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mirror of https://github.com/golang/go synced 2024-11-19 23:44:43 -07:00
go/src/pkg/runtime/runtime.h
Ian Lance Taylor e9a3087e29 runtime, runtime/cgo: track memory allocated by non-Go code
Otherwise a poorly timed GC can collect the memory before it
is returned to the Go program.

R=golang-dev, dave, dvyukov, minux.ma
CC=golang-dev
https://golang.org/cl/6819119
2012-11-10 11:19:06 -08:00

876 lines
23 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.
/*
* basic types
*/
typedef signed char int8;
typedef unsigned char uint8;
typedef signed short int16;
typedef unsigned short uint16;
typedef signed int int32;
typedef unsigned int uint32;
typedef signed long long int int64;
typedef unsigned long long int uint64;
typedef float float32;
typedef double float64;
#ifdef _64BIT
typedef uint64 uintptr;
typedef int64 intptr;
typedef int64 intgo; // Go's int
typedef uint64 uintgo; // Go's uint
#else
typedef uint32 uintptr;
typedef int32 intptr;
typedef int32 intgo; // Go's int
typedef uint32 uintgo; // Go's uint
#endif
/*
* get rid of C types
* the / / / forces a syntax error immediately,
* which will show "last name: XXunsigned".
*/
#define unsigned XXunsigned / / /
#define signed XXsigned / / /
#define char XXchar / / /
#define short XXshort / / /
#define int XXint / / /
#define long XXlong / / /
#define float XXfloat / / /
#define double XXdouble / / /
/*
* defined types
*/
typedef uint8 bool;
typedef uint8 byte;
typedef struct Func Func;
typedef struct G G;
typedef struct Gobuf Gobuf;
typedef union Lock Lock;
typedef struct M M;
typedef struct Mem Mem;
typedef union Note Note;
typedef struct Slice Slice;
typedef struct Stktop Stktop;
typedef struct String String;
typedef struct SigTab SigTab;
typedef struct MCache MCache;
typedef struct FixAlloc FixAlloc;
typedef struct Iface Iface;
typedef struct Itab Itab;
typedef struct InterfaceType InterfaceType;
typedef struct Eface Eface;
typedef struct Type Type;
typedef struct ChanType ChanType;
typedef struct MapType MapType;
typedef struct Defer Defer;
typedef struct Panic Panic;
typedef struct Hmap Hmap;
typedef struct Hchan Hchan;
typedef struct Complex64 Complex64;
typedef struct Complex128 Complex128;
typedef struct WinCall WinCall;
typedef struct SEH SEH;
typedef struct Timers Timers;
typedef struct Timer Timer;
typedef struct GCStats GCStats;
typedef struct LFNode LFNode;
typedef struct ParFor ParFor;
typedef struct ParForThread ParForThread;
typedef struct CgoMal CgoMal;
/*
* Per-CPU declaration.
*
* "extern register" is a special storage class implemented by 6c, 8c, etc.
* On the ARM, it is an actual register; elsewhere it is a slot in thread-
* local storage indexed by a segment register. See zasmhdr in
* src/cmd/dist/buildruntime.c for details, and be aware that the linker may
* make further OS-specific changes to the compiler's output. For example,
* 6l/linux rewrites 0(GS) as -16(FS).
*
* Every C file linked into a Go program must include runtime.h so that the
* C compiler (6c, 8c, etc.) knows to avoid other uses of these dedicated
* registers. The Go compiler (6g, 8g, etc.) knows to avoid them.
*/
extern register G* g;
extern register M* m;
/*
* defined constants
*/
enum
{
// G status
//
// If you add to this list, add to the list
// of "okay during garbage collection" status
// in mgc0.c too.
