mcall called on m->g0 stack");
|
||
|
||
if(gp != nil) {
|
||
|
||
#ifdef USING_SPLIT_STACK
|
||
__splitstack_getcontext((void*)(&gp->stackcontext[0]));
|
||
#else
|
||
// We have to point to an address on the stack that is
|
||
// below the saved registers.
|
||
gp->gcnextsp = (uintptr)(&afterregs);
|
||
gp->gcnextsp2 = (uintptr)(secondary_stack_pointer());
|
||
#endif
|
||
gp->fromgogo = false;
|
||
__go_getcontext(ucontext_arg(&gp->context[0]));
|
||
|
||
// When we return from getcontext, we may be running
|
||
// in a new thread. That means that g may have
|
||
// changed. It is a global variables so we will
|
||
// reload it, but the address of g may be cached in
|
||
// our local stack frame, and that address may be
|
||
// wrong. Call the function to reload the value for
|
||
// this thread.
|
||
gp = runtime_g();
|
||
mp = gp->m;
|
||
|
||
if(gp->traceback != 0)
|
||
gtraceback(gp);
|
||
if(gp->scang != 0)
|
||
gscanstack(gp);
|
||
}
|
||
if (gp == nil || !gp->fromgogo) {
|
||
#ifdef USING_SPLIT_STACK
|
||
__splitstack_setcontext((void*)(&mp->g0->stackcontext[0]));
|
||
#endif
|
||
mp->g0->entry = fv;
|
||
mp->g0->param = gp;
|
||
|
||
// It's OK to set g directly here because this case
|
||
// can not occur if we got here via a setcontext to
|
||
// the getcontext call just above.
|
||
g = mp->g0;
|
||
|
||
fixcontext(ucontext_arg(&mp->g0->context[0]));
|
||
__go_setcontext(ucontext_arg(&mp->g0->context[0]));
|
||
runtime_throw("runtime: mcall function returned");
|
||
}
|
||
}
|
||
|
||
// Goroutine scheduler
|
||
// The scheduler's job is to distribute ready-to-run goroutines over worker threads.
|
||
//
|
||
// The main concepts are:
|
||
// G - goroutine.
|
||
// M - worker thread, or machine.
|
||
// P - processor, a resource that is required to execute Go code.
|
||
// M must have an associated P to execute Go code, however it can be
|
||
// blocked or in a syscall w/o an associated P.
|
||
//
|
||
// Design doc at http://golang.org/s/go11sched.
|
||
|
||
extern G* allocg(void)
|
||
__asm__ (GOSYM_PREFIX "runtime.allocg");
|
||
|
||
bool runtime_isarchive;
|
||
|
||
extern void kickoff(void)
|
||
__asm__(GOSYM_PREFIX "runtime.kickoff");
|
||
extern void minit(void)
|
||
__asm__(GOSYM_PREFIX "runtime.minit");
|
||
extern void mstart1()
|
||
__asm__(GOSYM_PREFIX "runtime.mstart1");
|
||
extern void stopm(void)
|
||
__asm__(GOSYM_PREFIX "runtime.stopm");
|
||
extern void mexit(bool)
|
||
__asm__(GOSYM_PREFIX "runtime.mexit");
|
||
extern void handoffp(P*)
|
||
__asm__(GOSYM_PREFIX "runtime.handoffp");
|
||
extern void wakep(void)
|
||
__asm__(GOSYM_PREFIX "runtime.wakep");
|
||
extern void stoplockedm(void)
|
||
__asm__(GOSYM_PREFIX "runtime.stoplockedm");
|
||
extern void schedule(void)
|
||
__asm__(GOSYM_PREFIX "runtime.schedule");
|
||
extern void execute(G*, bool)
|
||
__asm__(GOSYM_PREFIX "runtime.execute");
|
||
extern void reentersyscall(uintptr, uintptr)
|
||
__asm__(GOSYM_PREFIX "runtime.reentersyscall");
|
||
extern void reentersyscallblock(uintptr, uintptr)
|
||
__asm__(GOSYM_PREFIX "runtime.reentersyscallblock");
|
||
extern G* gfget(P*)
|
||
__asm__(GOSYM_PREFIX "runtime.gfget");
|
||
extern void acquirep(P*)
|
||
__asm__(GOSYM_PREFIX "runtime.acquirep");
|
||
extern P* releasep(void)
|
||
__asm__(GOSYM_PREFIX "runtime.releasep");
|
||
extern void incidlelocked(int32)
|
||
__asm__(GOSYM_PREFIX "runtime.incidlelocked");
|
||
extern void globrunqput(G*)
|
||
__asm__(GOSYM_PREFIX "runtime.globrunqput");
|
||
extern P* pidleget(void)
|
||
__asm__(GOSYM_PREFIX "runtime.pidleget");
|
||
extern struct mstats* getMemstats(void)
|
||
__asm__(GOSYM_PREFIX "runtime.getMemstats");
|
||
|
||
bool runtime_isstarted;
|
||
|
||
// Used to determine the field alignment.
