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-rw-r--r--3rdparty/plibsys/src/pshmbuffer.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/3rdparty/plibsys/src/pshmbuffer.c b/3rdparty/plibsys/src/pshmbuffer.c
new file mode 100644
index 0000000..7bdbbd3
--- /dev/null
+++ b/3rdparty/plibsys/src/pshmbuffer.c
@@ -0,0 +1,334 @@
+/*
+ * The MIT License
+ *
+ * Copyright (C) 2010-2020 Alexander Saprykin <saprykin.spb@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * 'Software'), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include "pmem.h"
+#include "pshm.h"
+#include "pshmbuffer.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#define P_SHM_BUFFER_READ_OFFSET 0
+#define P_SHM_BUFFER_WRITE_OFFSET sizeof (psize)
+#define P_SHM_BUFFER_DATA_OFFSET sizeof (psize) * 2
+
+struct PShmBuffer_ {
+ PShm *shm;
+ psize size;
+};
+
+static psize pp_shm_buffer_get_free_space (PShmBuffer *buf);
+static psize pp_shm_buffer_get_used_space (PShmBuffer *buf);
+
+/* Warning: this function is not thread-safe, only for internal usage */
+static psize
+pp_shm_buffer_get_free_space (PShmBuffer *buf)
+{
+ psize read_pos, write_pos;
+ ppointer addr;
+
+ addr = p_shm_get_address (buf->shm);
+
+ memcpy (&read_pos, (pchar *) addr + P_SHM_BUFFER_READ_OFFSET, sizeof (read_pos));
+ memcpy (&write_pos, (pchar *) addr + P_SHM_BUFFER_WRITE_OFFSET, sizeof (write_pos));
+
+ if (write_pos < read_pos)
+ return read_pos - write_pos - 1;
+ else if (write_pos > read_pos)
+ return buf->size - (write_pos - read_pos) - 1;
+ else
+ return buf->size - 1;
+}
+
+static psize
+pp_shm_buffer_get_used_space (PShmBuffer *buf)
+{
+ psize read_pos, write_pos;
+ ppointer addr;
+
+ addr = p_shm_get_address (buf->shm);
+
+ memcpy (&read_pos, (pchar *) addr + P_SHM_BUFFER_READ_OFFSET, sizeof (read_pos));
+ memcpy (&write_pos, (pchar *) addr + P_SHM_BUFFER_WRITE_OFFSET, sizeof (write_pos));
+
+ if (write_pos > read_pos)
+ return write_pos - read_pos;
+ else if (write_pos < read_pos)
+ return (buf->size - (read_pos - write_pos));
+ else
+ return 0;
+}
+
+P_LIB_API PShmBuffer *
+p_shm_buffer_new (const pchar *name,
+ psize size,
+ PError **error)
+{
+ PShmBuffer *ret;
+ PShm *shm;
+
+ if (P_UNLIKELY (name == NULL)) {
+ p_error_set_error_p (error,
+ (pint) P_ERROR_IPC_INVALID_ARGUMENT,
+ 0,
+ "Invalid input argument");
+ return NULL;
+ }
+
+ if (P_UNLIKELY ((shm = p_shm_new (name,
+ (size != 0) ? size + P_SHM_BUFFER_DATA_OFFSET + 1 : 0,
+ P_SHM_ACCESS_READWRITE,
+ error)) == NULL))
+ return NULL;
+
+ if (P_UNLIKELY (p_shm_get_size (shm) <= P_SHM_BUFFER_DATA_OFFSET + 1)) {
+ p_error_set_error_p (error,
+ (pint) P_ERROR_IPC_INVALID_ARGUMENT,
+ 0,
+ "Too small memory segment to hold required data");
+ p_shm_free (shm);
+ return NULL;
+ }
+
+ if (P_UNLIKELY ((ret = p_malloc0 (sizeof (PShmBuffer))) == NULL)) {
+ p_error_set_error_p (error,
+ (pint) P_ERROR_IPC_NO_RESOURCES,
+ 0,
+ "Failed to allocate memory for shared buffer");
+ p_shm_free (shm);
+ return NULL;
+ }
+
+ ret->shm = shm;
+ ret->size = p_shm_get_size (shm) - P_SHM_BUFFER_DATA_OFFSET;
+
+ return ret;
+}
+
+P_LIB_API void
+p_shm_buffer_free (PShmBuffer *buf)
+{
+ if (P_UNLIKELY (buf == NULL))
+ return;
+
+ p_shm_free (buf->shm);
+ p_free (buf);
+}
+
+P_LIB_API void
+p_shm_buffer_take_ownership (PShmBuffer *buf)
+{
+ if (P_UNLIKELY (buf == NULL))
+ return;
+
+ p_shm_take_ownership (buf->shm);
+}
+
+P_LIB_API pint
+p_shm_buffer_read (PShmBuffer *buf,
+ ppointer storage,
+ psize len,
+ PError **error)
+{
+ psize read_pos, write_pos;
+ psize data_aval, to_copy;
+ puint i;
+ ppointer addr;
+
+ if (P_UNLIKELY (buf == NULL || storage == NULL || len == 0)) {
+ p_error_set_error_p (error,
+ (pint) P_ERROR_IPC_INVALID_ARGUMENT,
+ 0,
+ "Invalid input argument");
+ return -1;
+ }
+
+ if (P_UNLIKELY ((addr = p_shm_get_address (buf->shm)) == NULL)) {
+ p_error_set_error_p (error,
+ (pint) P_ERROR_IPC_INVALID_ARGUMENT,
+ 0,
