1 files changed, 370 insertions, 0 deletions

diff --git a/src/nvim/os/job.c b/src/nvim/os/job.c
new file mode 100644
index 0000000000..7940338b70
--- /dev/null
+++ b/src/nvim/os/job.c
@@ -0,0 +1,370 @@
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <uv.h>
+
+#include "os/uv_helpers.h"
+#include "os/job.h"
+#include "os/job_defs.h"
+#include "os/rstream.h"
+#include "os/rstream_defs.h"
+#include "os/wstream.h"
+#include "os/wstream_defs.h"
+#include "os/event.h"
+#include "os/event_defs.h"
+#include "os/time.h"
+#include "os/shell.h"
+#include "vim.h"
+#include "memory.h"
+#include "term.h"
+
+#define EXIT_TIMEOUT 25
+#define MAX_RUNNING_JOBS 100
+#define JOB_BUFFER_SIZE 1024
+#define JOB_WRITE_MAXMEM 1024 * 1024
+
+struct job {
+  // Job id the index in the job table plus one.
+  int id;
+  // Number of polls after a SIGTERM that will trigger a SIGKILL
+  int exit_timeout;
+  // exit_cb may be called while there's still pending data from stdout/stderr.
+  // We use this reference count to ensure the JobExit event is only emitted
+  // when stdout/stderr are drained
+  int pending_refs;
+  // Same as above, but for freeing the job memory which contains
+  // libuv handles. Only after all are closed the job can be safely freed.
+  int pending_closes;
+  // If the job was already stopped
+  bool stopped;
+  // Data associated with the job
+  void *data;
+  // Callbacks
+  job_exit_cb exit_cb;
+  rstream_cb stdout_cb, stderr_cb;
+  // Readable streams(std{out,err})
+  RStream *out, *err;
+  // Writable stream(stdin)
+  WStream *in;
+  // Structures for process spawning/management used by libuv
+  uv_process_t proc;
+  uv_process_options_t proc_opts;
+  uv_stdio_container_t stdio[3];
+  uv_pipe_t proc_stdin, proc_stdout, proc_stderr;
+};
+
+static Job *table[MAX_RUNNING_JOBS] = {NULL};
+static uint32_t job_count = 0;
+static uv_prepare_t job_prepare;
+
+// Some helpers shared in this module
+static bool is_alive(Job *job);
+static Job * find_job(int id);
+static void free_job(Job *job);
+
+// Callbacks for libuv
+static void job_prepare_cb(uv_prepare_t *handle);
+static void read_cb(RStream *rstream, void *data, bool eof);
+static void exit_cb(uv_process_t *proc, int64_t status, int term_signal);
+static void close_cb(uv_handle_t *handle);
+static void emit_exit_event(Job *job);
+
+void job_init()
+{
+  uv_disable_stdio_inheritance();
+  uv_prepare_init(uv_default_loop(), &job_prepare);
+}
+
+void job_teardown()
+{
+  // 20 tries will give processes about 1 sec to exit cleanly
+  uint32_t remaining_tries = 20;
+  bool all_dead = true;
+  int i;
+  Job *job;
+
+  // Politely ask each job to terminate
+  for (i = 0; i < MAX_RUNNING_JOBS; i++) {
+    if ((job = table[i]) != NULL) {
+      all_dead = false;
+      uv_process_kill(&job->proc, SIGTERM);
+    }
+  }
+
+  if (all_dead) {
+    return;
+  }
+
+  os_delay(10, 0);
+  // Right now any exited process are zombies waiting for us to acknowledge
+  // their status with `wait` or handling SIGCHLD. libuv does that
+  // automatically (and then calls `exit_cb`) but we have to give it a chance
+  // by running the loop one more time
+  uv_run(uv_default_loop(), UV_RUN_NOWAIT);
+
+  // Prepare to start shooting
+  for (i = 0; i < MAX_RUNNING_JOBS; i++) {
