mirror of
https://github.com/golang/go
synced 2024-10-05 06:21:24 -06:00
c19b373c8a
R=r CC=golang-dev https://golang.org/cl/4306043
1314 lines
30 KiB
C
1314 lines
30 KiB
C
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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#include "runtime.h"
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#include "arch.h"
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#include "defs.h"
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#include "malloc.h"
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#include "os.h"
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#include "stack.h"
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bool runtime·iscgo;
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static void unwindstack(G*, byte*);
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static void schedule(G*);
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static void acquireproc(void);
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static void releaseproc(void);
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typedef struct Sched Sched;
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M runtime·m0;
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G runtime·g0; // idle goroutine for m0
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static int32 debug = 0;
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int32 runtime·gcwaiting;
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// Go scheduler
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//
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// The go scheduler's job is to match ready-to-run goroutines (`g's)
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// with waiting-for-work schedulers (`m's). If there are ready gs
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// and no waiting ms, ready() will start a new m running in a new
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// OS thread, so that all ready gs can run simultaneously, up to a limit.
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// For now, ms never go away.
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//
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// By default, Go keeps only one kernel thread (m) running user code
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// at a single time; other threads may be blocked in the operating system.
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// Setting the environment variable $GOMAXPROCS or calling
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// runtime.GOMAXPROCS() will change the number of user threads
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// allowed to execute simultaneously. $GOMAXPROCS is thus an
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// approximation of the maximum number of cores to use.
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//
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// Even a program that can run without deadlock in a single process
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// might use more ms if given the chance. For example, the prime
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// sieve will use as many ms as there are primes (up to runtime·sched.mmax),
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// allowing different stages of the pipeline to execute in parallel.
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// We could revisit this choice, only kicking off new ms for blocking
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// system calls, but that would limit the amount of parallel computation
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// that go would try to do.
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//
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// In general, one could imagine all sorts of refinements to the
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// scheduler, but the goal now is just to get something working on
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// Linux and OS X.
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struct Sched {
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Lock;
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G *gfree; // available gs (status == Gdead)
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G *ghead; // gs waiting to run
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G *gtail;
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int32 gwait; // number of gs waiting to run
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int32 gcount; // number of gs that are alive
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M *mhead; // ms waiting for work
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int32 mwait; // number of ms waiting for work
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int32 mcount; // number of ms that have been created
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int32 mcpu; // number of ms executing on cpu
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int32 mcpumax; // max number of ms allowed on cpu
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int32 msyscall; // number of ms in system calls
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int32 predawn; // running initialization, don't run new gs.
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int32 profilehz; // cpu profiling rate
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Note stopped; // one g can wait here for ms to stop
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int32 waitstop; // after setting this flag
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};
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Sched runtime·sched;
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int32 gomaxprocs;
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// An m that is waiting for notewakeup(&m->havenextg). This may be
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// only be accessed while the scheduler lock is held. This is used to
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// minimize the number of times we call notewakeup while the scheduler
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// lock is held, since the m will normally move quickly to lock the
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// scheduler itself, producing lock contention.
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static M* mwakeup;
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// Scheduling helpers. Sched must be locked.
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static void gput(G*); // put/get on ghead/gtail
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static G* gget(void);
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static void mput(M*); // put/get on mhead
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static M* mget(G*);
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static void gfput(G*); // put/get on gfree
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static G* gfget(void);
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static void matchmg(void); // match ms to gs
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static void readylocked(G*); // ready, but sched is locked
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static void mnextg(M*, G*);
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// The bootstrap sequence is:
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//
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// call osinit
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// call schedinit
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// make & queue new G
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// call runtime·mstart
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//
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// The new G does:
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//
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// call main·init_function
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// call initdone
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// call main·main
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void
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runtime·schedinit(void)
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{
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int32 n;
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byte *p;
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runtime·allm = m;
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m->nomemprof++;
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runtime·mallocinit();
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runtime·goargs();
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runtime·goenvs();
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// For debugging:
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// Allocate internal symbol table representation now,
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// so that we don't need to call malloc when we crash.
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// runtime·findfunc(0);
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runtime·gomaxprocs = 1;
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p = runtime·getenv("GOMAXPROCS");
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if(p != nil && (n = runtime·atoi(p)) != 0)
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runtime·gomaxprocs = n;
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runtime·sched.mcpumax = runtime·gomaxprocs;
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runtime·sched.mcount = 1;
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runtime·sched.predawn = 1;
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m->nomemprof--;
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}
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// Lock the scheduler.
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static void
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schedlock(void)
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{
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runtime·lock(&runtime·sched);
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}
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// Unlock the scheduler.
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static void
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schedunlock(void)
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{
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M *m;
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m = mwakeup;
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mwakeup = nil;
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runtime·unlock(&runtime·sched);
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if(m != nil)
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runtime·notewakeup(&m->havenextg);
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}
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// Called after main·init_function; main·main will be called on return.
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void
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runtime·initdone(void)
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{
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// Let's go.
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runtime·sched.predawn = 0;
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mstats.enablegc = 1;
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// If main·init_function started other goroutines,
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// kick off new ms to handle them, like ready
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// would have, had it not been pre-dawn.
