From 65ba6fa43153036e0803bf27f7fe852f3ab34b4e Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Fri, 21 May 2021 10:09:31 -0300 Subject: nptl: Move Linux createthread to nptl git mv -f sysdeps/unix/sysv/linux/createthread.c nptl/createthread.c No functional change. --- nptl/createthread.c | 124 ++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 116 insertions(+), 8 deletions(-) (limited to 'nptl') diff --git a/nptl/createthread.c b/nptl/createthread.c index 46943b3..bc3409b 100644 --- a/nptl/createthread.c +++ b/nptl/createthread.c @@ -1,6 +1,7 @@ -/* Low-level thread creation for NPTL. Stub version. - Copyright (C) 2014-2021 Free Software Foundation, Inc. +/* Low-level thread creation for NPTL. Linux version. + Copyright (C) 2002-2021 Free Software Foundation, Inc. This file is part of the GNU C Library. + Contributed by Ulrich Drepper , 2002. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public @@ -16,30 +17,137 @@ License along with the GNU C Library; if not, see . */ +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#ifdef __NR_clone2 +# define ARCH_CLONE __clone2 +#else +# define ARCH_CLONE __clone +#endif + /* See the comments in pthread_create.c for the requirements for these two macros and the create_thread function. */ #define START_THREAD_DEFN \ - static void __attribute__ ((noreturn)) start_thread (void) -#define START_THREAD_SELF THREAD_SELF + static int __attribute__ ((noreturn)) start_thread (void *arg) +#define START_THREAD_SELF arg + +/* pthread_create.c defines this using START_THREAD_DEFN + We need a forward declaration here so we can take its address. */ +static int start_thread (void *arg) __attribute__ ((noreturn)); static int create_thread (struct pthread *pd, const struct pthread_attr *attr, bool *stopped_start, STACK_VARIABLES_PARMS, bool *thread_ran) { - /* If the implementation needs to do some tweaks to the thread after - it has been created at the OS level, it can set STOPPED_START here. */ + /* Determine whether the newly created threads has to be started + stopped since we have to set the scheduling parameters or set the + affinity. */ + bool need_setaffinity = (attr != NULL && attr->extension != NULL + && attr->extension->cpuset != 0); + if (attr != NULL + && (__glibc_unlikely (need_setaffinity) + || __glibc_unlikely ((attr->flags & ATTR_FLAG_NOTINHERITSCHED) != 0))) + *stopped_start = true; pd->stopped_start = *stopped_start; if (__glibc_unlikely (*stopped_start)) - /* See CONCURRENCY NOTES in nptl/pthread_create.c. */ + /* See CONCURRENCY NOTES in nptl/pthread_creat.c. */ lll_lock (pd->lock, LLL_PRIVATE); - return ENOSYS; + /* We rely heavily on various flags the CLONE function understands: + + CLONE_VM, CLONE_FS, CLONE_FILES + These flags select semantics with shared address space and + file descriptors according to what POSIX requires. + + CLONE_SIGHAND, CLONE_THREAD + This flag selects the POSIX signal semantics and various + other kinds of sharing (itimers, POSIX timers, etc.). + + CLONE_SETTLS + The sixth parameter to CLONE determines the TLS area for the + new thread. + + CLONE_PARENT_SETTID + The kernels writes the thread ID of the newly created thread + into the location pointed to by the fifth parameters to CLONE. + + Note that it would be semantically equivalent to use + CLONE_CHILD_SETTID but it is be more expensive in the kernel. + + CLONE_CHILD_CLEARTID + The kernels clears the thread ID of a thread that has called + sys_exit() in the location pointed to by the seventh parameter + to CLONE. + + The termination signal is chosen to be zero which means no signal + is sent. */ + const int clone_flags = (CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SYSVSEM + | CLONE_SIGHAND | CLONE_THREAD + | CLONE_SETTLS | CLONE_PARENT_SETTID + | CLONE_CHILD_CLEARTID + | 0); + + TLS_DEFINE_INIT_TP (tp, pd); + + if (__glibc_unlikely (ARCH_CLONE (&start_thread, STACK_VARIABLES_ARGS, + clone_flags, pd, &pd->tid, tp, &pd->tid) + == -1)) + return errno; /* It's started now, so if we fail below, we'll have to cancel it and let it clean itself up. */ *thread_ran = true; + /* Now we have the possibility to set scheduling parameters etc. */ + if (attr != NULL) + { + int res; + + /* Set the affinity mask if necessary. */ + if (need_setaffinity) + { + assert (*stopped_start); + + res = INTERNAL_SYSCALL_CALL (sched_setaffinity, pd->tid, + attr->extension->cpusetsize, + attr->extension->cpuset); + + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (res))) + err_out: + { + /* The operation failed. We have to kill the thread. + We let the normal cancellation mechanism do the work. */ + + pid_t pid = __getpid (); + INTERNAL_SYSCALL_CALL (tgkill, pid, pd->tid, SIGCANCEL); + + return INTERNAL_SYSCALL_ERRNO (res); + } + } + + /* Set the scheduling parameters. */ + if ((attr->flags & ATTR_FLAG_NOTINHERITSCHED) != 0) + { + assert (*stopped_start); + + res = INTERNAL_SYSCALL_CALL (sched_setscheduler, pd->tid, + pd->schedpolicy, &pd->schedparam); + + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (res))) + goto err_out; + } + } + return 0; } -- cgit v1.1