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testing/ostest: split the fork test into task_fork, vfork and fork

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nuttx implements fork() and vfork() as the same function, and is gaining the
three separate primitives its issue #19540 describes:  task_fork() (shares
memory, private stack copy, both running), vfork() (shares memory, parent
suspended) and POSIX fork() (child gets its own copy).  This is the apps side
of that, and it lands first:  it works against nuttx with or without the
split, so the tests keep running across the transition rather than silently
compiling out.

ostest's "vfork" test was never testing vfork().  It has the child write a
global and the parent observe the write -- which is the defining property of
*sharing*, not of vfork(), whose defining property is that the parent is
suspended and whose contract forbids the child to write anything at all.  It
is renamed to task_fork.c, unchanged, because that is the primitive it has
always described.

vfork.c is rewritten to test what vfork() promises.  The child does only what
POSIX permits -- it calls _exit(42), and nothing else, not even exit(), which
would run atexit handlers and flush stdio in the parent's address space.  The
observable is therefore the child's exit status rather than a memory write.
Where child status is not retained -- ostest_main() sets SA_NOCLDWAIT for the
whole run, deliberately -- waitpid() returning ECHILD is accepted as equally
good evidence:  it says the child was already gone when the parent asked.

fork.c is new and tests POSIX fork():  the child's writes to .data, .bss and
the heap are invisible to the parent and vice versa, a pointer to a stack
local taken before the fork names the same object in both, and the child does
everything a vfork() child may not -- calls malloc() and printf(), and returns
from the function that called fork().

All three run at the top of user_main() rather than in the middle.  They
exercise the lowest-level machinery in the suite -- address environments,
stack setup, the architecture's register context -- so a fault in one takes
the process down instead of reporting a failure, and finding that out in
seconds rather than after everything else has passed is the difference
between a usable iteration and a coffee break when a port is being brought
up.

The other in-tree callers are audited for which primitive they actually
meant.  nand_sim wants a daemon that outlives its caller and shares its
memory, which is task_fork().  bas's SHELL and EDIT statements, python's
_posixsubprocess and libwebsockets' feature macros want the fork-then-exec
path, which vfork() serves; python's os.fork() and libwebsockets'
LWS_HAVE_FORK stay on fork() proper.  fdsantest's vfork case follows vfork().

Two third-party suites need their source lists narrowed, because they call
fork() from code that is compiled unconditionally:

* system/libuv -- test-fork.c and test-pipe-close-stdout-read-stdin.c are
  filtered out of the test-*.c glob.  Every test they define is already
  excluded from the task list on NuttX by 0001-libuv-port-for-nuttx.patch --
  the nine fork_* entries and pipe_close_stdout_read_stdin -- so they were
  dead code being compiled only because fork() happened to be declared.
* testing/ltp -- the open_posix_testsuite is filtered through the existing
  BLACKWORDS mechanism, which already drops tests for absent features and is
  already conditioned on configuration symbols.  Where fork() is not
  provided this drops 278 of 1943 test files; the pattern is written to spare
  vfork() and task_fork(), which remain available.  Where fork() is provided
  -- which today is everywhere -- nothing is dropped.

Compatibility: the nuttx symbols this keys on do not exist yet.  task_fork.c
is built where CONFIG_TASK_FORK says task_fork() was built and, on a nuttx that
has no CONFIG_ARCH_HAVE_TASK_FORK at all -- which is the pre-split one -- where
CONFIG_ARCH_HAVE_FORK does.  Today's fork() *is* task_fork(), so the test that
has always covered that primitive keeps running, under its own name, and no
coverage is lost across the transition.  Both spellings are needed because
CONFIG_TASK_FORK is optional on the nuttx side:  ARCH_HAVE_TASK_FORK says the
architecture can clone a task, TASK_FORK says this build asked for it.  A
follow-up removes the fallback once the split has landed.

vfork_test() and fork_test() deliberately have no such fallback.  Both check
semantics a pre-split nuttx does not describe -- the parent suspension and the
private copy -- and ARCH_HAVE_VFORK is the evidence that the split has landed.
Mapping them onto ARCH_HAVE_FORK would also add a test to configurations that
never had one, which is not free:  vfork.c costs about 470 bytes of .text on
armv7-m at -Os, and that is what put lm3s6965-ek:qemu-protected over its 128
KiB user flash region.