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schedlock();
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matchmg();
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schedunlock();
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}
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void
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runtime·goexit(void)
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{
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g->status = Gmoribund;
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runtime·gosched();
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}
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void
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runtime·tracebackothers(G *me)
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{
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G *g;
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for(g = runtime·allg; g != nil; g = g->alllink) {
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if(g == me || g->status == Gdead)
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continue;
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runtime·printf("\ngoroutine %d [%d]:\n", g->goid, g->status);
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runtime·traceback(g->sched.pc, g->sched.sp, 0, g);
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}
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}
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// Mark this g as m's idle goroutine.
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// This functionality might be used in environments where programs
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// are limited to a single thread, to simulate a select-driven
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// network server. It is not exposed via the standard runtime API.
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void
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runtime·idlegoroutine(void)
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{
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if(g->idlem != nil)
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runtime·throw("g is already an idle goroutine");
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g->idlem = m;
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}
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// Put on `g' queue. Sched must be locked.
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static void
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gput(G *g)
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{
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M *m;
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// If g is wired, hand it off directly.
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if(runtime·sched.mcpu < runtime·sched.mcpumax && (m = g->lockedm) != nil) {
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mnextg(m, g);
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return;
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}
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// If g is the idle goroutine for an m, hand it off.
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if(g->idlem != nil) {
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if(g->idlem->idleg != nil) {
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runtime·printf("m%d idle out of sync: g%d g%d\n",
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g->idlem->id,
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g->idlem->idleg->goid, g->goid);
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runtime·throw("runtime: double idle");
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}
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g->idlem->idleg = g;
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return;
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}
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g->schedlink = nil;
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if(runtime·sched.ghead == nil)
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runtime·sched.ghead = g;
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else
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runtime·sched.gtail->schedlink = g;
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runtime·sched.gtail = g;
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runtime·sched.gwait++;
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}
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// Get from `g' queue. Sched must be locked.
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static G*
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gget(void)
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{
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G *g;
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g = runtime·sched.ghead;
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if(g){
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runtime·sched.ghead = g->schedlink;
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if(runtime·sched.ghead == nil)
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runtime·sched.gtail = nil;
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runtime·sched.gwait--;
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} else if(m->idleg != nil) {
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g = m->idleg;
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m->idleg = nil;
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}
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return g;
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}
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// Put on `m' list. Sched must be locked.
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static void
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mput(M *m)
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{
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m->schedlink = runtime·sched.mhead;
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runtime·sched.mhead = m;
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runtime·sched.mwait++;
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}
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// Get an `m' to run `g'. Sched must be locked.
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static M*
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mget(G *g)
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{
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M *m;
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// if g has its own m, use it.
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if((m = g->lockedm) != nil)
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return m;
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// otherwise use general m pool.
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if((m = runtime·sched.mhead) != nil){
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runtime·sched.mhead = m->schedlink;
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runtime·sched.mwait--;
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}
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return m;
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}
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// Mark g ready to run.
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void
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runtime·ready(G *g)
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{
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schedlock();
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readylocked(g);
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schedunlock();
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}
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// Mark g ready to run. Sched is already locked.
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// G might be running already and about to stop.
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// The sched lock protects g->status from changing underfoot.
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static void
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readylocked(G *g)
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{
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if(g->m){
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// Running on another machine.
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// Ready it when it stops.
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g->readyonstop = 1;
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return;
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}
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// Mark runnable.
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if(g->status == Grunnable || g->status == Grunning) {
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runtime·printf("goroutine %d has status %d\n", g->goid, g->status);
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runtime·throw("bad g->status in ready");
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}
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g->status = Grunnable;
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gput(g);
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if(!runtime·sched.predawn)
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matchmg();
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}
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static void
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nop(void)
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{
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}
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// Same as readylocked but a different symbol so that
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// debuggers can set a breakpoint here and catch all
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// new goroutines.
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static void
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newprocreadylocked(G *g)
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{
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nop(); // avoid inlining in 6l
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readylocked(g);
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}
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// Pass g to m for running.
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static void
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mnextg(M *m, G *g)
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{
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runtime·sched.mcpu++;
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m->nextg = g;
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if(m->waitnextg) {
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m->waitnextg = 0;
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if(mwakeup != nil)
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runtime·notewakeup(&mwakeup->havenextg);
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mwakeup = m;
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}
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}
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// Get the next goroutine that m should run.
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// Sched must be locked on entry, is unlocked on exit.
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// Makes sure that at most $GOMAXPROCS gs are
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// running on cpus (not in system calls) at any given time.
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static G*
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nextgandunlock(void)
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{
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G *gp;
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if(runtime·sched.mcpu < 0)
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runtime·throw("negative runtime·sched.mcpu");
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// If there is a g waiting as m->nextg,
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// mnextg took care of the runtime·sched.mcpu++.
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if(m->nextg != nil) {
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gp = m->nextg;
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m->nextg = nil;
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schedunlock();
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return gp;
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}
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if(m->lockedg != nil) {
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// We can only run one g, and it's not available.
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// Make sure some other cpu is running to handle
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// the ordinary run queue.
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if(runtime·sched.gwait != 0)
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matchmg();
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} else {
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// Look for work on global queue.
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while(runtime·sched.mcpu < runtime·sched.mcpumax && (gp=gget()) != nil) {
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if(gp->lockedm) {
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mnextg(gp->lockedm, gp);
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continue;
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}
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runtime·sched.mcpu++; // this m will run gp
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schedunlock();
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return gp;
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}
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// Otherwise, wait on global m queue.
