Implement thread creation.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4693 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
pbrook 2008-06-07 22:12:17 +00:00
parent d597536303
commit d865bab552

View File

@ -74,6 +74,11 @@
#if defined(USE_NPTL)
#include <linux/futex.h>
#define CLONE_NPTL_FLAGS2 (CLONE_SETTLS | \
CLONE_PARENT_SETTID | CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)
#else
/* XXX: Hardcode the above values. */
#define CLONE_NPTL_FLAGS2 0
#endif
//#define DEBUG
@ -2706,6 +2711,48 @@ abi_long do_arch_prctl(CPUX86State *env, int code, abi_ulong addr)
#endif /* defined(TARGET_I386) */
#if defined(USE_NPTL)
#define NEW_STACK_SIZE PTHREAD_STACK_MIN
static pthread_mutex_t clone_lock = PTHREAD_MUTEX_INITIALIZER;
typedef struct {
CPUState *env;
pthread_mutex_t mutex;
pthread_cond_t cond;
pthread_t thread;
uint32_t tid;
abi_ulong child_tidptr;
abi_ulong parent_tidptr;
sigset_t sigmask;
} new_thread_info;
static void *clone_func(void *arg)
{
new_thread_info *info = arg;
CPUState *env;
env = info->env;
thread_env = env;
info->tid = gettid();
if (info->child_tidptr)
put_user_u32(info->tid, info->child_tidptr);
if (info->parent_tidptr)
put_user_u32(info->tid, info->parent_tidptr);
/* Enable signals. */
sigprocmask(SIG_SETMASK, &info->sigmask, NULL);
/* Signal to the parent that we're ready. */
pthread_mutex_lock(&info->mutex);
pthread_cond_broadcast(&info->cond);
pthread_mutex_unlock(&info->mutex);
/* Wait until the parent has finshed initializing the tls state. */
pthread_mutex_lock(&clone_lock);
pthread_mutex_unlock(&clone_lock);
cpu_loop(env);
/* never exits */
return NULL;
}
#else
/* this stack is the equivalent of the kernel stack associated with a
thread/process */
#define NEW_STACK_SIZE 8192
@ -2717,24 +2764,27 @@ static int clone_func(void *arg)
/* never exits */
return 0;
}
#endif
/* do_fork() Must return host values and target errnos (unlike most
do_*() functions). */
int do_fork(CPUState *env, unsigned int flags, abi_ulong newsp)
static int do_fork(CPUState *env, unsigned int flags, abi_ulong newsp,
abi_ulong parent_tidptr, target_ulong newtls,
abi_ulong child_tidptr)
{
int ret;
TaskState *ts;
uint8_t *new_stack;
CPUState *new_env;
#if defined(USE_NPTL)
unsigned int nptl_flags;
sigset_t sigmask;
#endif
if (flags & CLONE_VM) {
#if defined(USE_NPTL)
/* qemu is not threadsafe. Bail out immediately if application
tries to create a thread. */
if (!(flags & CLONE_VFORK)) {
gemu_log ("clone(CLONE_VM) not supported\n");
return -EINVAL;
}
new_thread_info info;
pthread_attr_t attr;
#endif
ts = malloc(sizeof(TaskState) + NEW_STACK_SIZE);
init_task_state(ts);
@ -2744,19 +2794,94 @@ int do_fork(CPUState *env, unsigned int flags, abi_ulong newsp)
/* Init regs that differ from the parent. */
cpu_clone_regs(new_env, newsp);
new_env->opaque = ts;
#if defined(USE_NPTL)
nptl_flags = flags;
flags &= ~CLONE_NPTL_FLAGS2;
/* TODO: Implement CLONE_CHILD_CLEARTID. */
if (nptl_flags & CLONE_SETTLS)
cpu_set_tls (new_env, newtls);
/* Grab a mutex so that thread setup appears atomic. */
pthread_mutex_lock(&clone_lock);
memset(&info, 0, sizeof(info));
pthread_mutex_init(&info.mutex, NULL);
pthread_mutex_lock(&info.mutex);
