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Remove unnecessary double-fork from server start

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This commit is contained in:
Andrew Bettison 2012-06-26 17:27:19 +09:30
parent d7828f9409
commit 3822d067e7
1 changed files with 25 additions and 39 deletions
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64
commandline.c
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@ -725,51 +725,37 @@ int app_server_start(int argc, const char *const *argv, struct command_line_opti
overlayMode = 1;
if (foregroundP)
return server(NULL);
int cpid;
switch ((cpid = fork())) {
switch (fork()) {
case -1:
/* Main process. First fork failed. There is no child process. */
/* Main process. Fork failed. There is no child process. */
return WHY_perror("fork");
case 0: {
/* Child process. Fork again then exit, to disconnect daemon from parent process, so that
when daemon exits it does not live on as a zombie. N.B. Do not return from within this
process; that will unroll the JNI call stack and cause havoc. Use _exit(). */
switch (fork()) {
case -1:
/* Child process. Second fork failed. There is no grandchild process. */
_exit(WHY_perror("fork"));
case 0: {
/* Grandchild process. Disconnect from current directory, disconnect standard i/o
streams, and start a new process group so that if we are being started by an adb
shell session, then we don't receive a SIGHUP when the adb shell process ends. */
int fd;
if ((fd = open("/dev/null", O_RDWR, 0)) == -1)
exit(WHY_perror("open"));
if (setsid() == -1)
exit(WHY_perror("setsid"));
(void)chdir("/");
(void)dup2(fd, 0);
(void)dup2(fd, 1);
(void)dup2(fd, 2);
if (fd > 2)
(void)close(fd);
/* The execpath option is provided so that a JNI call to "start" can be made which
creates a new server daemon process with the correct argv[0]. Otherwise, the servald
process appears as a process with argv[0] = "org.servalproject". */
if (execpath) {
execl(execpath, execpath, "start", "foreground", NULL);
_exit(-1);
}
_exit(server(NULL));
}
/* Child process. Disconnect from current directory, disconnect standard I/O
streams, and start a new process group so that if we are being started by an adb
shell session, then we don't receive a SIGHUP when the adb shell process ends. */
int fd;
if ((fd = open("/dev/null", O_RDWR, 0)) == -1)
_exit(WHY_perror("open"));
if (setsid() == -1)
_exit(WHY_perror("setsid"));
(void)chdir("/");
(void)dup2(fd, 0);
(void)dup2(fd, 1);
(void)dup2(fd, 2);
if (fd > 2)
(void)close(fd);
/* The execpath option is provided so that a JNI call to "start" can be made which
creates a new server daemon process with the correct argv[0]. Otherwise, the servald
process appears as a process with argv[0] = "org.servalproject". */
if (execpath) {
execl(execpath, execpath, "start", "foreground", NULL);
_exit(-1);
}
/* Child process. Second fork succeeded. There is a grandchild process. */
_exit(0); // Main process is waitpid()-ing for this.
_exit(server(NULL));
// NOT REACHED
}
}
/* Main process. Wait for the child process to fork the grandchild then die. */
waitpid(cpid, NULL, 0);
/* Allow a few seconds for the grandchild process to report for duty. */
/* Main process. Allow a few seconds for the child process to report for duty. */
long long timeout = gettime_ms() + 5000;
do {
struct timespec delay;