#ifndef TRACKFDS_H
#define TRACKFDS_H 1
-/* List of tracked file descriptors. */
-static int *tracked_fds;
+/* Array of tracked file descriptors. Used for fast lookups for the normally
+ * used file descriptors (0 <= fd < TRACKFDS_STATIC_COUNT). */
+static int tracked_fds[TRACKFDS_STATIC_COUNT];
+
+/* List of tracked file descriptors >= TRACKFDS_STATIC_COUNT. */
+static int *tracked_fds_list;
/* Current number of items in the list. */
-static size_t tracked_fds_count;
+static size_t tracked_fds_list_count;
/* Allocated items, used to reduce realloc()s. */
-static size_t tracked_fds_space;
+static size_t tracked_fds_list_space;
+
+
+#ifdef DEBUG
+static void tracked_fds_debug(void) {
+ size_t i;
+
+ for (i = 0; i < TRACKFDS_STATIC_COUNT; i++) {
+ if (tracked_fds[i]) {
+ debug(" tracked_fds[%d]: %d\n", i, tracked_fds[i]);
+ }
+ }
+ debug(" tracked_fds_list: %d/%d\t[%d]\n", tracked_fds_list_count,
+ tracked_fds_list_space,
+ getpid());
+ for (i = 0; i < tracked_fds_list_count; i++) {
+ debug(" tracked_fds_list[%d]: %d\n", i, tracked_fds_list[i]);
+ }
+}
+#endif
+
+static int init_tracked_fds_list(size_t count) {
+ /* Reduce reallocs. */
+ count += TRACKFDS_REALLOC_STEP;
+
+ tracked_fds_list = malloc(count * sizeof(*tracked_fds_list));
+ if (!tracked_fds_list) {
+#ifdef WARNING
+ warning("malloc(tracked_fds_list, %d) failed [%d]\n",
+ count * sizeof(*tracked_fds_list), getpid());
+#endif
+ return 0;
+ }
+ tracked_fds_list_space = count;
+ return 1;
+}
/* Load tracked file descriptors from the environment. The environment is used
* to pass the information to child processes.
* ENV_NAME_FDS has the following format: Each descriptor as string followed
* by a comma; there's a trailing comma. Example: "2,4,". */
static void init_from_environment(void) {
- const char *env;
+#ifdef DEBUG
+ debug("init_from_environment()\t\t[%d]\n", getpid());
+#endif
+ char const *env;
+
+ int saved_errno = errno;
initialized = 1;
- tracked_fds_count = 0;
+ tracked_fds_list_count = 0;
/* If ENV_NAME_FORCE_WRITE is set and not empty, allow writes to a non-tty
* device. Use with care! Mainly used for the test suite. */
env = getenv(ENV_NAME_FDS);
if (!env) {
+ errno = saved_errno;
return;
}
+#ifdef DEBUG
+ debug(" getenv(\"%s\"): \"%s\"\n", ENV_NAME_FDS, env);
+#endif
/* Environment is read-only. */
- char *env_copy = strdup(env);
- if (!env_copy) {
- return;
- }
+ char env_copy[strlen(env) + 1];
+ strcpy(env_copy, env);
char *x;
count++;
}
}
- tracked_fds_space = count + TRACKFDS_REALLOC_STEP;
-
- tracked_fds = malloc(tracked_fds_space * sizeof(*tracked_fds));
- if (!tracked_fds) {
- free(env_copy);
- return;
- }
size_t i = 0;
/* Parse file descriptor numbers from environment string and store them as
- * integers in tracked_fds. */
+ * integers in tracked_fds and tracked_fds_list. */
char *last;
for (x = env_copy, last = env_copy; *x; x++) {
if (*x != ',') {
}
*x = 0;
- tracked_fds[i++] = atoi(last);
+ int fd = atoi(last);
+ if (fd < TRACKFDS_STATIC_COUNT) {
+ tracked_fds[fd] = 1;
+ } else {
+ if (!tracked_fds_list) {
