Add pthread_create(3).

libpthread/Makefile

@@ -21,6 +21,7 @@ pthread_cond_init.o \
 pthread_cond_signal.o \
 pthread_cond_timedwait.o \
 pthread_cond_wait.o \
+pthread_create.o \
 pthread_equal.o \
 pthread_exit.o \
 pthread_getspecific.o \

libpthread/include/pthread.h

@@ -138,6 +138,8 @@ typedef __pthread_t pthread_t;
 struct pthread
 {
 	struct uthread uthread;
+	void* (*entry_function)(void*);
+	void* entry_cookie;
 	void** keys;
 	size_t keys_length;
 };
@@ -175,6 +177,10 @@ extern pthread_mutex_t __pthread_keys_lock;
 extern struct pthread_key* __pthread_keys;
 extern size_t __pthread_keys_used;
 extern size_t __pthread_keys_length;
+extern pthread_mutex_t __pthread_num_threads_lock;
+extern size_t __pthread_num_threads;
+
+struct pthread* pthread_allocate_tls(void);
 
 #endif
 
@@ -223,7 +229,10 @@ int pthread_condattr_getclock(const pthread_condattr_t* __restrict,
 int pthread_condattr_init(pthread_condattr_t*);
 int pthread_condattr_setclock(pthread_condattr_t*, clockid_t);
 /* TODO: pthread_condattr_setpshared */
-/* TODO: pthread_create */
+int pthread_create(pthread_t* __restrict,
+                   const pthread_attr_t* __restrict,
+                   void* (*)(void*),
+                   void* __restrict);
 /* TODO: pthread_detach */
 int pthread_equal(pthread_t, pthread_t);
 __attribute__((__noreturn__))