Signed-off-by: Marco Casaroli <marco.casaroli@gmail.com>

Assisted-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
This commit is contained in:
Marco Casaroli 2026-07-28 00:36:25 +02:00
parent 636047a4e0
commit 7aac6c5cb8
16 changed files with 589 additions and 33 deletions
Download patch file Download diff file Expand all files Collapse all files

10
interpreters/python/Makefile
View file

@ -114,6 +114,11 @@ ifeq ($(CONFIG_ARCH_HAVE_FORK),y)
else
@echo "export ac_cv_func_fork=\"no\"" >> $@
endif
ifneq ($(CONFIG_ARCH_HAVE_VFORK)$(CONFIG_ARCH_HAVE_FORK),)
@echo "export ac_cv_func_vfork=\"yes\"" >> $@
else
@echo "export ac_cv_func_vfork=\"no\"" >> $@
endif
ifeq ($(CONFIG_SYSTEM_SYSTEM),y)
@echo "export ac_cv_func_system=\"yes\"" >> $@
else
@ -135,7 +140,10 @@ endif
$(SETUP_LOCAL):
$(Q) ( cp $(SETUP_LOCAL).in $(SETUP_LOCAL))
ifneq ($(CONFIG_ARCH_HAVE_FORK),y)
# _posixsubprocess is the fork-then-exec path, so vfork() is enough for it;
# os.fork() itself needs a real fork() and is governed by ac_cv_func_fork
# above.
ifeq ($(CONFIG_ARCH_HAVE_FORK)$(CONFIG_ARCH_HAVE_VFORK),)
@echo "_posixsubprocess" >> $@
endif
ifneq ($(CONFIG_LIBC_DLFCN),y)

7
netutils/libwebsockets/lws_config_private.h
View file

@ -43,7 +43,10 @@
/* #undef USE_CYASSL */
/* Define to 1 if you have the `fork' function. */
#ifdef CONFIG_ARCH_HAVE_FORK
#define LWS_HAVE_FORK
#endif
#ifndef CONFIG_DISABLE_ENVIRON
/* Define to 1 if you have the `getenv' function. */
@ -111,10 +114,14 @@
/* #undef LWS_HAVE_VFORK_H */
/* Define to 1 if `fork' works. */
#ifdef CONFIG_ARCH_HAVE_FORK
#define LWS_HAVE_WORKING_FORK
#endif
/* Define to 1 if `vfork' works. */
#if defined(CONFIG_ARCH_HAVE_VFORK) || defined(CONFIG_ARCH_HAVE_FORK)
#define LWS_HAVE_WORKING_VFORK
#endif
/* Define to 1 if execvpe() exists */
#define LWS_HAVE_EXECVPE

5
system/libuv/CMakeLists.txt
View file

@ -171,6 +171,11 @@ if(CONFIG_LIBUV)
${LIBUV_TEST_DIR}/run-tests.c ${LIBUV_TEST_DIR}/runner.c
${LIBUV_TEST_DIR}/runner-unix.c ${LIBUV_TEST_DIR}/echo-server.c)
file(GLOB TEST_CSRCS ${LIBUV_TEST_DIR}/test-*.c)
# See system/libuv/Makefile.
list(REMOVE_ITEM TEST_CSRCS ${LIBUV_TEST_DIR}/test-fork.c
${LIBUV_TEST_DIR}/test-pipe-close-stdout-read-stdin.c)
list(APPEND LIBUV_UTILS_TEST_SRCS ${TEST_CSRCS})
nuttx_add_application(
NAME