|
||
|
||
struct field_align
|
||
{
|
||
char c;
|
||
Hchan *p;
|
||
};
|
||
|
||
void getTraceback(G*, G*) __asm__(GOSYM_PREFIX "runtime.getTraceback");
|
||
|
||
// getTraceback stores a traceback of gp in the g's traceback field
|
||
// and then returns to me. We expect that gp's traceback is not nil.
|
||
// It works by saving me's current context, and checking gp's traceback field.
|
||
// If gp's traceback field is not nil, it starts running gp.
|
||
// In places where we call getcontext, we check the traceback field.
|
||
// If it is not nil, we collect a traceback, and then return to the
|
||
// goroutine stored in the traceback field, which is me.
|
||
void getTraceback(G* me, G* gp)
|
||
{
|
||
M* holdm;
|
||
|
||
holdm = gp->m;
|
||
gp->m = me->m;
|
||
|
||
#ifdef USING_SPLIT_STACK
|
||
__splitstack_getcontext((void*)(&me->stackcontext[0]));
|
||
#endif
|
||
__go_getcontext(ucontext_arg(&me->context[0]));
|
||
|
||
if (gp->traceback != 0) {
|
||
runtime_gogo(gp);
|
||
}
|
||
|
||
gp->m = holdm;
|
||
}
|
||
|
||
// Do a stack trace of gp, and then restore the context to
|
||
// gp->traceback->gp.
|
||
|
||
void
|
||
gtraceback(G* gp)
|
||
{
|
||
Traceback* traceback;
|
||
|
||
traceback = (Traceback*)gp->traceback;
|
||
gp->traceback = 0;
|
||
traceback->c = runtime_callers(1, traceback->locbuf,
|
||
sizeof traceback->locbuf / sizeof traceback->locbuf[0], false);
|
||
runtime_gogo(traceback->gp);
|
||
}
|
||
|
||
void doscanstackswitch(G*, G*) __asm__(GOSYM_PREFIX "runtime.doscanstackswitch");
|
||
|
||
// Switch to gp and let it scan its stack.
|
||
// The first time gp->scang is set (to me). The second time here
|
||
// gp is done scanning, and has unset gp->scang, so we just return.
|
||
void
|
||
doscanstackswitch(G* me, G* gp)
|
||
{
|
||
M* holdm;
|
||
|
||
__go_assert(me->entry == nil);
|
||
me->fromgogo = false;
|
||
|
||
holdm = gp->m;
|
||
gp->m = me->m;
|
||
|
||
#ifdef USING_SPLIT_STACK
|
||
__splitstack_getcontext((void*)(&me->stackcontext[0]));
|
||
#endif
|
||
__go_getcontext(ucontext_arg(&me->context[0]));
|
||
|
||
if(me->entry != nil) {
|
||
// Got here from mcall.
|
||
// The stack scanning code may call systemstack, which calls
|
||
// mcall, which calls setcontext.