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mput(m);
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}
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if(runtime·sched.mcpu == 0 && runtime·sched.msyscall == 0)
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runtime·throw("all goroutines are asleep - deadlock!");
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m->nextg = nil;
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m->waitnextg = 1;
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runtime·noteclear(&m->havenextg);
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if(runtime·sched.waitstop && runtime·sched.mcpu <= runtime·sched.mcpumax) {
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runtime·sched.waitstop = 0;
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runtime·notewakeup(&runtime·sched.stopped);
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}
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schedunlock();
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runtime·notesleep(&m->havenextg);
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if((gp = m->nextg) == nil)
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runtime·throw("bad m->nextg in nextgoroutine");
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m->nextg = nil;
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return gp;
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}
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// TODO(rsc): Remove. This is only temporary,
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// for the mark and sweep collector.
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void
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runtime·stoptheworld(void)
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{
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schedlock();
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runtime·gcwaiting = 1;
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runtime·sched.mcpumax = 1;
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while(runtime·sched.mcpu > 1) {
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// It would be unsafe for multiple threads to be using
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// the stopped note at once, but there is only
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// ever one thread doing garbage collection,
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// so this is okay.
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runtime·noteclear(&runtime·sched.stopped);
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runtime·sched.waitstop = 1;
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schedunlock();
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runtime·notesleep(&runtime·sched.stopped);
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schedlock();
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}
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schedunlock();
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}
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// TODO(rsc): Remove. This is only temporary,
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// for the mark and sweep collector.
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void
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runtime·starttheworld(void)
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{
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schedlock();
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runtime·gcwaiting = 0;
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runtime·sched.mcpumax = runtime·gomaxprocs;
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matchmg();
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schedunlock();
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}
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// Called to start an M.
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void
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runtime·mstart(void)
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{
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if(g != m->g0)
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runtime·throw("bad runtime·mstart");
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if(m->mcache == nil)
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m->mcache = runtime·allocmcache();
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// Record top of stack for use by mcall.
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// Once we call schedule we're never coming back,
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// so other calls can reuse this stack space.
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runtime·gosave(&m->g0->sched);
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m->g0->sched.pc = (void*)-1; // make sure it is never used
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runtime·minit();
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schedule(nil);
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}
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// When running with cgo, we call libcgo_thread_start
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// to start threads for us so that we can play nicely with
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// foreign code.
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void (*libcgo_thread_start)(void*);
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typedef struct CgoThreadStart CgoThreadStart;
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struct CgoThreadStart
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{
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M *m;
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G *g;
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void (*fn)(void);
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};
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// Kick off new ms as needed (up to mcpumax).
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// There are already `other' other cpus that will
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// start looking for goroutines shortly.
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// Sched is locked.
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static void
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matchmg(void)
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{
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G *g;
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if(m->mallocing || m->gcing)
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return;
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while(runtime·sched.mcpu < runtime·sched.mcpumax && (g = gget()) != nil){
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M *m;
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// Find the m that will run g.
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if((m = mget(g)) == nil){
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m = runtime·malloc(sizeof(M));
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// Add to runtime·allm so garbage collector doesn't free m
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// when it is just in a register or thread-local storage.
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m->alllink = runtime·allm;
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runtime·allm = m;
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m->id = runtime·sched.mcount++;
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if(runtime·iscgo) {
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CgoThreadStart ts;
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if(libcgo_thread_start == nil)
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runtime·throw("libcgo_thread_start missing");
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// pthread_create will make us a stack.
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m->g0 = runtime·malg(-1);
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ts.m = m;
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ts.g = m->g0;
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ts.fn = runtime·mstart;
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runtime·asmcgocall(libcgo_thread_start, &ts);
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} else {
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if(Windows)
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// windows will layout sched stack on os stack
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m->g0 = runtime·malg(-1);
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else
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m->g0 = runtime·malg(8192);
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runtime·newosproc(m, m->g0, m->g0->stackbase, runtime·mstart);
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}
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}
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mnextg(m, g);
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}
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}
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// One round of scheduler: find a goroutine and run it.
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// The argument is the goroutine that was running before
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// schedule was called, or nil if this is the first call.
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// Never returns.
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static void
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schedule(G *gp)
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{
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int32 hz;
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|
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schedlock();
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if(gp != nil) {
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if(runtime·sched.predawn)
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runtime·throw("init rescheduling");
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// Just finished running gp.
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gp->m = nil;
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runtime·sched.mcpu--;
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if(runtime·sched.mcpu < 0)
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runtime·throw("runtime·sched.mcpu < 0 in scheduler");
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switch(gp->status){
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case Grunnable:
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case Gdead:
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// Shouldn't have been running!
