[WIP] Threading phase 2 (#301)

* Exponential back-off
* Removed "native" specifier
* Abstract away Futex for cthread
* Complete setup for TLS (including main thread)
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Florian Lemaitre 2021-10-26 01:02:26 +02:00 committed by GitHub
parent 660ff56d40
commit 45a7435788
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11 changed files with 249 additions and 78 deletions

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@ -45,6 +45,7 @@ cosmo: push %rbp
pop %rax
#endif
call _init
call _main_thread_init # FIXME: use .init.start macro
ezlea __init_array_start,ax # static ctors in forward order
.weak __init_array_start # could be called multiple times
ezlea __init_array_end,cx # idempotency recommended

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@ -0,0 +1,68 @@
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi
Copyright 2020 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/calls/calls.h"
#include "libc/runtime/runtime.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/nr.h"
#include "libc/sysv/consts/prot.h"
#include "libc/thread/descriptor.h"
// TLS boundaries
extern char _tbss_start, _tbss_end, _tdata_start, _tdata_end;
void _main_thread_init(void) {
size_t tbsssize = &_tbss_end - &_tbss_start;
size_t tdatasize = &_tdata_end - &_tdata_start;
size_t tlssize = tbsssize + tdatasize;
size_t totalsize = tlssize + sizeof(struct cthread_descriptor_t);
totalsize = (totalsize + PAGESIZE - 1) & -PAGESIZE;
uintptr_t mem = (uintptr_t)mmap(NULL, totalsize, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
if (mem == -1) {
abort();
}
void* bottom = (void*)mem;
void* top = (void*)(mem + totalsize);
cthread_t td = (cthread_t)top - 1;
td->self = td;
td->stack.top = NULL;
td->stack.bottom = NULL;
td->tls.top = top;
td->tls.bottom = bottom;
td->alloc.top = top;
td->alloc.bottom = bottom;
td->state = cthread_main;
// Initialize TLS with content of .tdata section
memmove((void*)((uintptr_t)td - tlssize), &_tdata_start, tdatasize);
// Get TID of main thread
int gettid = __NR_gettid;
if (gettid == 0xfff) gettid = __NR_getpid;
td->tid = syscall(gettid);
// Set FS
if (arch_prctl(ARCH_SET_FS, td) != 0) {
abort();
}
}