From: Matthew John Cheetham <mjcheetham@xxxxxxxxxxx>
Extract functions and structures for managing child processes started
from the parent daemon-like process from `daemon.c` to the new shared
`daemon-utils.{c,h}` files.
One minor functional change is introduced to `check_dead_children()`
where the logging of a dead/disconnected child is now optional. With the
'libification' of these functions we extract the call to `loginfo` to a
call to a function pointer, and guard the log message creation and
logging behind a `NULL` check. Callers can now skip logging by passing
`NULL` as the `log_fn loginfo` argument.
The behaviour of callers in `daemon.c` remains the same (save one extra
NULL check) however as a pointer to `loginfo` is always passed.
Signed-off-by: Matthew John Cheetham <mjcheetham@xxxxxxxxxxx>
---
daemon-utils.c | 77 ++++++++++++++++++++++++++++++++++++++++++
daemon-utils.h | 32 ++++++++++++++++++
daemon.c | 92 +++-----------------------------------------------
3 files changed, 114 insertions(+), 87 deletions(-)
diff --git a/daemon-utils.c b/daemon-utils.c
index b96b55962db..8506664b440 100644
--- a/daemon-utils.c
+++ b/daemon-utils.c
@@ -207,3 +207,80 @@ void socksetup(struct string_list *listen_addr, int listen_port,
}
}
}
+
+static int addrcmp(const struct sockaddr_storage *s1,
+ const struct sockaddr_storage *s2)
+{
+ const struct sockaddr *sa1 = (const struct sockaddr*) s1;
+ const struct sockaddr *sa2 = (const struct sockaddr*) s2;
+
+ if (sa1->sa_family != sa2->sa_family)
+ return sa1->sa_family - sa2->sa_family;
+ if (sa1->sa_family == AF_INET)
+ return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
+ &((struct sockaddr_in *)s2)->sin_addr,
+ sizeof(struct in_addr));
+#ifndef NO_IPV6
+ if (sa1->sa_family == AF_INET6)
+ return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
+ &((struct sockaddr_in6 *)s2)->sin6_addr,
+ sizeof(struct in6_addr));
+#endif
+ return 0;
+}
+
+void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen,
+ struct child *firstborn , unsigned int *live_children)
+{
+ struct child *newborn, **cradle;
+
+ CALLOC_ARRAY(newborn, 1);
+ (*live_children)++;
+ memcpy(&newborn->cld, cld, sizeof(*cld));
+ memcpy(&newborn->address, addr, addrlen);
+ for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
+ if (!addrcmp(&(*cradle)->address, &newborn->address))
+ break;
+ newborn->next = *cradle;
+ *cradle = newborn;
+}
+
+void kill_some_child(struct child *firstborn)
+{
+ const struct child *blanket, *next;
+
+ if (!(blanket = firstborn))
+ return;
+
+ for (; (next = blanket->next); blanket = next)
+ if (!addrcmp(&blanket->address, &next->address)) {
+ kill(blanket->cld.pid, SIGTERM);
+ break;
+ }
+}
+
+void check_dead_children(struct child *firstborn, unsigned int *live_children,
+ log_fn loginfo)
+{
+ int status;
+ pid_t pid;
+
+ struct child **cradle, *blanket;
+ for (cradle = &firstborn; (blanket = *cradle);)
+ if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
+ if (loginfo) {
+ const char *dead = "";
+ if (status)
+ dead = " (with error)";
+ loginfo("[%"PRIuMAX"] Disconnected%s",
+ (uintmax_t)pid, dead);
+ }
+
+ /* remove the child */
+ *cradle = blanket->next;
+ (*live_children)--;
+ child_process_clear(&blanket->cld);
+ free(blanket);
+ } else
+ cradle = &blanket->next;
+}
diff --git a/daemon-utils.h b/daemon-utils.h
index 6710a2a6dc0..97e5cae20b8 100644
--- a/daemon-utils.h
+++ b/daemon-utils.h
@@ -2,6 +2,7 @@
#define DAEMON_UTILS_H
#include "git-compat-util.h"
+#include "run-command.h"
#include "string-list.h"
typedef void (*log_fn)(const char *msg, ...);
@@ -20,4 +21,35 @@ void socksetup(struct string_list *listen_addr, int listen_port,
struct socketlist *socklist, int reuseaddr,
log_fn logerror);
+struct child {
+ struct child *next;
+ struct child_process cld;
+ struct sockaddr_storage address;
+};
+
+/*
+ * Add the child_process to the set of children and increment the number of
+ * live children.