+ /* Pessimistic count estimate, but allocating a few more
+ * elements doesn't hurt. */
+ if (!init_tracked_fds_list(count)) {
+ /* Couldn't allocate memory, skip this entry. */
+ goto next;
+ }
+ }
+ tracked_fds_list[i++] = fd;
+#ifdef DEBUG
+ debug(" large fd: %d\n", fd);
+#endif
+ }
+
+next:
last = x + 1;
}
- tracked_fds_count = count;
+ tracked_fds_list_count = i;
+
+#ifdef DEBUG
+ tracked_fds_debug();
+#endif
- free(env_copy);
+ errno = saved_errno;
}
-static void update_environment(void) {
- /* An integer (32-bit) has at most 10 digits, + 1 for the comma after each
- * number. Bigger file descriptors (which shouldn't occur in reality) are
- * skipped. */
- char env[tracked_fds_count * (10 + 1) + 1 /* to fit '\0' */ ];
- env[0] = 0;
+static char *update_environment_buffer_entry(char *x, int fd) {
+ int length = snprintf(x, 10 + 1, "%d", fd);
+ if (length >= 10 + 1) {
+ /* Integer too big to fit the buffer, skip it. */
+#ifdef WARNING
+ warning("update_environment_buffer_entry(): truncated fd: %d [%d]\n",
+ fd, getpid());
+#endif
+ return x;
+ }
- char *x = env;
+ /* Write comma after number. */
+ x += length;
+ *x++ = ',';
+ /* Make sure the string is always zero terminated. */
+ *x = 0;
+ return x;
+}
+static void update_environment_buffer(char *x) {
size_t i;
- for (i = 0; i < tracked_fds_count; i++) {
- int length = snprintf(x, 10 + 1, "%d", tracked_fds[i]);
- if (length >= 10 + 1) {
- /* Integer too bit to fit the buffer, skip it. */
- continue;
+ for (i = 0; i < TRACKFDS_STATIC_COUNT; i++) {
+ if (tracked_fds[i]) {
+ x = update_environment_buffer_entry(x, (int)i);
}
+ }
+ for (i = 0; i < tracked_fds_list_count; i++) {
+ x = update_environment_buffer_entry(x, tracked_fds_list[i]);
+ }
+}
+inline static size_t update_environment_buffer_size(void) {
+ /* Use the maximum count (TRACKFDS_STATIC_COUNT) of used descriptors
+ * because it's simple and small enough not to be a problem.
+ *
+ * An integer (32-bit) has at most 10 digits, + 1 for the comma after each
+ * number. Bigger file descriptors (which shouldn't occur in reality) are
+ * skipped. */
+ return (TRACKFDS_STATIC_COUNT + tracked_fds_list_count)
+ * (10 + 1) + 1 /* to fit '\0' */;
+}
+static void update_environment(void) {
+#ifdef DEBUG
+ debug("update_environment()\t\t[%d]\n", getpid());
+#endif
- /* Write comma after number. */
- x += length;
- *x++ = ',';
- /* Make sure the string is always zero terminated. */
- *x = 0;
+ /* If we haven't parsed the environment we also haven't modified it - so
+ * nothing to do. */
+ if (!initialized) {
+ return;
}
+ char env[update_environment_buffer_size()];
+ env[0] = 0;
+
+ update_environment_buffer(env);
+
+#if 0
+ debug(" setenv(\"%s\", \"%s\", 1)\n", ENV_NAME_FDS, env);
+#endif
+
setenv(ENV_NAME_FDS, env, 1 /* overwrite */);
}
-#ifdef DEBUG
-static void tracked_fds_debug(void) {
- debug("tracked_fds: %d/%d\t[%d]\n", tracked_fds_count, tracked_fds_space,
- getpid());
- size_t i;
- for (i = 0; i < tracked_fds_count; i++) {
- debug("tracked_fds[%d]: %d\n", i, tracked_fds[i]);
- }
-}
-#endif
static void tracked_fds_add(int fd) {