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runtime·throw("bad gp->status in sched");
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case Grunning:
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gp->status = Grunnable;
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gput(gp);
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break;
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case Gmoribund:
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gp->status = Gdead;
|
|
if(gp->lockedm) {
|
|
gp->lockedm = nil;
|
|
m->lockedg = nil;
|
|
}
|
|
gp->idlem = nil;
|
|
unwindstack(gp, nil);
|
|
gfput(gp);
|
|
if(--runtime·sched.gcount == 0)
|
|
runtime·exit(0);
|
|
break;
|
|
}
|
|
if(gp->readyonstop){
|
|
gp->readyonstop = 0;
|
|
readylocked(gp);
|
|
}
|
|
}
|
|
|
|
// Find (or wait for) g to run. Unlocks runtime·sched.
|
|
gp = nextgandunlock();
|
|
gp->readyonstop = 0;
|
|
gp->status = Grunning;
|
|
m->curg = gp;
|
|
gp->m = m;
|
|
|
|
// Check whether the profiler needs to be turned on or off.
|
|
hz = runtime·sched.profilehz;
|
|
if(m->profilehz != hz)
|
|
runtime·resetcpuprofiler(hz);
|
|
|
|
if(gp->sched.pc == (byte*)runtime·goexit) { // kickoff
|
|
runtime·gogocall(&gp->sched, (void(*)(void))gp->entry);
|
|
}
|
|
runtime·gogo(&gp->sched, 0);
|
|
}
|
|
|
|
// Enter scheduler. If g->status is Grunning,
|
|
// re-queues g and runs everyone else who is waiting
|
|
// before running g again. If g->status is Gmoribund,
|
|
// kills off g.
|
|
void
|
|
runtime·gosched(void)
|
|
{
|
|
if(m->locks != 0)
|
|
runtime·throw("gosched holding locks");
|
|
if(g == m->g0)
|
|
runtime·throw("gosched of g0");
|
|
runtime·mcall(schedule);
|
|
}
|
|
|
|
// 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 pointer.
|
|
// It's okay to call matchmg and notewakeup even after
|
|
// decrementing mcpu, because we haven't released the
|
|
// sched lock yet.
|
|
#pragma textflag 7
|
|
void
|
|
runtime·entersyscall(void)
|
|
{
|
|
// Leave SP around for gc and traceback.
|
|
// Do before notewakeup so that gc
|
|
// never sees Gsyscall with wrong stack.
|
|
runtime·gosave(&g->sched);
|
|
if(runtime·sched.predawn)
|
|
return;
|
|
schedlock();
|
|
g->status = Gsyscall;
|
|
runtime·sched.mcpu--;
|
|
runtime·sched.msyscall++;
|
|
if(runtime·sched.gwait != 0)
|
|
matchmg();
|
|
if(runtime·sched.waitstop && runtime·sched.mcpu <= runtime·sched.mcpumax) {
|
|
runtime·sched.waitstop = 0;
|
|
runtime·notewakeup(&runtime·sched.stopped);
|
|
}
|
|
schedunlock();
|
|
}
|
|
|
|
// The goroutine g exited its system call.
|
|
// Arrange for it to run on a cpu again.
|
|
// This is called only from the go syscall library, not
|
|
// from the low-level system calls used by the runtime.
|
|
void
|
|
runtime·exitsyscall(void)
|
|
{
|
|
if(runtime·sched.predawn)
|
|
return;
|
|
|
|
schedlock();
|
|
runtime·sched.msyscall--;
|
|
runtime·sched.mcpu++;
|
|
// Fast path - if there's room for this m, we're done.
|
|
if(m->profilehz == runtime·sched.profilehz && runtime·sched.mcpu <= runtime·sched.mcpumax) {
|
|
g->status = Grunning;
|
|
schedunlock();
|
|
return;
|
|
}
|
|
// Tell scheduler to put g back on the run queue:
|
|
// mostly equivalent to g->status = Grunning,
|
|
// but keeps the garbage collector from thinking
|
|
// that g is running right now, which it's not.
|
|
g->readyonstop = 1;
|
|
schedunlock();
|
|
|
|
// Slow path - all the cpus are taken.
|
|
// The scheduler will ready g and put this m to sleep.
|
|
// When the scheduler takes g away from m,
|
|
// it will undo the runtime·sched.mcpu++ above.
|
|
runtime·gosched();
|
|
}
|
|
|
|
void
|
|
runtime·oldstack(void)
|
|
{
|
|
Stktop *top, old;
|
|
uint32 argsize;
|
|
byte *sp;
|
|
G *g1;
|
|
static int32 goid;
|
|
|
|
//printf("oldstack m->cret=%p\n", m->cret);
|
|
|
|
g1 = m->curg;
|
|
top = (Stktop*)g1->stackbase;
|
|
sp = (byte*)top;
|
|
old = *top;
|
|
argsize = old.argsize;
|
|
if(argsize > 0) {
|
|
sp -= argsize;
|
|
runtime·mcpy(top->argp, sp, argsize);
|
|
}
|
|
goid = old.gobuf.g->goid; // fault if g is bad, before gogo
|
|
|
|
if(old.free != 0)
|
|
runtime·stackfree(g1->stackguard - StackGuard - StackSystem, old.free);
|
|
g1->stackbase = old.stackbase;
|
|
g1->stackguard = old.stackguard;
|
|
|
|
runtime·gogo(&old.gobuf, m->cret);
|
|
}
|
|
|
|
void
|
|
runtime·newstack(void)
|
|
{
|
|
int32 framesize, argsize;
|
|
Stktop *top;
|
|
byte *stk, *sp;
|
|
G *g1;
|
|
Gobuf label;
|
|
bool reflectcall;
|
|
uintptr free;
|
|
|
|
framesize = m->moreframesize;
|
|
argsize = m->moreargsize;
|
|
g1 = m->curg;
|
|
|
|
if(m->morebuf.sp < g1->stackguard - StackGuard) {
|
|
runtime·printf("runtime: split stack overflow: %p < %p\n", m->morebuf.sp, g1->stackguard - StackGuard);
|
|
runtime·throw("runtime: split stack overflow");
|
|
}
|
|
if(argsize % sizeof(uintptr) != 0) {
|
|
runtime·printf("runtime: stack split with misaligned argsize %d\n", argsize);
|
|
runtime·throw("runtime: stack split argsize");
|
|
}
|
|
|
|
reflectcall = framesize==1;
|
|
if(reflectcall)
|
|
framesize = 0;
|
|
|
|
if(reflectcall && m->morebuf.sp - sizeof(Stktop) - argsize - 32 > g1->stackguard) {
|
|
// special case: called from reflect.call (framesize==1)
|
|
// to call code with an arbitrary argument size,
|
|
// and we have enough space on the current stack.