10
system/libuv/Makefile
View file

@ -144,7 +144,15 @@ CSRCS += runner.c
CSRCS += runner-unix.c
CSRCS += echo-server.c
CSRCS += $(wildcard libuv/test/test-*.c)
# test-fork.c and test-pipe-close-stdout-read-stdin.c call fork(). Every
# test they define is already excluded from the task list on NuttX by
# 0001-libuv-port-for-nuttx.patch, so they are dead code here.
LIBUV_TEST_CSRCS = $(wildcard libuv/test/test-*.c)
LIBUV_TEST_CSRCS := $(filter-out libuv/test/test-fork.c,$(LIBUV_TEST_CSRCS))
LIBUV_TEST_CSRCS := $(filter-out libuv/test/test-pipe-close-stdout-read-stdin.c,$(LIBUV_TEST_CSRCS))
CSRCS += $(LIBUV_TEST_CSRCS)
endif
ifneq ($(CONFIG_LIBUV_UTILS_BENCHMARK),)

1
testing/drivers/nand_sim/Kconfig
View file

@ -6,6 +6,7 @@
config TESTING_NAND_SIM
boolean "NAND Flash Simulator"
depends on MTD_NAND_RAM && ENABLE_ALL_SIGNALS
depends on TASK_FORK || (ARCH_HAVE_FORK && !ARCH_HAVE_TASK_FORK)
default n
---help---
Enable the NAND Flash Simulator device.

13
testing/drivers/nand_sim/nand_sim_main.c
View file

@ -25,7 +25,9 @@
****************************************************************************/
#include <nuttx/debug.h>
#include <sched.h>
#include <stdio.h>
#include <unistd.h>
#include <nuttx/drivers/drivers.h>
#include <nuttx/mtd/nand.h>
@ -140,9 +142,16 @@ int main(int argc, FAR char *argv[])
int ret;
pid_t pid;
/* Daemon */
/* task_fork() rather than fork(): this wants a clone that outlives the
* caller and shares its memory. The fallback below covers a nuttx that
* does not have task_fork() yet.
*/
pid = fork();
#ifndef CONFIG_TASK_FORK
# define task_fork() fork()
#endif
pid = task_fork();
if (pid > 0)
{

4
testing/fs/fdsantest/fdsantest_simple.c
View file

@ -96,6 +96,7 @@ static void test_case_overflow(void **state)
assert_int_equal(open_count, close_count);
}
#if defined(CONFIG_ARCH_HAVE_VFORK) || defined(CONFIG_ARCH_HAVE_FORK)
static void test_case_vfork(void **state)
{
int fd = open("/dev/null", O_RDONLY);
@ -112,6 +113,7 @@ static void test_case_vfork(void **state)
android_fdsan_close_with_tag(fd, 0xbadc0de);
}
#endif
/****************************************************************************
* Public Functions
@ -129,7 +131,9 @@ int main(int argc, FAR char *argv[])
cmocka_unit_test(test_case_unowned_tagged_close),
cmocka_unit_test(test_case_owned_tagged_close),
cmocka_unit_test(test_case_overflow),
#if defined(CONFIG_ARCH_HAVE_VFORK) || defined(CONFIG_ARCH_HAVE_FORK)
cmocka_unit_test(test_case_vfork),
#endif
};
return cmocka_run_group_tests(tests, NULL, NULL);

6
testing/ltp/CMakeLists.txt
View file

@ -86,6 +86,12 @@ if(CONFIG_TESTING_LTP)
list(APPEND BLACKWORDS "pthread_spin_init" "pthread_spin_destroy"
"pthread_spin_trylock")
endif()
# See testing/ltp/Makefile.
if(NOT CONFIG_ARCH_HAVE_FORK AND NOT CONFIG_FORK_IS_TASK_FORK)
list(APPEND BLACKWORDS "[^v_]fork(")
endif()
list(
APPEND
BLACKWORDS

7
testing/ltp/Makefile
View file

@ -44,6 +44,13 @@ BLACKWORDS += "pthread_spin_destroy"
BLACKWORDS += "pthread_spin_trylock"
endif
# Where NuttX does not declare fork(), a test that calls it cannot be built.
# The pattern spares vfork() and task_fork(), which remain available.
ifeq ($(CONFIG_ARCH_HAVE_FORK)$(CONFIG_FORK_IS_TASK_FORK),)
BLACKWORDS += "[^v_]fork("
endif
BLACKWORDS += "CHILD_MAX"
BLACKWORDS += "setpgid("
BLACKWORDS += "PTHREAD_SCOPE_PROCESS"