Gidle,
Grunnable,
Grunning,
Gsyscall,
Gwaiting,
Gmoribund,
Gdead,
};
enum
{
true = 1,
false = 0,
};
enum
{
PtrSize = sizeof(void*),
};
/*
* structures
*/
union Lock
{
uint32 key; // futex-based impl
M* waitm; // linked list of waiting M's (sema-based impl)
};
union Note
{
uint32 key; // futex-based impl
M* waitm; // waiting M (sema-based impl)
};
struct String
{
byte* str;
intgo len;
};
struct Iface
{
Itab* tab;
void* data;
};
struct Eface
{
Type* type;
void* data;
};
struct Complex64
{
float32 real;
float32 imag;
};
struct Complex128
{
float64 real;
float64 imag;
};
struct Slice
{ // must not move anything
byte* array; // actual data
uintgo len; // number of elements
uintgo cap; // allocated number of elements
};
struct Gobuf
{
// The offsets of these fields are known to (hard-coded in) libmach.
uintptr sp;
byte* pc;
G* g;
};
struct GCStats
{
// the struct must consist of only uint64's,
// because it is casted to uint64[].
uint64 nhandoff;
uint64 nhandoffcnt;
uint64 nprocyield;
uint64 nosyield;
uint64 nsleep;
};
struct G
{
uintptr stackguard; // cannot move - also known to linker, libmach, runtime/cgo
uintptr stackbase; // cannot move - also known to libmach, runtime/cgo
Defer* defer;
Panic* panic;
Gobuf sched;
uintptr gcstack; // if status==Gsyscall, gcstack = stackbase to use during gc
uintptr gcsp; // if status==Gsyscall, gcsp = sched.sp to use during gc
uintptr gcguard; // if status==Gsyscall, gcguard = stackguard to use during gc
uintptr stack0;
byte* entry; // initial function
G* alllink; // on allg
void* param; // passed parameter on wakeup
int16 status;
int64 goid;
uint32 selgen; // valid sudog pointer
int8* waitreason; // if status==Gwaiting
G* schedlink;
bool readyonstop;
bool ispanic;
int8 raceignore; // ignore race detection events
M* m; // for debuggers, but offset not hard-coded
M* lockedm;
M* idlem;
int32 sig;
int32 writenbuf;
byte* writebuf;
uintptr sigcode0;
uintptr sigcode1;
uintptr sigpc;
uintptr gopc; // pc of go statement that created this goroutine
uintptr end[];
};
struct M
{
// The offsets of these fields are known to (hard-coded in) libmach.
G* g0; // goroutine with scheduling stack
void (*morepc)(void);
void* moreargp; // argument pointer for more stack
Gobuf morebuf; // gobuf arg to morestack
// Fields not known to debuggers.
uint32 moreframesize; // size arguments to morestack
uint32 moreargsize;
uintptr cret; // return value from C
uint64 procid; // for debuggers, but offset not hard-coded
G* gsignal; // signal-handling G
uint32 tls[8]; // thread-local storage (for 386 extern register)
G* curg; // current running goroutine
int32 id;
int32 mallocing;
int32 gcing;
int32 locks;
int32 nomemprof;
int32 waitnextg;
int32 dying;
int32 profilehz;
int32 helpgc;
uint32 fastrand;
uint64 ncgocall; // number of cgo calls in total
int32 ncgo; // number of cgo calls currently in progress
CgoMal* cgomal;
Note havenextg;
G* nextg;
M* alllink; // on allm
M* schedlink;
uint32 machport; // Return address for Mach IPC (OS X)
MCache *mcache;
FixAlloc *stackalloc;
G* lockedg;
G* idleg;
uintptr createstack[32]; // Stack that created this thread.
uint32 freglo[16]; // D[i] lsb and F[i]
uint32 freghi[16]; // D[i] msb and F[i+16]
uint32 fflag; // floating point compare flags
M* nextwaitm; // next M waiting for lock
uintptr waitsema; // semaphore for parking on locks
uint32 waitsemacount;
uint32 waitsemalock;
GCStats gcstats;
bool racecall;
void* racepc;
uintptr settype_buf[1024];
uintptr settype_bufsize;
#ifdef GOOS_windows
void* thread; // thread handle
#endif
SEH* seh;
uintptr end[];
};
struct Stktop
{
// The offsets of these fields are known to (hard-coded in) libmach.
uint8* stackguard;
uint8* stackbase;
Gobuf gobuf;
uint32 argsize;
uint8* argp; // pointer to arguments in old frame
uintptr free; // if free>0, call stackfree using free as size
bool panic; // is this frame the top of a panic?
