From 2d5eaea1cd6a6d1f83f7771d55288ad1dc2b3547 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sa=C3=BAl=20Ibarra=20Corretg=C3=A9?= <saghul@gmail.com>
Date: Mon, 5 May 2014 17:15:15 -0300
Subject: [PATCH] unix: simplify how process handle queue is managed

---
 include/uv-unix.h  |  2 +-
 src/unix/loop.c    |  5 +--
 src/unix/process.c | 92 ++++++++++++++++++++--------------------------
 3 files changed, 41 insertions(+), 58 deletions(-)

diff --git a/include/uv-unix.h b/include/uv-unix.h
index fe74f327..e7249256 100644
--- a/include/uv-unix.h
+++ b/include/uv-unix.h
@@ -219,7 +219,7 @@ typedef struct {
   uv_async_t wq_async;                                                        \
   uv_rwlock_t cloexec_lock;                                                   \
   uv_handle_t* closing_handles;                                               \
-  void* process_handles[1][2];                                                \
+  void* process_handles[2];                                                   \
   void* prepare_handles[2];                                                   \
   void* check_handles[2];                                                     \
   void* idle_handles[2];                                                      \
diff --git a/src/unix/loop.c b/src/unix/loop.c
index aa74be64..00222485 100644
--- a/src/unix/loop.c
+++ b/src/unix/loop.c
@@ -99,7 +99,6 @@ void uv_loop_delete(uv_loop_t* loop) {
 
 
 static int uv__loop_init(uv_loop_t* loop, int default_loop) {
-  unsigned int i;
   int err;
 
   uv__signal_global_once_init();
@@ -138,9 +137,7 @@ static int uv__loop_init(uv_loop_t* loop, int default_loop) {
   uv_signal_init(loop, &loop->child_watcher);
   uv__handle_unref(&loop->child_watcher);
   loop->child_watcher.flags |= UV__HANDLE_INTERNAL;
-
-  for (i = 0; i < ARRAY_SIZE(loop->process_handles); i++)
-    QUEUE_INIT(loop->process_handles + i);
+  QUEUE_INIT(&loop->process_handles);
 
   if (uv_rwlock_init(&loop->cloexec_lock))
     abort();
diff --git a/src/unix/process.c b/src/unix/process.c
index 52e4eb28..9d13721e 100644
--- a/src/unix/process.c
+++ b/src/unix/process.c
@@ -45,77 +45,65 @@ extern char **environ;
 #endif
 
 
-static QUEUE* uv__process_queue(uv_loop_t* loop, int pid) {
-  assert(pid > 0);
-  return loop->process_handles + pid % ARRAY_SIZE(loop->process_handles);
-}
-
-
 static void uv__chld(uv_signal_t* handle, int signum) {
   uv_process_t* process;
   uv_loop_t* loop;
   int exit_status;
   int term_signal;
-  unsigned int i;
   int status;
   pid_t pid;
   QUEUE pending;
-  QUEUE* h;
   QUEUE* q;
+  QUEUE* h;
 
   assert(signum == SIGCHLD);
 
   QUEUE_INIT(&pending);
   loop = handle->loop;
 
-  for (i = 0; i < ARRAY_SIZE(loop->process_handles); i++) {
-    h = loop->process_handles + i;
-    q = QUEUE_HEAD(h);
+  h = &loop->process_handles;
+  q = QUEUE_HEAD(h);
+  while (q != h) {
+    process = QUEUE_DATA(q, uv_process_t, queue);
+    q = QUEUE_NEXT(q);
 
-    while (q != h) {
-      process = QUEUE_DATA(q, uv_process_t, queue);
-      q = QUEUE_NEXT(q);
+    do
+      pid = waitpid(process->pid, &status, WNOHANG);
+    while (pid == -1 && errno == EINTR);
 
-      do
-        pid = waitpid(process->pid, &status, WNOHANG);
-      while (pid == -1 && errno == EINTR);
+    if (pid == 0)
+      continue;
 
-      if (pid == 0)
-        continue;
-
-      if (pid == -1) {
-        if (errno != ECHILD)
-          abort();
-        continue;
-      }
-
-      process->status = status;
-      QUEUE_REMOVE(&process->queue);
-      QUEUE_INSERT_TAIL(&pending, &process->queue);
+    if (pid == -1) {
+      if (errno != ECHILD)
+        abort();
+      continue;
     }
 
-    while (!QUEUE_EMPTY(&pending)) {
-      q = QUEUE_HEAD(&pending);
-      QUEUE_REMOVE(q);
-      QUEUE_INIT(q);
-
-      process = QUEUE_DATA(q, uv_process_t, queue);
-      uv__handle_stop(process);
-
-      if (process->exit_cb == NULL)
-        continue;
-
-      exit_status = 0;
-      if (WIFEXITED(process->status))
-        exit_status = WEXITSTATUS(process->status);
-
-      term_signal = 0;
-      if (WIFSIGNALED(process->status))
-        term_signal = WTERMSIG(process->status);
-
-      process->exit_cb(process, exit_status, term_signal);
-    }
+    process->status = status;
+    QUEUE_REMOVE(&process->queue);
+    QUEUE_INSERT_TAIL(&pending, &process->queue);
   }
+
+  QUEUE_FOREACH(q, &pending) {
+    process = QUEUE_DATA(q, uv_process_t, queue);
+    QUEUE_REMOVE(q);
+    uv__handle_stop(process);
+
+    if (process->exit_cb == NULL)
+      continue;
+
+    exit_status = 0;
+    if (WIFEXITED(process->status))
+      exit_status = WEXITSTATUS(process->status);
+
+    term_signal = 0;
+    if (WIFSIGNALED(process->status))
+      term_signal = WTERMSIG(process->status);
+
+    process->exit_cb(process, exit_status, term_signal);
+  }
+  assert(QUEUE_EMPTY(&pending));
 }
 
 
@@ -369,7 +357,6 @@ int uv_spawn(uv_loop_t* loop,
   int signal_pipe[2] = { -1, -1 };
   int (*pipes)[2];
   int stdio_count;
-  QUEUE* q;
   ssize_t r;
   pid_t pid;
   int err;
@@ -483,8 +470,7 @@ int uv_spawn(uv_loop_t* loop,
 
   /* Only activate this handle if exec() happened successfully */
   if (exec_errorno == 0) {
-    q = uv__process_queue(loop, pid);
-    QUEUE_INSERT_TAIL(q, &process->queue);
+    QUEUE_INSERT_TAIL(&loop->process_handles, &process->queue);
     uv__handle_start(process);
   }