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author | 2015-01-10 16:58:11 +0100 | |
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committer | 2015-01-10 16:58:11 +0100 | |
commit | 1273e97e73d7856a668b4419aae27065c81b06be (patch) | |
tree | 49ef6f3811122b79ae93bad45756ab0a77f3a04e /src/lib/portmidi/pmutil.c | |
parent | d103debef2830bd0e28b54348c21492f89c269c4 (diff) |
Placed full code of portmidi in 3rdparty folder (nw)
Diffstat (limited to 'src/lib/portmidi/pmutil.c')
-rw-r--r-- | src/lib/portmidi/pmutil.c | 283 |
1 files changed, 0 insertions, 283 deletions
diff --git a/src/lib/portmidi/pmutil.c b/src/lib/portmidi/pmutil.c deleted file mode 100644 index 0b00a35d8fb..00000000000 --- a/src/lib/portmidi/pmutil.c +++ /dev/null @@ -1,283 +0,0 @@ -/* pmutil.c -- some helpful utilities for building midi - applications that use PortMidi - */ -#include <stdlib.h> -#include <assert.h> -#include <string.h> -#include "portmidi.h" -#include "pmutil.h" -#include "pminternal.h" - -#if defined(WIN32) || defined(_MSC_VER) -#define bzero(addr, siz) memset(addr, 0, siz) -#endif - -// #define QUEUE_DEBUG 1 -#ifdef QUEUE_DEBUG -#include "stdio.h" -#endif - -typedef struct { - long head; - long tail; - long len; - long overflow; - int32_t msg_size; /* number of int32_t in a message including extra word */ - int32_t peek_overflow; - int32_t *buffer; - int32_t *peek; - int32_t peek_flag; -} PmQueueRep; - - -PMEXPORT PmQueue *Pm_QueueCreate(long num_msgs, int32_t bytes_per_msg) -{ - int32_t int32s_per_msg = - (int32_t) (((bytes_per_msg + sizeof(int32_t) - 1) & - ~(sizeof(int32_t) - 1)) / sizeof(int32_t)); - PmQueueRep *queue = (PmQueueRep *) pm_alloc(sizeof(PmQueueRep)); - if (!queue) /* memory allocation failed */ - return NULL; - - /* need extra word per message for non-zero encoding */ - queue->len = num_msgs * (int32s_per_msg + 1); - queue->buffer = (int32_t *) pm_alloc(queue->len * sizeof(int32_t)); - bzero(queue->buffer, queue->len * sizeof(int32_t)); - if (!queue->buffer) { - pm_free(queue); - return NULL; - } else { /* allocate the "peek" buffer */ - queue->peek = (int32_t *) pm_alloc(int32s_per_msg * sizeof(int32_t)); - if (!queue->peek) { - /* free everything allocated so far and return */ - pm_free(queue->buffer); - pm_free(queue); - return NULL; - } - } - bzero(queue->buffer, queue->len * sizeof(int32_t)); - queue->head = 0; - queue->tail = 0; - /* msg_size is in words */ - queue->msg_size = int32s_per_msg + 1; /* note extra word is counted */ - queue->overflow = FALSE; - queue->peek_overflow = FALSE; - queue->peek_flag = FALSE; - return queue; -} - - -PMEXPORT PmError Pm_QueueDestroy(PmQueue *q) -{ - PmQueueRep *queue = (PmQueueRep *) q; - - /* arg checking */ - if (!queue || !queue->buffer || !queue->peek) - return pmBadPtr; - - pm_free(queue->peek); - pm_free(queue->buffer); - pm_free(queue); - return pmNoError; -} - - -PMEXPORT PmError Pm_Dequeue(PmQueue *q, void *msg) -{ - long head; - PmQueueRep *queue = (PmQueueRep *) q; - int i; - int32_t *msg_as_int32 = (int32_t *) msg; - - /* arg checking */ - if (!queue) - return pmBadPtr; - /* a previous peek operation encountered an overflow, but the overflow - * has not yet been reported to client, so do it now. No message is - * returned, but on the next call, we will return the peek buffer. - */ - if (queue->peek_overflow) { - queue->peek_overflow = FALSE; - return pmBufferOverflow; - } - if (queue->peek_flag) { - memcpy(msg, queue->peek, (queue->msg_size - 1) * sizeof(int32_t)); - queue->peek_flag = FALSE; - return pmGotData; - } - - head = queue->head; - /* if writer overflows, it writes queue->overflow = tail+1 so that - * when the reader gets to that position in the buffer, it can - * return the overflow condition to the reader. The problem is that - * at overflow, things have wrapped around, so tail == head, and the - * reader will detect overflow immediately instead of waiting until - * it reads everything in the buffer, wrapping around again to the - * point where tail == head. So the condition also checks that - * queue->buffer[head] is zero -- if so, then the buffer is now - * empty, and we're at the point in the msg stream where overflow - * occurred. It's time to signal overflow to the reader. If - * queue->buffer[head] is non-zero, there's a message there and we - * should read all the way around the buffer before signalling overflow. - * There is a write-order dependency here, but to fail, the overflow - * field would have to be written while an entire buffer full of - * writes are still pending. I'm assuming out-of-order writes are - * possible, but not that many. - */ - if (queue->overflow == head + 1 && !queue->buffer[head]) { - queue->overflow = 0; /* non-overflow condition */ - return pmBufferOverflow; - } - - /* test to see if there is data in the queue -- test from back - * to front so if writer is simultaneously writing, we don't - * waste time discovering the write is not finished - */ - for (i = queue->msg_size - 1; i >= 0; i--) { - if (!queue->buffer[head + i]) { - return pmNoData; - } - } - memcpy(msg, (char *) &queue->buffer[head + 1], - sizeof(int32_t) * (queue->msg_size - 1)); - /* fix up zeros */ - i = queue->buffer[head]; - while (i < queue->msg_size) { - int32_t j; - i--; /* msg does not have extra word so shift down */ - j = msg_as_int32[i]; - msg_as_int32[i] = 0; - i = j; - } - /* signal that data has been removed by zeroing: */ - bzero((char *) &queue->buffer[head], sizeof(int32_t) * queue->msg_size); - - /* update head */ - head += queue->msg_size; - if (head == queue->len) head = 0; - queue->head = head; - return pmGotData; /* success */ -} - - - -PMEXPORT PmError Pm_SetOverflow(PmQueue *q) -{ - PmQueueRep *queue = (PmQueueRep *) q; - long tail; - /* arg checking */ - if (!queue) - return pmBadPtr; - /* no more enqueue until receiver acknowledges overflow */ - if (queue->overflow) return pmBufferOverflow; - tail = queue->tail; - queue->overflow = tail + 1; - return pmBufferOverflow; -} - - -PMEXPORT PmError Pm_Enqueue(PmQueue *q, void *msg) -{ - PmQueueRep *queue = (PmQueueRep *) q; - long tail; - int i; - int32_t *src = (int32_t *) msg; - int32_t *ptr; - int32_t *dest; - int rslt; - if (!queue) - return pmBadPtr; - /* no more enqueue until receiver acknowledges overflow */ - if (queue->overflow) return pmBufferOverflow; - rslt = Pm_QueueFull(q); - /* already checked above: if (rslt == pmBadPtr) return rslt; */ - tail = queue->tail; - if (rslt) { - queue->overflow = tail + 1; - return pmBufferOverflow; - } - - /* queue is has room for message, and overflow flag is cleared */ - ptr = &queue->buffer[tail]; - dest = ptr + 1; - for (i = 1; i < queue->msg_size; i++) { - int32_t j = src[i - 1]; - if (!j) { - *ptr = i; - ptr = dest; - } else { - *dest = j; - } - dest++; - } - *ptr = i; - tail += queue->msg_size; - if (tail == queue->len) tail = 0; - queue->tail = tail; - return pmNoError; -} - - -PMEXPORT int Pm_QueueEmpty(PmQueue *q) -{ - PmQueueRep *queue = (PmQueueRep *) q; - return (!queue) || /* null pointer -> return "empty" */ - (queue->buffer[queue->head] == 0 && !queue->peek_flag); -} - - -PMEXPORT int Pm_QueueFull(PmQueue *q) -{ - long tail; - int i; - PmQueueRep *queue = (PmQueueRep *) q; - /* arg checking */ - if (!queue) - return pmBadPtr; - tail = queue->tail; - /* test to see if there is space in the queue */ - for (i = 0; i < queue->msg_size; i++) { - if (queue->buffer[tail + i]) { - return TRUE; - } - } - return FALSE; -} - - -PMEXPORT void *Pm_QueuePeek(PmQueue *q) -{ - PmError rslt; - int32_t temp; - PmQueueRep *queue = (PmQueueRep *) q; - /* arg checking */ - if (!queue) - return NULL; - - if (queue->peek_flag) { - return queue->peek; - } - /* this is ugly: if peek_overflow is set, then Pm_Dequeue() - * returns immediately with pmBufferOverflow, but here, we - * want Pm_Dequeue() to really check for data. If data is - * there, we can return it - */ - temp = queue->peek_overflow; - queue->peek_overflow = FALSE; - rslt = Pm_Dequeue(q, queue->peek); - queue->peek_overflow = temp; - - if (rslt == 1) { - queue->peek_flag = TRUE; - return queue->peek; - } else if (rslt == pmBufferOverflow) { - /* when overflow is indicated, the queue is empty and the - * first message that was dropped by Enqueue (signalling - * pmBufferOverflow to its caller) would have been the next - * message in the queue. Pm_QueuePeek will return NULL, but - * remember that an overflow occurred. (see Pm_Dequeue) - */ - queue->peek_overflow = TRUE; - } - return NULL; -} |