libevent/cmake/CheckWaitpidSupportWNOWAIT.cmake

include(CheckCSourceRuns)

check_c_source_runs(
"
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdlib.h>

int
main(int argc, char** argv)
{
    pid_t pid;
    int status;
    if ((pid = fork()) == 0) _exit(0);
    _exit(waitpid(pid, &status, WNOWAIT) == -1);
}"
EVENT__HAVE_WAITPID_WITH_WNOWAIT)
tests: use waitpid(..., WNOWAIT) to fix failing of main/fork under solaris According to solaris docs: "One instance of a SIGCHLD signal is queued for each child process whose status has changed. If waitpid() returns because the status of a child process is available, and WNOWAIT was not specified in options, any pending SIGCHLD signal associated with the process ID of that child process is discarded. Any other pending SIGCHLD signals remain pending." And interesting thing that it works if you add sleep(1) before waitpid(), and also if you run with --verbose (some race or what). But linux doesn't support WNOWAIT in waitpid() so add detection into cmake/autotools. Fixes: #387 Link: https://bugzilla.redhat.com/show_bug.cgi?id=840782 2016-08-11 16:15:45 +03:00			`include(CheckCSourceRuns)`

			`check_c_source_runs(`
			`"`
			`#include <unistd.h>`
			`#include <sys/types.h>`
			`#include <sys/wait.h>`
			`#include <stdlib.h>`

			`int`
			`main(int argc, char** argv)`
			`{`
			`pid_t pid;`
			`int status;`
			`if ((pid = fork()) == 0) _exit(0);`
			`_exit(waitpid(pid, &status, WNOWAIT) == -1);`
			`}"`
			`EVENT__HAVE_WAITPID_WITH_WNOWAIT)`