t3508: add check_head_differs_from() helper function and use it

diff --git a/run-command.c b/run-command.c
index c7793f50fbe0a43495c2b2d36a47c0b5aac37483..2a1041ef6599c84fff6a8d9faf5dea23a2af3ab0 100644 (file)
--- a/run-command.c
+++ b/run-command.c
@@ -84,6 +84,7 @@ static NORETURN void die_child(const char *err, va_list params)
        unused = write(child_err, "\n", 1);
        exit(128);
 }
+#endif
 
 static inline void set_cloexec(int fd)
 {
@@ -91,7 +92,6 @@ static inline void set_cloexec(int fd)
        if (flags >= 0)
                fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
 }
-#endif
 
 static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
 {
@@ -449,11 +449,35 @@ int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const
        return run_command(&cmd);
 }
 
-#ifdef WIN32
-static unsigned __stdcall run_thread(void *data)
+#ifndef NO_PTHREADS
+static pthread_t main_thread;
+static int main_thread_set;
+static pthread_key_t async_key;
+
+static void *run_thread(void *data)
 {
        struct async *async = data;
-       return async->proc(async->proc_in, async->proc_out, async->data);
+       intptr_t ret;
+
+       pthread_setspecific(async_key, async);
+       ret = async->proc(async->proc_in, async->proc_out, async->data);
+       return (void *)ret;
+}
+
+static NORETURN void die_async(const char *err, va_list params)
+{
+       vreportf("fatal: ", err, params);
+
+       if (!pthread_equal(main_thread, pthread_self())) {
+               struct async *async = pthread_getspecific(async_key);
+               if (async->proc_in >= 0)
+                       close(async->proc_in);
+               if (async->proc_out >= 0)
+                       close(async->proc_out);
+               pthread_exit((void *)128);
+       }
+
+       exit(128);
 }
 #endif
 
@@ -499,7 +523,7 @@ int start_async(struct async *async)
        else
                proc_out = -1;
 
-#ifndef WIN32
+#ifdef NO_PTHREADS
        /* Flush stdio before fork() to avoid cloning buffers */
        fflush(NULL);
 
@@ -526,12 +550,29 @@ int start_async(struct async *async)
        else if (async->out)
                close(async->out);
 #else
+       if (!main_thread_set) {
+               /*
+                * We assume that the first time that start_async is called
+                * it is from the main thread.
+                */
+               main_thread_set = 1;
+               main_thread = pthread_self();
+               pthread_key_create(&async_key, NULL);
+               set_die_routine(die_async);
+       }
+
+       if (proc_in >= 0)
+               set_cloexec(proc_in);
+       if (proc_out >= 0)
+               set_cloexec(proc_out);
        async->proc_in = proc_in;
        async->proc_out = proc_out;
-       async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
-       if (!async->tid) {
-               error("cannot create thread: %s", strerror(errno));
-               goto error;
+       {
+               int err = pthread_create(&async->tid, NULL, run_thread, async);
+               if (err) {
+                       error("cannot create thread: %s", strerror(err));
+                       goto error;
+               }
        }
 #endif
        return 0;
@@ -551,17 +592,15 @@ int start_async(struct async *async)
 
 int finish_async(struct async *async)
 {
-#ifndef WIN32
-       int ret = wait_or_whine(async->pid, "child process", 0);
+#ifdef NO_PTHREADS
+       return wait_or_whine(async->pid, "child process", 0);
 #else
-       DWORD ret = 0;
-       if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
-               ret = error("waiting for thread failed: %lu", GetLastError());
-       else if (!GetExitCodeThread(async->tid, &ret))
-               ret = error("cannot get thread exit code: %lu", GetLastError());
-       CloseHandle(async->tid);
+       void *ret = (void *)(intptr_t)(-1);
+
+       if (pthread_join(async->tid, &ret))
+               error("pthread_join failed");
+       return (int)(intptr_t)ret;
 #endif
-       return ret;
 }
 
 int run_hook(const char *index_file, const char *name, ...)