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mxshadowsrv.c

@@ -7,10 +7,6 @@
 #include <string.h>
 #include <getopt.h>
 #include <pthread.h>
-#include <semaphore.h>
-#ifdef DEBUG_MAX_CONNECTS
-#include <sys/wait.h>
-#endif
 
 #include "common.h"
 
@@ -66,14 +62,15 @@ static void unmap_shadow(char *shadow_buf, struct stat *statbuf) {
     if (sts == -1) { perror("munmap"); exit(1); }
 }
 
-#define MAX_THREADS 8
+#define THREADS 8
 #define TIMEOUT 30000     // client timeout in msec
 
 static pthread_mutex_t shadow_mutex = PTHREAD_MUTEX_INITIALIZER ;
 static char *shadow_buf = NULL;   // protected by shadow_mutex
 static struct stat statbuf;       // protected by shadow_mutex
 static SSL_CTX *ssl_ctx;
-static sem_t free_worker;
+static int listen_socket;
+static char *filename;
 #ifdef DEBUG_MAX_CONNECTS
 static int debug_remaining_connects = DEBUG_MAX_CONNECTS;
 #endif
@@ -193,12 +190,17 @@ static void process_client(int socket) {
 }
 
 static void *client_thread(void *arg) {
-    int socket = *((int *)arg);
-    process_client(socket);
-    close(socket);
-    free(arg);
-    int status = sem_post(&free_worker);
-    if (status != 0) { errno = status; perror("sem_post"); exit(1); }
+
+    while (1) {
+#ifdef DEBUG_MAX_CONNECTS
+        if ( __sync_fetch_and_sub(&debug_remaining_connects, 1) <= 0)
+            return NULL;
+#endif
+        int _cleanup_(free_fd) socket = accept4(listen_socket, NULL, NULL, SOCK_NONBLOCK);
+        if (socket == -1 ) { perror("accept"); exit(1); }
+        validate_shadow(&shadow_buf, filename, &statbuf);
+        process_client(socket);
+   }
     return NULL;
 }
 
@@ -239,7 +241,7 @@ int main(int argc, char **argv) {
         die_usage(argv[0]);
     if (optind+1 != argc)
         die_usage(argv[0]);
-    char *filename = argv[optind++];
+    filename = argv[optind++];
 
     SSL_CTX *_ssl_ctx _cleanup_(free_ssl_ctx) = SSL_CTX_new(TLS_server_method());
     if (_ssl_ctx == NULL) { psslerror("SSL_CTX_new"); return 1; }
@@ -248,7 +250,7 @@ int main(int argc, char **argv) {
     if (SSL_CTX_use_PrivateKey_file(ssl_ctx, key_file, SSL_FILETYPE_PEM) <= 0 ) { psslerror("SSL_CTX_use_PrivateKey_file"); return 1; }
     if (SSL_CTX_use_certificate_file(ssl_ctx, cert_file, SSL_FILETYPE_PEM) <= 0) { psslerror("SSL_CTX_use_certificate_file"); return 1; }
 
-    int listen_socket = socket(AF_INET, SOCK_STREAM, 0);
+    listen_socket = socket(AF_INET, SOCK_STREAM, 0);
     if (listen_socket == -1) { perror("socket"); return 1; }
 
     static int true = 1;
@@ -265,38 +267,13 @@ int main(int argc, char **argv) {
     status = listen(listen_socket, 40);
     if (status == -1) { perror("listen"); exit(1); }
 
-    status = sem_init(&free_worker, 0, MAX_THREADS);
-    if (status) { errno = status; perror("sem_init"); exit(1); }
-
-    while (1) {
-#ifdef DEBUG_MAX_CONNECTS
-        if (debug_remaining_connects-- == 0)
-            break;
-#endif
-        int _cleanup_(free_fd) socket = accept4(listen_socket, NULL, NULL, SOCK_NONBLOCK);
-        if (socket == -1 ) { perror("accept"); exit(1); }
-        status = sem_wait(&free_worker);
-        if (status == -1) { perror("sem_wait"); exit(1); }
-        validate_shadow(&shadow_buf, filename, &statbuf);
-        pthread_t thread;
-        int *arg = malloc(sizeof *arg);
-        if (arg == NULL) { perror("malloc"); exit(1); }
-        *arg = socket;
-        status = pthread_create(&thread, NULL, client_thread, arg);
+    pthread_t thread[THREADS];
+    for (int i=0; i<THREADS; i++) {
+        int status = pthread_create(&thread[i], NULL, client_thread, NULL);
         if (status != 0) { errno = status; perror("pthread_create"); exit(1); }
-        socket = -1;
-        status = pthread_detach(thread);
-        if (status != 0) { errno = status; perror("pthread_detach"); exit(1); }
-
-   }
-#ifdef DEBUG_MAX_CONNECTS
-    for (int i=0; i<MAX_THREADS; i++) {
-        status = sem_wait(&free_worker);
-        if (status == -1) { perror("sem_wait"); exit(1); }
     }
-    /* Valgrinds checks on exit() race with pthread_exit() and Valgrind might report
-     * a threads stack as lost memory or a Helgrind detected data race. Give threads
-     * a little time to exit after they posted the semaphore */
-    sleep(1);
-#endif
+    for (int i=0; i<THREADS; i++) {
+        int status = pthread_join(thread[i], NULL);
+        if (status != 0) { errno = status; perror("pthread_join"); exit(1); }
+    }
 }