18
testing/ostest/CMakeLists.txt
View file

@ -143,10 +143,20 @@ if(CONFIG_TESTING_OSTEST)
endif()
endif()
if(CONFIG_ARCH_HAVE_FORK)
if(CONFIG_SCHED_WAITPID)
list(APPEND SRCS vfork.c)
endif()
# See testing/ostest/ostest.h for the one transitional exception.
if(CONFIG_TASK_FORK)
list(APPEND SRCS task_fork.c)
elseif(CONFIG_ARCH_HAVE_FORK AND NOT CONFIG_ARCH_HAVE_TASK_FORK)
list(APPEND SRCS task_fork.c)
endif()
if(CONFIG_ARCH_HAVE_VFORK)
list(APPEND SRCS vfork.c)
endif()
if(CONFIG_ARCH_HAVE_FORK AND CONFIG_ARCH_HAVE_VFORK)
list(APPEND SRCS fork.c)
endif()
if(CONFIG_ARCH_SETJMP_H)

19
testing/ostest/Makefile
View file

@ -144,10 +144,27 @@ CSRCS += sigev_thread.c
endif
endif
# Each test is built where the primitive it tests exists. See ostest.h for the
# one transitional exception.
ifeq ($(CONFIG_TASK_FORK),y)
CSRCS += task_fork.c
else ifeq ($(CONFIG_ARCH_HAVE_TASK_FORK),)
# A nuttx with no ARCH_HAVE_TASK_FORK at all is the pre-split one, where
# fork() is task_fork(). This branch comes out with the split.
ifeq ($(CONFIG_ARCH_HAVE_FORK),y)
ifeq ($(CONFIG_SCHED_WAITPID),y)
CSRCS += task_fork.c
endif
endif
ifeq ($(CONFIG_ARCH_HAVE_VFORK),y)
CSRCS += vfork.c
endif
ifeq ($(CONFIG_ARCH_HAVE_FORK),y)
ifeq ($(CONFIG_ARCH_HAVE_VFORK),y)
CSRCS += fork.c
endif
endif
ifeq ($(CONFIG_ARCH_SETJMP_H),y)