|
|
// the new Stktop* is necessary to unwind, but
|
|
// we don't need to create a new segment.
|
|
top = (Stktop*)(m->morebuf.sp - sizeof(*top));
|
|
stk = g1->stackguard - StackGuard - StackSystem;
|
|
free = 0;
|
|
} else {
|
|
// allocate new segment.
|
|
framesize += argsize;
|
|
framesize += StackExtra; // room for more functions, Stktop.
|
|
if(framesize < StackMin)
|
|
framesize = StackMin;
|
|
framesize += StackSystem;
|
|
stk = runtime·stackalloc(framesize);
|
|
top = (Stktop*)(stk+framesize-sizeof(*top));
|
|
free = framesize;
|
|
}
|
|
|
|
//runtime·printf("newstack framesize=%d argsize=%d morepc=%p moreargp=%p gobuf=%p, %p top=%p old=%p\n",
|
|
//framesize, argsize, m->morepc, m->moreargp, m->morebuf.pc, m->morebuf.sp, top, g1->stackbase);
|
|
|
|
top->stackbase = g1->stackbase;
|
|
top->stackguard = g1->stackguard;
|
|
top->gobuf = m->morebuf;
|
|
top->argp = m->moreargp;
|
|
top->argsize = argsize;
|
|
top->free = free;
|
|
|
|
// copy flag from panic
|
|
top->panic = g1->ispanic;
|
|
g1->ispanic = false;
|
|
|
|
g1->stackbase = (byte*)top;
|
|
g1->stackguard = stk + StackGuard + StackSystem;
|
|
|
|
sp = (byte*)top;
|
|
if(argsize > 0) {
|
|
sp -= argsize;
|
|
runtime·mcpy(sp, m->moreargp, argsize);
|
|
}
|
|
if(thechar == '5') {
|
|
// caller would have saved its LR below args.
|
|
sp -= sizeof(void*);
|
|
*(void**)sp = nil;
|
|
}
|
|
|
|
// Continue as if lessstack had just called m->morepc
|
|
// (the PC that decided to grow the stack).
|
|
label.sp = sp;
|
|
label.pc = (byte*)runtime·lessstack;
|
|
label.g = m->curg;
|
|
runtime·gogocall(&label, m->morepc);
|
|
|
|
*(int32*)345 = 123; // never return
|
|
}
|
|
|
|
static void
|
|
mstackalloc(G *gp)
|
|
{
|
|
gp->param = runtime·stackalloc((uintptr)gp->param);
|
|
runtime·gogo(&gp->sched, 0);
|
|
}
|
|
|
|
G*
|
|
runtime·malg(int32 stacksize)
|
|
{
|
|
G *newg;
|
|
byte *stk;
|
|
|
|
newg = runtime·malloc(sizeof(G));
|
|
if(stacksize >= 0) {
|
|
if(g == m->g0) {
|
|
// running on scheduler stack already.
|
|
stk = runtime·stackalloc(StackSystem + stacksize);
|
|
} else {
|
|
// have to call stackalloc on scheduler stack.
|
|
g->param = (void*)(StackSystem + stacksize);
|
|
runtime·mcall(mstackalloc);
|
|
stk = g->param;
|
|
g->param = nil;
|
|
}
|
|
newg->stack0 = stk;
|
|
newg->stackguard = stk + StackSystem + StackGuard;
|
|
newg->stackbase = stk + StackSystem + stacksize - sizeof(Stktop);
|
|
runtime·memclr(newg->stackbase, sizeof(Stktop));
|
|
}
|
|
return newg;
|
|
}
|
|
|
|
/*
|
|
* Newproc and deferproc need to be textflag 7
|
|
* (no possible stack split when nearing overflow)
|
|
* because they assume that the arguments to fn
|
|
* are available sequentially beginning at &arg0.
|
|
* If a stack split happened, only the one word
|
|
* arg0 would be copied. It's okay if any functions
|
|
* they call split the stack below the newproc frame.
|
|
*/
|
|
#pragma textflag 7
|
|
void
|
|
runtime·newproc(int32 siz, byte* fn, ...)
