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sortix--sortix/kernel/thread.cpp
Jonas 'Sortie' Termansen 8c2befc140 Clean up scheduler.
2014-08-24 14:02:42 +02:00

316 lines
8.7 KiB
C++

/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2013, 2014.
This file is part of Sortix.
Sortix is free software: you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.
Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
details.
You should have received a copy of the GNU General Public License along with
Sortix. If not, see <http://www.gnu.org/licenses/>.
thread.cpp
Describes a thread belonging to a process.
*******************************************************************************/
#include <sys/wait.h>
#include <assert.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <sortix/exit.h>
#include <sortix/mman.h>
#include <sortix/signal.h>
#include <sortix/kernel/copy.h>
#include <sortix/kernel/interrupt.h>
#include <sortix/kernel/kernel.h>
#include <sortix/kernel/kthread.h>
#include <sortix/kernel/memorymanagement.h>
#include <sortix/kernel/process.h>
#include <sortix/kernel/scheduler.h>
#include <sortix/kernel/syscall.h>
#include <sortix/kernel/thread.h>
#include <sortix/kernel/time.h>
namespace Sortix {
Thread::Thread()
{
id = 0; // TODO: Make a thread id.
process = NULL;
prevsibling = NULL;
nextsibling = NULL;
scheduler_list_prev = NULL;
scheduler_list_next = NULL;
state = NONE;
memset(&registers, 0, sizeof(registers));
fsbase = 0;
gsbase = 0;
kernelstackpos = 0;
kernelstacksize = 0;
kernelstackmalloced = false;
pledged_destruction = false;
fpuinitialized = false;
// If malloc isn't 16-byte aligned, then we can't rely on offsets in
// our own class, so we'll just fix ourselves nicely up.
unsigned long fpuaddr = ((unsigned long) fpuenv+16UL) & ~(16UL-1UL);
fpuenvaligned = (uint8_t*) fpuaddr;
sigemptyset(&signal_pending);
sigemptyset(&signal_mask);
memset(&signal_stack, 0, sizeof(signal_stack));
signal_stack.ss_flags = SS_DISABLE;
}
Thread::~Thread()
{
if ( process )
process->OnThreadDestruction(this);
assert(CurrentThread() != this);
if ( kernelstackmalloced )
delete[] (uint8_t*) kernelstackpos;
}
addr_t Thread::SwitchAddressSpace(addr_t newaddrspace)
{
bool wasenabled = Interrupt::SetEnabled(false);
addr_t result = addrspace;
addrspace = newaddrspace;
Memory::SwitchAddressSpace(newaddrspace);
Interrupt::SetEnabled(wasenabled);
return result;
}
extern "C" void BootstrapKernelThread(void* user, ThreadEntry entry)
{
entry(user);
kthread_exit();
}
Thread* CreateKernelThread(Process* process, CPU::InterruptRegisters* regs,
unsigned long fsbase, unsigned long gsbase)
{
#if defined(__x86_64__)
if ( fsbase >> 48 != 0x0000 && fsbase >> 48 != 0xFFFF )
return errno = EINVAL, (Thread*) NULL;
if ( gsbase >> 48 != 0x0000 && gsbase >> 48 != 0xFFFF )
return errno = EINVAL, (Thread*) NULL;
#endif
assert(process && regs && process->addrspace);
Thread* thread = new Thread;
if ( !thread )
return NULL;
thread->addrspace = process->addrspace;
thread->SaveRegisters(regs);
thread->fsbase = fsbase;
thread->gsbase = gsbase;
kthread_mutex_lock(&process->threadlock);
// Create the family tree.