276
testing/ostest/fork.c Normal file
View file

@ -0,0 +1,276 @@
/****************************************************************************
* apps/testing/ostest/fork.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#include <unistd.h>
#include "ostest.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define FORK_HEAPSIZE 256
#define FORK_PARENTMARK 0x5a
#define FORK_CHILDMARK 0xa5
/* Distinct values written through a pointer to a stack local, to check that
* the child's stack is at the same virtual address as the parent's.
*/
#define FORK_STACKPARENT 0x1234
#define FORK_STACKCHILD 0x5678
/****************************************************************************
* Private Data
****************************************************************************/
/* .data and .bss, which a fork() child must get its own copy of */
static volatile int g_forkdata = 1;
static volatile int g_forkbss;
static FAR unsigned char *g_forkheap;
/* Pointer to a local in fork_test()'s frame, taken before fork(). In .data
* rather than on the stack: the compiler could rematerialise a local
* pointer from the current stack pointer, which would test nothing.
*/
static FAR volatile int *g_forkstackptr;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: fork_child
*
* Description:
* Everything here is forbidden to a vfork() child and permitted to a
* fork() child. Returns the child's exit status.
*
****************************************************************************/
static int fork_child(void)
{
FAR char *scratch;
/* The parent must see none of this. */
g_forkdata = 2;
g_forkbss = 2;
memset(g_forkheap, FORK_CHILDMARK, FORK_HEAPSIZE);
/* A vfork() child may not call these; a fork() child may. */
scratch = malloc(64);
if (scratch == NULL)
{
printf("fork_test: ERROR Child could not malloc()\n");
return 1;
}
strlcpy(scratch, "child", 64);
printf("fork_test: Child running independently (%s)\n", scratch);
free(scratch);
/* Give the parent time to make its own writes, so that if the two shared
* memory we would see the parent's values below rather than our own.
*/
usleep(200 * 1000);
if (g_forkdata != 2 || g_forkbss != 2)
{
printf("fork_test: ERROR Child saw the parent's writes: "
"data=%d bss=%d\n", g_forkdata, g_forkbss);
return 1;
}
if (g_forkheap[0] != FORK_CHILDMARK ||
g_forkheap[FORK_HEAPSIZE - 1] != FORK_CHILDMARK)
{
printf("fork_test: ERROR Child saw the parent's heap writes\n");
return 1;
}
return 0;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: fork_test
*
* Description:
* Verify the defining property of POSIX fork(): the child gets its own
* copy of the parent's memory, in both directions. That is the exact
* opposite of what task_fork_test() checks. Also verifies that none of
* vfork()'s restrictions apply.
*
****************************************************************************/
int fork_test(void)
{
pid_t pid;
int status = 0;
int ret = 0;
/* volatile so it is really in memory and the compare is not folded. */
volatile int stackvar = FORK_STACKPARENT;
printf("fork_test: Started\n");
/* Publish its address before forking. See g_forkstackptr. */
g_forkstackptr = &stackvar;
g_forkdata = 1;
g_forkbss = 1;
g_forkheap = malloc(FORK_HEAPSIZE);
if (g_forkheap == NULL)
{
printf("fork_test: ERROR Failed to allocate the heap probe\n");
ASSERT(false);
return -1;
}
memset(g_forkheap, FORK_PARENTMARK, FORK_HEAPSIZE);
pid = fork();
if (pid == 0)
{
/* The child's stack is at the parent's virtual addresses, so this
* pointer names the child's own live local. A relocated stack would
* write into the copy of the parent's instead.
*/
*g_forkstackptr = FORK_STACKCHILD;
if (stackvar != FORK_STACKCHILD)
{
printf("fork_test: ERROR Child stack was relocated: wrote %d "
"through %p, local at %p reads %d\n",
FORK_STACKCHILD, g_forkstackptr, &stackvar, stackvar);
_exit(1);
}
/* Returns from fork_child() and from this branch -- both illegal
* for a vfork() child.
*/
_exit(fork_child());
}
else if (pid < 0)
{
printf("fork_test: ERROR fork() failed: %d\n", errno);
free(g_forkheap);
ASSERT(false);
return -1;
}
/* Parent runs concurrently: write now, check isolation afterwards. */
g_forkdata = 3;
g_forkbss = 3;
memset(g_forkheap, FORK_PARENTMARK, FORK_HEAPSIZE);
#ifdef CONFIG_SCHED_WAITPID
/* Wait for the child to be done before comparing memory. waitpid() blocks
* on a child that is still alive whether or not its exit status will be
* retained, so this synchronises either way; ECHILD simply means the child
* had already finished, which is just as good. It is not a failure:
* ostest_main() sets SA_NOCLDWAIT on SIGCHLD for the whole run, so an
* exited child's status is not kept even where CONFIG_SCHED_CHILD_STATUS
* is enabled.
*/
if (waitpid(pid, &status, 0) != pid && errno != ECHILD)
{
printf("fork_test: ERROR waitpid() failed: %d\n", errno);
free(g_forkheap);
ASSERT(false);
return -1;
}
#else
sleep(1);
#endif
if (g_forkdata != 3 || g_forkbss != 3)
{
printf("fork_test: ERROR Parent saw the child's writes: "
"data=%d bss=%d (expected 3, 3)\n", g_forkdata, g_forkbss);
ret = -1;
}
if (g_forkheap[0] != FORK_PARENTMARK ||
g_forkheap[FORK_HEAPSIZE - 1] != FORK_PARENTMARK)
{
printf("fork_test: ERROR Parent saw the child's heap writes\n");
ret = -1;
}
/* The child wrote to the same stack address; the parent must not see it */
if (stackvar != FORK_STACKPARENT)
{
printf("fork_test: ERROR Parent saw the child's stack write: "
"%d (expected %d)\n", stackvar, FORK_STACKPARENT);
ret = -1;
}
#ifdef CONFIG_SCHED_WAITPID
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
{
printf("fork_test: ERROR Child reported failure, status 0x%04x\n",
status);
ret = -1;
}
#endif
free(g_forkheap);
g_forkheap = NULL;
if (ret < 0)
{
ASSERT(false);
return ret;
}
printf("fork_test: Parent and child had independent memory\n");
return 0;
}