- if (tracked_fds_count >= tracked_fds_space) {
- size_t new_space = tracked_fds_space + TRACKFDS_REALLOC_STEP;
- if (!realloc(tracked_fds, sizeof(*tracked_fds) * new_space)) {
+ if (fd < TRACKFDS_STATIC_COUNT) {
+ tracked_fds[fd] = 1;
+#if 0
+ debug("tracked_fds_add(): %-3d\t\t[%d]\n", fd, getpid());
+ tracked_fds_debug();
+#endif
+ return;
+ }
+
+ if (tracked_fds_list_count >= tracked_fds_list_space) {
+ int saved_errno = errno;
+
+ size_t new_space = tracked_fds_list_space + TRACKFDS_REALLOC_STEP;
+ int *tmp = realloc(tracked_fds_list,
+ sizeof(*tracked_fds_list) * new_space);
+ if (!tmp) {
/* We can do nothing, just ignore the error. We made sure not to
* destroy our state, so the new descriptor is ignored without any
* other consequences. */
+#ifdef WARNING
+ warning("realloc(tracked_fds_list, %zu) failed! [%d]\n",
+ sizeof(*tracked_fds_list) * new_space, getpid());
+#endif
+ errno = saved_errno;
return;
}
- tracked_fds_space = new_space;
+ errno = saved_errno;
+
+ tracked_fds_list = tmp;
+ tracked_fds_list_space = new_space;
}
- tracked_fds[tracked_fds_count++] = fd;
+ tracked_fds_list[tracked_fds_list_count++] = fd;
#ifdef DEBUG
+ debug("tracked_fds_add(): %-3d\t\t[%d]\n", fd, getpid());
tracked_fds_debug();
#endif
}
static int tracked_fds_remove(int fd) {
+ if (fd < TRACKFDS_STATIC_COUNT) {
+ int old_value = tracked_fds[fd];
+ tracked_fds[fd] = 0;
+
+#if 0
+ debug("tracked_fds_remove(): %-3d\t[%d]\n", fd, getpid());
+ tracked_fds_debug();
+#endif
+ return old_value; /* Found vs. not found. */
+ }
+
size_t i;
- for (i = 0; i < tracked_fds_count; i++) {
- if (fd != tracked_fds[i]) {
+ for (i = 0; i < tracked_fds_list_count; i++) {
+ if (fd != tracked_fds_list[i]) {
continue;
}
- memmove(tracked_fds + i, tracked_fds + i + 1,
- sizeof(*tracked_fds) * (tracked_fds_count - i - 1));
- tracked_fds_count--;
+ memmove(tracked_fds_list + i, tracked_fds_list + i + 1,
+ sizeof(*tracked_fds_list) * (tracked_fds_list_count - i - 1));
+ tracked_fds_list_count--;
#ifdef DEBUG
+ debug("tracked_fds_remove(): %-3d\t[%d]\n", fd, getpid());
tracked_fds_debug();
#endif
/* Not found. */
return 0;
}
+
+static int tracked_fds_find_slow(int fd) noinline;
+/*
+ * tracked_fds_find() is called for each hook call and should be as fast as
+ * possible. As most file descriptors are < TRACKFDS_STATIC_COUNT, force the
+ * compiler to inline that part which is almost exclusively used.
+ *
+ * Inlining tracked_fds_add()/tracked_fds_remove() isn't worth the effort as
+ * they are not called often enough.
+ */
+inline static int tracked_fds_find(int fd) always_inline;
static int tracked_fds_find(int fd) {
+ if (fd < TRACKFDS_STATIC_COUNT) {
+ return tracked_fds[fd];
+ }
+
+ return tracked_fds_find_slow(fd);
+}
+static int tracked_fds_find_slow(int fd) {
+ if (tracked_fds_list_count == 0) {
+ return 0;
+ }
+
size_t i;
- for (i = 0; i < tracked_fds_count; i++) {
- if (fd == tracked_fds[i]) {
+ for (i = 0; i < tracked_fds_list_count; i++) {
+ if (fd == tracked_fds_list[i]) {
return 1;
}
}
ruderich.org/simon / coloredstderr / coloredstderr.git / blobdiff