thread->process = process;
Thread* firsty = process->firstthread;
if ( firsty )
firsty->prevsibling = thread;
thread->nextsibling = firsty;
process->firstthread = thread;
kthread_mutex_unlock(&process->threadlock);
return thread;
}
Thread* CreateKernelThread(Process* process, ThreadEntry entry, void* user,
size_t stacksize)
{
const size_t DEFAULT_KERNEL_STACK_SIZE = 8 * 1024UL;
if ( !stacksize )
stacksize = DEFAULT_KERNEL_STACK_SIZE;
uint8_t* stack = new uint8_t[stacksize];
if ( !stack )
return NULL;
CPU::InterruptRegisters regs;
SetupKernelThreadRegs(&regs, entry, user, (addr_t) stack, stacksize);
Thread* thread = CreateKernelThread(process, &regs, 0, 0);
if ( !thread ) { delete[] stack; return NULL; }
thread->kernelstackpos = (addr_t) stack;
thread->kernelstacksize = stacksize;
thread->kernelstackmalloced = true;
return thread;
}
Thread* CreateKernelThread(ThreadEntry entry, void* user, size_t stacksize)
{
return CreateKernelThread(CurrentProcess(), entry, user, stacksize);
}
void StartKernelThread(Thread* thread)
{
Scheduler::SetThreadState(thread, ThreadState::RUNNABLE);
}
Thread* RunKernelThread(Process* process, CPU::InterruptRegisters* regs)
{
Thread* thread = CreateKernelThread(process, regs, 0, 0);
if ( !thread )
return NULL;
StartKernelThread(thread);
return thread;
}
Thread* RunKernelThread(Process* process, ThreadEntry entry, void* user,
size_t stacksize)
{
Thread* thread = CreateKernelThread(process, entry, user, stacksize);
if ( !thread )
return NULL;
StartKernelThread(thread);
return thread;
}
Thread* RunKernelThread(ThreadEntry entry, void* user, size_t stacksize)
{
Thread* thread = CreateKernelThread(entry, user, stacksize);
if ( !thread )
return NULL;
StartKernelThread(thread);
return thread;
}
static int sys_exit_thread(int requested_exit_code,
int flags,
const struct exit_thread* user_extended)
{
if ( flags & ~(EXIT_THREAD_ONLY_IF_OTHERS |
EXIT_THREAD_UNMAP |
EXIT_THREAD_ZERO |
EXIT_THREAD_TLS_UNMAP |
EXIT_THREAD_PROCESS |
EXIT_THREAD_DUMP_CORE) )
return errno = EINVAL, -1;
if ( (flags & EXIT_THREAD_ONLY_IF_OTHERS) && (flags & EXIT_THREAD_PROCESS) )
return errno = EINVAL, -1;
Thread* thread = CurrentThread();
Process* process = CurrentProcess();
struct exit_thread extended;
if ( !user_extended )
memset(&extended, 0, sizeof(extended));
else if ( !CopyFromUser(&extended, user_extended, sizeof(extended)) )
return -1;
extended.unmap_size = Page::AlignUp(extended.unmap_size);
kthread_mutex_lock(&thread->process->threadlock);
bool is_others = false;
for ( Thread* iter = thread->process->firstthread;
!is_others && iter;
iter = iter->nextsibling )
{
if ( iter == thread )
continue;
if ( iter->pledged_destruction )
continue;
is_others = true;
}
if ( !(flags & EXIT_THREAD_ONLY_IF_OTHERS) || is_others )
thread->pledged_destruction = true;
bool are_threads_exiting = false;
if ( (flags & EXIT_THREAD_PROCESS) || !is_others )
process->threads_exiting = true;
else if ( process->threads_exiting )
are_threads_exiting = true;
kthread_mutex_unlock(&thread->process->threadlock);
// Self-destruct if another thread began exiting the process.
if ( are_threads_exiting )
kthread_exit();
if ( (flags & EXIT_THREAD_ONLY_IF_OTHERS) && !is_others )
return errno = ESRCH, -1;
if ( flags & EXIT_THREAD_UNMAP &&
Page::IsAligned((uintptr_t) extended.unmap_from) &&
extended.unmap_size )
{
ScopedLock lock(&process->segment_lock);
Memory::UnmapMemory(process, (uintptr_t) extended.unmap_from,
extended.unmap_size);
Memory::Flush();
// TODO: The segment is not actually removed!
}
if ( flags & EXIT_THREAD_TLS_UNMAP &&
Page::IsAligned((uintptr_t) extended.tls_unmap_from) &&
extended.tls_unmap_size )
{
ScopedLock lock(&process->segment_lock);
Memory::UnmapMemory(process, (uintptr_t) extended.tls_unmap_from,
extended.tls_unmap_size);
Memory::Flush();
}
if ( flags & EXIT_THREAD_ZERO )
ZeroUser(extended.zero_from, extended.zero_size);
if ( !is_others )
{
// Validate the requested exit code such that the process can't exit
// with an impossible exit status or that it wasn't actually terminated.
int the_nature = WNATURE(requested_exit_code);
int the_status = WEXITSTATUS(requested_exit_code);
int the_signal = WTERMSIG(requested_exit_code);
if ( the_nature == WNATURE_EXITED )
the_signal = 0;
else if ( the_nature == WNATURE_SIGNALED )
{
if ( the_signal == 0 /* null signal */ ||
the_signal == SIGSTOP ||
the_signal == SIGTSTP ||
the_signal == SIGTTIN ||
the_signal == SIGTTOU ||
the_signal == SIGCONT )
the_signal = SIGKILL;
the_status = 128 + the_signal;
}
else
{
the_nature = WNATURE_SIGNALED;
the_signal = SIGKILL;
}
requested_exit_code = WCONSTRUCT(the_nature, the_status, the_signal);
thread->process->ExitWithCode(requested_exit_code);
}
kthread_exit();
}
void Thread::Init()
{
Syscall::Register(SYSCALL_EXIT_THREAD, (void*) sys_exit_thread);
}
} // namespace Sortix