libpthread/pthread_create.c++

@@ -0,0 +1,235 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013, 2014.
+
+    This file is part of Sortix libpthread.
+
+    Sortix libpthread is free software: you can redistribute it and/or modify it
+    under the terms of the GNU Lesser General Public License as published by the
+    Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    Sortix libpthread 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 Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with Sortix libpthread. If not, see <http://www.gnu.org/licenses/>.
+
+    pthread_create.c++
+    Creates a new thread.
+
+*******************************************************************************/
+
+#include <sys/mman.h>
+
+#include <assert.h>
+#include <errno.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <unistd.h>
+
+// Utility function that rounds size upwards to a multiple of alignment.
+static size_t align_size(size_t size, size_t alignment)
+{
+	return -(-size & ~(alignment-1));
+}
+
+__attribute__((noreturn))
+static void pthread_entrance(struct pthread* thread)
+{
+	pthread_exit(thread->entry_function(thread->entry_cookie));
+}
+
+#if defined(__i386__) || defined(__x86_64__)
+const unsigned long FLAGS_CARRY        = 1 << 0; // 0x000001
+const unsigned long FLAGS_RESERVED1    = 1 << 1; // 0x000002, read as one
+const unsigned long FLAGS_PARITY       = 1 << 2; // 0x000004
+const unsigned long FLAGS_RESERVED2    = 1 << 3; // 0x000008
+const unsigned long FLAGS_AUX          = 1 << 4; // 0x000010
+const unsigned long FLAGS_RESERVED3    = 1 << 5; // 0x000020
+const unsigned long FLAGS_ZERO         = 1 << 6; // 0x000040
+const unsigned long FLAGS_SIGN         = 1 << 7; // 0x000080
+const unsigned long FLAGS_TRAP         = 1 << 8; // 0x000100
+const unsigned long FLAGS_INTERRUPT    = 1 << 9; // 0x000200
+const unsigned long FLAGS_DIRECTION    = 1 << 10; // 0x000400
+const unsigned long FLAGS_OVERFLOW     = 1 << 11; // 0x000800
+const unsigned long FLAGS_IOPRIVLEVEL  = 1 << 12 | 1 << 13;
+const unsigned long FLAGS_NESTEDTASK   = 1 << 14; // 0x004000
+const unsigned long FLAGS_RESERVED4    = 1 << 15; // 0x008000
+const unsigned long FLAGS_RESUME       = 1 << 16; // 0x010000
+const unsigned long FLAGS_VIRTUAL8086  = 1 << 17; // 0x020000
+const unsigned long FLAGS_ALIGNCHECK   = 1 << 18; // 0x040000
+const unsigned long FLAGS_VIRTINTR     = 1 << 19; // 0x080000
+const unsigned long FLAGS_VIRTINTRPEND = 1 << 20; // 0x100000
+const unsigned long FLAGS_ID           = 1 << 21; // 0x200000
+#endif
+
+#if defined(__i386__)
+static const unsigned long MINIMUM_STACK_SIZE = 4 * sizeof(unsigned long);
+static void setup_thread_state(struct pthread* thread, tforkregs_t* regs)
+{
+	assert(MINIMUM_STACK_SIZE <= thread->uthread.stack_size);
+
+	memset(regs, 0, sizeof(*regs));
+	regs->eip = (uintptr_t) pthread_entrance;
+	regs->eflags = FLAGS_RESERVED1 | FLAGS_INTERRUPT | FLAGS_ID;
+	regs->gsbase = (unsigned long) thread;
+
+	unsigned long* stack =
+		(unsigned long*) ((uint8_t*) thread->uthread.stack_mmap +
+		                             thread->uthread.stack_size);
+
+	*--stack = 0; // rip=0
+	*--stack = 0; // rbp=0
+
+	regs->ebp = (uintptr_t) stack;
+
+	*--stack = (unsigned long) thread;
+	*--stack = 0;
+
+	regs->esp = (uintptr_t) stack;
+}
+
+#endif
+
+#if defined(__x86_64__)
+static const unsigned long MINIMUM_STACK_SIZE = 2 * sizeof(unsigned long);
+static void setup_thread_state(struct pthread* thread, tforkregs_t* regs)
+{
+	assert(MINIMUM_STACK_SIZE <= thread->uthread.stack_size);
+
+	memset(regs, 0, sizeof(*regs));
+	regs->rip = (uintptr_t) pthread_entrance;
+	regs->rdi = (uintptr_t) thread;
+	regs->rflags = FLAGS_RESERVED1 | FLAGS_INTERRUPT | FLAGS_ID;
+	regs->fsbase = (unsigned long) thread;
+
+	unsigned long* stack =
+		(unsigned long*) ((uint8_t*) thread->uthread.stack_mmap +
+		                             thread->uthread.stack_size);
+
+	*--stack = 0; // rip=0
+	*--stack = 0; // rbp=0
+
+	regs->rsp = (uintptr_t) stack;
+	regs->rbp = regs->rsp;
+}
+#endif
+
+static const unsigned long DEFAULT_STACK_SIZE = 64 * 1024;
+
+extern "C"
+{
+	pthread_mutex_t __pthread_num_threads_lock = PTHREAD_MUTEX_INITIALIZER;
+	size_t __pthread_num_threads = 1;
+}
+
+extern "C"
+int pthread_create(pthread_t* restrict thread_ptr,
+                   const pthread_attr_t* restrict /*attr*/,