};
struct SigTab
{
int32 flags;
int8 *name;
};
enum
{
SigNotify = 1<<0, // let signal.Notify have signal, even if from kernel
SigKill = 1<<1, // if signal.Notify doesn't take it, exit quietly
SigThrow = 1<<2, // if signal.Notify doesn't take it, exit loudly
SigPanic = 1<<3, // if the signal is from the kernel, panic
SigDefault = 1<<4, // if the signal isn't explicitly requested, don't monitor it
};
// NOTE(rsc): keep in sync with extern.go:/type.Func.
// Eventually, the loaded symbol table should be closer to this form.
struct Func
{
String name;
String type; // go type string
String src; // src file name
Slice pcln; // pc/ln tab for this func
uintptr entry; // entry pc
uintptr pc0; // starting pc, ln for table
int32 ln0;
int32 frame; // stack frame size
int32 args; // number of 32-bit in/out args
int32 locals; // number of 32-bit locals
};
// layout of Itab known to compilers
struct Itab
{
InterfaceType* inter;
Type* type;
Itab* link;
int32 bad;
int32 unused;
void (*fun[])(void);
};
struct WinCall
{
void (*fn)(void*);
uintptr n; // number of parameters
void* args; // parameters
uintptr r1; // return values
uintptr r2;
uintptr err; // error number
};
struct SEH
{
void* prev;
void* handler;
};
#ifdef GOOS_windows
enum {
Windows = 1
};
#else
enum {
Windows = 0
};
#endif
struct Timers
{
Lock;
G *timerproc;
bool sleeping;
bool rescheduling;
Note waitnote;
Timer **t;
int32 len;
int32 cap;
};
// Package time knows the layout of this structure.
// If this struct changes, adjust ../time/sleep.go:/runtimeTimer.
struct Timer
{
int32 i; // heap index
// Timer wakes up at when, and then at when+period, ... (period > 0 only)
// each time calling f(now, arg) in the timer goroutine, so f must be
// a well-behaved function and not block.
int64 when;
int64 period;
void (*f)(int64, Eface);
Eface arg;
};
// Lock-free stack node.
struct LFNode
{
LFNode *next;
uintptr pushcnt;
};
// Parallel for descriptor.
struct ParFor
{
void (*body)(ParFor*, uint32); // executed for each element
uint32 done; // number of idle threads
uint32 nthr; // total number of threads
uint32 nthrmax; // maximum number of threads
uint32 thrseq; // thread id sequencer
uint32 cnt; // iteration space [0, cnt)
void *ctx; // arbitrary user context
bool wait; // if true, wait while all threads finish processing,
// otherwise parfor may return while other threads are still working
ParForThread *thr; // array of thread descriptors
// stats
uint64 nsteal;
uint64 nstealcnt;
uint64 nprocyield;
uint64 nosyield;
uint64 nsleep;
};
// Track memory allocated by code not written in Go during a cgo call,
// so that the garbage collector can see them.
struct CgoMal
{
CgoMal *next;
byte *alloc;
};
/*
* defined macros
* you need super-gopher-guru privilege
* to add this list.
