srbchannel: Trivial whitespace and style fixes

Mostly to improve readability and make things a bit more consistent.

src/pulsecore/srbchannel.c

@@ -31,11 +31,12 @@
 /* #define DEBUG_SRBCHANNEL */
 
 /* This ringbuffer might be useful in other contexts too, but
-   right now it's only used inside the srbchannel, so let's keep it here
+ * right now it's only used inside the srbchannel, so let's keep it here
-   for the time being. */
+ * for the time being. */
 typedef struct pa_ringbuffer pa_ringbuffer;
+
 struct pa_ringbuffer {
-    pa_atomic_t *count;
+    pa_atomic_t *count; /* amount of data in the buffer, can be negative */
     int capacity;
     uint8_t *memory;
     int readindex, writeindex;
@@ -43,24 +44,30 @@ struct pa_ringbuffer {
 
 static void *pa_ringbuffer_peek(pa_ringbuffer *r, int *count) {
     int c = pa_atomic_load(r->count);
+
     if (r->readindex + c > r->capacity)
         *count = r->capacity - r->readindex;
     else
         *count = c;
+
     return r->memory + r->readindex;
 }
 
 /* Returns true only if the buffer was completely full before the drop. */
 static bool pa_ringbuffer_drop(pa_ringbuffer *r, int count) {
     bool b = pa_atomic_sub(r->count, count) >= r->capacity;
+
     r->readindex += count;
     r->readindex %= r->capacity;
+
     return b;
 }
 
 static void *pa_ringbuffer_begin_write(pa_ringbuffer *r, int *count) {
     int c = pa_atomic_load(r->count);
+
     *count = PA_MIN(r->capacity - r->writeindex, r->capacity - c);
+
     return r->memory + r->writeindex;
 }
 
@@ -74,34 +81,40 @@ struct pa_srbchannel {
     pa_ringbuffer rb_read, rb_write;
     pa_fdsem *sem_read, *sem_write;
     pa_memblock *memblock;
+
     void *cb_userdata;
     pa_srbchannel_cb_t callback;
+
     pa_io_event *read_event;
     pa_mainloop_api *mainloop;
 };
 
 /* We always listen to sem_read, and always signal on sem_write.
-
+ *
-   This means we signal the same semaphore for two scenarios:
+ * This means we signal the same semaphore for two scenarios:
-   1) We have written something to our send buffer, and want the other
+ * 1) We have written something to our send buffer, and want the other
-      side to read it
+ *    side to read it
-   2) We have read something from our receive buffer that was previously
+ * 2) We have read something from our receive buffer that was previously
-      completely full, and want the other side to continue writing
+ *    completely full, and want the other side to continue writing
 */
 
 size_t pa_srbchannel_write(pa_srbchannel *sr, const void *data, size_t l) {
     size_t written = 0;
+
     while (l > 0) {
         int towrite;
         void *ptr = pa_ringbuffer_begin_write(&sr->rb_write, &towrite);
+
         if ((size_t) towrite > l)
             towrite = l;
+
         if (towrite == 0) {
 #ifdef DEBUG_SRBCHANNEL
             pa_log("srbchannel output buffer full");
 #endif
             break;
         }
+
         memcpy(ptr, data, towrite);
         pa_ringbuffer_end_write(&sr->rb_write, towrite);
         written += towrite;
@@ -111,20 +124,26 @@ size_t pa_srbchannel_write(pa_srbchannel *sr, const void *data, size_t l) {
 #ifdef DEBUG_SRBCHANNEL
     pa_log("Wrote %d bytes to srbchannel, signalling fdsem", (int) written);
 #endif
+
     pa_fdsem_post(sr->sem_write);
     return written;
 }
 
 size_t pa_srbchannel_read(pa_srbchannel *sr, void *data, size_t l) {
     size_t isread = 0;
+
     while (l > 0) {
         int toread;
         void *ptr = pa_ringbuffer_peek(&sr->rb_read, &toread);
+
         if ((size_t) toread > l)
             toread = l;
+
         if (toread == 0)
             break;
+
         memcpy(data, ptr, toread);
+
         if (pa_ringbuffer_drop(&sr->rb_read, toread)) {
 #ifdef DEBUG_SRBCHANNEL
             pa_log("Read from full output buffer, signalling fdsem");
@@ -136,9 +155,11 @@ size_t pa_srbchannel_read(pa_srbchannel *sr, void *data, size_t l) {
         data = (uint8_t*) data + toread;
         l -= toread;
     }
+
 #ifdef DEBUG_SRBCHANNEL
     pa_log("Read %d bytes from srbchannel", (int) isread);
 #endif
+
     return isread;
 }
 
@@ -147,11 +168,14 @@ size_t pa_srbchannel_read(pa_srbchannel *sr, void *data, size_t l) {
 struct srbheader {
     pa_atomic_t read_count;
     pa_atomic_t write_count;
+
     pa_fdsem_data read_semdata;
     pa_fdsem_data write_semdata;
+
     int capacity;
     int readbuf_offset;
     int writebuf_offset;
+
     /* TODO: Maybe a marker here to make sure we talk to a server with equally sized struct */
 };
 