+                   void* (*entry_function)(void*),
+                   void* restrict entry_cookie)
+{
+	assert(thread_ptr);
+
+	struct pthread* self = pthread_self();
+
+	// We can't create a thread local storage copy (and thus a new thread) if
+	// the kernel failed to allocate the thread local storage master copy.
+	if ( self->uthread.tls_master_size && !self->uthread.tls_master_mmap )
+		return errno = ENOMEM;
+
+	size_t raw_tls_size = self->uthread.tls_master_size;
+	size_t raw_tls_size_aligned = align_size(raw_tls_size, self->uthread.tls_master_align);
+	if ( raw_tls_size && raw_tls_size_aligned == 0 /* overflow */ )
+		return errno = EINVAL;
+
+	size_t tls_size = raw_tls_size_aligned + sizeof(struct pthread);
+	size_t tls_offset_tls = 0;
+	size_t tls_offset_pthread = raw_tls_size_aligned;
+	if ( self->uthread.tls_master_align < alignof(struct pthread) )
+	{
+		size_t more_aligned = align_size(raw_tls_size_aligned, alignof(struct pthread));
+		if ( raw_tls_size_aligned && more_aligned == 0 /* overflow */ )
+			return errno = EINVAL;
+		size_t difference = more_aligned - raw_tls_size_aligned;
+		tls_size += difference;
+		tls_offset_tls += difference;
+		tls_offset_pthread += difference;
+	}
+	assert((tls_offset_tls & (self->uthread.tls_master_align-1)) == 0);
+	assert((tls_offset_pthread & (alignof(struct pthread)-1)) == 0);
+
+	// Allocate a copy of the base thread-local storage area for use by the new
+	// thread, followed by the struct pthread for the new thread.
+	int prot = PROT_READ | PROT_WRITE;
+	int flags = MAP_PRIVATE | MAP_ANONYMOUS;
+	uint8_t* mapping = (uint8_t*) mmap(NULL, tls_size, prot, flags, -1, 0);
+	if ( (void*) mapping == MAP_FAILED )
+		return errno;
+
+	// We'll put the struct pthread nicely aligned in the new mapping.
+	struct pthread* thread =
+		(struct pthread*) (mapping + tls_offset_pthread);
+	assert((((uintptr_t) thread) & (alignof(struct pthread)-1)) == 0);
+
+	// Let's put the thread-local storage just before the struct pthread.
+	uint8_t* tls = mapping + tls_offset_tls;
+
+	// We will now initialize the thread-local storage of the new thread.
+	memcpy(tls, self->uthread.tls_master_mmap, self->uthread.tls_master_size);
+
+	// We'll clean up the new struct pthread before initializing it.
+	memset(thread, 0, sizeof(struct pthread));
+
+	// Initialize the thread object.
+	thread->uthread.uthread_pointer = &thread->uthread;
+	thread->uthread.uthread_size = sizeof(struct pthread);
+	thread->uthread.uthread_flags = 0;
+	thread->uthread.tls_master_mmap = self->uthread.tls_master_mmap;
+	thread->uthread.tls_master_size = self->uthread.tls_master_size;
+	thread->uthread.tls_master_align = self->uthread.tls_master_align;
+	thread->uthread.tls_mmap = mapping;
+	thread->uthread.tls_size = tls_size;
+	thread->uthread.arg_mmap = self->uthread.arg_mmap;
+	thread->uthread.arg_size = self->uthread.arg_size;
+	thread->entry_function = entry_function;
+	thread->entry_cookie = entry_cookie;
+
+	// Set up a stack for the new thread.
+	int stack_prot = PROT_READ | PROT_WRITE;
+	int stack_flags = MAP_PRIVATE | MAP_ANONYMOUS;
+	thread->uthread.stack_size = DEFAULT_STACK_SIZE;
+	thread->uthread.stack_mmap =
+		mmap(NULL, thread->uthread.stack_size, stack_prot, stack_flags, -1, 0);
+	if ( thread->uthread.stack_mmap == MAP_FAILED )
+	{
+		munmap(thread->uthread.tls_mmap, thread->uthread.tls_size);
+		return errno;
+	}
+
+	// Prepare the registers and initial stack for the new thread.
+	tforkregs_t regs;
+	setup_thread_state(thread, &regs);
+
+	// Create a new thread with the requested state.
+	pthread_mutex_lock(&__pthread_num_threads_lock);
+	if ( tfork(SFTHREAD, &regs) < 0 )
+	{
+		pthread_mutex_unlock(&__pthread_num_threads_lock);
+		munmap(thread->uthread.stack_mmap, thread->uthread.stack_size);
+		munmap(thread->uthread.tls_mmap, thread->uthread.tls_size);
+		return errno;
+	}
+	__pthread_num_threads++;
+	pthread_mutex_unlock(&__pthread_num_threads_lock);
+
+	*thread_ptr = thread;
+
+	return 0;
+}

libpthread/pthread_exit.c++

@@ -56,7 +56,9 @@ void pthread_exit(void* /*return_value*/)
 	thread->keys_length = 0;
 	pthread_mutex_unlock(&__pthread_keys_lock);
 
-	size_t num_threads = 1;
+	pthread_mutex_lock(&__pthread_num_threads_lock);
+	size_t num_threads = __pthread_num_threads--;
+	pthread_mutex_unlock(&__pthread_num_threads_lock);
 	if ( num_threads == 1 )
 		exit(0);
 	struct exit_thread extended;