|
|
{
|
|
byte *argp;
|
|
|
|
if(thechar == '5')
|
|
argp = (byte*)(&fn+2); // skip caller's saved LR
|
|
else
|
|
argp = (byte*)(&fn+1);
|
|
runtime·newproc1(fn, argp, siz, 0, runtime·getcallerpc(&siz));
|
|
}
|
|
|
|
G*
|
|
runtime·newproc1(byte *fn, byte *argp, int32 narg, int32 nret, void *callerpc)
|
|
{
|
|
byte *sp;
|
|
G *newg;
|
|
int32 siz;
|
|
|
|
//printf("newproc1 %p %p narg=%d nret=%d\n", fn, argp, narg, nret);
|
|
siz = narg + nret;
|
|
siz = (siz+7) & ~7;
|
|
if(siz > 1024)
|
|
runtime·throw("runtime.newproc: too many args");
|
|
|
|
schedlock();
|
|
|
|
if((newg = gfget()) != nil){
|
|
newg->status = Gwaiting;
|
|
if(newg->stackguard - StackGuard - StackSystem != newg->stack0)
|
|
runtime·throw("invalid stack in newg");
|
|
} else {
|
|
newg = runtime·malg(StackMin);
|
|
newg->status = Gwaiting;
|
|
newg->alllink = runtime·allg;
|
|
runtime·allg = newg;
|
|
}
|
|
|
|
sp = newg->stackbase;
|
|
sp -= siz;
|
|
runtime·mcpy(sp, argp, narg);
|
|
if(thechar == '5') {
|
|
// caller's LR
|
|
sp -= sizeof(void*);
|
|
*(void**)sp = nil;
|
|
}
|
|
|
|
newg->sched.sp = sp;
|
|
newg->sched.pc = (byte*)runtime·goexit;
|
|
newg->sched.g = newg;
|
|
newg->entry = fn;
|
|
newg->gopc = (uintptr)callerpc;
|
|
|
|
runtime·sched.gcount++;
|
|
runtime·goidgen++;
|
|
newg->goid = runtime·goidgen;
|
|
|
|
newprocreadylocked(newg);
|
|
schedunlock();
|
|
|
|
return newg;
|
|
//printf(" goid=%d\n", newg->goid);
|
|
}
|
|
|
|
#pragma textflag 7
|
|
uintptr
|
|
runtime·deferproc(int32 siz, byte* fn, ...)
|
|
{
|
|
Defer *d;
|
|
|
|
d = runtime·malloc(sizeof(*d) + siz - sizeof(d->args));
|
|
d->fn = fn;
|
|
d->siz = siz;
|
|
d->pc = runtime·getcallerpc(&siz);
|
|
if(thechar == '5')
|
|
d->argp = (byte*)(&fn+2); // skip caller's saved link register
|
|
else
|
|
d->argp = (byte*)(&fn+1);
|
|
runtime·mcpy(d->args, d->argp, d->siz);
|
|
|
|
d->link = g->defer;
|
|
g->defer = d;
|
|
|
|
// deferproc returns 0 normally.
|
|
// a deferred func that stops a panic
|
|
// makes the deferproc return 1.
|
|
// the code the compiler generates always
|
|
// checks the return value and jumps to the
|
|
// end of the function if deferproc returns != 0.
|
|
return 0;
|
|
}
|
|
|
|
#pragma textflag 7
|
|
void
|
|
runtime·deferreturn(uintptr arg0)
|
|
{
|
|
Defer *d;
|
|
byte *argp, *fn;
|
|
|
|
d = g->defer;
|
|
if(d == nil)
|
|
return;
|
|
argp = (byte*)&arg0;
|
|
if(d->argp != argp)
|
|
return;
|
|
runtime·mcpy(argp, d->args, d->siz);
|
|
g->defer = d->link;
|
|
fn = d->fn;
|
|
runtime·free(d);
|
|
runtime·jmpdefer(fn, argp);
|
|
}
|
|
|
|
static void
|
|
rundefer(void)
|
|
{
|
|
Defer *d;
|
|
|
|
while((d = g->defer) != nil) {
|
|
g->defer = d->link;
|
|
reflect·call(d->fn, d->args, d->siz);
|
|
runtime·free(d);
|
|
}
|
|
}
|
|
|
|
// Free stack frames until we hit the last one
|
|
// or until we find the one that contains the argp.
|
|
static void
|
|
unwindstack(G *gp, byte *sp)
|
|
{
|
|
Stktop *top;
|
|
byte *stk;
|
|
|
|
// Must be called from a different goroutine, usually m->g0.
|
|
if(g == gp)
|
|
runtime·throw("unwindstack on self");
|
|
|
|
while((top = (Stktop*)gp->stackbase) != nil && top->stackbase != nil) {
|
|
stk = gp->stackguard - StackGuard;
|
|
if(stk <= sp && sp < gp->stackbase)
|
|
break;
|
|
gp->stackbase = top->stackbase;
|
|
gp->stackguard = top->stackguard;
|
|
if(top->free != 0)
|
|
runtime·stackfree(stk, top->free);
|
|
}
|
|
|
|
if(sp != nil && (sp < gp->stackguard - StackGuard || gp->stackbase < sp)) {
|
|
runtime·printf("recover: %p not in [%p, %p]\n", sp, gp->stackguard - StackGuard, gp->stackbase);
|
|
runtime·throw("bad unwindstack");
|
|
}
|
|
}
|
|
|
|
static void
|
|
printpanics(Panic *p)
|
|
{
|
|
if(p->link) {
|
|
printpanics(p->link);
|
|
runtime·printf("\t");
|
|
}
|
|
runtime·printf("panic: ");
|
|
runtime·printany(p->arg);
|
|
if(p->recovered)
|
|
runtime·printf(" [recovered]");
|
|
runtime·printf("\n");
|
|
}
|
|
|
|
static void recovery(G*);
|
|
|
|
void
|
|
runtime·panic(Eface e)
|
|
{
|
|
Defer *d;
|
|
Panic *p;
|
|
|
|
p = runtime·mal(sizeof *p);
|
|
p->arg = e;
|
|
p->link = g->panic;
|
|
p->stackbase = g->stackbase;
|
|
g->panic = p;
|
|
|
|
for(;;) {
|
|
d = g->defer;
|
|
if(d == nil)
|
|
break;
|
|
// take defer off list in case of recursive panic
|
|
g->defer = d->link;
|
|
g->ispanic = true; // rock for newstack, where reflect.call ends up
|
|
reflect·call(d->fn, d->args, d->siz);
|
|
if(p->recovered) {
|
|
g->panic = p->link;
|
|
if(g->panic == nil) // must be done with signal
|
|
g->sig = 0;
|
|
runtime·free(p);
|
|
// put recovering defer back on list
|
|
// for scheduler to find.