|
||
// Run the function, which at the end will switch back to gp.
|
||
FuncVal *fv = me->entry;
|
||
void (*pfn)(G*) = (void (*)(G*))fv->fn;
|
||
G* gp1 = (G*)me->param;
|
||
__go_assert(gp1 == gp);
|
||
me->entry = nil;
|
||
me->param = nil;
|
||
__builtin_call_with_static_chain(pfn(gp1), fv);
|
||
abort();
|
||
}
|
||
|
||
if (gp->scang != 0)
|
||
runtime_gogo(gp);
|
||
|
||
gp->m = holdm;
|
||
}
|
||
|
||
// Do a stack scan, then switch back to the g that triggers this scan.
|
||
// We come here from doscanstackswitch.
|
||
static void
|
||
gscanstack(G *gp)
|
||
{
|
||
G *oldg, *oldcurg;
|
||
|
||
oldg = (G*)gp->scang;
|
||
oldcurg = oldg->m->curg;
|
||
oldg->m->curg = gp;
|
||
gp->scang = 0;
|
||
|
||
doscanstack(gp, (void*)gp->scangcw);
|
||
|
||
gp->scangcw = 0;
|
||
oldg->m->curg = oldcurg;
|
||
runtime_gogo(oldg);
|
||
}
|
||
|
||
// Called by pthread_create to start an M.
|
||
void*
|
||
runtime_mstart(void *arg)
|
||
{
|
||
M* mp;
|
||
G* gp;
|
||
|
||
mp = (M*)(arg);
|
||
gp = mp->g0;
|
||
gp->m = mp;
|
||
|
||
g = gp;
|
||
|
||
gp->entry = nil;
|
||
gp->param = nil;
|
||
|
||
// We have to call minit before we call getcontext,
|
||
// because getcontext will copy the signal mask.
|
||
minit();
|
||
|
||
initcontext();
|
||
|
||
// Record top of stack for use by mcall.
|
||
// Once we call schedule we're never coming back,
|
||
// so other calls can reuse this stack space.
|
||
#ifdef USING_SPLIT_STACK
|
||
__splitstack_getcontext((void*)(&gp->stackcontext[0]));
|
||
#else
|
||
gp->gcinitialsp = &arg;
|
||
// Setting gcstacksize to 0 is a marker meaning that gcinitialsp
|
||
// is the top of the stack, not the bottom.
|
||
gp->gcstacksize = 0;
|
||
gp->gcnextsp = (uintptr)(&arg);
|
||
gp->gcinitialsp2 = secondary_stack_pointer();
|
||
gp->gcnextsp2 = (uintptr)(gp->gcinitialsp2);
|
||
#endif
|
||
|
||
// Save the currently active context. This will return
|
||
// multiple times via the setcontext call in mcall.
|
||
__go_getcontext(ucontext_arg(&gp->context[0]));
|
||
|
||
if(gp->traceback != 0) {
|
||
// Got here from getTraceback.
|
||
// I'm not sure this ever actually happens--getTraceback
|
||
// may always go to the getcontext call in mcall.
|
||
gtraceback(gp);
|
||
}
|
||
if(gp->scang != 0)
|
||
// Got here from doscanswitch. Should not happen.
|
||
runtime_throw("mstart with scang");
|
||
|
||
if(gp->entry != nil) {
|
||
// Got here from mcall.
|
||
FuncVal *fv = gp->entry;
|
||
void (*pfn)(G*) = (void (*)(G*))fv->fn;
|
||
G* gp1 = (G*)gp->param;
|
||
gp->entry = nil;
|
||
gp->param = nil;
|
||
__builtin_call_with_static_chain(pfn(gp1), fv);
|
||
abort();
|
||
}
|
||
|
||
if(mp->exiting) {
|
||
mexit(true);
|
||
return nil;
|
||
}
|
||
|
||
// Initial call to getcontext--starting thread.
