userspace/wrsw_hal: add support for shmem init-time lock

Release write lock when HAL's shm is populated with correct data. Requires commit: "userspace/libwr: shmem init-time lock" Signed-off-by: Adam Wujek <adam.wujek@cern.ch>

userspace/wrsw_hal: add support for shmem init-time lock
Release write lock when HAL's shm is populated with correct data. Requires commit: "userspace/libwr: shmem init-time lock" Signed-off-by: Adam Wujek <adam.wujek@cern.ch>
bb856b66 · Adam Wujek · 838035d2 · bb856b66
Commit bb856b66 authored Jan 08, 2015 by Adam Wujek 💬
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Showing with 10 additions and 2 deletions

hal_ports.c userspace/wrsw_hal/hal_ports.c +10 -2

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--- a/userspace/wrsw_hal/hal_ports.c
+++ b/userspace/wrsw_hal/hal_ports.c
@@ -196,8 +196,10 @@ int hal_port_init_all()
 			__func__, strerror(errno));
 		return -1;
 	}
-	/* Allocate the ports in shared memory, so wr_mon etc can see them */
-	hal_port_shmem = wrs_shm_get(wrs_shm_hal, "wrsw_hal", WRS_SHM_WRITE);
+	/* Allocate the ports in shared memory, so wr_mon etc can see them
+	   Use lock since some (like rtud) wait for hal to be available */
+	hal_port_shmem = wrs_shm_get(wrs_shm_hal, "wrsw_hal",
+				WRS_SHM_WRITE | WRS_SHM_LOCKED);
 	if (!hal_port_shmem) {
 		fprintf(stderr, "%s: Can't join shmem: %s\n", __func__,
 			strerror(errno));
@@ -227,6 +229,12 @@ int hal_port_init_all()
 	hal_hdr->nports = hal_port_nports;
 	head->version = HAL_SHMEM_VERSION;

+	/* Release processes waiting for HAL's to fill shm with correct data
+	   When shm is opened successfully data in shm is still not populated!
+	   Read data with wrs_shm_seqbegin and wrs_shm_seqend!
+	   Especially for nports it is important */
+	wrs_shm_write(head, WRS_SHM_WRITE_END);
+
 	/* Create a WRIPC server for HAL public API */
 	return hal_init_wripc(ports);