48
testing/ostest/ostest.h
View file

@ -282,12 +282,58 @@ void priority_inheritance(void);
void sched_lock_test(void);
/* The fork family **********************************************************/
/* Until nuttx has the three separate primitives, ARCH_HAVE_FORK stands in
* for task_fork(): today's fork() *is* task_fork(), so the test that has
* always covered that primitive keeps running under its own name. A nuttx
* without ARCH_HAVE_TASK_FORK is the pre-split one, and only there does the
* substitution apply -- once the split has landed, TASK_FORK says whether
* task_fork() was built, and nothing stands in for it.
*
* vfork_test() and fork_test() deliberately have no such mapping. They
* check semantics a pre-split nuttx does not describe -- the parent
* suspension and the private copy -- and ARCH_HAVE_VFORK is the evidence
* that the split has landed.
*
* This block comes out with the split.
*/
#if defined(CONFIG_TASK_FORK) || \
(defined(CONFIG_ARCH_HAVE_FORK) && !defined(CONFIG_ARCH_HAVE_TASK_FORK))
# define OSTEST_HAVE_TASK_FORK 1
#endif
#ifdef CONFIG_ARCH_HAVE_VFORK
# define OSTEST_HAVE_VFORK 1
#endif
#if defined(CONFIG_ARCH_HAVE_FORK) && defined(CONFIG_ARCH_HAVE_VFORK)
# define OSTEST_HAVE_FORK 1
#endif
#if defined(OSTEST_HAVE_TASK_FORK) && !defined(CONFIG_TASK_FORK)
# define task_fork() fork()
#endif
/* task_fork.c **************************************************************/
#ifdef OSTEST_HAVE_TASK_FORK
int task_fork_test(void);
#endif
/* vfork.c ******************************************************************/
#if defined(CONFIG_ARCH_HAVE_FORK) && defined(CONFIG_SCHED_WAITPID)
#ifdef OSTEST_HAVE_VFORK
int vfork_test(void);
#endif
/* fork.c *******************************************************************/
#ifdef OSTEST_HAVE_FORK
int fork_test(void);
#endif
/* setjmp.c *****************************************************************/
void setjmp_test(void);

29
testing/ostest/ostest_main.c
View file

@ -224,6 +224,29 @@ static int user_main(int argc, char *argv[])
g_mmbefore = mallinfo();
g_mmprevious = g_mmbefore;
/* Run the three fork primitives first. They exercise the lowest-level
* machinery in the suite, so a fault takes the process down rather than
* reporting a failure -- better to learn that in seconds.
*/
#ifdef OSTEST_HAVE_TASK_FORK
printf("\nuser_main: task_fork() test\n");
task_fork_test();
check_test_memory_usage();
#endif
#ifdef OSTEST_HAVE_VFORK
printf("\nuser_main: vfork() test\n");
vfork_test();
check_test_memory_usage();
#endif
#ifdef OSTEST_HAVE_FORK
printf("\nuser_main: fork() test\n");
fork_test();
check_test_memory_usage();
#endif
printf("\nuser_main: Begin argument test\n");
printf("user_main: Started with argc=%d\n", argc);
@ -637,12 +660,6 @@ static int user_main(int argc, char *argv[])
check_test_memory_usage();
#endif
#if defined(CONFIG_ARCH_HAVE_FORK) && defined(CONFIG_SCHED_WAITPID) && \
!defined(CONFIG_ARCH_SIM)
printf("\nuser_main: vfork() test\n");
vfork_test();
#endif
#if defined(CONFIG_SMP) && defined(CONFIG_BUILD_FLAT)
printf("\nuser_main: smp call test\n");
smp_call_test();