|
||
|
||
#ifdef USING_SPLIT_STACK
|
||
{
|
||
int dont_block_signals = 0;
|
||
__splitstack_block_signals(&dont_block_signals, nil);
|
||
}
|
||
#endif
|
||
|
||
mstart1();
|
||
|
||
// mstart1 does not return, but we need a return statement
|
||
// here to avoid a compiler warning.
|
||
return nil;
|
||
}
|
||
|
||
typedef struct CgoThreadStart CgoThreadStart;
|
||
struct CgoThreadStart
|
||
{
|
||
M *m;
|
||
G *g;
|
||
uintptr *tls;
|
||
void (*fn)(void);
|
||
};
|
||
|
||
void setGContext(void) __asm__ (GOSYM_PREFIX "runtime.setGContext");
|
||
|
||
// setGContext sets up a new goroutine context for the current g.
|
||
void
|
||
setGContext(void)
|
||
{
|
||
int val;
|
||
G *gp;
|
||
|
||
initcontext();
|
||
gp = g;
|
||
gp->entry = nil;
|
||
gp->param = nil;
|
||
#ifdef USING_SPLIT_STACK
|
||
__splitstack_getcontext((void*)(&gp->stackcontext[0]));
|
||
val = 0;
|
||
__splitstack_block_signals(&val, nil);
|
||
#else
|
||
gp->gcinitialsp = &val;
|
||
gp->gcstack = 0;
|
||
gp->gcstacksize = 0;
|
||
gp->gcnextsp = (uintptr)(&val);
|
||
gp->gcinitialsp2 = secondary_stack_pointer();
|
||
gp->gcnextsp2 = (uintptr)(gp->gcinitialsp2);
|
||
#endif
|
||
__go_getcontext(ucontext_arg(&gp->context[0]));
|
||
|
||
if(gp->entry != nil) {
|
||
// Got here from mcall.
|
||
FuncVal *fv = gp->entry;
|
||
void (*pfn)(G*) = (void (*)(G*))fv->fn;
|
||
G* gp1 = (G*)gp->param;
|
||
gp->entry = nil;
|
||
gp->param = nil;
|
||
__builtin_call_with_static_chain(pfn(gp1), fv);
|
||
abort();
|
||
}
|
||
}
|
||
|
||
void makeGContext(G*, byte*, uintptr)
|
||
__asm__(GOSYM_PREFIX "runtime.makeGContext");
|
||
|
||
// makeGContext makes a new context for a g.
|
||
void
|
||
makeGContext(G* gp, byte* sp, uintptr spsize) {
|
||
__go_context_t *uc;
|
||
|
||
uc = ucontext_arg(&gp->context[0]);
|
||
__go_getcontext(uc);
|
||
__go_makecontext(uc, kickoff, sp, (size_t)spsize);
|
||
}
|
||
|
||
// The goroutine g is about to enter a system call.
|
||
// Record that it's not using the cpu anymore.
|
||
// This is called only from the go syscall library and cgocall,
|
||
// not from the low-level system calls used by the runtime.
|
||
//
|
||
// Entersyscall cannot split the stack: the runtime_gosave must
|
||
// make g->sched refer to the caller's stack segment, because
|
||
// entersyscall is going to return immediately after.
|
||
|
||
void runtime_entersyscall() __attribute__ ((no_split_stack));
|
||
static void doentersyscall(uintptr, uintptr)
|
||
__attribute__ ((no_split_stack, noinline));
|
||
|
||
void
|
||
runtime_entersyscall()
|
||
{
|
||
// Save the registers in the g structure so that any pointers
|
||
// held in registers will be seen by the garbage collector.
|
||
if (!runtime_usestackmaps)
|
||
__go_getcontext(ucontext_arg(&g->gcregs[0]));
|
||
|
||
// Note that if this function does save any registers itself,
|
||
// we might store the wrong value in the call to getcontext.
|
||
// FIXME: This assumes that we do not need to save any
|
||
// callee-saved registers to access the TLS variable g. We
|
||
// don't want to put the ucontext_t on the stack because it is
|
||
// large and we can not split the stack here.