+ */
+void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen,
+ struct child *firstborn, unsigned int *live_children);
+
+/*
+ * Kill the newest connection from a duplicate IP.
+ *
+ * This function should be called if the number of connections grows
+ * past the maximum number of allowed connections.
+ */
+void kill_some_child(struct child *firstborn);
+
+/*
+ * Check for children that have disconnected and remove them from the
+ * active set, decrementing the number of live children.
+ *
+ * Optionally log the child PID that disconnected by passing a loginfo
+ * function.
+ */
+void check_dead_children(struct child *firstborn, unsigned int *live_children,
+ log_fn loginfo);
+
#endif
diff --git a/daemon.c b/daemon.c
index 1ed4e705680..ec3b407ecbc 100644
--- a/daemon.c
+++ b/daemon.c
@@ -785,93 +785,11 @@ static int execute(void)
return -1;
}
-static int addrcmp(const struct sockaddr_storage *s1,
- const struct sockaddr_storage *s2)
-{
- const struct sockaddr *sa1 = (const struct sockaddr*) s1;
- const struct sockaddr *sa2 = (const struct sockaddr*) s2;
-
- if (sa1->sa_family != sa2->sa_family)
- return sa1->sa_family - sa2->sa_family;
- if (sa1->sa_family == AF_INET)
- return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
- &((struct sockaddr_in *)s2)->sin_addr,
- sizeof(struct in_addr));
-#ifndef NO_IPV6
- if (sa1->sa_family == AF_INET6)
- return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
- &((struct sockaddr_in6 *)s2)->sin6_addr,
- sizeof(struct in6_addr));
-#endif
- return 0;
-}
-
static int max_connections = 32;
static unsigned int live_children;
-static struct child {
- struct child *next;
- struct child_process cld;
- struct sockaddr_storage address;
-} *firstborn;
-
-static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
-{
- struct child *newborn, **cradle;
-
- CALLOC_ARRAY(newborn, 1);
- live_children++;
- memcpy(&newborn->cld, cld, sizeof(*cld));
- memcpy(&newborn->address, addr, addrlen);
- for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
- if (!addrcmp(&(*cradle)->address, &newborn->address))
- break;
- newborn->next = *cradle;
- *cradle = newborn;
-}
-
-/*
- * This gets called if the number of connections grows
- * past "max_connections".
- *
- * We kill the newest connection from a duplicate IP.
- */
-static void kill_some_child(void)
-{
- const struct child *blanket, *next;
-
- if (!(blanket = firstborn))
- return;
-
- for (; (next = blanket->next); blanket = next)
- if (!addrcmp(&blanket->address, &next->address)) {
- kill(blanket->cld.pid, SIGTERM);
- break;
- }
-}
-
-static void check_dead_children(void)
-{
- int status;
- pid_t pid;
-
- struct child **cradle, *blanket;
- for (cradle = &firstborn; (blanket = *cradle);)
- if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
- const char *dead = "";
- if (status)
- dead = " (with error)";
- loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
-
- /* remove the child */
- *cradle = blanket->next;
- live_children--;
- child_process_clear(&blanket->cld);
- free(blanket);
- } else
- cradle = &blanket->next;
-}
+static struct child *firstborn;
static struct strvec cld_argv = STRVEC_INIT;
static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
@@ -879,9 +797,9 @@ static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
struct child_process cld = CHILD_PROCESS_INIT;
if (max_connections && live_children >= max_connections) {
- kill_some_child();
+ kill_some_child(firstborn);
sleep(1); /* give it some time to die */
- check_dead_children();
+ check_dead_children(firstborn, &live_children, loginfo);
if (live_children >= max_connections) {
close(incoming);
logerror("Too many children, dropping connection");
@@ -914,7 +832,7 @@ static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
if (start_command(&cld))
logerror("unable to fork");
else
- add_child(&cld, addr, addrlen);
+ add_child(&cld, addr, addrlen, firstborn, &live_children);
}
static void child_handler(int signo)
@@ -944,7 +862,7 @@ static int service_loop(struct socketlist *socklist)
for (;;) {
int i;
- check_dead_children();
+ check_dead_children(firstborn, &live_children, loginfo);
if (poll(pfd, socklist->nr, -1) < 0) {
if (errno != EINTR) {
--
gitgitgadget