98
testing/ostest/task_fork.c Normal file
View file

@ -0,0 +1,98 @@
/****************************************************************************
* apps/testing/ostest/task_fork.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <errno.h>
#include <sched.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "ostest.h"
#ifdef OSTEST_HAVE_TASK_FORK
/****************************************************************************
* Private Data
****************************************************************************/
static volatile bool g_taskforkchild;
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: task_fork_test
*
* Description:
* Verify the defining property of task_fork(): the child shares the
* parent's memory, so the parent observes the child's write. This is the
* test that used to be called the "vfork" test. A real fork() child's
* write would be invisible here; see fork_test().
*
****************************************************************************/
int task_fork_test(void)
{
pid_t pid;
printf("task_fork_test: Started\n");
g_taskforkchild = false;
pid = task_fork();
if (pid == 0)
{
/* Shared memory, so the parent sees this. Runs concurrently. */
g_taskforkchild = true;
exit(0);
}
else if (pid < 0)
{
printf("task_fork_test: ERROR task_fork() failed: %d\n", errno);
ASSERT(false);
return -1;
}
sleep(1);
if (!g_taskforkchild)
{
printf("task_fork_test: ERROR Child %d did not run, or its write to "
"shared memory was not visible\n", pid);
ASSERT(false);
return -1;
}
printf("task_fork_test: Child %d ran successfully\n", pid);
return 0;
}
#endif /* OSTEST_HAVE_TASK_FORK */

71
testing/ostest/vfork.c
View file

@ -31,36 +31,49 @@
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <unistd.h>
#include "ostest.h"
#if defined(CONFIG_ARCH_HAVE_FORK) && defined(CONFIG_SCHED_WAITPID)
/****************************************************************************
* Private Data
****************************************************************************/
static volatile bool g_vforkchild;
/* Set and cleared by the parent only: a vfork() child may not write it. */
static volatile bool g_vforkrunning;
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: vfork_test
*
* Description:
* Verify the defining property of vfork(): the parent is suspended until
* the child _exit()s or exec()s. The child does only what POSIX
* permits -- _exit(), not exit(), which would flush stdio in the parent's
* address space. Since the child may not write memory, the observable is
* its exit status: an unsuspended parent would reach waitpid() first.
*
****************************************************************************/
int vfork_test(void)
{
pid_t pid;
g_vforkchild = false;
printf("vfork_test: Started\n");
g_vforkrunning = true;
pid = vfork();
if (pid == 0)
{
/* There is not very much that the child is permitted to do. Perhaps
* it can just set g_vforkchild.
*/
/* The only thing a vfork() child may do is leave. */
g_vforkchild = true;
exit(0);
_exit(42);
}
else if (pid < 0)
{
@ -68,22 +81,46 @@ int vfork_test(void)
ASSERT(false);
return -1;
}
else
/* Reached only once the child has exited or exec'ed. */
g_vforkrunning = false;
#ifdef CONFIG_SCHED_WAITPID
{
sleep(1);
if (g_vforkchild)
int status = 0;
pid_t ret;
ret = waitpid(pid, &status, 0);
/* Two answers are correct, and which one comes back is a property of
* the configuration: a retained status must be exit(42), and ECHILD
* is equally good evidence -- it says the child was already gone when
* we asked. ostest_main() sets SA_NOCLDWAIT for the whole run, so
* testing CONFIG_SCHED_CHILD_STATUS alone is not enough.
*/
if (ret == pid)
{
printf("vfork_test: Child %d ran successfully\n", pid);
if (!WIFEXITED(status) || WEXITSTATUS(status) != 42)
{
printf("vfork_test: ERROR Child %d status 0x%04x, expected "
"exit(42)\n", pid, status);
ASSERT(false);
return -1;
}
}
else
else if (ret >= 0 || errno != ECHILD)
{
printf("vfork_test: ERROR Child %d did not run\n", pid);
printf("vfork_test: ERROR waitpid() returned %d (%d), expected "
"the child's status or ECHILD\n", ret, errno);
ASSERT(false);
return -1;
}
}
#endif
printf("vfork_test: Child %d ran and exited before the parent resumed\n",
pid);
return 0;
}
#endif /* CONFIG_ARCH_HAVE_FORK && CONFIG_SCHED_WAITPID */