@@ -163,13 +187,14 @@ static void srbchannel_rwloop(pa_srbchannel* sr) {
         pa_log("In rw loop from srbchannel, before callback, count = %d", q);
 #endif
 
-        if (sr->callback)
+        if (sr->callback) {
             if (!sr->callback(sr, sr->cb_userdata)) {
 #ifdef DEBUG_SRBCHANNEL
                 pa_log("Aborting read loop from srbchannel");
 #endif
                 return;
             }
+        }
 
 #ifdef DEBUG_SRBCHANNEL
         pa_ringbuffer_peek(&sr->rb_read, &q);
@@ -199,14 +224,19 @@ pa_srbchannel* pa_srbchannel_new(pa_mainloop_api *m, pa_mempool *p) {
 
     sr->rb_read.memory = (uint8_t*) srh + PA_ALIGN(sizeof(*srh));
     srh->readbuf_offset = sr->rb_read.memory - (uint8_t*) srh;
+
     capacity = (pa_memblock_get_length(sr->memblock) - srh->readbuf_offset) / 2;
+
     sr->rb_write.memory = PA_ALIGN_PTR(sr->rb_read.memory + capacity);
     srh->writebuf_offset = sr->rb_write.memory - (uint8_t*) srh;
+
     capacity = PA_MIN(capacity, srh->writebuf_offset - srh->readbuf_offset);
+
     pa_log_debug("SHM block is %d bytes, ringbuffer capacity is 2 * %d bytes",
         (int) pa_memblock_get_length(sr->memblock), capacity);
 
     srh->capacity = sr->rb_read.capacity = sr->rb_write.capacity = capacity;
+
     sr->rb_read.count = &srh->read_count;
     sr->rb_write.count = &srh->write_count;
 
@@ -219,9 +249,11 @@ pa_srbchannel* pa_srbchannel_new(pa_mainloop_api *m, pa_mempool *p) {
         goto fail;
 
     readfd = pa_fdsem_get(sr->sem_read);
+
 #ifdef DEBUG_SRBCHANNEL
     pa_log("Enabling io event on fd %d", readfd);
 #endif
+
     sr->read_event = m->io_new(m, readfd, PA_IO_EVENT_INPUT, semread_cb, sr);
     m->io_enable(sr->read_event, PA_IO_EVENT_INPUT);
 
@@ -235,6 +267,7 @@ fail:
 
 static void pa_srbchannel_swap(pa_srbchannel *sr) {
     pa_srbchannel temp = *sr;
+
     sr->sem_read = temp.sem_write;
     sr->sem_write = temp.sem_read;
     sr->rb_read = temp.rb_write;
@@ -255,6 +288,7 @@ pa_srbchannel* pa_srbchannel_new_from_template(pa_mainloop_api *m, pa_srbchannel
     sr->rb_read.capacity = sr->rb_write.capacity = srh->capacity;
     sr->rb_read.count = &srh->read_count;
     sr->rb_write.count = &srh->write_count;
+
     sr->rb_read.memory = (uint8_t*) srh + srh->readbuf_offset;
     sr->rb_write.memory = (uint8_t*) srh + srh->writebuf_offset;
 
@@ -272,6 +306,7 @@ pa_srbchannel* pa_srbchannel_new_from_template(pa_mainloop_api *m, pa_srbchannel
 #ifdef DEBUG_SRBCHANNEL
     pa_log("Enabling io event on fd %d", t->readfd);
 #endif
+
     sr->read_event = m->io_new(m, t->readfd, PA_IO_EVENT_INPUT, semread_cb, sr);
     m->io_enable(sr->read_event, PA_IO_EVENT_INPUT);
 

src/pulsecore/srbchannel.h

@@ -27,7 +27,7 @@
 #include <pulsecore/memblock.h>
 
 /* An shm ringbuffer that is used for low overhead server-client communication.
-   Signaling is done through eventfd semaphores (pa_fdsem). */
+ * Signaling is done through eventfd semaphores (pa_fdsem). */
 
 typedef struct pa_srbchannel pa_srbchannel;
 
@@ -48,13 +48,13 @@ size_t pa_srbchannel_write(pa_srbchannel *sr, const void *data, size_t l);
 size_t pa_srbchannel_read(pa_srbchannel *sr, void *data, size_t l);
 
 /* Set the callback function that is called whenever data becomes available for reading.
-   It can also be called if the output buffer was full and can now be written to.
+ * It can also be called if the output buffer was full and can now be written to.
-
+ *
-   Return false to abort all processing (e g if the srbchannel has been freed during the callback).
+ * Return false to abort all processing (e g if the srbchannel has been freed during the callback).
-   Otherwise return true.
+ * Otherwise return true.
-
+ *
-   Note that the callback will be called immediately, to be able to process stuff that
+ * Note that the callback will be called immediately, to be able to process stuff that
-   might already be in the buffer.
+ * might already be in the buffer.
 */
 typedef bool (*pa_srbchannel_cb_t)(pa_srbchannel *sr, void *userdata);
 void pa_srbchannel_set_callback(pa_srbchannel *sr, pa_srbchannel_cb_t callback, void *userdata);