*/
#define nelem(x) (sizeof(x)/sizeof((x)[0]))
#define nil ((void*)0)
#define offsetof(s,m) (uint32)(&(((s*)0)->m))
#define ROUND(x, n) (((x)+(n)-1)&~((n)-1)) /* all-caps to mark as macro: it evaluates n twice */
/*
* known to compiler
*/
enum {
Structrnd = sizeof(uintptr)
};
/*
* type algorithms - known to compiler
*/
enum
{
AMEM,
AMEM0,
AMEM8,
AMEM16,
AMEM32,
AMEM64,
AMEM128,
ANOEQ,
ANOEQ0,
ANOEQ8,
ANOEQ16,
ANOEQ32,
ANOEQ64,
ANOEQ128,
ASTRING,
AINTER,
ANILINTER,
ASLICE,
AFLOAT32,
AFLOAT64,
ACPLX64,
ACPLX128,
Amax
};
typedef struct Alg Alg;
struct Alg
{
void (*hash)(uintptr*, uintptr, void*);
void (*equal)(bool*, uintptr, void*, void*);
void (*print)(uintptr, void*);
void (*copy)(uintptr, void*, void*);
};
extern Alg runtime·algarray[Amax];
void runtime·memhash(uintptr*, uintptr, void*);
void runtime·nohash(uintptr*, uintptr, void*);
void runtime·strhash(uintptr*, uintptr, void*);
void runtime·interhash(uintptr*, uintptr, void*);
void runtime·nilinterhash(uintptr*, uintptr, void*);
void runtime·memequal(bool*, uintptr, void*, void*);
void runtime·noequal(bool*, uintptr, void*, void*);
void runtime·strequal(bool*, uintptr, void*, void*);
void runtime·interequal(bool*, uintptr, void*, void*);
void runtime·nilinterequal(bool*, uintptr, void*, void*);
void runtime·memprint(uintptr, void*);
void runtime·strprint(uintptr, void*);
void runtime·interprint(uintptr, void*);
void runtime·nilinterprint(uintptr, void*);
void runtime·memcopy(uintptr, void*, void*);
void runtime·memcopy8(uintptr, void*, void*);
void runtime·memcopy16(uintptr, void*, void*);
void runtime·memcopy32(uintptr, void*, void*);
void runtime·memcopy64(uintptr, void*, void*);
void runtime·memcopy128(uintptr, void*, void*);
void runtime·memcopy(uintptr, void*, void*);
void runtime·strcopy(uintptr, void*, void*);
void runtime·algslicecopy(uintptr, void*, void*);
void runtime·intercopy(uintptr, void*, void*);
void runtime·nilintercopy(uintptr, void*, void*);
/*
* deferred subroutine calls
*/
struct Defer
{
int32 siz;
bool nofree;
byte* argp; // where args were copied from
byte* pc;
byte* fn;
Defer* link;
void* args[1]; // padded to actual size
};
/*
* panics
*/
struct Panic
{
Eface arg; // argument to panic
byte* stackbase; // g->stackbase in panic
Panic* link; // link to earlier panic
bool recovered; // whether this panic is over
};
/*
* external data
*/
extern String runtime·emptystring;
extern uintptr runtime·zerobase;
G* runtime·allg;
G* runtime·lastg;
M* runtime·allm;
extern int32 runtime·gomaxprocs;
extern bool runtime·singleproc;
extern uint32 runtime·panicking;
extern int32 runtime·gcwaiting; // gc is waiting to run
int8* runtime·goos;
int32 runtime·ncpu;
extern bool runtime·iscgo;
extern void (*runtime·sysargs)(int32, uint8**);
extern uint32 runtime·maxstring;
/*
* common functions and data
*/
int32 runtime·strcmp(byte*, byte*);
byte* runtime·strstr(byte*, byte*);
int32 runtime·findnull(byte*);
int32 runtime·findnullw(uint16*);
void runtime·dump(byte*, int32);
int32 runtime·runetochar(byte*, int32);
int32 runtime·charntorune(int32*, uint8*, int32);
/*
* very low level c-called
*/
#define FLUSH(x) USED(x)
void runtime·gogo(Gobuf*, uintptr);
void runtime·gogocall(Gobuf*, void(*)(void));
void runtime·gosave(Gobuf*);
void runtime·lessstack(void);
void runtime·goargs(void);