+    if ((job = table[i]) == NULL) {
+      continue;
+    }
+
+    // Still alive
+    while (is_alive(job) && remaining_tries--) {
+      os_delay(50, 0);
+      // Acknowledge child exits
+      uv_run(uv_default_loop(), UV_RUN_NOWAIT);
+    }
+
+    if (is_alive(job)) {
+      uv_process_kill(&job->proc, SIGKILL);
+    }
+  }
+}
+
+int job_start(char **argv,
+              void *data,
+              rstream_cb stdout_cb,
+              rstream_cb stderr_cb,
+              job_exit_cb job_exit_cb)
+{
+  int i;
+  Job *job;
+
+  // Search for a free slot in the table
+  for (i = 0; i < MAX_RUNNING_JOBS; i++) {
+    if (table[i] == NULL) {
+      break;
+    }
+  }
+
+  if (i == MAX_RUNNING_JOBS) {
+    // No free slots
+    return 0;
+  }
+
+  job = xmalloc(sizeof(Job));
+  // Initialize
+  job->id = i + 1;
+  job->pending_refs = 3;
+  job->pending_closes = 4;
+  job->data = data;
+  job->stdout_cb = stdout_cb;
+  job->stderr_cb = stderr_cb;
+  job->exit_cb = job_exit_cb;
+  job->stopped = false;
+  job->exit_timeout = EXIT_TIMEOUT;
+  job->proc_opts.file = argv[0];
+  job->proc_opts.args = argv;
+  job->proc_opts.stdio = job->stdio;
+  job->proc_opts.stdio_count = 3;
+  job->proc_opts.flags = UV_PROCESS_WINDOWS_HIDE;
+  job->proc_opts.exit_cb = exit_cb;
+  job->proc_opts.cwd = NULL;
+  job->proc_opts.env = NULL;
+  job->proc.data = NULL;
+  job->proc_stdin.data = NULL;
+  job->proc_stdout.data = NULL;
+  job->proc_stderr.data = NULL;
+
+  // Initialize the job std{in,out,err}
+  uv_pipe_init(uv_default_loop(), &job->proc_stdin, 0);
+  job->stdio[0].flags = UV_CREATE_PIPE | UV_READABLE_PIPE;
+  job->stdio[0].data.stream = (uv_stream_t *)&job->proc_stdin;
+
+  uv_pipe_init(uv_default_loop(), &job->proc_stdout, 0);
+  job->stdio[1].flags = UV_CREATE_PIPE | UV_WRITABLE_PIPE;
+  job->stdio[1].data.stream = (uv_stream_t *)&job->proc_stdout;
+
+  uv_pipe_init(uv_default_loop(), &job->proc_stderr, 0);
+  job->stdio[2].flags = UV_CREATE_PIPE | UV_WRITABLE_PIPE;
+  job->stdio[2].data.stream = (uv_stream_t *)&job->proc_stderr;
+
+  // Spawn the job
+  if (uv_spawn(uv_default_loop(), &job->proc, &job->proc_opts) != 0) {
+    free_job(job);
+    return -1;
+  }
+
+  // Give all handles a reference to the job
+  handle_set_job((uv_handle_t *)&job->proc, job);
+  handle_set_job((uv_handle_t *)&job->proc_stdin, job);
+  handle_set_job((uv_handle_t *)&job->proc_stdout, job);
+  handle_set_job((uv_handle_t *)&job->proc_stderr, job);
+
+  job->in = wstream_new(JOB_WRITE_MAXMEM);
+  wstream_set_stream(job->in, (uv_stream_t *)&job->proc_stdin);
+  // Start the readable streams
+  job->out = rstream_new(read_cb, JOB_BUFFER_SIZE, job, true);
+  job->err = rstream_new(read_cb, JOB_BUFFER_SIZE, job, true);
+  rstream_set_stream(job->out, (uv_stream_t *)&job->proc_stdout);
+  rstream_set_stream(job->err, (uv_stream_t *)&job->proc_stderr);
+  rstream_start(job->out);
+  rstream_start(job->err);
+  // Save the job to the table
+  table[i] = job;
+
+  // Start polling job status if this is the first
+  if (job_count == 0) {
+    uv_prepare_start(&job_prepare, job_prepare_cb);
+  }
+  job_count++;
+
+  return job->id;
+}
+
+bool job_stop(int id)
+{
+  Job *job = find_job(id);
+
+  if (job == NULL || job->stopped) {
