[PATCH] blktrace: smaller code cleanups

diff --git a/blktrace.c b/blktrace.c
index b508d4e635cf23d33bacde0c2e26f6b0739bbf7b..5c30d30021f3c8494ffad8a8b1d171127798a7cb 100644 (file)
--- a/blktrace.c
+++ b/blktrace.c
@@ -138,7 +138,7 @@ struct thread_information {
        FILE *ofile;
        char *ofile_buffer;
 
-       int closed;
+       volatile int closed;
 
        unsigned long events_processed;
        struct device_information *device;
@@ -148,7 +148,7 @@ struct device_information {
        int fd;
        char *path;
        char buts_name[32];
-       int trace_started;
+       volatile int trace_started;
        struct thread_information *threads;
 };
 
@@ -176,6 +176,16 @@ static void exit_trace(int status);
 #define tip_closed(tip)                (*(volatile int *)(&(tip)->closed))
 #define set_tip_closed(tip)    ((tip)->closed = 1)
 
+#define dip_tracing(dip)       (*(volatile int *)(&(dip)->trace_started))
+#define dip_set_tracing(dip, v)        ((dip)->trace_started = (v))
+
+#define __for_each_dip(__d, __i, __e)  \
+       for (__i = 0, __d = device_information; __i < __e; __i++, __d++)
+
+#define for_each_dip(__d, __i) __for_each_dip(__d, __i, ndevs)
+#define for_each_tip(__d, __t, __i)    \
+       for (__i = 0, __t = (__d)->threads; __i < ncpus; __i++, __t++)
+
 static int start_trace(struct device_information *dip)
 {
        struct blk_user_trace_setup buts;
@@ -191,14 +201,14 @@ static int start_trace(struct device_information *dip)
        }
 
        memcpy(dip->buts_name, buts.name, sizeof(dip->buts_name));
-       dip->trace_started = 1;
+       dip_set_tracing(dip, 1);
        return 0;
 }
 
 static void stop_trace(struct device_information *dip)
 {
-       if (dip->trace_started || kill_running_trace) {
-               dip->trace_started = 0;
+       if (dip_tracing(dip) || kill_running_trace) {
+               dip_set_tracing(dip, 0);
 
                if (ioctl(dip->fd, BLKSTOPTRACE) < 0)
                        perror("BLKSTOPTRACE");
@@ -213,7 +223,7 @@ static void stop_all_traces(void)
        struct device_information *dip;
        int i;
 
-       for (dip = device_information, i = 0; i < ndevs; i++, dip++)
+       for_each_dip(dip, i)
                stop_trace(dip);
 }
 
@@ -467,7 +477,7 @@ static int start_threads(struct device_information *dip)
        int j, pipeline = output_name && !strcmp(output_name, "-");
        int len, mode;
 
-       for (tip = dip->threads, j = 0; j < ncpus; j++, tip++) {
+       for_each_tip(dip, tip, j) {
                tip->cpu = j;
                tip->device = dip;
                tip->fd_lock = NULL;
@@ -524,9 +534,7 @@ static void stop_threads(struct device_information *dip)
        long ret;
        int i;
 
-       for (i = 0; i < ncpus; i++) {
-               tip = &dip->threads[i];
-
+       for_each_tip(dip, tip, i) {
                if (pthread_join(tip->thread, (void *) &ret))
                        perror("thread_join");
 
@@ -539,11 +547,8 @@ static void stop_all_threads(void)
        struct device_information *dip;
        int i;
 
-       for (i = 0; i < ndevs; i++) {
-               dip = &device_information[i];
-
+       for_each_dip(dip, i)
                stop_threads(dip);
-       }
 }
 
 static void stop_all_tracing(void)
@@ -552,14 +557,9 @@ static void stop_all_tracing(void)
        struct thread_information *tip;
        int i, j;
 
-       for (i = 0; i < ndevs; i++) {
-               dip = &device_information[i];
-
-               for (j = 0; j < ncpus; j++) {
-                       tip = &dip->threads[j];
-
+       for_each_dip(dip, i) {
+               for_each_tip(dip, tip, j)
                        close_thread(tip);
-               }
 
                stop_trace(dip);
        }
@@ -590,13 +590,14 @@ static int open_devices(void)
        struct device_information *dip;
        int i;
 
-       for (dip = device_information, i = 0; i < ndevs; i++, dip++) {
+       for_each_dip(dip, i) {
                dip->fd = open(dip->path, O_RDONLY | O_NONBLOCK);
                if (dip->fd < 0) {
                        perror(dip->path);
                        return 1;
                }
        }
+
        return 0;
 }
 
@@ -612,7 +613,7 @@ static int start_devices(void)
                return 1;
        }
 
-       for (dip = device_information, i = 0; i < ndevs; i++, dip++) {
+       for_each_dip(dip, i) {
                if (start_trace(dip)) {
                        close(dip->fd);
                        fprintf(stderr, "Failed to start trace on %s\n",
@@ -620,24 +621,28 @@ static int start_devices(void)
                        break;
                }
        }
+
        if (i != ndevs) {
-               for (dip = device_information, j = 0; j < i; j++, dip++)
+               __for_each_dip(dip, j, i)
                        stop_trace(dip);
+
                return 1;
        }
 
-       for (dip = device_information, i = 0; i < ndevs; i++, dip++) {
+       for_each_dip(dip, i) {
                dip->threads = thread_information + (i * ncpus);
                if (start_threads(dip)) {
                        fprintf(stderr, "Failed to start worker threads\n");
                        break;
                }
        }
+
        if (i != ndevs) {
-               for (dip = device_information, j = 0; j < i; j++, dip++)
+               __for_each_dip(dip, j, i)
                        stop_threads(dip);
-               for (dip = device_information, i = 0; i < ndevs; i++, dip++)
+               for_each_dip(dip, i)
                        stop_trace(dip);
+
                return 1;
        }
 
@@ -654,10 +659,10 @@ static void show_stats(void)
        if (output_name && !strcmp(output_name, "-"))
                return;
 
-       for (dip = device_information, i = 0; i < ndevs; i++, dip++) {
+       for_each_dip(dip, i) {
                printf("Device: %s\n", dip->path);
                events_processed = 0;
-               for (tip = dip->threads, j = 0; j < ncpus; j++, tip++) {
+               for_each_tip(dip, tip, j) {
                        printf("  CPU%3d: %20ld events\n",
                               tip->cpu, tip->events_processed);
                        events_processed += tip->events_processed;