Merge branch 'master' into iwyu

1 files changed, 74 insertions, 0 deletions

diff --git a/src/postfork.h b/src/postfork.h
new file mode 100644
index 00000000..c277da52
--- /dev/null
+++ b/src/postfork.h
@@ -0,0 +1,74 @@
+/** \file postfork.h
+
+  Functions that we may safely call after fork(), of which there are very few. In particular we cannot allocate memory, since we're insane enough to call fork from a multithreaded process.
+*/
+
+#ifndef FISH_POSTFORK_H
+#define FISH_POSTFORK_H
+
+#include <stddef.h>
+#include <unistd.h>
+
+#include "config.h"
+#include "io.h"
+
+#if HAVE_SPAWN_H
+#include <spawn.h>
+#endif
+
+#ifndef FISH_USE_POSIX_SPAWN
+#define FISH_USE_POSIX_SPAWN HAVE_SPAWN_H
+#endif
+
+
+/**
+   This function should be called by both the parent process and the
+   child right after fork() has been called. If job control is
+   enabled, the child is put in the jobs group, and if the child is
+   also in the foreground, it is also given control of the
+   terminal. When called in the parent process, this function may
+   fail, since the child might have already finished and called
+   exit. The parent process may safely ignore the exit status of this
+   call.
+
+   Returns 0 on sucess, -1 on failiure.
+*/
+class job_t;
+class process_t;
+int set_child_group(job_t *j, process_t *p, int print_errors);
+
+/**
+   Initialize a new child process. This should be called right away
+   after forking in the child process. If job control is enabled for
+   this job, the process is put in the process group of the job, all
+   signal handlers are reset, signals are unblocked (this function may
+   only be called inside the exec function, which blocks all signals),
+   and all IO redirections and other file descriptor actions are
+   performed.
+
+   \param j the job to set up the IO for
+   \param p the child process to set up
+   \param io_chain the IO chain to use
+
+   \return 0 on sucess, -1 on failiure. When this function returns,
+   signals are always unblocked. On failiure, signal handlers, io
+   redirections and process group of the process is undefined.
+*/
+int setup_child_process(job_t *j, process_t *p, const io_chain_t &io_chain);
+
+/* Call fork(), optionally waiting until we are no longer multithreaded. If the forked child doesn't do anything that could allocate memory, take a lock, etc. (like call exec), then it's not necessary to wait for threads to die. If the forked child may do those things, it should wait for threads to die.
+*/
+pid_t execute_fork(bool wait_for_threads_to_die);
+
+/* Perform output from builtins. Returns true on success. */
+bool do_builtin_io(const char *out, size_t outlen, const char *err, size_t errlen);
+
+/** Report an error from failing to exec or posix_spawn a command */
+void safe_report_exec_error(int err, const char *actual_cmd, const char * const *argv, const char * const *envv);
+
+#if FISH_USE_POSIX_SPAWN
+/* Initializes and fills in a posix_spawnattr_t; on success, the caller should destroy it via posix_spawnattr_destroy */
+bool fork_actions_make_spawn_properties(posix_spawnattr_t *attr, posix_spawn_file_actions_t *actions, job_t *j, process_t *p, const io_chain_t &io_chain);
+#endif
+
+#endif