|
|
d->link = g->defer;
|
|
g->defer = d;
|
|
runtime·mcall(recovery);
|
|
runtime·throw("recovery failed"); // mcall should not return
|
|
}
|
|
runtime·free(d);
|
|
}
|
|
|
|
// ran out of deferred calls - old-school panic now
|
|
runtime·startpanic();
|
|
printpanics(g->panic);
|
|
runtime·dopanic(0);
|
|
}
|
|
|
|
static void
|
|
recovery(G *gp)
|
|
{
|
|
Defer *d;
|
|
|
|
// Rewind gp's stack; we're running on m->g0's stack.
|
|
d = gp->defer;
|
|
gp->defer = d->link;
|
|
|
|
// Unwind to the stack frame with d's arguments in it.
|
|
unwindstack(gp, d->argp);
|
|
|
|
// Make the deferproc for this d return again,
|
|
// this time returning 1. The calling function will
|
|
// jump to the standard return epilogue.
|
|
// The -2*sizeof(uintptr) makes up for the
|
|
// two extra words that are on the stack at
|
|
// each call to deferproc.
|
|
// (The pc we're returning to does pop pop
|
|
// before it tests the return value.)
|
|
// On the arm there are 2 saved LRs mixed in too.
|
|
if(thechar == '5')
|
|
gp->sched.sp = (byte*)d->argp - 4*sizeof(uintptr);
|
|
else
|
|
gp->sched.sp = (byte*)d->argp - 2*sizeof(uintptr);
|
|
gp->sched.pc = d->pc;
|
|
runtime·free(d);
|
|
runtime·gogo(&gp->sched, 1);
|
|
}
|
|
|
|
#pragma textflag 7 /* no split, or else g->stackguard is not the stack for fp */
|
|
void
|
|
runtime·recover(byte *argp, Eface ret)
|
|
{
|
|
Stktop *top, *oldtop;
|
|
Panic *p;
|
|
|
|
// Must be a panic going on.
|
|
if((p = g->panic) == nil || p->recovered)
|
|
goto nomatch;
|
|
|
|
// Frame must be at the top of the stack segment,
|
|
// because each deferred call starts a new stack
|
|
// segment as a side effect of using reflect.call.
|
|
// (There has to be some way to remember the
|
|
// variable argument frame size, and the segment
|
|
// code already takes care of that for us, so we
|
|
// reuse it.)
|
|
//
|
|
// As usual closures complicate things: the fp that
|
|
// the closure implementation function claims to have
|
|
// is where the explicit arguments start, after the
|
|
// implicit pointer arguments and PC slot.
|
|
// If we're on the first new segment for a closure,
|
|
// then fp == top - top->args is correct, but if
|
|
// the closure has its own big argument frame and
|
|
// allocated a second segment (see below),
|
|
// the fp is slightly above top - top->args.
|
|
// That condition can't happen normally though
|
|
// (stack pointers go down, not up), so we can accept
|
|
// any fp between top and top - top->args as
|
|
// indicating the top of the segment.
|
|
top = (Stktop*)g->stackbase;
|
|
if(argp < (byte*)top - top->argsize || (byte*)top < argp)
|
|
goto nomatch;
|
|
|
|
// The deferred call makes a new segment big enough
|
|
// for the argument frame but not necessarily big
|
|
// enough for the function's local frame (size unknown
|
|
// at the time of the call), so the function might have
|
|
// made its own segment immediately. If that's the
|
|
// case, back top up to the older one, the one that
|
|
// reflect.call would have made for the panic.
|
|
//
|
|
// The fp comparison here checks that the argument
|
|
// frame that was copied during the split (the top->args
|
|
// bytes above top->fp) abuts the old top of stack.
|
|
// This is a correct test for both closure and non-closure code.
|
|
oldtop = (Stktop*)top->stackbase;
|
|
if(oldtop != nil && top->argp == (byte*)oldtop - top->argsize)
|
|
top = oldtop;
|
|
|
|
// Now we have the segment that was created to
|
|
// run this call. It must have been marked as a panic segment.
|
|
if(!top->panic)
|
|
goto nomatch;
|
|
|
|
// Okay, this is the top frame of a deferred call
|
|
// in response to a panic. It can see the panic argument.
|
|
p->recovered = 1;
|
|
ret = p->arg;
|
|
FLUSH(&ret);
|
|
return;
|
|
|
|
nomatch:
|
|
ret.type = nil;
|
|
ret.data = nil;
|
|
FLUSH(&ret);
|
|
}
|
|
|
|
|
|
// Put on gfree list. Sched must be locked.
