tests: fall back to fork() if posix_spawnp() is not available

Android only started supporting posix_spawnp() in API level 28 (Android 9), so
it is not going to be available on most devices. If the system doesn't provide
it, then fall back to using fork() and execve().

Author: adierking

CMakeLists.txt

@@ -190,6 +190,7 @@ check_function_exists(mach_approximate_time HAVE_MACH_APPROXIMATE_TIME)
 check_function_exists(mach_port_construct HAVE_MACH_PORT_CONSTRUCT)
 check_function_exists(malloc_create_zone HAVE_MALLOC_CREATE_ZONE)
 check_function_exists(posix_fadvise HAVE_POSIX_FADVISE)
+check_function_exists(posix_spawnp HAVE_POSIX_SPAWNP)
 check_function_exists(pthread_key_init_np HAVE_PTHREAD_KEY_INIT_NP)
 check_function_exists(pthread_main_np HAVE_PTHREAD_MAIN_NP)
 check_function_exists(pthread_workqueue_setdispatch_np HAVE_PTHREAD_WORKQUEUE_SETDISPATCH_NP)

cmake/config.h.in

@@ -135,6 +135,9 @@
 /* Define to 1 if you have the `posix_fadvise' function. */
 #cmakedefine HAVE_POSIX_FADVISE
 
+/* Define to 1 if you have the `posix_spawnp' function. */
+#cmakedefine HAVE_POSIX_SPAWNP
+
 /* Define to 1 if you have the `pthread_key_init_np' function. */
 #cmakedefine HAVE_PTHREAD_KEY_INIT_NP
 

tests/CMakeLists.txt

@@ -27,7 +27,10 @@ target_include_directories(bsdtests
                            PRIVATE
                              ${CMAKE_CURRENT_BINARY_DIR}
                              ${CMAKE_CURRENT_SOURCE_DIR}
-                             ${PROJECT_SOURCE_DIR})
+                             ${PROJECT_SOURCE_DIR}
+                           PUBLIC
+                             # bsdtests.h needs config_ac.h
+                             ${PROJECT_BINARY_DIR})
 if(BSD_OVERLAY_FOUND)
   target_compile_options(bsdtests
                          PRIVATE

tests/bsdtestharness.c

@@ -60,21 +60,21 @@ main(int argc, char *argv[])
 		exit(1);
 	}
 
+#ifdef HAVE_POSIX_SPAWNP
+	short spawnflags = 0;
 #ifdef __APPLE__
-	short spawnflags = POSIX_SPAWN_START_SUSPENDED;
+	spawnflags |= POSIX_SPAWN_START_SUSPENDED;
 #if TARGET_OS_EMBEDDED
 	spawnflags |= POSIX_SPAWN_SETEXEC;
 #endif
-#else
-#define POSIX_SPAWN_SETEXEC 0      /* ignore... */
-	short spawnflags = 0;
 #endif
 
 	posix_spawnattr_t attr;
 	res = posix_spawnattr_init(&attr);
 	assert(res == 0);
 	res = posix_spawnattr_setflags(&attr, spawnflags);
 	assert(res == 0);
+#endif
 
 	uint64_t to = 0;
 	char *tos = getenv("BSDTEST_TIMEOUT");
@@ -104,9 +104,12 @@ main(int argc, char *argv[])
 	struct timeval tv_start;
 	gettimeofday(&tv_start, NULL);
 
+#ifdef HAVE_POSIX_SPAWNP
+#ifdef __APPLE__
 	if (spawnflags & POSIX_SPAWN_SETEXEC) {
 		pid = fork();
 	}
+#endif
 	if (!pid) {
 		res = posix_spawnp(&pid, newargv[0], NULL, &attr, newargv, environ);
 		if (res) {
@@ -115,6 +118,22 @@ main(int argc, char *argv[])
 			exit(EXIT_FAILURE);
 		}
 	}
+#elif defined(__unix__)
+	(void)res;
+	pid = fork();
+	if (pid == -1) {
+		perror("fork");
+		exit(EXIT_FAILURE);
+	} else if (pid == 0) {
+		// Child process
+		if (execve(newargv[0], newargv, environ) == -1) {
+			perror(newargv[0]);
+			_Exit(EXIT_FAILURE);
+		}
+	}
+#else
+#error "bsdtestharness not implemented on this platform"
+#endif
 
 	//fprintf(stderr, "pid = %d\n", pid);
 	assert(pid > 0);

tests/bsdtests.h

@@ -21,6 +21,14 @@
 #ifndef __BSD_TEST_H__
 #define __BSD_TEST_H__
 
+#if defined(HAVE_CONFIG_H)
+#if __has_include(<config/config_ac.h>)
+#include <config/config_ac.h>
+#else
+#include <config/config.h>
+#endif
+#endif
+
 
 #if !HAVE_PRINTFLIKE
 #ifndef __printflike

tests/dispatch_io_net.c

@@ -218,12 +218,28 @@ main(int argc, char** argv)
 		arguments[1] = port_str;
 		arguments[2] = NULL;
 
+#ifdef HAVE_POSIX_SPAWNP
 		int error;
 		if ((error = posix_spawnp(&clientid, exec_filename, NULL, NULL,
 				arguments, environ)) != 0) {
 			test_errno("Server-posix_spawnp()", error, 0);
 			test_stop();
 		}
+#elif defined(__unix__)
+		clientid = fork();
+		if (clientid == -1) {
+			test_errno("Server-fork()", errno, 0);
+			test_stop();
+		} else if (clientid == 0) {
+			// Child process
+			if (execve(exec_filename, arguments, environ) == -1) {
+				perror(exec_filename);
+				_Exit(EXIT_FAILURE);
+			}
+		}
+#else
+#error "dispatch_io_net not implemented on this platform"
+#endif
 
 		addr2len = sizeof(struct sockaddr_in);
 		clientfd = accept(sockfd, (struct sockaddr *)&addr2, &addr2len);