void runtime·goenvs(void);
void runtime·goenvs_unix(void);
void* runtime·getu(void);
void runtime·throw(int8*);
void runtime·panicstring(int8*);
void runtime·prints(int8*);
void runtime·printf(int8*, ...);
byte* runtime·mchr(byte*, byte, byte*);
int32 runtime·mcmp(byte*, byte*, uint32);
void runtime·memmove(void*, void*, uint32);
void* runtime·mal(uintptr);
String runtime·catstring(String, String);
String runtime·gostring(byte*);
String runtime·gostringn(byte*, intgo);
Slice runtime·gobytes(byte*, intgo);
String runtime·gostringnocopy(byte*);
String runtime·gostringw(uint16*);
void runtime·initsig(void);
void runtime·sigenable(uint32 sig);
int32 runtime·gotraceback(void);
void runtime·goroutineheader(G*);
void runtime·traceback(uint8 *pc, uint8 *sp, uint8 *lr, G* gp);
void runtime·tracebackothers(G*);
int32 runtime·write(int32, void*, int32);
int32 runtime·mincore(void*, uintptr, byte*);
bool runtime·cas(uint32*, uint32, uint32);
bool runtime·cas64(uint64*, uint64*, uint64);
bool runtime·casp(void**, void*, void*);
// Don't confuse with XADD x86 instruction,
// this one is actually 'addx', that is, add-and-fetch.
uint32 runtime·xadd(uint32 volatile*, int32);
uint64 runtime·xadd64(uint64 volatile*, int64);
uint32 runtime·xchg(uint32 volatile*, uint32);
uint32 runtime·atomicload(uint32 volatile*);
void runtime·atomicstore(uint32 volatile*, uint32);
void runtime·atomicstore64(uint64 volatile*, uint64);
uint64 runtime·atomicload64(uint64 volatile*);
void* runtime·atomicloadp(void* volatile*);
void runtime·atomicstorep(void* volatile*, void*);
void runtime·jmpdefer(byte*, void*);
void runtime·exit1(int32);
void runtime·ready(G*);
byte* runtime·getenv(int8*);
int32 runtime·atoi(byte*);
void runtime·newosproc(M *m, G *g, void *stk, void (*fn)(void));
void runtime·signalstack(byte*, int32);
G* runtime·malg(int32);
void runtime·asminit(void);
void runtime·minit(void);
Func* runtime·findfunc(uintptr);
int32 runtime·funcline(Func*, uintptr);
void* runtime·stackalloc(uint32);
void runtime·stackfree(void*, uintptr);
MCache* runtime·allocmcache(void);
void runtime·freemcache(MCache*);
void runtime·mallocinit(void);
bool runtime·ifaceeq_c(Iface, Iface);
bool runtime·efaceeq_c(Eface, Eface);
uintptr runtime·ifacehash(Iface);
uintptr runtime·efacehash(Eface);
void* runtime·malloc(uintptr size);
void runtime·free(void *v);
bool runtime·addfinalizer(void*, void(*fn)(void*), uintptr);
void runtime·runpanic(Panic*);
void* runtime·getcallersp(void*);
int32 runtime·mcount(void);
int32 runtime·gcount(void);
void runtime·mcall(void(*)(G*));
uint32 runtime·fastrand1(void);
void runtime·exit(int32);
void runtime·breakpoint(void);
void runtime·gosched(void);
void runtime·park(void(*)(Lock*), Lock*, int8*);
void runtime·tsleep(int64, int8*);
M* runtime·newm(void);
void runtime·goexit(void);
void runtime·asmcgocall(void (*fn)(void*), void*);
void runtime·entersyscall(void);
void runtime·exitsyscall(void);
G* runtime·newproc1(byte*, byte*, int32, int32, void*);
bool runtime·sigsend(int32 sig);
int32 runtime·callers(int32, uintptr*, int32);
int32 runtime·gentraceback(byte*, byte*, byte*, G*, int32, uintptr*, int32);
int64 runtime·nanotime(void);
void runtime·dopanic(int32);
void runtime·startpanic(void);
void runtime·unwindstack(G*, byte*);