|
||
doentersyscall((uintptr)runtime_getcallerpc(),
|
||
(uintptr)runtime_getcallersp());
|
||
}
|
||
|
||
static void
|
||
doentersyscall(uintptr pc, uintptr sp)
|
||
{
|
||
// Leave SP around for GC and traceback.
|
||
#ifdef USING_SPLIT_STACK
|
||
{
|
||
size_t gcstacksize;
|
||
g->gcstack = (uintptr)(__splitstack_find(nil, nil, &gcstacksize,
|
||
(void**)(&g->gcnextsegment),
|
||
(void**)(&g->gcnextsp),
|
||
&g->gcinitialsp));
|
||
g->gcstacksize = (uintptr)gcstacksize;
|
||
}
|
||
#else
|
||
{
|
||
void *v;
|
||
|
||
g->gcnextsp = (uintptr)(&v);
|
||
g->gcnextsp2 = (uintptr)(secondary_stack_pointer());
|
||
}
|
||
#endif
|
||
|
||
reentersyscall(pc, sp);
|
||
}
|
||
|
||
static void doentersyscallblock(uintptr, uintptr)
|
||
__attribute__ ((no_split_stack, noinline));
|
||
|
||
// The same as runtime_entersyscall(), but with a hint that the syscall is blocking.
|
||
void
|
||
runtime_entersyscallblock()
|
||
{
|
||
// Save the registers in the g structure so that any pointers
|
||
// held in registers will be seen by the garbage collector.
|
||
if (!runtime_usestackmaps)
|
||
__go_getcontext(ucontext_arg(&g->gcregs[0]));
|
||
|
||
// See comment in runtime_entersyscall.
|
||
doentersyscallblock((uintptr)runtime_getcallerpc(),
|
||
(uintptr)runtime_getcallersp());
|
||
}
|
||
|
||
static void
|
||
doentersyscallblock(uintptr pc, uintptr sp)
|
||
{
|
||
// Leave SP around for GC and traceback.
|
||
#ifdef USING_SPLIT_STACK
|
||
{
|
||
size_t gcstacksize;
|
||
g->gcstack = (uintptr)(__splitstack_find(nil, nil, &gcstacksize,
|
||
(void**)(&g->gcnextsegment),
|
||
(void**)(&g->gcnextsp),
|
||
&g->gcinitialsp));
|
||
g->gcstacksize = (uintptr)gcstacksize;
|
||
}
|
||
#else
|
||
{
|
||
void *v;
|
||
|
||
g->gcnextsp = (uintptr)(&v);
|
||
g->gcnextsp2 = (uintptr)(secondary_stack_pointer());
|
||
}
|
||
#endif
|
||
|
||
reentersyscallblock(pc, sp);
|
||
}
|
||
|
||
// Allocate a new g, with a stack big enough for stacksize bytes.
|
||
G*
|
||
runtime_malg(bool allocatestack, bool signalstack, byte** ret_stack, uintptr* ret_stacksize)
|
||
{
|
||
uintptr stacksize;
|
||
G *newg;
|
||
byte* unused_stack;
|
||
uintptr unused_stacksize;
|
||
#ifdef USING_SPLIT_STACK
|
||
int dont_block_signals = 0;
|
||
size_t ss_stacksize;
|
||
#endif
|
||
|
||
if (ret_stack == nil) {
|
||
ret_stack = &unused_stack;
|
||
}
|
||
if (ret_stacksize == nil) {
|
||
ret_stacksize = &unused_stacksize;
|
||
}
|
||
newg = allocg();
|
||
if(allocatestack) {
|
||
stacksize = StackMin;
|
||
if(signalstack) {
|
||
stacksize = 32 * 1024; // OS X wants >= 8K, GNU/Linux >= 2K
|
||
#ifdef SIGSTKSZ
|
||
if(stacksize < (uintptr)(SIGSTKSZ))
|
||
stacksize = (uintptr)(SIGSTKSZ);
|
||
#endif
|
||
}
|
||
|
||
#ifdef USING_SPLIT_STACK
|
||
*ret_stack = __splitstack_makecontext(stacksize,
|
||
(void*)(&newg->stackcontext[0]),
|
||
&ss_stacksize);
|
||
*ret_stacksize = (uintptr)ss_stacksize;
|
||
__splitstack_block_signals_context((void*)(&newg->stackcontext[0]),
|
||
&dont_block_signals, nil);
|
||
#else
|
||
// In 64-bit mode, the maximum Go allocation space is
|
||
// 128G. Our stack size is 4M, which only permits 32K
|
||
// goroutines. In order to not limit ourselves,
|
||
// allocate the stacks out of separate memory. In
|
||
// 32-bit mode, the Go allocation space is all of
|
||
// memory anyhow.