|
|
static void
|
|
gfput(G *g)
|
|
{
|
|
if(g->stackguard - StackGuard - StackSystem != g->stack0)
|
|
runtime·throw("invalid stack in gfput");
|
|
g->schedlink = runtime·sched.gfree;
|
|
runtime·sched.gfree = g;
|
|
}
|
|
|
|
// Get from gfree list. Sched must be locked.
|
|
static G*
|
|
gfget(void)
|
|
{
|
|
G *g;
|
|
|
|
g = runtime·sched.gfree;
|
|
if(g)
|
|
runtime·sched.gfree = g->schedlink;
|
|
return g;
|
|
}
|
|
|
|
void
|
|
runtime·Breakpoint(void)
|
|
{
|
|
runtime·breakpoint();
|
|
}
|
|
|
|
void
|
|
runtime·Goexit(void)
|
|
{
|
|
rundefer();
|
|
runtime·goexit();
|
|
}
|
|
|
|
void
|
|
runtime·Gosched(void)
|
|
{
|
|
runtime·gosched();
|
|
}
|
|
|
|
void
|
|
runtime·LockOSThread(void)
|
|
{
|
|
if(runtime·sched.predawn)
|
|
runtime·throw("cannot wire during init");
|
|
m->lockedg = g;
|
|
g->lockedm = m;
|
|
}
|
|
|
|
// delete when scheduler is stronger
|
|
int32
|
|
runtime·gomaxprocsfunc(int32 n)
|
|
{
|
|
int32 ret;
|
|
|
|
schedlock();
|
|
ret = runtime·gomaxprocs;
|
|
if (n <= 0)
|
|
n = ret;
|
|
runtime·gomaxprocs = n;
|
|
runtime·sched.mcpumax = n;
|
|
// handle fewer procs?
|
|
if(runtime·sched.mcpu > runtime·sched.mcpumax) {
|
|
schedunlock();
|
|
// just give up the cpu.
|
|
// we'll only get rescheduled once the
|
|
// number has come down.
|
|
runtime·gosched();
|
|
return ret;
|
|
}
|
|
// handle more procs
|
|
matchmg();
|
|
schedunlock();
|
|
return ret;
|
|
}
|
|
|
|
void
|
|
runtime·UnlockOSThread(void)
|
|
{
|
|
m->lockedg = nil;
|
|
g->lockedm = nil;
|
|
}
|
|
|
|
bool
|
|
runtime·lockedOSThread(void)
|
|
{
|
|
return g->lockedm != nil && m->lockedg != nil;
|
|
}
|
|
|
|
// for testing of wire, unwire
|
|
void
|
|
runtime·mid(uint32 ret)
|
|
{
|
|
ret = m->id;
|
|
FLUSH(&ret);
|
|
}
|
|
|
|
void
|
|
runtime·Goroutines(int32 ret)
|
|
{
|
|
ret = runtime·sched.gcount;
|
|
FLUSH(&ret);
|
|
}
|
|
|
|
int32
|
|
runtime·mcount(void)
|
|
{
|
|
return runtime·sched.mcount;
|
|
}
|
|
|
|
void
|
|
runtime·badmcall(void) // called from assembly
|
|
{
|
|
runtime·throw("runtime: mcall called on m->g0 stack");
|
|
}
|
|
|
|
void
|
|
runtime·badmcall2(void) // called from assembly
|
|
{
|
|
runtime·throw("runtime: mcall function returned");
|
|
}
|
|
|
|
static struct {
|
|
Lock;
|
|
void (*fn)(uintptr*, int32);
|
|
int32 hz;
|
|
uintptr pcbuf[100];
|
|
} prof;
|
|
|
|
void
|
|
runtime·sigprof(uint8 *pc, uint8 *sp, uint8 *lr, G *gp)
|
|
{
|
|
int32 n;
|
|
|
|
if(prof.fn == nil || prof.hz == 0)
|
|
return;
|
|
|
|
runtime·lock(&prof);
|
|
if(prof.fn == nil) {
|
|
runtime·unlock(&prof);
|
|
return;
|
|
}
|
|
n = runtime·gentraceback(pc, sp, lr, gp, 0, prof.pcbuf, nelem(prof.pcbuf));
|
|
if(n > 0)
|
|
prof.fn(prof.pcbuf, n);
|
|
runtime·unlock(&prof);
|
|
}
|
|
|
|
void
|
|
runtime·setcpuprofilerate(void (*fn)(uintptr*, int32), int32 hz)
|
|
{
|
|
// Force sane arguments.
|
|
if(hz < 0)
|
|
hz = 0;
|
|
if(hz == 0)
|
|
fn = nil;
|
|
if(fn == nil)
|
|
hz = 0;
|
|
|
|
// Stop profiler on this cpu so that it is safe to lock prof.
|
|
// if a profiling signal came in while we had prof locked,
|
|
// it would deadlock.
|
|
runtime·resetcpuprofiler(0);
|
|
|
|
runtime·lock(&prof);
|
|
prof.fn = fn;
|
|
prof.hz = hz;
|
|
runtime·unlock(&prof);
|
|
runtime·lock(&runtime·sched);
|
|
runtime·sched.profilehz = hz;
|
|
runtime·unlock(&runtime·sched);
|
|
|
|
if(hz != 0)
|
|
runtime·resetcpuprofiler(hz);
|
|
}
|