void runtime·sigprof(uint8 *pc, uint8 *sp, uint8 *lr, G *gp);
void runtime·resetcpuprofiler(int32);
void runtime·setcpuprofilerate(void(*)(uintptr*, int32), int32);
void runtime·usleep(uint32);
int64 runtime·cputicks(void);
int64 runtime·tickspersecond(void);
void runtime·blockevent(int64, int32);
extern int64 runtime·blockprofilerate;
#pragma varargck argpos runtime·printf 1
#pragma varargck type "d" int32
#pragma varargck type "d" uint32
#pragma varargck type "D" int64
#pragma varargck type "D" uint64
#pragma varargck type "x" int32
#pragma varargck type "x" uint32
#pragma varargck type "X" int64
#pragma varargck type "X" uint64
#pragma varargck type "p" void*
#pragma varargck type "p" uintptr
#pragma varargck type "s" int8*
#pragma varargck type "s" uint8*
#pragma varargck type "S" String
void runtime·stoptheworld(void);
void runtime·starttheworld(void);
extern uint32 runtime·worldsema;
/*
* mutual exclusion locks. in the uncontended case,
* as fast as spin locks (just a few user-level instructions),
* but on the contention path they sleep in the kernel.
* a zeroed Lock is unlocked (no need to initialize each lock).
*/
void runtime·lock(Lock*);
void runtime·unlock(Lock*);
/*
* sleep and wakeup on one-time events.
* before any calls to notesleep or notewakeup,
* must call noteclear to initialize the Note.
* then, exactly one thread can call notesleep
* and exactly one thread can call notewakeup (once).
* once notewakeup has been called, the notesleep
* will return. future notesleep will return immediately.
* subsequent noteclear must be called only after
* previous notesleep has returned, e.g. it's disallowed
* to call noteclear straight after notewakeup.
*
* notetsleep is like notesleep but wakes up after
* a given number of nanoseconds even if the event
* has not yet happened. if a goroutine uses notetsleep to
* wake up early, it must wait to call noteclear until it
* can be sure that no other goroutine is calling
* notewakeup.
*/
void runtime·noteclear(Note*);
void runtime·notesleep(Note*);
void runtime·notewakeup(Note*);
void runtime·notetsleep(Note*, int64);
/*
* low-level synchronization for implementing the above
*/
uintptr runtime·semacreate(void);
int32 runtime·semasleep(int64);
void runtime·semawakeup(M*);
// or
void runtime·futexsleep(uint32*, uint32, int64);
void runtime·futexwakeup(uint32*, uint32);
/*
* Lock-free stack.
* Initialize uint64 head to 0, compare with 0 to test for emptiness.
* The stack does not keep pointers to nodes,
* so they can be garbage collected if there are no other pointers to nodes.
*/
void runtime·lfstackpush(uint64 *head, LFNode *node);
LFNode* runtime·lfstackpop(uint64 *head);
/*
* Parallel for over [0, n).
* body() is executed for each iteration.
* nthr - total number of worker threads.
* ctx - arbitrary user context.
* if wait=true, threads return from parfor() when all work is done;
* otherwise, threads can return while other threads are still finishing processing.
*/
ParFor* runtime·parforalloc(uint32 nthrmax);
void runtime·parforsetup(ParFor *desc, uint32 nthr, uint32 n, void *ctx, bool wait, void (*body)(ParFor*, uint32));
void runtime·parfordo(ParFor *desc);
/*
* This is consistent across Linux and BSD.
* If a new OS is added that is different, move this to
* $GOOS/$GOARCH/defs.h.