|
||
if(sizeof(void*) == 8) {
|
||
void *p = runtime_sysAlloc(stacksize, &getMemstats()->stacks_sys);
|
||
if(p == nil)
|
||
runtime_throw("runtime: cannot allocate memory for goroutine stack");
|
||
*ret_stack = (byte*)p;
|
||
} else {
|
||
*ret_stack = runtime_mallocgc(stacksize, nil, false);
|
||
runtime_xadd(&runtime_stacks_sys, stacksize);
|
||
}
|
||
*ret_stacksize = (uintptr)stacksize;
|
||
newg->gcinitialsp = *ret_stack;
|
||
newg->gcstacksize = (uintptr)stacksize;
|
||
newg->gcinitialsp2 = initial_secondary_stack_pointer(*ret_stack);
|
||
#endif
|
||
}
|
||
return newg;
|
||
}
|
||
|
||
void stackfree(G*)
|
||
__asm__(GOSYM_PREFIX "runtime.stackfree");
|
||
|
||
// stackfree frees the stack of a g.
|
||
void
|
||
stackfree(G* gp)
|
||
{
|
||
#ifdef USING_SPLIT_STACK
|
||
__splitstack_releasecontext((void*)(&gp->stackcontext[0]));
|
||
#else
|
||
// If gcstacksize is 0, the stack is allocated by libc and will be
|
||
// released when the thread exits. Otherwise, in 64-bit mode it was
|
||
// allocated using sysAlloc and in 32-bit mode it was allocated
|
||
// using garbage collected memory.
|
||
if (gp->gcstacksize != 0) {
|
||
if (sizeof(void*) == 8) {
|
||
runtime_sysFree(gp->gcinitialsp, gp->gcstacksize, &getMemstats()->stacks_sys);
|
||
}
|
||
gp->gcinitialsp = nil;
|
||
gp->gcstacksize = 0;
|
||
}
|
||
#endif
|
||
}
|
||
|
||
void resetNewG(G*, void **, uintptr*)
|
||
__asm__(GOSYM_PREFIX "runtime.resetNewG");
|
||
|
||
// Reset stack information for g pulled out of the cache to start a
|
||
// new goroutine.
|
||
void
|
||
resetNewG(G *newg, void **sp, uintptr *spsize)
|
||
{
|
||
#ifdef USING_SPLIT_STACK
|
||
int dont_block_signals = 0;
|
||
size_t ss_spsize;
|
||
|
||
*sp = __splitstack_resetcontext((void*)(&newg->stackcontext[0]), &ss_spsize);
|
||
*spsize = ss_spsize;
|
||
__splitstack_block_signals_context((void*)(&newg->stackcontext[0]),
|
||
&dont_block_signals, nil);
|
||
#else
|
||
*sp = newg->gcinitialsp;
|
||
*spsize = newg->gcstacksize;
|
||
if(*spsize == 0)
|
||
runtime_throw("bad spsize in resetNewG");
|
||
newg->gcnextsp = (uintptr)(*sp);
|
||
newg->gcnextsp2 = (uintptr)(newg->gcinitialsp2);
|
||
#endif
|
||
}
|