+ "Unable to get shared memory address");
+ return -1;
+ }
+
+ if (P_UNLIKELY (p_shm_lock (buf->shm, error) == FALSE))
+ return -1;
+
+ memcpy (&read_pos, (pchar *) addr + P_SHM_BUFFER_READ_OFFSET, sizeof (read_pos));
+ memcpy (&write_pos, (pchar *) addr + P_SHM_BUFFER_WRITE_OFFSET, sizeof (write_pos));
+
+ if (read_pos == write_pos) {
+ if (P_UNLIKELY (p_shm_unlock (buf->shm, error) == FALSE))
+ return -1;
+
+ return 0;
+ }
+
+ data_aval = pp_shm_buffer_get_used_space (buf);
+ to_copy = (data_aval <= len) ? data_aval : len;
+
+ for (i = 0; i < to_copy; ++i)
+ memcpy ((pchar *) storage + i,
+ (pchar *) addr + P_SHM_BUFFER_DATA_OFFSET + ((read_pos + i) % buf->size),
+ 1);
+
+ read_pos = (read_pos + to_copy) % buf->size;
+ memcpy ((pchar *) addr + P_SHM_BUFFER_READ_OFFSET, &read_pos, sizeof (read_pos));
+
+ if (P_UNLIKELY (p_shm_unlock (buf->shm, error) == FALSE))
+ return -1;
+
+ return (pint) to_copy;
+}
+
+P_LIB_API pssize
+p_shm_buffer_write (PShmBuffer *buf,
+ ppointer data,
+ psize len,
+ PError **error)
+{
+ psize read_pos, write_pos;
+ puint i;
+ ppointer addr;
+
+ if (P_UNLIKELY (buf == NULL || data == NULL || len == 0)) {
+ p_error_set_error_p (error,
+ (pint) P_ERROR_IPC_INVALID_ARGUMENT,
+ 0,
+ "Invalid input argument");
+ return -1;
+ }
+
+ if (P_UNLIKELY ((addr = p_shm_get_address (buf->shm)) == NULL)) {
+ p_error_set_error_p (error,
+ (pint) P_ERROR_IPC_INVALID_ARGUMENT,
+ 0,
+ "Unable to get shared memory address");
+ return -1;
+ }
+
+ if (P_UNLIKELY (p_shm_lock (buf->shm, error) == FALSE))
+ return -1;
+
+ memcpy (&read_pos, (pchar *) addr + P_SHM_BUFFER_READ_OFFSET, sizeof (read_pos));
+ memcpy (&write_pos, (pchar *) addr + P_SHM_BUFFER_WRITE_OFFSET, sizeof (write_pos));
+
+ if (pp_shm_buffer_get_free_space (buf) < len) {
+ if (P_UNLIKELY (p_shm_unlock (buf->shm, error) == FALSE))
+ return -1;
+
+ return 0;
+ }
+
+ for (i = 0; i < len; ++i)
+ memcpy ((pchar *) addr + P_SHM_BUFFER_DATA_OFFSET + ((write_pos + i) % buf->size),
+ (pchar *) data + i,
+ 1);
+
+ write_pos = (write_pos + len) % buf->size;
+ memcpy ((pchar *) addr + P_SHM_BUFFER_WRITE_OFFSET, &write_pos, sizeof (write_pos));
+
+ if (P_UNLIKELY (p_shm_unlock (buf->shm, error) == FALSE))
+ return -1;
+
+ return (pssize) len;
+}
+
+P_LIB_API pssize
+p_shm_buffer_get_free_space (PShmBuffer *buf,
+ PError **error)
+{
+ psize space;
+
+ if (P_UNLIKELY (buf == NULL)) {
+ p_error_set_error_p (error,
+ (pint) P_ERROR_IPC_INVALID_ARGUMENT,
+ 0,
+ "Invalid input argument");
+ return -1;
+ }
+
+ if (P_UNLIKELY (p_shm_lock (buf->shm, error) == FALSE))
+ return -1;
+
+ space = pp_shm_buffer_get_free_space (buf);
+
+ if (P_UNLIKELY (p_shm_unlock (buf->shm, error) == FALSE))
+ return -1;
+
+ return (pssize) space;
+}
+
+P_LIB_API pssize
+p_shm_buffer_get_used_space (PShmBuffer *buf,
+ PError **error)
+{
+ psize space;
+
+ if (P_UNLIKELY (buf == NULL)) {
+ p_error_set_error_p (error,
+ (pint) P_ERROR_IPC_INVALID_ARGUMENT,
+ 0,
+ "Invalid input argument");
+ return -1;
+ }
+
+ if (P_UNLIKELY (p_shm_lock (buf->shm, error) == FALSE))
+ return -1;
+
+ space = pp_shm_buffer_get_used_space (buf);
+
+ if (P_UNLIKELY (p_shm_unlock (buf->shm, error) == FALSE))
+ return -1;
+
+ return (pssize) space;
+}
+
+P_LIB_API void
+p_shm_buffer_clear (PShmBuffer *buf)
+{
+ ppointer addr;
+ psize size;
+
+ if (P_UNLIKELY (buf == NULL))
+ return;
+
+ if (P_UNLIKELY ((addr = p_shm_get_address (buf->shm)) == NULL)) {
+ P_ERROR ("PShmBuffer::p_shm_buffer_clear: p_shm_get_address() failed");
+ return;
+ }
+
+ size = p_shm_get_size (buf->shm);
+
+ if (P_UNLIKELY (p_shm_lock (buf->shm, NULL) == FALSE)) {
+ P_ERROR ("PShmBuffer::p_shm_buffer_clear: p_shm_lock() failed");
+ return;
+ }
+
+ memset (addr, 0, size);
+
+ if (P_UNLIKELY (p_shm_unlock (buf->shm, NULL) == FALSE))
+ P_ERROR ("PShmBuffer::p_shm_buffer_clear: p_shm_unlock() failed");
+}
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