pthread_cond_init(&info.cond, NULL);
info.env = new_env;
if (nptl_flags & CLONE_CHILD_SETTID)
info.child_tidptr = child_tidptr;
if (nptl_flags & CLONE_PARENT_SETTID)
info.parent_tidptr = parent_tidptr;
ret = pthread_attr_init(&attr);
ret = pthread_attr_setstack(&attr, new_stack, NEW_STACK_SIZE);
/* It is not safe to deliver signals until the child has finished
initializing, so temporarily block all signals. */
sigfillset(&sigmask);
sigprocmask(SIG_BLOCK, &sigmask, &info.sigmask);
ret = pthread_create(&info.thread, &attr, clone_func, &info);
sigprocmask(SIG_SETMASK, &info.sigmask, NULL);
pthread_attr_destroy(&attr);
if (ret == 0) {
/* Wait for the child to initialize. */
pthread_cond_wait(&info.cond, &info.mutex);
ret = info.tid;
if (flags & CLONE_PARENT_SETTID)
put_user_u32(ret, parent_tidptr);
} else {
ret = -1;
}
pthread_mutex_unlock(&info.mutex);
pthread_cond_destroy(&info.cond);
pthread_mutex_destroy(&info.mutex);
pthread_mutex_unlock(&clone_lock);
#else
if (flags & CLONE_NPTL_FLAGS2)
return -EINVAL;
/* This is probably going to die very quickly, but do it anyway. */
#ifdef __ia64__
ret = __clone2(clone_func, new_stack + NEW_STACK_SIZE, flags, new_env);
#else
ret = clone(clone_func, new_stack + NEW_STACK_SIZE, flags, new_env);
#endif
#endif
} else {
/* if no CLONE_VM, we consider it is a fork */
if ((flags & ~CSIGNAL) != 0)
if ((flags & ~(CSIGNAL | CLONE_NPTL_FLAGS2)) != 0)
return -EINVAL;
fork_start();
ret = fork();
#if defined(USE_NPTL)
/* There is a race condition here. The parent process could
theoretically read the TID in the child process before the child
tid is set. This would require using either ptrace
(not implemented) or having *_tidptr to point at a shared memory
mapping. We can't repeat the spinlock hack used above because
the child process gets its own copy of the lock. */
if (ret == 0) {
cpu_clone_regs(env, newsp);
fork_end(1);
/* Child Process. */
if (flags & CLONE_CHILD_SETTID)
put_user_u32(gettid(), child_tidptr);
if (flags & CLONE_PARENT_SETTID)
put_user_u32(gettid(), parent_tidptr);
ts = (TaskState *)env->opaque;
if (flags & CLONE_SETTLS)
cpu_set_tls (env, newtls);
/* TODO: Implement CLONE_CHILD_CLEARTID. */
} else {
fork_end(0);
}
#else
if (ret == 0) {
cpu_clone_regs(env, newsp);
}
#endif
}
return ret;
}
@ -3153,7 +3278,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
ret = do_brk(arg1);
break;
case TARGET_NR_fork:
ret = get_errno(do_fork(cpu_env, SIGCHLD, 0));
ret = get_errno(do_fork(cpu_env, SIGCHLD, 0, 0, 0, 0));
break;
#ifdef TARGET_NR_waitpid
case TARGET_NR_waitpid:
@ -4531,7 +4656,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
ret = get_errno(fsync(arg1));
break;
case TARGET_NR_clone:
ret = get_errno(do_fork(cpu_env, arg1, arg2));
ret = get_errno(do_fork(cpu_env, arg1, arg2, arg3, arg4, arg5));
break;
#ifdef __NR_exit_group
/* new thread calls */
@ -4967,7 +5092,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
#endif
#ifdef TARGET_NR_vfork
case TARGET_NR_vfork:
ret = get_errno(do_fork(cpu_env, CLONE_VFORK | CLONE_VM | SIGCHLD, 0));
ret = get_errno(do_fork(cpu_env, CLONE_VFORK | CLONE_VM | SIGCHLD,
0, 0, 0, 0));
break;
#endif
#ifdef TARGET_NR_ugetrlimit