mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-02-07 15:03:34 +00:00
a4b455185b
Renaming gc() to _gc() was a mistake since the better thing to do is put it behind the _COSMO_SOURCE macro. We need this change because I haven't wanted to use my amazing garbage collector ever since we renamed it. You now need to define _COSMO_SOURCE yourself when using amalgamation header and cosmocc users need to pass the -mcosmo flag to get the gc() function Some other issues relating to cancelation have been fixed along the way. We're also now putting cosmocc in a folder named `.cosmocc` so it can be more safely excluded by grep --exclude-dir=.cosmocc --exclude-dir=o etc.
98 lines
4 KiB
C
98 lines
4 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
|
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright 2021 Justine Alexandra Roberts Tunney │
|
|
│ │
|
|
│ Permission to use, copy, modify, and/or distribute this software for │
|
|
│ any purpose with or without fee is hereby granted, provided that the │
|
|
│ above copyright notice and this permission notice appear in all copies. │
|
|
│ │
|
|
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
|
|
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
|
|
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
|
|
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
|
|
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
|
|
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
|
|
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
|
|
│ PERFORMANCE OF THIS SOFTWARE. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/mem/gc.h"
|
|
#include "libc/assert.h"
|
|
#include "libc/intrin/likely.h"
|
|
#include "libc/mem/mem.h"
|
|
#include "libc/nexgen32e/gc.internal.h"
|
|
#include "libc/nexgen32e/stackframe.h"
|
|
#include "libc/runtime/runtime.h"
|
|
#include "libc/str/str.h"
|
|
#include "libc/thread/tls.h"
|
|
|
|
forceinline bool PointerNotOwnedByParentStackFrame(struct StackFrame *frame,
|
|
struct StackFrame *parent,
|
|
void *ptr) {
|
|
return !(((intptr_t)ptr > (intptr_t)frame) &&
|
|
((intptr_t)ptr < (intptr_t)parent));
|
|
}
|
|
|
|
static void TeardownGc(void) {
|
|
struct Garbages *g;
|
|
struct CosmoTib *t;
|
|
if (__tls_enabled) {
|
|
t = __get_tls();
|
|
if ((g = t->tib_garbages)) {
|
|
// exit() currently doesn't use gclongjmp() like pthread_exit()
|
|
// so we need to run the deferred functions manually.
|
|
while (g->i) {
|
|
--g->i;
|
|
((void (*)(intptr_t))g->p[g->i].fn)(g->p[g->i].arg);
|
|
}
|
|
free(g->p);
|
|
free(g);
|
|
}
|
|
}
|
|
}
|
|
|
|
__attribute__((__constructor__)) static void InitializeGc(void) {
|
|
atexit(TeardownGc);
|
|
}
|
|
|
|
// add item to garbage shadow stack.
|
|
// then rewrite caller's return address on stack.
|
|
static void DeferFunction(struct StackFrame *frame, void *fn, void *arg) {
|
|
int n2;
|
|
struct Garbage *p2;
|
|
struct Garbages *g;
|
|
struct CosmoTib *t;
|
|
t = __get_tls();
|
|
g = t->tib_garbages;
|
|
if (UNLIKELY(!g)) {
|
|
if (!(g = malloc(sizeof(struct Garbages)))) notpossible;
|
|
g->i = 0;
|
|
g->n = 4;
|
|
if (!(g->p = malloc(g->n * sizeof(struct Garbage)))) notpossible;
|
|
t->tib_garbages = g;
|
|
} else if (UNLIKELY(g->i == g->n)) {
|
|
p2 = g->p;
|
|
n2 = g->n + (g->n >> 1);
|
|
if ((p2 = realloc(p2, n2 * sizeof(*p2)))) {
|
|
g->p = p2;
|
|
g->n = n2;
|
|
} else {
|
|
notpossible;
|
|
}
|
|
}
|
|
g->p[g->i].frame = frame;
|
|
g->p[g->i].fn = (intptr_t)fn;
|
|
g->p[g->i].arg = (intptr_t)arg;
|
|
g->p[g->i].ret = frame->addr;
|
|
g->i++;
|
|
frame->addr = (intptr_t)__gc;
|
|
}
|
|
|
|
// the gnu extension macros for gc / defer point here
|
|
void __defer(void *rbp, void *fn, void *arg) {
|
|
struct StackFrame *f, *frame = rbp;
|
|
f = __builtin_frame_address(0);
|
|
unassert(f->next == frame);
|
|
unassert(PointerNotOwnedByParentStackFrame(f, frame, arg));
|
|
DeferFunction(frame, fn, arg);
|
|
}
|