+    return false;
+  }
+
+  job->stopped = true;
+
+  return true;
+}
+
+bool job_write(int id, char *data, uint32_t len)
+{
+  Job *job = find_job(id);
+
+  if (job == NULL || job->stopped) {
+    free(data);
+    return false;
+  }
+
+  if (!wstream_write(job->in, data, len, true)) {
+    job_stop(job->id);
+    return false;
+  }
+
+  return true;
+}
+
+void job_exit_event(Event event)
+{
+  Job *job = event.data.job;
+
+  // Free the slot now, 'exit_cb' may want to start another job to replace
+  // this one
+  table[job->id - 1] = NULL;
+
+  if (job->exit_cb) {
+    // Invoke the exit callback
+    job->exit_cb(job, job->data);
+  }
+
+  // Free the job resources
+  free_job(job);
+
+  // Stop polling job status if this was the last
+  job_count--;
+  if (job_count == 0) {
+    uv_prepare_stop(&job_prepare);
+  }
+}
+
+int job_id(Job *job)
+{
+  return job->id;
+}
+
+void *job_data(Job *job)
+{
+  return job->data;
+}
+
+static bool is_alive(Job *job)
+{
+  return uv_process_kill(&job->proc, 0) == 0;
+}
+
+static Job * find_job(int id)
+{
+  if (id <= 0 || id > MAX_RUNNING_JOBS) {
+    return NULL;
+  }
+
+  return table[id - 1];
+}
+
+static void free_job(Job *job)
+{
+  uv_close((uv_handle_t *)&job->proc_stdout, close_cb);
+  uv_close((uv_handle_t *)&job->proc_stdin, close_cb);
+  uv_close((uv_handle_t *)&job->proc_stderr, close_cb);
+  uv_close((uv_handle_t *)&job->proc, close_cb);
+}
+
+/// Iterates the table, sending SIGTERM to stopped jobs and SIGKILL to those
+/// that didn't die from SIGTERM after a while(exit_timeout is 0).
+static void job_prepare_cb(uv_prepare_t *handle)
+{
+  Job *job;
+  int i;
+
+  for (i = 0; i < MAX_RUNNING_JOBS; i++) {
+    if ((job = table[i]) == NULL || !job->stopped) {
+      continue;
+    }
+
+    if ((job->exit_timeout--) == EXIT_TIMEOUT) {
+      // Job was just stopped, close all stdio handles and send SIGTERM
+      uv_process_kill(&job->proc, SIGTERM);
+    } else if (job->exit_timeout == 0) {
+      // We've waited long enough, send SIGKILL
+      uv_process_kill(&job->proc, SIGKILL);
+    }
+  }
+}
+
+// Wraps the call to std{out,err}_cb and emits a JobExit event if necessary.
+static void read_cb(RStream *rstream, void *data, bool eof)
+{
+  Job *job = data;
+
+  if (rstream == job->out) {
+    job->stdout_cb(rstream, data, eof);
+  } else {
+    job->stderr_cb(rstream, data, eof);
+  }
+
+  if (eof && --job->pending_refs == 0) {
+    emit_exit_event(job);
+  }
+}
+
+// Emits a JobExit event if both rstreams are closed
+static void exit_cb(uv_process_t *proc, int64_t status, int term_signal)
+{
+  Job *job = handle_get_job((uv_handle_t *)proc);
+
+  if (--job->pending_refs == 0) {
+    emit_exit_event(job);
+  }
+}
+
+static void emit_exit_event(Job *job)
+{
+  Event event;
+  event.type = kEventJobExit;
+  event.data.job = job;
+  event_push(event);
+}
+
+static void close_cb(uv_handle_t *handle)
+{
+  Job *job = handle_get_job(handle);
+
+  if (--job->pending_closes == 0) {
+    // Only free the job memory after all the associated handles are properly
+    // closed by libuv
+    rstream_free(job->out);
+    rstream_free(job->err);
+    wstream_free(job->in);
+    shell_free_argv(job->proc_opts.args);
+    free(job->data);
+    free(job);
+  }
+}