*/
#define EACCES 13
/*
* low level C-called
*/
// for mmap, we only pass the lower 32 bits of file offset to the
// assembly routine; the higher bits (if required), should be provided
// by the assembly routine as 0.
uint8* runtime·mmap(byte*, uintptr, int32, int32, int32, uint32);
void runtime·munmap(byte*, uintptr);
void runtime·madvise(byte*, uintptr, int32);
void runtime·memclr(byte*, uintptr);
void runtime·setcallerpc(void*, void*);
void* runtime·getcallerpc(void*);
/*
* runtime go-called
*/
void runtime·printbool(bool);
void runtime·printfloat(float64);
void runtime·printint(int64);
void runtime·printiface(Iface);
void runtime·printeface(Eface);
void runtime·printstring(String);
void runtime·printpc(void*);
void runtime·printpointer(void*);
void runtime·printuint(uint64);
void runtime·printhex(uint64);
void runtime·printslice(Slice);
void runtime·printcomplex(Complex128);
void reflect·call(byte*, byte*, uint32);
void runtime·panic(Eface);
void runtime·panicindex(void);
void runtime·panicslice(void);
/*
* runtime c-called (but written in Go)
*/
void runtime·printany(Eface);
void runtime·newTypeAssertionError(String*, String*, String*, String*, Eface*);
void runtime·newErrorString(String, Eface*);
void runtime·fadd64c(uint64, uint64, uint64*);
void runtime·fsub64c(uint64, uint64, uint64*);
void runtime·fmul64c(uint64, uint64, uint64*);
void runtime·fdiv64c(uint64, uint64, uint64*);
void runtime·fneg64c(uint64, uint64*);
void runtime·f32to64c(uint32, uint64*);
void runtime·f64to32c(uint64, uint32*);
void runtime·fcmp64c(uint64, uint64, int32*, bool*);
void runtime·fintto64c(int64, uint64*);
void runtime·f64tointc(uint64, int64*, bool*);
/*
* wrapped for go users
*/
float64 runtime·Inf(int32 sign);
float64 runtime·NaN(void);
float32 runtime·float32frombits(uint32 i);
uint32 runtime·float32tobits(float32 f);
float64 runtime·float64frombits(uint64 i);
uint64 runtime·float64tobits(float64 f);
float64 runtime·frexp(float64 d, int32 *ep);
bool runtime·isInf(float64 f, int32 sign);
bool runtime·isNaN(float64 f);
float64 runtime·ldexp(float64 d, int32 e);
float64 runtime·modf(float64 d, float64 *ip);
void runtime·semacquire(uint32*);
void runtime·semrelease(uint32*);
int32 runtime·gomaxprocsfunc(int32 n);
void runtime·procyield(uint32);
void runtime·osyield(void);
void runtime·LockOSThread(void);
void runtime·UnlockOSThread(void);
void runtime·mapassign(MapType*, Hmap*, byte*, byte*);
void runtime·mapaccess(MapType*, Hmap*, byte*, byte*, bool*);
void runtime·mapiternext(struct hash_iter*);
bool runtime·mapiterkey(struct hash_iter*, void*);
void runtime·mapiterkeyvalue(struct hash_iter*, void*, void*);
Hmap* runtime·makemap_c(MapType*, int64);
Hchan* runtime·makechan_c(ChanType*, int64);
void runtime·chansend(ChanType*, Hchan*, byte*, bool*, void*);
void runtime·chanrecv(ChanType*, Hchan*, byte*, bool*, bool*);
bool runtime·showframe(Func*);
void runtime·ifaceE2I(InterfaceType*, Eface, Iface*);
uintptr runtime·memlimit(void);
// If appropriate, ask the operating system to control whether this
// thread should receive profiling signals. This is only necessary on OS X.
// An operating system should not deliver a profiling signal to a
// thread that is not actually executing (what good is that?), but that's
// what OS X prefers to do. When profiling is turned on, we mask
// away the profiling signal when threads go to sleep, so that OS X
// is forced to deliver the signal to a thread that's actually running.
// This is a no-op on other systems.
void runtime·setprof(bool);
// float.c
extern float64 runtime·nan;
extern float64 runtime·posinf;
extern float64 runtime·neginf;
extern uint64 ·nan;
extern uint64 ·posinf;
extern uint64 ·neginf;
#define ISNAN(f) ((f) != (f))
enum
{
UseSpanType = 1,
};